diff options
| -rw-r--r-- | Makefile | 2 | ||||
| -rw-r--r-- | astobj2.c | 722 | ||||
| -rw-r--r-- | channels/chan_iax2.c | 389 | ||||
| -rw-r--r-- | include/asterisk/astobj2.h | 541 | ||||
| -rw-r--r-- | include/asterisk/dlinkedlists.h | 974 |
5 files changed, 2493 insertions, 135 deletions
@@ -354,7 +354,7 @@ OBJS=io.o sched.o logger.o frame.o loader.o config.o channel.o \ astmm.o enum.o srv.o dns.o aescrypt.o aestab.o aeskey.o \ utils.o plc.o jitterbuf.o dnsmgr.o devicestate.o \ netsock.o slinfactory.o ast_expr2.o ast_expr2f.o \ - cryptostub.o + cryptostub.o astobj2.o ifeq ($(wildcard $(CROSS_COMPILE_TARGET)/usr/include/sys/poll.h),) OBJS+= poll.o diff --git a/astobj2.c b/astobj2.c new file mode 100644 index 000000000..66c5a2cc3 --- /dev/null +++ b/astobj2.c @@ -0,0 +1,722 @@ +/* + * astobj2 - replacement containers for asterisk data structures. + * + * Copyright (C) 2006 Marta Carbone, Luigi Rizzo - Univ. di Pisa, Italy + * + * See http://www.asterisk.org for more information about + * the Asterisk project. Please do not directly contact + * any of the maintainers of this project for assistance; + * the project provides a web site, mailing lists and IRC + * channels for your use. + * + * This program is free software, distributed under the terms of + * the GNU General Public License Version 2. See the LICENSE file + * at the top of the source tree. + */ + +/* + * Function implementing astobj2 objects. + */ +#include "asterisk.h" + +ASTERISK_FILE_VERSION(__FILE__, "$Revision$") + +#include <stdlib.h> + +#include "asterisk/astobj2.h" +#include "asterisk/utils.h" +#include "asterisk/cli.h" +#include "asterisk/linkedlists.h" + +/*! + * astobj2 objects are always prepended this data structure, + * which contains a lock, a reference counter, + * the flags and a pointer to a destructor. + * The refcount is used to decide when it is time to + * invoke the destructor. + * The magic number is used for consistency check. + * XXX the lock is not always needed, and its initialization may be + * expensive. Consider making it external. + */ +struct __priv_data { + ast_mutex_t lock; + int ref_counter; + ao2_destructor_fn destructor_fn; + /*! for stats */ + size_t data_size; + /*! magic number. This is used to verify that a pointer passed in is a + * valid astobj2 */ + uint32_t magic; +}; + +#define AO2_MAGIC 0xa570b123 + +/*! + * What an astobj2 object looks like: fixed-size private data + * followed by variable-size user data. + */ +struct astobj2 { + struct __priv_data priv_data; + void *user_data[0]; +}; + +#ifdef AST_DEVMODE +#define AO2_DEBUG 1 +#endif + +#ifdef AO2_DEBUG +struct ao2_stats { + volatile int total_objects; + volatile int total_mem; + volatile int total_containers; + volatile int total_refs; + volatile int total_locked; +}; + +static struct ao2_stats ao2; +#endif + +#ifndef HAVE_BKTR /* backtrace support */ +void ao2_bt(void) {} +#else +#include <execinfo.h> /* for backtrace */ + +void ao2_bt(void) +{ + int c, i; +#define N1 20 + void *addresses[N1]; + char **strings; + + c = backtrace(addresses, N1); + strings = backtrace_symbols(addresses,c); + ast_verbose("backtrace returned: %d\n", c); + for(i = 0; i < c; i++) { + ast_verbose("%d: %p %s\n", i, addresses[i], strings[i]); + } + free(strings); +} +#endif + +/*! + * \brief convert from a pointer _p to a user-defined object + * + * \return the pointer to the astobj2 structure + */ +static inline struct astobj2 *INTERNAL_OBJ(void *user_data) +{ + struct astobj2 *p; + + if (!user_data) { + ast_log(LOG_ERROR, "user_data is NULL\n"); + return NULL; + } + + p = (struct astobj2 *) ((char *) user_data - sizeof(*p)); + if (AO2_MAGIC != (p->priv_data.magic) ) { + ast_log(LOG_ERROR, "bad magic number 0x%x for %p\n", p->priv_data.magic, p); + p = NULL; + } + + return p; +} + +/*! + * \brief convert from a pointer _p to an astobj2 object + * + * \return the pointer to the user-defined portion. + */ +#define EXTERNAL_OBJ(_p) ((_p) == NULL ? NULL : (_p)->user_data) + +int ao2_lock(void *user_data) +{ + struct astobj2 *p = INTERNAL_OBJ(user_data); + + if (p == NULL) + return -1; + +#ifdef AO2_DEBUG + ast_atomic_fetchadd_int(&ao2.total_locked, 1); +#endif + + return ast_mutex_lock(&p->priv_data.lock); +} + +int ao2_unlock(void *user_data) +{ + struct astobj2 *p = INTERNAL_OBJ(user_data); + + if (p == NULL) + return -1; + +#ifdef AO2_DEBUG + ast_atomic_fetchadd_int(&ao2.total_locked, -1); +#endif + + return ast_mutex_unlock(&p->priv_data.lock); +} + +/* + * The argument is a pointer to the user portion. + */ +int ao2_ref(void *user_data, const int delta) +{ + int current_value; + int ret; + struct astobj2 *obj = INTERNAL_OBJ(user_data); + + if (obj == NULL) + return -1; + + /* if delta is 0, just return the refcount */ + if (delta == 0) + return (obj->priv_data.ref_counter); + + /* we modify with an atomic operation the reference counter */ + ret = ast_atomic_fetchadd_int(&obj->priv_data.ref_counter, delta); + current_value = ret + delta; + +#ifdef AO2_DEBUG + ast_atomic_fetchadd_int(&ao2.total_refs, delta); +#endif + + /* this case must never happen */ + if (current_value < 0) + ast_log(LOG_ERROR, "refcount %d on object %p\n", current_value, user_data); + + if (current_value <= 0) { /* last reference, destroy the object */ + if (obj->priv_data.destructor_fn != NULL) + obj->priv_data.destructor_fn(user_data); + + ast_mutex_destroy(&obj->priv_data.lock); +#ifdef AO2_DEBUG + ast_atomic_fetchadd_int(&ao2.total_mem, - obj->priv_data.data_size); + ast_atomic_fetchadd_int(&ao2.total_objects, -1); +#endif + /* for safety, zero-out the astobj2 header and also the + * first word of the user-data, which we make sure is always + * allocated. */ + bzero(obj, sizeof(struct astobj2 *) + sizeof(void *) ); + free(obj); + } + + return ret; +} + +/* + * We always alloc at least the size of a void *, + * for debugging purposes. + */ +void *ao2_alloc(size_t data_size, ao2_destructor_fn destructor_fn) +{ + /* allocation */ + struct astobj2 *obj; + + if (data_size < sizeof(void *)) + data_size = sizeof(void *); + + obj = calloc(1, sizeof(*obj) + data_size); + + if (obj == NULL) + return NULL; + + ast_mutex_init(&obj->priv_data.lock); + obj->priv_data.magic = AO2_MAGIC; + obj->priv_data.data_size = data_size; + obj->priv_data.ref_counter = 1; + obj->priv_data.destructor_fn = destructor_fn; /* can be NULL */ + +#ifdef AO2_DEBUG + ast_atomic_fetchadd_int(&ao2.total_objects, 1); + ast_atomic_fetchadd_int(&ao2.total_mem, data_size); + ast_atomic_fetchadd_int(&ao2.total_refs, 1); +#endif + + /* return a pointer to the user data */ + return EXTERNAL_OBJ(obj); +} + +/* internal callback to destroy a container. */ +static void container_destruct(void *c); + +/* each bucket in the container is a tailq. */ +AST_LIST_HEAD_NOLOCK(bucket, bucket_list); + +/*! + * A container; stores the hash and callback functions, information on + * the size, the hash bucket heads, and a version number, starting at 0 + * (for a newly created, empty container) + * and incremented every time an object is inserted or deleted. + * The assumption is that an object is never moved in a container, + * but removed and readded with the new number. + * The version number is especially useful when implementing iterators. + * In fact, we can associate a unique, monotonically increasing number to + * each object, which means that, within an iterator, we can store the + * version number of the current object, and easily look for the next one, + * which is the next one in the list with a higher number. + * Since all objects have a version >0, we can use 0 as a marker for + * 'we need the first object in the bucket'. + * + * \todo Linking and unlink objects is typically expensive, as it + * involves a malloc() of a small object which is very inefficient. + * To optimize this, we allocate larger arrays of bucket_list's + * when we run out of them, and then manage our own freelist. + * This will be more efficient as we can do the freelist management while + * we hold the lock (that we need anyways). + */ +struct ao2_container { + ao2_hash_fn hash_fn; + ao2_callback_fn cmp_fn; + int n_buckets; + /*! Number of elements in the container */ + int elements; + /*! described above */ + int version; + /*! variable size */ + struct bucket buckets[0]; +}; + +/*! + * \brief always zero hash function + * + * it is convenient to have a hash function that always returns 0. + * This is basically used when we want to have a container that is + * a simple linked list. + * + * \returns 0 + */ +static int hash_zero(const void *user_obj, const int flags) +{ + return 0; +} + +/* + * A container is just an object, after all! + */ +struct ao2_container * +ao2_container_alloc(const uint n_buckets, ao2_hash_fn hash_fn, + ao2_callback_fn cmp_fn) +{ + /* XXX maybe consistency check on arguments ? */ + /* compute the container size */ + size_t container_size = sizeof(struct ao2_container) + n_buckets * sizeof(struct bucket); + + struct ao2_container *c = ao2_alloc(container_size, container_destruct); + + if (!c) + return NULL; + + c->version = 1; /* 0 is a reserved value here */ + c->n_buckets = n_buckets; + c->hash_fn = hash_fn ? hash_fn : hash_zero; + c->cmp_fn = cmp_fn; + +#ifdef AO2_DEBUG + ast_atomic_fetchadd_int(&ao2.total_containers, 1); +#endif + + return c; +} + +/*! + * return the number of elements in the container + */ +int ao2_container_count(struct ao2_container *c) +{ + return c->elements; +} + +/*! + * A structure to create a linked list of entries, + * used within a bucket. + * XXX \todo this should be private to the container code + */ +struct bucket_list { + AST_LIST_ENTRY(bucket_list) entry; + int version; + struct astobj2 *astobj; /* pointer to internal data */ +}; + +/* + * link an object to a container + */ +void *__ao2_link(struct ao2_container *c, void *user_data, int iax2_hack) +{ + int i; + /* create a new list entry */ + struct bucket_list *p; + struct astobj2 *obj = INTERNAL_OBJ(user_data); + + if (!obj) + return NULL; + + if (INTERNAL_OBJ(c) == NULL) + return NULL; + + p = calloc(1, sizeof(*p)); + if (!p) + return NULL; + + i = c->hash_fn(user_data, OBJ_POINTER); + + ao2_lock(c); + i %= c->n_buckets; + p->astobj = obj; + p->version = ast_atomic_fetchadd_int(&c->version, 1); + if (iax2_hack) + AST_LIST_INSERT_HEAD(&c->buckets[i], p, entry); + else + AST_LIST_INSERT_TAIL(&c->buckets[i], p, entry); + ast_atomic_fetchadd_int(&c->elements, 1); + ao2_ref(user_data, +1); + ao2_unlock(c); + + return p; +} + +/*! + * \brief another convenience function is a callback that matches on address + */ +int ao2_match_by_addr(void *user_data, void *arg, int flags) +{ + return (user_data == arg) ? (CMP_MATCH | CMP_STOP) : 0; +} + +/* + * Unlink an object from the container + * and destroy the associated * ao2_bucket_list structure. + */ +void *ao2_unlink(struct ao2_container *c, void *user_data) +{ + if (INTERNAL_OBJ(user_data) == NULL) /* safety check on the argument */ + return NULL; + + ao2_callback(c, OBJ_UNLINK | OBJ_POINTER | OBJ_NODATA, ao2_match_by_addr, user_data); + + return NULL; +} + +/*! + * \brief special callback that matches all + */ +static int cb_true(void *user_data, void *arg, int flags) +{ + return CMP_MATCH; +} + +/*! + * Browse the container using different stategies accoding the flags. + * \return Is a pointer to an object or to a list of object if OBJ_MULTIPLE is + * specified. + */ +void *ao2_callback(struct ao2_container *c, + const enum search_flags flags, + ao2_callback_fn cb_fn, void *arg) +{ + int i, last; /* search boundaries */ + void *ret = NULL; + + if (INTERNAL_OBJ(c) == NULL) /* safety check on the argument */ + return NULL; + + if ((flags & (OBJ_MULTIPLE | OBJ_NODATA)) == OBJ_MULTIPLE) { + ast_log(LOG_WARNING, "multiple data return not implemented yet (flags %x)\n", flags); + return NULL; + } + + /* override the match function if necessary */ +#if 0 + /* Removing this slightly changes the meaning of OBJ_POINTER, but makes it + * do what I want it to. I'd like to hint to ao2_callback that the arg is + * of the same object type, so it can be passed to the hash function. + * However, I don't want to imply that this is the object being searched for. */ + if (flags & OBJ_POINTER) + cb_fn = match_by_addr; + else +#endif + if (cb_fn == NULL) /* if NULL, match everything */ + cb_fn = cb_true; + /* + * XXX this can be optimized. + * If we have a hash function and lookup by pointer, + * run the hash function. Otherwise, scan the whole container + * (this only for the time being. We need to optimize this.) + */ + if ((flags & OBJ_POINTER)) /* we know hash can handle this case */ + i = c->hash_fn(arg, flags & OBJ_POINTER) % c->n_buckets; + else /* don't know, let's scan all buckets */ + i = -1; /* XXX this must be fixed later. */ + + /* determine the search boundaries: i..last-1 */ + if (i < 0) { + i = 0; + last = c->n_buckets; + } else { + last = i + 1; + } + + ao2_lock(c); /* avoid modifications to the content */ + + for (; i < last ; i++) { + /* scan the list with prev-cur pointers */ + struct bucket_list *cur; + + AST_LIST_TRAVERSE_SAFE_BEGIN(&c->buckets[i], cur, entry) { + int match = cb_fn(EXTERNAL_OBJ(cur->astobj), arg, flags) & (CMP_MATCH | CMP_STOP); + + /* we found the object, performing operations according flags */ + if (match == 0) { /* no match, no stop, continue */ + continue; + } else if (match == CMP_STOP) { /* no match but stop, we are done */ + i = last; + break; + } + /* we have a match (CMP_MATCH) here */ + if (!(flags & OBJ_NODATA)) { /* if must return the object, record the value */ + /* it is important to handle this case before the unlink */ + ret = EXTERNAL_OBJ(cur->astobj); + ao2_ref(ret, 1); + } + + if (flags & OBJ_UNLINK) { /* must unlink */ + struct bucket_list *x = cur; + + /* we are going to modify the container, so update version */ + ast_atomic_fetchadd_int(&c->version, 1); + AST_LIST_REMOVE_CURRENT(&c->buckets[i], entry); + /* update number of elements and version */ + ast_atomic_fetchadd_int(&c->elements, -1); + ao2_ref(EXTERNAL_OBJ(x->astobj), -1); + free(x); /* free the link record */ + } + + if ((match & CMP_STOP) || (flags & OBJ_MULTIPLE) == 0) { + /* We found the only match we need */ + i = last; /* force exit from outer loop */ + break; + } + if (!(flags & OBJ_NODATA)) { +#if 0 /* XXX to be completed */ + /* + * This is the multiple-return case. We need to link + * the object in a list. The refcount is already increased. + */ +#endif + } + } + AST_LIST_TRAVERSE_SAFE_END + } + ao2_unlock(c); + return ret; +} + +/*! + * the find function just invokes the default callback with some reasonable flags. + */ +void *ao2_find(struct ao2_container *c, void *arg, enum search_flags flags) +{ + return ao2_callback(c, flags, c->cmp_fn, arg); +} + +/*! + * initialize an iterator so we start from the first object + */ +struct ao2_iterator ao2_iterator_init(struct ao2_container *c, int flags) +{ + struct ao2_iterator a = { + .c = c, + .flags = flags + }; + + return a; +} + +/* + * move to the next element in the container. + */ +void * ao2_iterator_next(struct ao2_iterator *a) +{ + int lim; + struct bucket_list *p = NULL; + void *ret = NULL; + + if (INTERNAL_OBJ(a->c) == NULL) + return NULL; + + if (!(a->flags & F_AO2I_DONTLOCK)) + ao2_lock(a->c); + + /* optimization. If the container is unchanged and + * we have a pointer, try follow it + */ + if (a->c->version == a->c_version && (p = a->obj) ) { + if ( (p = AST_LIST_NEXT(p, entry)) ) + goto found; + /* nope, start from the next bucket */ + a->bucket++; + a->version = 0; + a->obj = NULL; + } + + lim = a->c->n_buckets; + + /* Browse the buckets array, moving to the next + * buckets if we don't find the entry in the current one. + * Stop when we find an element with version number greater + * than the current one (we reset the version to 0 when we + * switch buckets). + */ + for (; a->bucket < lim; a->bucket++, a->version = 0) { + /* scan the current bucket */ + AST_LIST_TRAVERSE(&a->c->buckets[a->bucket], p, entry) { + if (p->version > a->version) + goto found; + } + } + +found: + if (p) { + a->version = p->version; + a->obj = p; + a->c_version = a->c->version; + ret = EXTERNAL_OBJ(p->astobj); + /* inc refcount of returned object */ + ao2_ref(ret, 1); + } + + if (!(a->flags & F_AO2I_DONTLOCK)) + ao2_unlock(a->c); + + return ret; +} + +/* callback for destroying container. + * we can make it simple as we know what it does + */ +static int cd_cb(void *obj, void *arg, int flag) +{ + ao2_ref(obj, -1); + return 0; +} + +static void container_destruct(void *_c) +{ + struct ao2_container *c = _c; + + ao2_callback(c, OBJ_UNLINK, cd_cb, NULL); + +#ifdef AO2_DEBUG + ast_atomic_fetchadd_int(&ao2.total_containers, -1); +#endif +} + +#ifdef AO2_DEBUG +static int print_cb(void *obj, void *arg, int flag) +{ + int *fd = arg; + char *s = (char *)obj; + + ast_cli(*fd, "string <%s>\n", s); + return 0; +} + +/* + * Print stats + */ +static int handle_astobj2_stats(int fd, int argc, char *argv[]) +{ + ast_cli(fd, "Objects : %d\n", ao2.total_objects); + ast_cli(fd, "Containers : %d\n", ao2.total_containers); + ast_cli(fd, "Memory : %d\n", ao2.total_mem); + ast_cli(fd, "Locked : %d\n", ao2.total_locked); + ast_cli(fd, "Refs : %d\n", ao2.total_refs); + return 0; +} + +/* + * This is testing code for astobj + */ +static int handle_astobj2_test(int fd, int argc, char *argv[]) +{ + struct ao2_container *c1; + int i, lim; + char *obj; + static int prof_id = -1; + + if (prof_id == -1) + prof_id = ast_add_profile("ao2_alloc", 0); + + ast_cli(fd, "argc %d argv %s %s %s\n", argc, argv[0], argv[1], argv[2]); + lim = atoi(argv[2]); + ast_cli(fd, "called astobj_test\n"); + + handle_astobj2_stats(fd, 0, NULL); + /* + * allocate a container with no default callback, and no hash function. + * No hash means everything goes in the same bucket. + */ + c1 = ao2_container_alloc(100, NULL /* no callback */, NULL /* no hash */); + ast_cli(fd, "container allocated as %p\n", c1); + + /* + * fill the container with objects. + * ao2_alloc() gives us a reference which we pass to the + * container when we do the insert. + */ + for (i = 0; i < lim; i++) { + ast_mark(prof_id, 1 /* start */); + obj = ao2_alloc(80, NULL); + ast_mark(prof_id, 0 /* stop */); + ast_cli(fd, "object %d allocated as %p\n", i, obj); + sprintf(obj, "-- this is obj %d --", i); + ao2_link(c1, obj); + } + ast_cli(fd, "testing callbacks\n"); + ao2_callback(c1, 0, print_cb, &fd); + + ast_cli(fd, "testing iterators, remove every second object\n"); + { + struct ao2_iterator ai; + int x = 0; + + ai = ao2_iterator_init(c1, 0); + while ( (obj = ao2_iterator_next(&ai)) ) { + ast_cli(fd, "iterator on <%s>\n", obj); + if (x++ & 1) + ao2_unlink(c1, obj); + ao2_ref(obj, -1); + } + ast_cli(fd, "testing iterators again\n"); + ai = ao2_iterator_init(c1, 0); + while ( (obj = ao2_iterator_next(&ai)) ) { + ast_cli(fd, "iterator on <%s>\n", obj); + ao2_ref(obj, -1); + } + } + ast_cli(fd, "testing callbacks again\n"); + ao2_callback(c1, 0, print_cb, &fd); + + ast_verbose("now you should see an error message:\n"); + ao2_ref(&i, -1); /* i is not a valid object so we print an error here */ + + ast_cli(fd, "destroy container\n"); + ao2_ref(c1, -1); /* destroy container */ + handle_astobj2_stats(fd, 0, NULL); + return 0; +} + +static struct ast_cli_entry cli_astobj2[] = { + { { "astobj2", "stats", NULL }, + handle_astobj2_stats, "Print astobj2 statistics", }, + { { "astobj2", "test", NULL } , handle_astobj2_test, "Test astobj2", }, +}; +#endif /* AO2_DEBUG */ + +int astobj2_init(void) +{ +#ifdef AO2_DEBUG + ast_cli_register_multiple(cli_astobj2, ARRAY_LEN(cli_astobj2)); +#endif + + return 0; +} diff --git a/channels/chan_iax2.c b/channels/chan_iax2.c index 8d031f7ea..454c4ee86 100644 --- a/channels/chan_iax2.c +++ b/channels/chan_iax2.c @@ -89,6 +89,8 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$") #include "asterisk/dnsmgr.h" #include "asterisk/devicestate.h" #include "asterisk/netsock.h" +#include "asterisk/dlinkedlists.h" +#include "asterisk/astobj2.h" #include "iax2.h" #include "iax2-parser.h" @@ -611,6 +613,8 @@ struct chan_iax2_pvt { int frames_dropped; /*! received frame count: (just for stats) */ int frames_received; + + AST_DLLIST_ENTRY(chan_iax2_pvt) entry; }; static struct ast_iax2_queue { @@ -736,6 +740,16 @@ static struct chan_iax2_pvt *iaxs[IAX_MAX_CALLS]; static ast_mutex_t iaxsl[IAX_MAX_CALLS]; static struct timeval lastused[IAX_MAX_CALLS]; +/*! + * \brief Another container of iax2_pvt structures + * + * Active IAX2 pvt structs are also stored in this container, if they are a part + * of an active call where we know the remote side's call number. The reason + * for this is that incoming media frames do not contain our call number. So, + * instead of having to iterate the entire iaxs array, we use this container to + * look up calls where the remote side is using a given call number. + */ +static struct ao2_container *iax_peercallno_pvts; static int send_command(struct chan_iax2_pvt *, char, int, unsigned int, const unsigned char *, int, int); static int send_command_locked(unsigned short callno, char, int, unsigned int, const unsigned char *, int, int); @@ -913,17 +927,188 @@ static int iax2_getpeername(struct sockaddr_in sin, char *host, int len, int loc return res; } +static void update_max_trunk(void) +{ + int max = TRUNK_CALL_START; + int x; + /* XXX Prolly don't need locks here XXX */ + for (x=TRUNK_CALL_START;x<IAX_MAX_CALLS - 1; x++) { + if (iaxs[x]) + max = x + 1; + } + maxtrunkcall = max; + if (option_debug && iaxdebug) + ast_log(LOG_DEBUG, "New max trunk callno is %d\n", max); +} + +static void iax2_destroy_helper(struct chan_iax2_pvt *pvt) +{ + if (ast_test_flag(pvt, IAX_MAXAUTHREQ)) { + struct iax2_user *user; + + ast_mutex_lock(&userl.lock); + user = userl.users; + while (user) { + if (!strcmp(user->name, pvt->username)) { + user->curauthreq--; + break; + } + user = user->next; + } + ast_mutex_unlock(&userl.lock); + } + + /* No more pings or lagrq's */ + if (pvt->pingid > -1) + ast_sched_del(sched, pvt->pingid); + if (pvt->lagid > -1) + ast_sched_del(sched, pvt->lagid); + if (pvt->autoid > -1) + ast_sched_del(sched, pvt->autoid); + if (pvt->authid > -1) + ast_sched_del(sched, pvt->authid); + if (pvt->initid > -1) + ast_sched_del(sched, pvt->initid); +#ifdef NEWJB + if (pvt->jbid > -1) + ast_sched_del(sched, pvt->jbid); + pvt->jbid = -1; +#endif + pvt->pingid = -1; + pvt->lagid = -1; + pvt->autoid = -1; + pvt->authid = -1; + pvt->initid = -1; +} + +static void store_by_peercallno(struct chan_iax2_pvt *pvt) +{ + if (!pvt->peercallno) { + ast_log(LOG_ERROR, "This should not be called without a peer call number.\n"); + return; + } + + ao2_link(iax_peercallno_pvts, pvt); +} + +static void remove_by_peercallno(struct chan_iax2_pvt *pvt) +{ + if (!pvt->peercallno) { + ast_log(LOG_ERROR, "This should not be called without a peer call number.\n"); + return; + } + + ao2_unlink(iax_peercallno_pvts, pvt); +} + + + +static void iax2_destroy(int callno) +{ + struct chan_iax2_pvt *pvt; + struct ast_channel *owner; + +retry: + ast_mutex_lock(&iaxsl[callno]); + pvt = iaxs[callno]; + gettimeofday(&lastused[callno], NULL); + + if (pvt) + owner = pvt->owner; + else + owner = NULL; + if (owner) { + if (ast_mutex_trylock(&owner->lock)) { + ast_log(LOG_NOTICE, "Avoiding IAX destroy deadlock\n"); + ast_mutex_unlock(&iaxsl[callno]); + usleep(1); + goto retry; + } + } + if (!owner) + iaxs[callno] = NULL; + if (pvt) { + if (owner) { + /* If there's an owner, prod it to give up */ + owner->_softhangup |= AST_SOFTHANGUP_DEV; + ast_queue_hangup(owner); + } else { + pvt->owner = NULL; + } + + if (pvt->peercallno) { + remove_by_peercallno(pvt); + } + + if (!owner) { + ao2_ref(pvt, -1); + pvt = NULL; + } + } + + if (owner) { + ast_mutex_unlock(&owner->lock); + } + + ast_mutex_unlock(&iaxsl[callno]); + + if (callno & 0x4000) { + update_max_trunk(); + } +} + +static void iax2_frame_free(struct iax_frame *fr) +{ + if (fr->retrans > -1) + ast_sched_del(sched, fr->retrans); + iax_frame_free(fr); +} + +static void pvt_destructor(void *obj) +{ + struct chan_iax2_pvt *pvt = obj; + struct iax_frame *cur; + + iax2_destroy_helper(pvt); + + if (pvt->bridgetrans) + ast_translator_free_path(pvt->bridgetrans); + pvt->bridgetrans = NULL; + + /* Already gone */ + ast_set_flag(pvt, IAX_ALREADYGONE); + + for (cur = iaxq.head; cur ; cur = cur->next) { + /* Cancel any pending transmissions */ + if (cur->callno == pvt->callno) + cur->retries = -1; + } + if (pvt->reg) { + pvt->reg->callno = 0; + } + if (!pvt->owner) { + if (pvt->vars) { + ast_variables_destroy(pvt->vars); + pvt->vars = NULL; + } +#ifdef NEWJB + { + jb_frame frame; + while (jb_getall(pvt->jb,&frame) == JB_OK) + iax2_frame_free(frame.data); + jb_destroy(pvt->jb); + } +#endif + } +} + static struct chan_iax2_pvt *new_iax(struct sockaddr_in *sin, int lockpeer, const char *host) { struct chan_iax2_pvt *tmp; - tmp = malloc(sizeof(struct chan_iax2_pvt)); + + tmp = ao2_alloc(sizeof(*tmp), pvt_destructor); if (tmp) { - memset(tmp, 0, sizeof(struct chan_iax2_pvt)); tmp->prefs = prefs; - tmp->callno = 0; - tmp->peercallno = 0; - tmp->transfercallno = 0; - tmp->bridgecallno = 0; tmp->pingid = -1; tmp->lagid = -1; tmp->autoid = -1; @@ -987,20 +1172,6 @@ static int match(struct sockaddr_in *sin, unsigned short callno, unsigned short return 0; } -static void update_max_trunk(void) -{ - int max = TRUNK_CALL_START; - int x; - /* XXX Prolly don't need locks here XXX */ - for (x=TRUNK_CALL_START;x<IAX_MAX_CALLS - 1; x++) { - if (iaxs[x]) - max = x + 1; - } - maxtrunkcall = max; - if (option_debug && iaxdebug) - ast_log(LOG_DEBUG, "New max trunk callno is %d\n", max); -} - static void update_max_nontrunk(void) { int max = 1; @@ -1070,6 +1241,25 @@ static int find_callno(unsigned short callno, unsigned short dcallno, struct soc char iabuf[INET_ADDRSTRLEN]; char host[80]; if (new <= NEW_ALLOW) { + if (callno) { + struct chan_iax2_pvt *pvt; + struct chan_iax2_pvt tmp_pvt = { + .callno = dcallno, + .peercallno = callno, + /* hack!! */ + .frames_received = full_frame, + }; + + memcpy(&tmp_pvt.addr, sin, sizeof(tmp_pvt.addr)); + + if ((pvt = ao2_find(iax_peercallno_pvts, &tmp_pvt, OBJ_POINTER))) { + res = pvt->callno; + ao2_ref(pvt, -1); + pvt = NULL; + return res; + } + } + /* Look for an existing connection first */ for (x=1;(res < 1) && (x<maxnontrunkcall);x++) { ast_mutex_lock(&iaxsl[x]); @@ -1148,6 +1338,9 @@ static int find_callno(unsigned short callno, unsigned short dcallno, struct soc iaxs[x]->amaflags = amaflags; ast_copy_flags(iaxs[x], (&globalflags), IAX_NOTRANSFER | IAX_USEJITTERBUF | IAX_FORCEJITTERBUF); ast_copy_string(iaxs[x]->accountcode, accountcode, sizeof(iaxs[x]->accountcode)); + if (iaxs[x]->peercallno) { + store_by_peercallno(iaxs[x]); + } } else { ast_log(LOG_WARNING, "Out of resources\n"); ast_mutex_unlock(&iaxsl[x]); @@ -1159,13 +1352,6 @@ static int find_callno(unsigned short callno, unsigned short dcallno, struct soc return res; } -static void iax2_frame_free(struct iax_frame *fr) -{ - if (fr->retrans > -1) - ast_sched_del(sched, fr->retrans); - iax_frame_free(fr); -} - static int iax2_queue_frame(int callno, struct ast_frame *f) { /* Assumes lock for callno is already held... */ @@ -1639,112 +1825,7 @@ static int iax2_predestroy_nolock(int callno) return res; } -static void iax2_destroy(int callno) -{ - struct chan_iax2_pvt *pvt; - struct iax_frame *cur; - struct ast_channel *owner; - struct iax2_user *user; -retry: - ast_mutex_lock(&iaxsl[callno]); - pvt = iaxs[callno]; - gettimeofday(&lastused[callno], NULL); - - if (pvt) - owner = pvt->owner; - else - owner = NULL; - if (owner) { - if (ast_mutex_trylock(&owner->lock)) { - ast_log(LOG_NOTICE, "Avoiding IAX destroy deadlock\n"); - ast_mutex_unlock(&iaxsl[callno]); - usleep(1); - goto retry; - } - } - if (!owner) - iaxs[callno] = NULL; - if (pvt) { - if (!owner) - pvt->owner = NULL; - if (ast_test_flag(pvt, IAX_MAXAUTHREQ)) { - ast_mutex_lock(&userl.lock); - user = userl.users; - while (user) { - if (!strcmp(user->name, pvt->username)) { - user->curauthreq--; - break; - } - user = user->next; - } - ast_mutex_unlock(&userl.lock); - } - /* No more pings or lagrq's */ - if (pvt->pingid > -1) - ast_sched_del(sched, pvt->pingid); - if (pvt->lagid > -1) - ast_sched_del(sched, pvt->lagid); - if (pvt->autoid > -1) - ast_sched_del(sched, pvt->autoid); - if (pvt->authid > -1) - ast_sched_del(sched, pvt->authid); - if (pvt->initid > -1) - ast_sched_del(sched, pvt->initid); -#ifdef NEWJB - if (pvt->jbid > -1) - ast_sched_del(sched, pvt->jbid); - pvt->jbid = -1; -#endif - pvt->pingid = -1; - pvt->lagid = -1; - pvt->autoid = -1; - pvt->authid = -1; - pvt->initid = -1; - if (pvt->bridgetrans) - ast_translator_free_path(pvt->bridgetrans); - pvt->bridgetrans = NULL; - - /* Already gone */ - ast_set_flag(pvt, IAX_ALREADYGONE); - - if (owner) { - /* If there's an owner, prod it to give up */ - owner->_softhangup |= AST_SOFTHANGUP_DEV; - ast_queue_hangup(owner); - } - - for (cur = iaxq.head; cur ; cur = cur->next) { - /* Cancel any pending transmissions */ - if (cur->callno == pvt->callno) - cur->retries = -1; - } - if (pvt->reg) { - pvt->reg->callno = 0; - } - if (!owner) { - if (pvt->vars) { - ast_variables_destroy(pvt->vars); - pvt->vars = NULL; - } -#ifdef NEWJB - { - jb_frame frame; - while(jb_getall(pvt->jb,&frame) == JB_OK) - iax2_frame_free(frame.data); - jb_destroy(pvt->jb); - } -#endif - free(pvt); - } - } - if (owner) { - ast_mutex_unlock(&owner->lock); - } - ast_mutex_unlock(&iaxsl[callno]); - if (callno & 0x4000) - update_max_trunk(); -} static void iax2_destroy_nolock(int callno) { /* Actually it's easier to unlock, kill it, and relock */ @@ -5578,7 +5659,13 @@ static int complete_transfer(int callno, struct iax_ies *ies) pvt->rseqno = 0; pvt->iseqno = 0; pvt->aseqno = 0; + + if (pvt->peercallno) { + remove_by_peercallno(pvt); + } pvt->peercallno = peercallno; + store_by_peercallno(pvt); + pvt->transferring = TRANSFER_NONE; pvt->svoiceformat = -1; pvt->voiceformat = 0; @@ -6738,8 +6825,18 @@ static int socket_read(int *id, int fd, short events, void *cbdata) if (!inaddrcmp(&sin, &iaxs[fr->callno]->addr) && !minivid && f.subclass != IAX_COMMAND_TXCNT && /* for attended transfer */ - f.subclass != IAX_COMMAND_TXACC) /* for attended transfer */ - iaxs[fr->callno]->peercallno = (unsigned short)(ntohs(mh->callno) & ~IAX_FLAG_FULL); + f.subclass != IAX_COMMAND_TXACC) { /* for attended transfer */ + unsigned short new_peercallno; + + new_peercallno = (unsigned short) (ntohs(mh->callno) & ~IAX_FLAG_FULL); + if (new_peercallno && new_peercallno != iaxs[fr->callno]->peercallno) { + if (iaxs[fr->callno]->peercallno) { + remove_by_peercallno(iaxs[fr->callno]); + } + iaxs[fr->callno]->peercallno = new_peercallno; + store_by_peercallno(iaxs[fr->callno]); + } + } if (ntohs(mh->callno) & IAX_FLAG_FULL) { if (option_debug && iaxdebug) ast_log(LOG_DEBUG, "Received packet %d, (%d, %d)\n", fh->oseqno, f.frametype, f.subclass); @@ -9858,6 +9955,8 @@ static int __unload_module(void) for (x = 0; x < IAX_MAX_CALLS; x++) ast_mutex_destroy(&iaxsl[x]); + ao2_ref(iax_peercallno_pvts, -1); + return 0; } @@ -9867,6 +9966,23 @@ int unload_module() return __unload_module(); } +static int pvt_hash_cb(const void *obj, const int flags) +{ + const struct chan_iax2_pvt *pvt = obj; + + return pvt->peercallno; +} + +static int pvt_cmp_cb(void *obj, void *arg, int flags) +{ + struct chan_iax2_pvt *pvt = obj, *pvt2 = arg; + + /* The frames_received field is used to hold whether we're matching + * against a full frame or not ... */ + + return match(&pvt2->addr, pvt2->peercallno, pvt2->callno, pvt, + pvt2->frames_received) ? CMP_MATCH : 0; +} /*--- load_module: Load IAX2 module, load configuraiton ---*/ int load_module(void) @@ -9955,6 +10071,11 @@ int load_module(void) ast_netsock_release(outsock); } + iax_peercallno_pvts = ao2_container_alloc(IAX_MAX_CALLS, pvt_hash_cb, pvt_cmp_cb); + if (!iax_peercallno_pvts) { + res = -1; + } + ast_mutex_lock(®_lock); for (reg = registrations; reg; reg = reg->next) iax2_do_register(reg); diff --git a/include/asterisk/astobj2.h b/include/asterisk/astobj2.h new file mode 100644 index 000000000..bcb8addda --- /dev/null +++ b/include/asterisk/astobj2.h @@ -0,0 +1,541 @@ +/* + * astobj2 - replacement containers for asterisk data structures. + * + * Copyright (C) 2006 Marta Carbone, Luigi Rizzo - Univ. di Pisa, Italy + * + * See http://www.asterisk.org for more information about + * the Asterisk project. Please do not directly contact + * any of the maintainers of this project for assistance; + * the project provides a web site, mailing lists and IRC + * channels for your use. + * + * This program is free software, distributed under the terms of + * the GNU General Public License Version 2. See the LICENSE file + * at the top of the source tree. + */ + +#ifndef _ASTERISK_ASTOBJ2_H +#define _ASTERISK_ASTOBJ2_H + +/*! \file + * + * \brief Object Model implementing objects and containers. + +These functions implement an abstraction for objects (with +locks and reference counts) and containers for these user-defined objects, +supporting locking, reference counting and callbacks. + +The internal implementation of the container is opaque to the user, +so we can use different data structures as needs arise. + +At the moment, however, the only internal data structure is a hash +table. When other structures will be implemented, the initialization +function may change. + +USAGE - OBJECTS + +An object is a block of memory that must be allocated with the +function ao2_alloc(), and for which the system keeps track (with +abit of help from the programmer) of the number of references around. +When an object has no more references, it is destroyed, by first +invoking whatever 'destructor' function the programmer specifies +(it can be NULL), and then freeing the memory. +This way objects can be shared without worrying who is in charge +of freeing them. + +Basically, creating an object requires the size of the object and +and a pointer to the destructor function: + + struct foo *o; + + o = ao2_alloc(sizeof(struct foo), my_destructor_fn); + +The object returned has a refcount = 1. +Note that the memory for the object is allocated and zeroed. +- We cannot realloc() the object itself. +- We cannot call free(o) to dispose of the object; rather we + tell the system that we do not need the reference anymore: + + ao2_ref(o, -1) + + causing the destructor to be called (and then memory freed) when + the refcount goes to 0. This is also available as ao2_unref(o), + and returns NULL as a convenience, so you can do things like + o = ao2_unref(o); + and clean the original pointer to prevent errors. + +- ao2_ref(o, +1) can be used to modify the refcount on the + object in case we want to pass it around. + + +- other calls on the object are ao2_lock(obj), ao2_unlock(), + ao2_trylock(), to manipulate the lock. + + +USAGE - CONTAINERS + +A containers is an abstract data structure where we can store +objects, search them (hopefully in an efficient way), and iterate +or apply a callback function to them. A container is just an object +itself. + +A container must first be allocated, specifying the initial +parameters. At the moment, this is done as follows: + + <b>Sample Usage:</b> + \code + + struct ao2_container *c; + + c = ao2_container_alloc(MAX_BUCKETS, my_hash_fn, my_cmp_fn); + +where +- MAX_BUCKETS is the number of buckets in the hash table, +- my_hash_fn() is the (user-supplied) function that returns a + hash key for the object (further reduced moduly MAX_BUCKETS + by the container's code); +- my_cmp_fn() is the default comparison function used when doing + searches on the container, + +A container knows little or nothing about the object itself, +other than the fact that it has been created by ao2_alloc() +All knowledge of the (user-defined) internals of the object +is left to the (user-supplied) functions passed as arguments +to ao2_container_alloc(). + +If we want to insert the object in the container, we should +initialize its fields -- especially, those used by my_hash_fn() -- +to compute the bucket to use. +Once done, we can link an object to a container with + + ao2_link(c, o); + +The function returns NULL in case of errors (and the object +is not inserted in the container). Other values mean success +(we are not supposed to use the value as a pointer to anything). + +\note While an object o is in a container, we expect that +my_hash_fn(o) will always return the same value. The function +does not lock the object to be computed, so modifications of +those fields that affect the computation of the hash should +be done by extractiong the object from the container, and +reinserting it after the change (this is not terribly expensive). + +\note A container with a single buckets is effectively a linked +list. However there is no ordering among elements. + +Objects implement a reference counter keeping the count +of the number of references that reference an object. + +When this number becomes zero the destructor will be +called and the object will be free'd. + */ + +/*! + * Invoked just before freeing the memory for the object. + * It is passed a pointer to user data. + */ +typedef void (*ao2_destructor_fn)(void *); + +void ao2_bt(void); /* backtrace */ +/*! + * Allocate and initialize an object. + * + * \param data_size The sizeof() of user-defined structure. + * \param destructor_fn The function destructor (can be NULL) + * \return A pointer to user data. + * + * Allocates a struct astobj2 with sufficient space for the + * user-defined structure. + * \notes: + * - storage is zeroed; XXX maybe we want a flag to enable/disable this. + * - the refcount of the object just created is 1 + * - the returned pointer cannot be free()'d or realloc()'ed; + * rather, we just call ao2_ref(o, -1); + */ +void *ao2_alloc(const size_t data_size, ao2_destructor_fn destructor_fn); + +/*! + * Reference/unreference an object and return the old refcount. + * + * \param o A pointer to the object + * \param delta Value to add to the reference counter. + * \return The value of the reference counter before the operation. + * + * Increase/decrease the reference counter according + * the value of delta. + * + * If the refcount goes to zero, the object is destroyed. + * + * \note The object must not be locked by the caller of this function, as + * it is invalid to try to unlock it after releasing the reference. + * + * \note if we know the pointer to an object, it is because we + * have a reference count to it, so the only case when the object + * can go away is when we release our reference, and it is + * the last one in existence. + */ +int ao2_ref(void *o, int delta); + +/*! + * Lock an object. + * + * \param a A pointer to the object we want lock. + * \return 0 on success, other values on error. + */ +int ao2_lock(void *a); + +/*! + * Unlock an object. + * + * \param a A pointer to the object we want unlock. + * \return 0 on success, other values on error. + */ +int ao2_unlock(void *a); + +/*! + * + * Containers + +containers are data structures meant to store several objects, +and perform various operations on them. +Internally, objects are stored in lists, hash tables or other +data structures depending on the needs. + +NOTA BENE: at the moment the only container we support is the +hash table and its degenerate form, the list. + +Operations on container include: + + c = ao2_container_alloc(size, cmp_fn, hash_fn) + allocate a container with desired size and default compare + and hash function + + ao2_find(c, arg, flags) + returns zero or more element matching a given criteria + (specified as arg). Flags indicate how many results we + want (only one or all matching entries), and whether we + should unlink the object from the container. + + ao2_callback(c, flags, fn, arg) + apply fn(obj, arg) to all objects in the container. + Similar to find. fn() can tell when to stop, and + do anything with the object including unlinking it. + Note that the entire operation is run with the container + locked, so noone else can change its content while we work on it. + However, we pay this with the fact that doing + anything blocking in the callback keeps the container + blocked. + The mechanism is very flexible because the callback function fn() + can do basically anything e.g. counting, deleting records, etc. + possibly using arg to store the results. + + iterate on a container + this is done with the following sequence + + struct ao2_container *c = ... // our container + struct ao2_iterator i; + void *o; + + i = ao2_iterator_init(c, flags); + + while ( (o = ao2_iterator_next(&i)) ) { + ... do something on o ... + ao2_ref(o, -1); + } + + The difference with the callback is that the control + on how to iterate is left to us. + + ao2_ref(c, -1) + dropping a reference to a container destroys it, very simple! + +Containers are astobj2 object themselves, and this is why their +implementation is simple too. + + */ + +/*! + * We can perform different operation on an object. We do this + * according the following flags. + */ +enum search_flags { + /*! unlink the object found */ + OBJ_UNLINK = (1 << 0), + /*! on match, don't return the object or increase its reference count. */ + OBJ_NODATA = (1 << 1), + /*! don't stop at the first match + * \note This is not fully implemented. */ + OBJ_MULTIPLE = (1 << 2), + /*! obj is an object of the same type as the one being searched for. + * This implies that it can be passed to the object's hash function + * for optimized searching. */ + OBJ_POINTER = (1 << 3), +}; + +/*! + * Type of a generic function to generate a hash value from an object. + * + */ +typedef int (*ao2_hash_fn)(const void *obj, const int flags); + +/*! + * valid callback results: + * We return a combination of + * CMP_MATCH when the object matches the request, + * and CMP_STOP when we should not continue the search further. + */ +enum _cb_results { + CMP_MATCH = 0x1, + CMP_STOP = 0x2, +}; + +/*! + * generic function to compare objects. + * This, as other callbacks, should return a combination of + * _cb_results as described above. + * + * \param o object from container + * \param arg search parameters (directly from ao2_find) + * \param flags passed directly from ao2_find + * XXX explain. + */ + +/*! + * Type of a generic callback function + * \param obj pointer to the (user-defined part) of an object. + * \param arg callback argument from ao2_callback() + * \param flags flags from ao2_callback() + * The return values are the same as a compare function. + * In fact, they are the same thing. + */ +typedef int (*ao2_callback_fn)(void *obj, void *arg, int flags); + +/*! + * Here start declarations of containers. + */ +struct ao2_container; + +/*! + * Allocate and initialize a container + * with the desired number of buckets. + * + * We allocate space for a struct astobj_container, struct container + * and the buckets[] array. + * + * \param my_hash_fn Pointer to a function computing a hash value. + * \param my_cmp_fn Pointer to a function comparating key-value + * with a string. (can be NULL) + * \return A pointer to a struct container. + * + * destructor is set implicitly. + */ +struct ao2_container *ao2_container_alloc(const uint n_buckets, + ao2_hash_fn hash_fn, ao2_callback_fn cmp_fn); + +/*! + * Returns the number of elements in a container. + */ +int ao2_container_count(struct ao2_container *c); + +/* + * Here we have functions to manage objects. + * + * We can use the functions below on any kind of + * object defined by the user. + */ + +/*! + * \brief Add an object to a container. + * + * \param c the container to operate on. + * \param newobj the object to be added. + * + * \return NULL on errors, other values on success. + * + * This function inserts an object in a container according its key. + * + * \note Remember to set the key before calling this function. + * + * \note This function automatically increases the reference count to + * account for the reference to the object that the container now holds. + * + * For Asterisk 1.4 only, there is a dirty hack here to ensure that chan_iax2 + * can have objects linked in to the container at the head instead of tail + * when it is just a linked list. This is to maintain some existing behavior + * where the order must be maintained as it was before this conversion so that + * matching behavior doesn't change. + */ +#define ao2_link(c, o) __ao2_link(c, o, 0) +void *__ao2_link(struct ao2_container *c, void *newobj, int iax2_hack); + +/*! + * \brief Remove an object from the container + * + * \arg c the container + * \arg obj the object to unlink + * + * \retval NULL, always + * + * \note The object requested to be unlinked must be valid. However, if it turns + * out that it is not in the container, this function is still safe to + * be called. + * + * \note If the object gets unlinked from the container, the container's + * reference to the object will be automatically released. + */ +void *ao2_unlink(struct ao2_container *c, void *obj); + +/*! \struct Used as return value if the flag OBJ_MULTIPLE is set */ +struct ao2_list { + struct ao2_list *next; + void *obj; /* pointer to the user portion of the object */ +}; + +/*! + * ao2_callback() and astob2_find() are the same thing with only one difference: + * the latter uses as a callback the function passed as my_cmp_f() at + * the time of the creation of the container. + * + * \param c A pointer to the container to operate on. + * \param arg passed to the callback. + * \param flags A set of flags specifying the operation to perform, + partially used by the container code, but also passed to + the callback. + * \return A pointer to the object found/marked, + * a pointer to a list of objects matching comparison function, + * NULL if not found. + * If the function returns any objects, their refcount is incremented, + * and the caller is in charge of decrementing them once done. + * Also, in case of multiple values returned, the list used + * to store the objects must be freed by the caller. + * + * This function searches through a container and performs operations + * on objects according on flags passed. + * XXX describe better + * The comparison is done calling the compare function set implicitly. + * The p pointer can be a pointer to an object or to a key, + * we can say this looking at flags value. + * If p points to an object we will search for the object pointed + * by this value, otherwise we serch for a key value. + * If the key is not uniq we only find the first matching valued. + * If we use the OBJ_MARK flags, we mark all the objects matching + * the condition. + * + * The use of flags argument is the follow: + * + * OBJ_UNLINK unlinks the object found + * OBJ_NODATA on match, do return an object + * Callbacks use OBJ_NODATA as a default + * functions such as find() do + * OBJ_MULTIPLE return multiple matches + * Default for _find() is no. + * to a key (not yet supported) + * OBJ_POINTER the pointer is an object pointer + * + * In case we return a list, the callee must take care to destroy + * that list when no longer used. + * + * \note When the returned object is no longer in use, ao2_ref() should + * be used to free the additional reference possibly created by this function. + */ +/* XXX order of arguments to find */ +void *ao2_find(struct ao2_container *c, void *arg, enum search_flags flags); +void *ao2_callback(struct ao2_container *c, + enum search_flags flags, + ao2_callback_fn cb_fn, void *arg); + +int ao2_match_by_addr(void *user_data, void *arg, int flags); +/*! + * + * + * When we need to walk through a container, we use + * ao2_iterator to keep track of the current position. + * + * Because the navigation is typically done without holding the + * lock on the container across the loop, + * objects can be inserted or deleted or moved + * while we work. As a consequence, there is no guarantee that + * the we manage to touch all the elements on the list, or it + * is possible that we touch the same object multiple times. + * However, within the current hash table container, the following is true: + * - It is not possible to miss an object in the container while iterating + * unless it gets added after the iteration begins and is added to a bucket + * that is before the one the current object is in. In this case, even if + * you locked the container around the entire iteration loop, you still would + * not see this object, because it would still be waiting on the container + * lock so that it can be added. + * - It would be extremely rare to see an object twice. The only way this can + * happen is if an object got unlinked from the container and added again + * during the same iteration. Furthermore, when the object gets added back, + * it has to be in the current or later bucket for it to be seen again. + * + * An iterator must be first initialized with ao2_iterator_init(), + * then we can use o = ao2_iterator_next() to move from one + * element to the next. Remember that the object returned by + * ao2_iterator_next() has its refcount incremented, + * and the reference must be explicitly released when done with it. + * + * Example: + * + * \code + * + * struct ao2_container *c = ... // the container we want to iterate on + * struct ao2_iterator i; + * struct my_obj *o; + * + * i = ao2_iterator_init(c, flags); + * + * while ( (o = ao2_iterator_next(&i)) ) { + * ... do something on o ... + * ao2_ref(o, -1); + * } + * + * \endcode + * + */ + +/*! + * You are not supposed to know the internals of an iterator! + * We would like the iterator to be opaque, unfortunately + * its size needs to be known if we want to store it around + * without too much trouble. + * Anyways... + * The iterator has a pointer to the container, and a flags + * field specifying various things e.g. whether the container + * should be locked or not while navigating on it. + * The iterator "points" to the current object, which is identified + * by three values: + * - a bucket number; + * - the object_id, which is also the container version number + * when the object was inserted. This identifies the object + * univoquely, however reaching the desired object requires + * scanning a list. + * - a pointer, and a container version when we saved the pointer. + * If the container has not changed its version number, then we + * can safely follow the pointer to reach the object in constant time. + * Details are in the implementation of ao2_iterator_next() + * A freshly-initialized iterator has bucket=0, version = 0. + */ + +struct ao2_iterator { + /*! the container */ + struct ao2_container *c; + /*! operation flags */ + int flags; +#define F_AO2I_DONTLOCK 1 /*!< don't lock when iterating */ + /*! current bucket */ + int bucket; + /*! container version */ + uint c_version; + /*! pointer to the current object */ + void *obj; + /*! container version when the object was created */ + uint version; +}; + +struct ao2_iterator ao2_iterator_init(struct ao2_container *c, int flags); + +void *ao2_iterator_next(struct ao2_iterator *a); + +#endif /* _ASTERISK_ASTOBJ2_H */ diff --git a/include/asterisk/dlinkedlists.h b/include/asterisk/dlinkedlists.h new file mode 100644 index 000000000..2f42fdd39 --- /dev/null +++ b/include/asterisk/dlinkedlists.h @@ -0,0 +1,974 @@ +/* + * Asterisk -- An open source telephony toolkit. + * + * Copyright (C) 2007, Digium, Inc. + * + * Steve Murphy <murf@digium.com> + * + * Doubly-Linked List Macros-- + * Based on linkedlists.h (to the point of plagiarism!), which is by: + * + * Mark Spencer <markster@digium.com> + * Kevin P. Fleming <kpfleming@digium.com> + * + * See http://www.asterisk.org for more information about + * the Asterisk project. Please do not directly contact + * any of the maintainers of this project for assistance; + * the project provides a web site, mailing lists and IRC + * channels for your use. + * + * This program is free software, distributed under the terms of + * the GNU General Public License Version 2. See the LICENSE file + * at the top of the source tree. + */ + +#ifndef ASTERISK_DLINKEDLISTS_H +#define ASTERISK_DLINKEDLISTS_H + +#include "asterisk/lock.h" + +/*! + \file dlinkedlists.h + \brief A set of macros to manage doubly-linked lists. +*/ + +/*! + \brief Locks a list. + \param head This is a pointer to the list head structure + + This macro attempts to place an exclusive lock in the + list head structure pointed to by head. + \retval 0 on success + \retval non-zero on failure +*/ +#define AST_DLLIST_LOCK(head) \ + ast_mutex_lock(&(head)->lock) + +/*! + \brief Write locks a list. + \param head This is a pointer to the list head structure + + This macro attempts to place an exclusive write lock in the + list head structure pointed to by head. + \retval 0 on success + \retval non-zero on failure +*/ +#define AST_RWDLLIST_WRLOCK(head) \ + ast_rwlock_wrlock(&(head)->lock) + +/*! + \brief Read locks a list. + \param head This is a pointer to the list head structure + + This macro attempts to place a read lock in the + list head structure pointed to by head. + \retval 0 on success + \retval non-zero on failure +*/ +#define AST_RWDLLIST_RDLOCK(head) \ + ast_rwlock_rdlock(&(head)->lock) + +/*! + \brief Locks a list, without blocking if the list is locked. + \param head This is a pointer to the list head structure + + This macro attempts to place an exclusive lock in the + list head structure pointed to by head. + \retval 0 on success + \retval non-zero on failure +*/ +#define AST_DLLIST_TRYLOCK(head) \ + ast_mutex_trylock(&(head)->lock) + +/*! + \brief Write locks a list, without blocking if the list is locked. + \param head This is a pointer to the list head structure + + This macro attempts to place an exclusive write lock in the + list head structure pointed to by head. + \retval 0 on success + \retval non-zero on failure +*/ +#define AST_RWDLLIST_TRYWRLOCK(head) \ + ast_rwlock_trywrlock(&(head)->lock) + +/*! + \brief Read locks a list, without blocking if the list is locked. + \param head This is a pointer to the list head structure + + This macro attempts to place a read lock in the + list head structure pointed to by head. + \retval 0 on success + \retval non-zero on failure +*/ +#define AST_RWDLLIST_TRYRDLOCK(head) \ + ast_rwlock_tryrdlock(&(head)->lock) + +/*! + \brief Attempts to unlock a list. + \param head This is a pointer to the list head structure + + This macro attempts to remove an exclusive lock from the + list head structure pointed to by head. If the list + was not locked by this thread, this macro has no effect. +*/ +#define AST_DLLIST_UNLOCK(head) \ + ast_mutex_unlock(&(head)->lock) + +/*! + \brief Attempts to unlock a read/write based list. + \param head This is a pointer to the list head structure + + This macro attempts to remove a read or write lock from the + list head structure pointed to by head. If the list + was not locked by this thread, this macro has no effect. +*/ +#define AST_RWDLLIST_UNLOCK(head) \ + ast_rwlock_unlock(&(head)->lock) + +/*! + \brief Defines a structure to be used to hold a list of specified type. + \param name This will be the name of the defined structure. + \param type This is the type of each list entry. + + This macro creates a structure definition that can be used + to hold a list of the entries of type \a type. It does not actually + declare (allocate) a structure; to do that, either follow this + macro with the desired name of the instance you wish to declare, + or use the specified \a name to declare instances elsewhere. + + Example usage: + \code + static AST_DLLIST_HEAD(entry_list, entry) entries; + \endcode + + This would define \c struct \c entry_list, and declare an instance of it named + \a entries, all intended to hold a list of type \c struct \c entry. +*/ +#define AST_DLLIST_HEAD(name, type) \ +struct name { \ + struct type *first; \ + struct type *last; \ + ast_mutex_t lock; \ +} + +/*! + \brief Defines a structure to be used to hold a read/write list of specified type. + \param name This will be the name of the defined structure. + \param type This is the type of each list entry. + + This macro creates a structure definition that can be used + to hold a list of the entries of type \a type. It does not actually + declare (allocate) a structure; to do that, either follow this + macro with the desired name of the instance you wish to declare, + or use the specified \a name to declare instances elsewhere. + + Example usage: + \code + static AST_RWDLLIST_HEAD(entry_list, entry) entries; + \endcode + + This would define \c struct \c entry_list, and declare an instance of it named + \a entries, all intended to hold a list of type \c struct \c entry. +*/ +#define AST_RWDLLIST_HEAD(name, type) \ +struct name { \ + struct type *first; \ + struct type *last; \ + ast_rwlock_t lock; \ +} + +/*! + \brief Defines a structure to be used to hold a list of specified type (with no lock). + \param name This will be the name of the defined structure. + \param type This is the type of each list entry. + + This macro creates a structure definition that can be used + to hold a list of the entries of type \a type. It does not actually + declare (allocate) a structure; to do that, either follow this + macro with the desired name of the instance you wish to declare, + or use the specified \a name to declare instances elsewhere. + + Example usage: + \code + static AST_DLLIST_HEAD_NOLOCK(entry_list, entry) entries; + \endcode + + This would define \c struct \c entry_list, and declare an instance of it named + \a entries, all intended to hold a list of type \c struct \c entry. +*/ +#define AST_DLLIST_HEAD_NOLOCK(name, type) \ +struct name { \ + struct type *first; \ + struct type *last; \ +} + +/*! + \brief Defines initial values for a declaration of AST_DLLIST_HEAD +*/ +#define AST_DLLIST_HEAD_INIT_VALUE { \ + .first = NULL, \ + .last = NULL, \ + .lock = AST_MUTEX_INIT_VALUE, \ + } + +/*! + \brief Defines initial values for a declaration of AST_RWDLLIST_HEAD +*/ +#define AST_RWDLLIST_HEAD_INIT_VALUE { \ + .first = NULL, \ + .last = NULL, \ + .lock = AST_RWLOCK_INIT_VALUE, \ + } + +/*! + \brief Defines initial values for a declaration of AST_DLLIST_HEAD_NOLOCK +*/ +#define AST_DLLIST_HEAD_NOLOCK_INIT_VALUE { \ + .first = NULL, \ + .last = NULL, \ + } + +/*! + \brief Defines a structure to be used to hold a list of specified type, statically initialized. + \param name This will be the name of the defined structure. + \param type This is the type of each list entry. + + This macro creates a structure definition that can be used + to hold a list of the entries of type \a type, and allocates an instance + of it, initialized to be empty. + + Example usage: + \code + static AST_DLLIST_HEAD_STATIC(entry_list, entry); + \endcode + + This would define \c struct \c entry_list, intended to hold a list of + type \c struct \c entry. +*/ +#if defined(AST_MUTEX_INIT_W_CONSTRUCTORS) +#define AST_DLLIST_HEAD_STATIC(name, type) \ +struct name { \ + struct type *first; \ + struct type *last; \ + ast_mutex_t lock; \ +} name; \ +static void __attribute__ ((constructor)) __init_##name(void) \ +{ \ + AST_DLLIST_HEAD_INIT(&name); \ +} \ +static void __attribute__ ((destructor)) __fini_##name(void) \ +{ \ + AST_DLLIST_HEAD_DESTROY(&name); \ +} \ +struct __dummy_##name +#else +#define AST_DLLIST_HEAD_STATIC(name, type) \ +struct name { \ + struct type *first; \ + struct type *last; \ + ast_mutex_t lock; \ +} name = AST_DLLIST_HEAD_INIT_VALUE +#endif + +/*! + \brief Defines a structure to be used to hold a read/write list of specified type, statically initialized. + \param name This will be the name of the defined structure. + \param type This is the type of each list entry. + + This macro creates a structure definition that can be used + to hold a list of the entries of type \a type, and allocates an instance + of it, initialized to be empty. + + Example usage: + \code + static AST_RWDLLIST_HEAD_STATIC(entry_list, entry); + \endcode + + This would define \c struct \c entry_list, intended to hold a list of + type \c struct \c entry. +*/ +#ifndef AST_RWLOCK_INIT_VALUE +#define AST_RWDLLIST_HEAD_STATIC(name, type) \ +struct name { \ + struct type *first; \ + struct type *last; \ + ast_rwlock_t lock; \ +} name; \ +static void __attribute__ ((constructor)) __init_##name(void) \ +{ \ + AST_RWDLLIST_HEAD_INIT(&name); \ +} \ +static void __attribute__ ((destructor)) __fini_##name(void) \ +{ \ + AST_RWDLLIST_HEAD_DESTROY(&name); \ +} \ +struct __dummy_##name +#else +#define AST_RWDLLIST_HEAD_STATIC(name, type) \ +struct name { \ + struct type *first; \ + struct type *last; \ + ast_rwlock_t lock; \ +} name = AST_RWDLLIST_HEAD_INIT_VALUE +#endif + +/*! + \brief Defines a structure to be used to hold a list of specified type, statically initialized. + + This is the same as AST_DLLIST_HEAD_STATIC, except without the lock included. +*/ +#define AST_DLLIST_HEAD_NOLOCK_STATIC(name, type) \ +struct name { \ + struct type *first; \ + struct type *last; \ +} name = AST_DLLIST_HEAD_NOLOCK_INIT_VALUE + +/*! + \brief Initializes a list head structure with a specified first entry. + \param head This is a pointer to the list head structure + \param entry pointer to the list entry that will become the head of the list + + This macro initializes a list head structure by setting the head + entry to the supplied value and recreating the embedded lock. +*/ +#define AST_DLLIST_HEAD_SET(head, entry) do { \ + (head)->first = (entry); \ + (head)->last = (entry); \ + ast_mutex_init(&(head)->lock); \ +} while (0) + +/*! + \brief Initializes an rwlist head structure with a specified first entry. + \param head This is a pointer to the list head structure + \param entry pointer to the list entry that will become the head of the list + + This macro initializes a list head structure by setting the head + entry to the supplied value and recreating the embedded lock. +*/ +#define AST_RWDLLIST_HEAD_SET(head, entry) do { \ + (head)->first = (entry); \ + (head)->last = (entry); \ + ast_rwlock_init(&(head)->lock); \ +} while (0) + +/*! + \brief Initializes a list head structure with a specified first entry. + \param head This is a pointer to the list head structure + \param entry pointer to the list entry that will become the head of the list + + This macro initializes a list head structure by setting the head + entry to the supplied value. +*/ +#define AST_DLLIST_HEAD_SET_NOLOCK(head, entry) do { \ + (head)->first = (entry); \ + (head)->last = (entry); \ +} while (0) + +/*! + \brief Declare previous/forward links inside a list entry. + \param type This is the type of each list entry. + + This macro declares a structure to be used to doubly link list entries together. + It must be used inside the definition of the structure named in + \a type, as follows: + + \code + struct list_entry { + ... + AST_DLLIST_ENTRY(list_entry) list; + } + \endcode + + The field name \a list here is arbitrary, and can be anything you wish. +*/ +#define AST_DLLIST_ENTRY(type) \ +struct { \ + struct type *prev; \ + struct type *next; \ +} + +#define AST_RWDLLIST_ENTRY AST_DLLIST_ENTRY + +/*! + \brief Returns the first entry contained in a list. + \param head This is a pointer to the list head structure + */ +#define AST_DLLIST_FIRST(head) ((head)->first) + +#define AST_RWDLLIST_FIRST AST_DLLIST_FIRST + +/*! + \brief Returns the last entry contained in a list. + \param head This is a pointer to the list head structure + */ +#define AST_DLLIST_LAST(head) ((head)->last) + +#define AST_RWDLLIST_LAST AST_DLLIST_LAST + +/*! + \brief Returns the next entry in the list after the given entry. + \param elm This is a pointer to the current entry. + \param field This is the name of the field (declared using AST_DLLIST_ENTRY()) + used to link entries of this list together. +*/ +#define AST_DLLIST_NEXT(elm, field) ((elm)->field.next) + +#define AST_RWDLLIST_NEXT AST_DLLIST_NEXT + +/*! + \brief Returns the previous entry in the list before the given entry. + \param elm This is a pointer to the current entry. + \param field This is the name of the field (declared using AST_DLLIST_ENTRY()) + used to link entries of this list together. +*/ +#define AST_DLLIST_PREV(elm, field) ((elm)->field.prev) + +#define AST_RWDLLIST_PREV AST_DLLIST_PREV + +/*! + \brief Checks whether the specified list contains any entries. + \param head This is a pointer to the list head structure + + \return non-zero if the list has entries + \return zero if not. + */ +#define AST_DLLIST_EMPTY(head) (AST_DLLIST_FIRST(head) == NULL) + +#define AST_RWDLLIST_EMPTY AST_DLLIST_EMPTY + +/*! + \brief Loops over (traverses) the entries in a list. + \param head This is a pointer to the list head structure + \param var This is the name of the variable that will hold a pointer to the + current list entry on each iteration. It must be declared before calling + this macro. + \param field This is the name of the field (declared using AST_DLLIST_ENTRY()) + used to link entries of this list together. + + This macro is use to loop over (traverse) the entries in a list. It uses a + \a for loop, and supplies the enclosed code with a pointer to each list + entry as it loops. It is typically used as follows: + \code + static AST_DLLIST_HEAD(entry_list, list_entry) entries; + ... + struct list_entry { + ... + AST_DLLIST_ENTRY(list_entry) list; + } + ... + struct list_entry *current; + ... + AST_DLLIST_TRAVERSE(&entries, current, list) { + (do something with current here) + } + \endcode + \warning If you modify the forward-link pointer contained in the \a current entry while + inside the loop, the behavior will be unpredictable. At a minimum, the following + macros will modify the forward-link pointer, and should not be used inside + AST_DLLIST_TRAVERSE() against the entry pointed to by the \a current pointer without + careful consideration of their consequences: + \li AST_DLLIST_NEXT() (when used as an lvalue) + \li AST_DLLIST_INSERT_AFTER() + \li AST_DLLIST_INSERT_HEAD() + \li AST_DLLIST_INSERT_TAIL() +*/ +#define AST_DLLIST_TRAVERSE(head,var,field) \ + for((var) = (head)->first; (var); (var) = (var)->field.next) + +#define AST_RWDLLIST_TRAVERSE AST_DLLIST_TRAVERSE + +/*! + \brief Loops over (traverses) the entries in a list in reverse order, starting at the end. + \param head This is a pointer to the list head structure + \param var This is the name of the variable that will hold a pointer to the + current list entry on each iteration. It must be declared before calling + this macro. + \param field This is the name of the field (declared using AST_DLLIST_ENTRY()) + used to link entries of this list together. + + This macro is use to loop over (traverse) the entries in a list in reverse order. It uses a + \a for loop, and supplies the enclosed code with a pointer to each list + entry as it loops. It is typically used as follows: + \code + static AST_DLLIST_HEAD(entry_list, list_entry) entries; + ... + struct list_entry { + ... + AST_DLLIST_ENTRY(list_entry) list; + } + ... + struct list_entry *current; + ... + AST_DLLIST_TRAVERSE_BACKWARDS(&entries, current, list) { + (do something with current here) + } + \endcode + \warning If you modify the forward-link pointer contained in the \a current entry while + inside the loop, the behavior will be unpredictable. At a minimum, the following + macros will modify the forward-link pointer, and should not be used inside + AST_DLLIST_TRAVERSE() against the entry pointed to by the \a current pointer without + careful consideration of their consequences: + \li AST_DLLIST_PREV() (when used as an lvalue) + \li AST_DLLIST_INSERT_BEFORE() + \li AST_DLLIST_INSERT_HEAD() + \li AST_DLLIST_INSERT_TAIL() +*/ +#define AST_DLLIST_TRAVERSE_BACKWARDS(head,var,field) \ + for((var) = (head)->last; (var); (var) = (var)->field.prev) + +#define AST_RWDLLIST_TRAVERSE_BACKWARDS AST_DLLIST_TRAVERSE_BACKWARDS + +/*! + \brief Loops safely over (traverses) the entries in a list. + \param head This is a pointer to the list head structure + \param var This is the name of the variable that will hold a pointer to the + current list entry on each iteration. It must be declared before calling + this macro. + \param field This is the name of the field (declared using AST_DLLIST_ENTRY()) + used to link entries of this list together. + + This macro is used to safely loop over (traverse) the entries in a list. It + uses a \a for loop, and supplies the enclosed code with a pointer to each list + entry as it loops. It is typically used as follows: + + \code + static AST_DLLIST_HEAD(entry_list, list_entry) entries; + ... + struct list_entry { + ... + AST_DLLIST_ENTRY(list_entry) list; + } + ... + struct list_entry *current; + ... + AST_DLLIST_TRAVERSE_SAFE_BEGIN(&entries, current, list) { + (do something with current here) + } + AST_DLLIST_TRAVERSE_SAFE_END; + \endcode + + It differs from AST_DLLIST_TRAVERSE() in that the code inside the loop can modify + (or even free, after calling AST_DLLIST_REMOVE_CURRENT()) the entry pointed to by + the \a current pointer without affecting the loop traversal. +*/ +#define AST_DLLIST_TRAVERSE_SAFE_BEGIN(head, var, field) { \ + typeof((head)) __list_head = head; \ + typeof(__list_head->first) __list_next; \ + typeof(__list_head->first) __list_prev = NULL; \ + typeof(__list_head->first) __new_prev = NULL; \ + for ((var) = __list_head->first, __new_prev = (var), \ + __list_next = (var) ? (var)->field.next : NULL; \ + (var); \ + __list_prev = __new_prev, (var) = __list_next, \ + __new_prev = (var), \ + __list_next = (var) ? (var)->field.next : NULL \ + ) + +#define AST_RWDLLIST_TRAVERSE_SAFE_BEGIN AST_DLLIST_TRAVERSE_SAFE_BEGIN + +/*! + \brief Loops safely over (traverses) the entries in a list. + \param head This is a pointer to the list head structure + \param var This is the name of the variable that will hold a pointer to the + current list entry on each iteration. It must be declared before calling + this macro. + \param field This is the name of the field (declared using AST_DLLIST_ENTRY()) + used to link entries of this list together. + + This macro is used to safely loop over (traverse) the entries in a list. It + uses a \a for loop, and supplies the enclosed code with a pointer to each list + entry as it loops. It is typically used as follows: + + \code + static AST_DLLIST_HEAD(entry_list, list_entry) entries; + ... + struct list_entry { + ... + AST_DLLIST_ENTRY(list_entry) list; + } + ... + struct list_entry *current; + ... + AST_DLLIST_TRAVERSE_SAFE_BEGIN(&entries, current, list) { + (do something with current here) + } + AST_DLLIST_TRAVERSE_SAFE_END; + \endcode + + It differs from AST_DLLIST_TRAVERSE() in that the code inside the loop can modify + (or even free, after calling AST_DLLIST_REMOVE_CURRENT()) the entry pointed to by + the \a current pointer without affecting the loop traversal. +*/ +#define AST_DLLIST_TRAVERSE_BACKWARDS_SAFE_BEGIN(head, var, field) { \ + typeof((head)) __list_head = head; \ + typeof(__list_head->first) __list_next; \ + typeof(__list_head->first) __list_prev = NULL; \ + typeof(__list_head->first) __new_prev = NULL; \ + for ((var) = __list_head->last, __new_prev = (var), \ + __list_next = NULL, __list_prev = (var) ? (var)->field.prev : NULL; \ + (var); \ + __list_next = __new_prev, (var) = __list_prev, \ + __new_prev = (var), \ + __list_prev = (var) ? (var)->field.prev : NULL \ + ) + +#define AST_RWDLLIST_TRAVERSE_BACKWARDS_SAFE_BEGIN AST_DLLIST_TRAVERSE_BACKWARDS_SAFE_BEGIN + +/*! + \brief Removes the \a current entry from a list during a traversal. + \param field This is the name of the field (declared using AST_DLLIST_ENTRY()) + used to link entries of this list together. + + \note This macro can \b only be used inside an AST_DLLIST_TRAVERSE_SAFE_BEGIN() + block; it is used to unlink the current entry from the list without affecting + the list traversal (and without having to re-traverse the list to modify the + previous entry, if any). + */ +#define AST_DLLIST_REMOVE_CURRENT(field) do { \ + __new_prev->field.next = NULL; \ + __new_prev->field.prev = NULL; \ + if (__list_next) \ + __new_prev = __list_prev; \ + else \ + __new_prev = NULL; \ + if (__list_prev) { \ + if (__list_next) \ + __list_next->field.prev = __list_prev; \ + __list_prev->field.next = __list_next; \ + } else { \ + __list_head->first = __list_next; \ + if (__list_next) \ + __list_next->field.prev = NULL; \ + } \ + if (!__list_next) \ + __list_head->last = __list_prev; \ + } while (0) + +#define AST_RWDLLIST_REMOVE_CURRENT AST_DLLIST_REMOVE_CURRENT + +#define AST_DLLIST_MOVE_CURRENT(newhead, field) do { \ + typeof ((newhead)->first) __list_cur = __new_prev; \ + AST_DLLIST_REMOVE_CURRENT(field); \ + AST_DLLIST_INSERT_TAIL((newhead), __list_cur, field); \ + } while (0) + +#define AST_RWDLLIST_MOVE_CURRENT AST_DLLIST_MOVE_CURRENT + +#define AST_DLLIST_MOVE_CURRENT_BACKWARDS(newhead, field) do { \ + typeof ((newhead)->first) __list_cur = __new_prev; \ + if (!__list_next) { \ + AST_DLLIST_REMOVE_CURRENT(field); \ + __new_prev = NULL; \ + AST_DLLIST_INSERT_HEAD((newhead), __list_cur, field); \ + } else { \ + AST_DLLIST_REMOVE_CURRENT(field); \ + AST_DLLIST_INSERT_HEAD((newhead), __list_cur, field); \ + }} while (0) + +#define AST_RWDLLIST_MOVE_CURRENT_BACKWARDS AST_DLLIST_MOVE_CURRENT + +/*! + \brief Inserts a list entry before the current entry during a traversal. + \param elm This is a pointer to the entry to be inserted. + \param field This is the name of the field (declared using AST_DLLIST_ENTRY()) + used to link entries of this list together. + + \note This macro can \b only be used inside an AST_DLLIST_TRAVERSE_SAFE_BEGIN() + block. + */ +#define AST_DLLIST_INSERT_BEFORE_CURRENT(elm, field) do { \ + if (__list_prev) { \ + (elm)->field.next = __list_prev->field.next; \ + (elm)->field.prev = __list_prev; \ + if (__list_prev->field.next) \ + __list_prev->field.next->field.prev = (elm); \ + __list_prev->field.next = (elm); \ + } else { \ + (elm)->field.next = __list_head->first; \ + __list_head->first->field.prev = (elm); \ + (elm)->field.prev = NULL; \ + __list_head->first = (elm); \ + } \ +} while (0) + +#define AST_RWDLLIST_INSERT_BEFORE_CURRENT AST_DLLIST_INSERT_BEFORE_CURRENT + +/*! + \brief Inserts a list entry after the current entry during a backwards traversal. Since + this is a backwards traversal, this will insert the entry AFTER the current + element. Since this is a backwards traveral, though, this would be BEFORE + the current entry in traversal order. Confusing? + \param elm This is a pointer to the entry to be inserted. + \param field This is the name of the field (declared using AST_DLLIST_ENTRY()) + used to link entries of this list together. + + \note This macro can \b only be used inside an AST_DLLIST_TRAVERSE_BACKWARDS_SAFE_BEGIN() + block. If you use this with the AST_DLLIST_TRAVERSE_SAFE_BEGIN(), be prepared for + strange things! + */ +#define AST_DLLIST_INSERT_BEFORE_CURRENT_BACKWARDS(elm, field) do { \ + if (__list_next) { \ + (elm)->field.next = __list_next; \ + (elm)->field.prev = __new_prev; \ + __new_prev->field.next = (elm); \ + __list_next->field.prev = (elm); \ + } else { \ + (elm)->field.prev = __list_head->last; \ + (elm)->field.next = NULL; \ + __list_head->last->field.next = (elm); \ + __list_head->last = (elm); \ + } \ +} while (0) + +#define AST_RWDLLIST_INSERT_BEFORE_CURRENT_BACKWARDS AST_DLLIST_INSERT_BEFORE_CURRENT_BACKWARDS + +/*! + \brief Closes a safe loop traversal block. + */ +#define AST_DLLIST_TRAVERSE_SAFE_END } + +#define AST_RWDLLIST_TRAVERSE_SAFE_END AST_DLLIST_TRAVERSE_SAFE_END + +/*! + \brief Closes a safe loop traversal block. + */ +#define AST_DLLIST_TRAVERSE_BACKWARDS_SAFE_END } + +#define AST_RWDLLIST_TRAVERSE_BACKWARDS_SAFE_END AST_DLLIST_TRAVERSE_BACKWARDS_SAFE_END + +/*! + \brief Initializes a list head structure. + \param head This is a pointer to the list head structure + + This macro initializes a list head structure by setting the head + entry to \a NULL (empty list) and recreating the embedded lock. +*/ +#define AST_DLLIST_HEAD_INIT(head) { \ + (head)->first = NULL; \ + (head)->last = NULL; \ + ast_mutex_init(&(head)->lock); \ +} + +/*! + \brief Initializes an rwlist head structure. + \param head This is a pointer to the list head structure + + This macro initializes a list head structure by setting the head + entry to \a NULL (empty list) and recreating the embedded lock. +*/ +#define AST_RWDLLIST_HEAD_INIT(head) { \ + (head)->first = NULL; \ + (head)->last = NULL; \ + ast_rwlock_init(&(head)->lock); \ +} + +/*! + \brief Destroys a list head structure. + \param head This is a pointer to the list head structure + + This macro destroys a list head structure by setting the head + entry to \a NULL (empty list) and destroying the embedded lock. + It does not free the structure from memory. +*/ +#define AST_DLLIST_HEAD_DESTROY(head) { \ + (head)->first = NULL; \ + (head)->last = NULL; \ + ast_mutex_destroy(&(head)->lock); \ +} + +/*! + \brief Destroys an rwlist head structure. + \param head This is a pointer to the list head structure + + This macro destroys a list head structure by setting the head + entry to \a NULL (empty list) and destroying the embedded lock. + It does not free the structure from memory. +*/ +#define AST_RWDLLIST_HEAD_DESTROY(head) { \ + (head)->first = NULL; \ + (head)->last = NULL; \ + ast_rwlock_destroy(&(head)->lock); \ +} + +/*! + \brief Initializes a list head structure. + \param head This is a pointer to the list head structure + + This macro initializes a list head structure by setting the head + entry to \a NULL (empty list). There is no embedded lock handling + with this macro. +*/ +#define AST_DLLIST_HEAD_INIT_NOLOCK(head) { \ + (head)->first = NULL; \ + (head)->last = NULL; \ +} + +/*! + \brief Inserts a list entry after a given entry. + \param head This is a pointer to the list head structure + \param listelm This is a pointer to the entry after which the new entry should + be inserted. + \param elm This is a pointer to the entry to be inserted. + \param field This is the name of the field (declared using AST_DLLIST_ENTRY()) + used to link entries of this list together. + */ +#define AST_DLLIST_INSERT_AFTER(head, listelm, elm, field) do { \ + (elm)->field.next = (listelm)->field.next; \ + (elm)->field.prev = (listelm); \ + if ((listelm)->field.next) \ + (listelm)->field.next->field.prev = (elm); \ + (listelm)->field.next = (elm); \ + if ((head)->last == (listelm)) \ + (head)->last = (elm); \ +} while (0) + +#define AST_RWDLLIST_INSERT_AFTER AST_DLLIST_INSERT_AFTER + +/*! + \brief Inserts a list entry before a given entry. + \param head This is a pointer to the list head structure + \param listelm This is a pointer to the entry before which the new entry should + be inserted. + \param elm This is a pointer to the entry to be inserted. + \param field This is the name of the field (declared using AST_DLLIST_ENTRY()) + used to link entries of this list together. + */ +#define AST_DLLIST_INSERT_BEFORE(head, listelm, elm, field) do { \ + (elm)->field.next = (listelm); \ + (elm)->field.prev = (listelm)->field.prev; \ + if ((listelm)->field.prev) \ + (listelm)->field.prev->field.next = (elm); \ + (listelm)->field.prev = (elm); \ + if ((head)->first == (listelm)) \ + (head)->first = (elm); \ +} while (0) + +#define AST_RWDLLIST_INSERT_BEFORE AST_DLLIST_INSERT_BEFORE + +/*! + \brief Inserts a list entry at the head of a list. + \param head This is a pointer to the list head structure + \param elm This is a pointer to the entry to be inserted. + \param field This is the name of the field (declared using AST_DLLIST_ENTRY()) + used to link entries of this list together. + */ +#define AST_DLLIST_INSERT_HEAD(head, elm, field) do { \ + (elm)->field.next = (head)->first; \ + if ((head)->first) \ + (head)->first->field.prev = (elm); \ + (elm)->field.prev = NULL; \ + (head)->first = (elm); \ + if (!(head)->last) \ + (head)->last = (elm); \ +} while (0) + +#define AST_RWDLLIST_INSERT_HEAD AST_DLLIST_INSERT_HEAD + +/*! + \brief Appends a list entry to the tail of a list. + \param head This is a pointer to the list head structure + \param elm This is a pointer to the entry to be appended. + \param field This is the name of the field (declared using AST_DLLIST_ENTRY()) + used to link entries of this list together. + + Note: The link field in the appended entry is \b not modified, so if it is + actually the head of a list itself, the entire list will be appended + temporarily (until the next AST_DLLIST_INSERT_TAIL is performed). + */ +#define AST_DLLIST_INSERT_TAIL(head, elm, field) do { \ + if (!(head)->first) { \ + (head)->first = (elm); \ + (head)->last = (elm); \ + (elm)->field.next = NULL; \ + (elm)->field.prev = NULL; \ + } else { \ + (head)->last->field.next = (elm); \ + (elm)->field.prev = (head)->last; \ + (elm)->field.next = NULL; \ + (head)->last = (elm); \ + } \ +} while (0) + +#define AST_RWDLLIST_INSERT_TAIL AST_DLLIST_INSERT_TAIL + +/*! + \brief Appends a whole list to the tail of a list. + \param head This is a pointer to the list head structure + \param list This is a pointer to the list to be appended. + \param field This is the name of the field (declared using AST_DLLIST_ENTRY()) + used to link entries of this list together. + + Note: The source list (the \a list parameter) will be empty after + calling this macro (the list entries are \b moved to the target list). + */ +#define AST_DLLIST_APPEND_DLLIST(head, list, field) do { \ + if (!(head)->first) { \ + (head)->first = (list)->first; \ + (head)->last = (list)->last; \ + } else { \ + (head)->last->field.next = (list)->first; \ + (list)->first->field.prev = (head)->last; \ + (head)->last = (list)->last; \ + } \ + (list)->first = NULL; \ + (list)->last = NULL; \ +} while (0) + +#define AST_RWDLLIST_APPEND_DLLIST AST_DLLIST_APPEND_DLLIST + +/*! + \brief Removes and returns the head entry from a list. + \param head This is a pointer to the list head structure + \param field This is the name of the field (declared using AST_DLLIST_ENTRY()) + used to link entries of this list together. + + Removes the head entry from the list, and returns a pointer to it. + This macro is safe to call on an empty list. + */ +#define AST_DLLIST_REMOVE_HEAD(head, field) ({ \ + typeof((head)->first) cur = (head)->first; \ + if (cur) { \ + (head)->first = cur->field.next; \ + if (cur->field.next) \ + cur->field.next->field.prev = NULL; \ + cur->field.next = NULL; \ + if ((head)->last == cur) \ + (head)->last = NULL; \ + } \ + cur; \ + }) + +#define AST_RWDLLIST_REMOVE_HEAD AST_DLLIST_REMOVE_HEAD + +/*! + \brief Removes a specific entry from a list. + \param head This is a pointer to the list head structure + \param elm This is a pointer to the entry to be removed. + \param field This is the name of the field (declared using AST_DLLIST_ENTRY()) + used to link entries of this list together. + \warning The removed entry is \b not freed nor modified in any way. + */ +#define AST_DLLIST_REMOVE(head, elm, field) ({ \ + __typeof(elm) __res = (elm); \ + if ((head)->first == (elm)) { \ + (head)->first = (elm)->field.next; \ + if ((elm)->field.next) \ + (elm)->field.next->field.prev = NULL; \ + if ((head)->last == (elm)) \ + (head)->last = NULL; \ + } else { \ + (elm)->field.prev->field.next = (elm)->field.next; \ + if ((elm)->field.next) \ + (elm)->field.next->field.prev = (elm)->field.prev; \ + if ((head)->last == (elm)) \ + (head)->last = (elm)->field.prev; \ + } \ + (elm)->field.next = NULL; \ + (elm)->field.prev = NULL; \ + (__res); \ +}) + +#define AST_RWDLLIST_REMOVE AST_DLLIST_REMOVE + +#endif /* _ASTERISK_DLINKEDLISTS_H */ |