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-rwxr-xr-xdoc/model.txt15
-rwxr-xr-xio.c259
2 files changed, 274 insertions, 0 deletions
diff --git a/doc/model.txt b/doc/model.txt
new file mode 100755
index 000000000..6afb3e04e
--- /dev/null
+++ b/doc/model.txt
@@ -0,0 +1,15 @@
+Description of call model:
+
+Incoming Call:
+
+ Channel backend waits for a RING or equivalent on some sort of
+interface. Typically this is done in its own thread. When a RING is
+detected, the backend should create a channel structure and then call
+ast_pbx_start() on that channel, which will create a thread to monitor
+that interface. At this point, the PBX and/or applications it launches
+will manage the interface, and it need not be montored by the
+aforementioned thread. When the applications are finished, the requisite
+hangup function will be called, at which the channel can be considered to
+be no longer valid, and the thread that controls it will immenantly be
+terminated.
+
diff --git a/io.c b/io.c
new file mode 100755
index 000000000..2ec5b0218
--- /dev/null
+++ b/io.c
@@ -0,0 +1,259 @@
+/*
+ * Asterisk
+ *
+ * Mark Spencer <markster@marko.net>
+ *
+ * Copyright(C) 1999, Adtran, Inc.
+ *
+ * Distributed under the terms of the GNU General Public License (GPL) Version 2
+ *
+ * I/O Managment (Derived from Cheops-NG)
+ *
+ */
+
+#include <stdio.h>
+#include <sys/poll.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <asterisk/io.h>
+#include <asterisk/logger.h>
+
+#ifdef DEBUG_IO
+#define DEBUG DEBUG_M
+#else
+#define DEBUG(a)
+#endif
+
+/*
+ * Kept for each file descriptor
+ */
+struct io_rec {
+ ast_io_cb callback; /* What is to be called */
+ void *data; /* Data to be passed */
+ int *id; /* ID number */
+};
+
+/* These two arrays are keyed with
+ the same index. it's too bad that
+ pollfd doesn't have a callback field
+ or something like that. They grow as
+ needed, by GROW_SHRINK_AMOUNT structures
+ at once */
+
+#define GROW_SHRINK_SIZE 512
+
+/* Global variables are now in a struct in order to be
+ made threadsafe */
+struct io_context {
+ /* Poll structure */
+ struct pollfd *fds;
+ /* Associated I/O records */
+ struct io_rec *ior;
+ /* First available fd */
+ unsigned int fdcnt;
+ /* Maximum available fd */
+ unsigned int maxfdcnt;
+ /* Currently used io callback */
+ int current_ioc;
+};
+
+
+struct io_context *io_context_create()
+{
+ /* Create an I/O context */
+ struct io_context *tmp;
+ tmp = malloc(sizeof(struct io_context));
+ if (tmp) {
+ tmp->fds = NULL;
+ tmp->ior = NULL;
+ tmp->fdcnt = 0;
+ tmp->maxfdcnt = -1;
+ tmp->current_ioc = -1;
+ }
+ return tmp;
+}
+
+void io_context_destroy(struct io_context *ioc)
+{
+ /* Free associated memory with an I/O context */
+ if (ioc->fds)
+ free(ioc->fds);
+ if (ioc->ior)
+ free(ioc->ior);
+ free(ioc);
+}
+
+static int io_grow(struct io_context *ioc)
+{
+ /*
+ * Grow the size of our arrays. Return 0 on success or
+ * -1 on failure
+ */
+ void *tmp;
+ DEBUG(ast_log(LOG_DEBUG, "io_grow()\n"));
+ ioc->maxfdcnt += GROW_SHRINK_SIZE;
+ tmp = realloc(ioc->ior, (ioc->maxfdcnt + 1) * sizeof(struct io_rec));
+ if (tmp) {
+ ioc->ior = (struct io_rec *)tmp;
+ tmp = realloc(ioc->fds, (ioc->maxfdcnt + 1) * sizeof(struct pollfd));
+ if (tmp) {
+ ioc->fds = tmp;
+ } else {
+ /*
+ * Not enough memory for the pollfd. Not really any need
+ * to shrink back the iorec's as we'll probably want to
+ * grow them again soon when more memory is available, and
+ * then they'll already be the right size
+ */
+ ioc->maxfdcnt -= GROW_SHRINK_SIZE;
+ return -1;
+ }
+
+ } else {
+ /*
+ * Out of memory. We return to the old size, and return a failure
+ */
+ ioc->maxfdcnt -= GROW_SHRINK_SIZE;
+ return -1;
+ }
+ return 0;
+}
+
+int *ast_io_add(struct io_context *ioc, int fd, ast_io_cb callback, short events, void *data)
+{
+ /*
+ * Add a new I/O entry for this file descriptor
+ * with the given event mask, to call callback with
+ * data as an argument. Returns NULL on failure.
+ */
+ DEBUG(ast_log(LOG_DEBUG, "ast_io_add()\n"));
+ if (ioc->fdcnt < ioc->maxfdcnt) {
+ /*
+ * We don't have enough space for this entry. We need to
+ * reallocate maxfdcnt poll fd's and io_rec's, or back out now.
+ */
+ if (io_grow(ioc))
+ return NULL;
+ }
+
+ /*
+ * At this point, we've got sufficiently large arrays going
+ * and we can make an entry for it in the pollfd and io_r
+ * structures.
+ */
+ ioc->fds[ioc->fdcnt].fd = fd;
+ ioc->fds[ioc->fdcnt].events = events;
+ ioc->ior[ioc->fdcnt].callback = callback;
+ ioc->ior[ioc->fdcnt].data = data;
+ ioc->ior[ioc->fdcnt].id = (int *)malloc(sizeof(int));
+ /* Bonk if we couldn't allocate an int */
+ if (!ioc->ior[ioc->fdcnt].id)
+ return NULL;
+ *ioc->ior[ioc->fdcnt].id = ioc->fdcnt;
+ return ioc->ior[ioc->fdcnt++].id;
+}
+
+int *ast_io_change(struct io_context *ioc, int *id, int fd, ast_io_cb callback, short events, void *data)
+{
+ if (*id < ioc->fdcnt) {
+ if (fd > -1)
+ ioc->fds[*id].fd = fd;
+ if (callback)
+ ioc->ior[*id].callback = callback;
+ if (events)
+ ioc->fds[*id].events = events;
+ if (data)
+ ioc->ior[*id].data = data;
+ return id;
+ } else return NULL;
+}
+
+static int io_shrink(struct io_context *ioc, int which)
+{
+ /*
+ * Bring the fields from the very last entry to cover over
+ * the entry we are removing, then decrease the size of the
+ * arrays by one.
+ */
+ ioc->fdcnt--;
+
+ /* Free the int */
+ free(ioc->ior[which].id);
+
+ /* If we're not deleting the last one, move the last one to
+ the current position */
+ if (which != ioc->fdcnt) {
+ ioc->fds[which] = ioc->fds[ioc->fdcnt];
+ ioc->ior[which] = ioc->ior[ioc->fdcnt];
+ *ioc->ior[which].id = which;
+ }
+ /* FIXME: We should free some memory if we have lots of unused
+ io structs */
+ return 0;
+}
+
+int ast_io_remove(struct io_context *ioc, int *id)
+{
+ if (ioc->current_ioc == *id) {
+ ast_log(LOG_NOTICE, "Callback for %d tried to remove itself\n", *id);
+ } else
+
+ if (*id < ioc->fdcnt) {
+ return io_shrink(ioc, *id);
+ } else
+ ast_log(LOG_NOTICE, "Unable to remove unknown id %d\n", *id);
+
+ return -1;
+}
+
+int ast_io_wait(struct io_context *ioc, int howlong)
+{
+ /*
+ * Make the poll call, and call
+ * the callbacks for anything that needs
+ * to be handled
+ */
+ int res;
+ int x;
+ DEBUG(ast_log(LOG_DEBUG, "ast_io_wait()\n"));
+ res = poll(ioc->fds, ioc->fdcnt, howlong);
+ if (res > 0) {
+ /*
+ * At least one event
+ */
+ for(x=0;x<ioc->fdcnt;x++) {
+ if (ioc->fds[x].revents) {
+ /* There's an event waiting */
+ ioc->current_ioc = *ioc->ior[x].id;
+ if (!ioc->ior[x].callback(ioc->ior[x].id, ioc->fds[x].fd, ioc->fds[x].revents, ioc->ior[x].data)) {
+ /* Time to delete them since they returned a 0 */
+ io_shrink(ioc, x);
+ }
+ ioc->current_ioc = -1;
+ }
+ }
+ }
+ return res;
+}
+
+void ast_io_dump(struct io_context *ioc)
+{
+ /*
+ * Print some debugging information via
+ * the logger interface
+ */
+ int x;
+ ast_log(LOG_DEBUG, "Asterisk IO Dump: %d entries, %d max entries\n", ioc->fdcnt, ioc->maxfdcnt);
+ ast_log(LOG_DEBUG, "================================================\n");
+ ast_log(LOG_DEBUG, "| ID FD Callback Data Events |\n");
+ ast_log(LOG_DEBUG, "+------+------+-----------+-----------+--------+\n");
+ for (x=0;x<ioc->fdcnt;x++) {
+ ast_log(LOG_DEBUG, "| %.4d | %.4d | %p | %p | %.6x |\n",
+ *ioc->ior[x].id,
+ ioc->fds[x].fd,
+ ioc->ior[x].callback,
+ ioc->ior[x].data,
+ ioc->fds[x].events);
+ }
+ ast_log(LOG_DEBUG, "================================================\n");
+}