diff options
Diffstat (limited to 'src/logging.c')
| -rw-r--r-- | src/logging.c | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/src/logging.c b/src/logging.c index 1c3544fa..b030f8a6 100644 --- a/src/logging.c +++ b/src/logging.c @@ -42,6 +42,7 @@ #include <time.h> #include <sys/time.h> #include <errno.h> +#include <pthread.h> #include <osmocom/core/talloc.h> #include <osmocom/core/utils.h> @@ -63,6 +64,56 @@ static struct log_context log_context; void *tall_log_ctx = NULL; LLIST_HEAD(osmo_log_target_list); +#if (!EMBEDDED) +/*! This mutex must be held while using osmo_log_target_list or any of its + log_targets in a multithread program. Prevents race conditions between threads + like producing unordered timestamps or VTY deleting a target while another + thread is writing to it */ +static pthread_mutex_t osmo_log_tgt_mutex; +static bool osmo_log_tgt_mutex_on = false; + +/*! Enable multithread support (mutex) in libosmocore logging system. + * Must be called by processes willing to use logging subsystem from several + * threads. Once enabled, it's not possible to disable it again. + */ +void log_enable_multithread(void) { + if (osmo_log_tgt_mutex_on) + return; + pthread_mutex_init(&osmo_log_tgt_mutex, NULL); + osmo_log_tgt_mutex_on = true; +} + +/*! Acquire the osmo_log_tgt_mutex. Don't use this function directly, always use + * macro log_tgt_mutex_lock() instead. + */ +void log_tgt_mutex_lock_impl(void) { + /* These lines are useful to debug scenarios where there's only 1 thread + and a double lock appears, for instance during startup and some + unlock() missing somewhere: + if (osmo_log_tgt_mutex_on && pthread_mutex_trylock(&osmo_log_tgt_mutex) != 0) + osmo_panic("acquiring already locked mutex!\n"); + return; + */ + + if (osmo_log_tgt_mutex_on) + pthread_mutex_lock(&osmo_log_tgt_mutex); +} + +/*! Release the osmo_log_tgt_mutex. Don't use this function directly, always use + * macro log_tgt_mutex_unlock() instead. + */ +void log_tgt_mutex_unlock_impl(void) { + if (osmo_log_tgt_mutex_on) + pthread_mutex_unlock(&osmo_log_tgt_mutex); +} + +#else /* if (!EMBEDDED) */ +#pragma message ("logging multithread support disabled in embedded build") +void log_enable_multithread(void) {} +void log_tgt_mutex_lock_impl(void) {} +void log_tgt_mutex_unlock_impl(void) {} +#endif /* if (!EMBEDDED) */ + const struct value_string loglevel_strs[] = { { LOGL_DEBUG, "DEBUG" }, { LOGL_INFO, "INFO" }, @@ -532,6 +583,8 @@ void osmo_vlogp(int subsys, int level, const char *file, int line, subsys = map_subsys(subsys); + log_tgt_mutex_lock(); + llist_for_each_entry(tar, &osmo_log_target_list, entry) { va_list bp; @@ -548,6 +601,8 @@ void osmo_vlogp(int subsys, int level, const char *file, int line, _output(tar, subsys, level, file, line, cont, format, bp); va_end(bp); } + + log_tgt_mutex_unlock(); } /*! logging function used by DEBUGP() macro @@ -870,6 +925,7 @@ struct log_target *log_target_create_file(const char *fname) * \param[in] type Log target type * \param[in] fname File name * \returns Log target (if found), NULL otherwise + * Must be called with mutex osmo_log_tgt_mutex held, see log_tgt_mutex_lock. */ struct log_target *log_target_find(int type, const char *fname) { @@ -942,6 +998,8 @@ int log_targets_reopen(void) struct log_target *tar; int rc = 0; + log_tgt_mutex_lock(); + llist_for_each_entry(tar, &osmo_log_target_list, entry) { switch (tar->type) { case LOG_TGT_TYPE_FILE: @@ -953,6 +1011,8 @@ int log_targets_reopen(void) } } + log_tgt_mutex_unlock(); + return rc; } @@ -1015,6 +1075,8 @@ void log_fini(void) { struct log_target *tar, *tar2; + log_tgt_mutex_lock(); + llist_for_each_entry_safe(tar, tar2, &osmo_log_target_list, entry) log_target_destroy(tar); @@ -1022,6 +1084,8 @@ void log_fini(void) osmo_log_info = NULL; talloc_free(tall_log_ctx); tall_log_ctx = NULL; + + log_tgt_mutex_unlock(); } /*! Check whether a log entry will be generated. @@ -1036,15 +1100,19 @@ int log_check_level(int subsys, unsigned int level) /* TODO: The following could/should be cached (update on config) */ + log_tgt_mutex_lock(); + llist_for_each_entry(tar, &osmo_log_target_list, entry) { if (!should_log_to_target(tar, subsys, level)) continue; /* This might get logged (ignoring filters) */ + log_tgt_mutex_unlock(); return 1; } /* We are sure, that this will not be logged. */ + log_tgt_mutex_unlock(); return 0; } |