Merged revisions 85158 via svnmerge from
authorTilghman Lesher <tilghman@meg.abyt.es>
Tue, 9 Oct 2007 22:21:49 +0000 (22:21 +0000)
committerTilghman Lesher <tilghman@meg.abyt.es>
Tue, 9 Oct 2007 22:21:49 +0000 (22:21 +0000)
https://origsvn.digium.com/svn/asterisk/branches/1.4

........
r85158 | tilghman | 2007-10-09 16:55:06 -0500 (Tue, 09 Oct 2007) | 5 lines

This commit fixes the following issues:
- Deadlock in ast_write (issue #10406)
- Deadlock in ast_read (issue #10406)
- Possible mutex initialization error in lock.h (issue #10571)

........

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@85176 65c4cc65-6c06-0410-ace0-fbb531ad65f3

include/asterisk/lock.h
main/channel.c
main/utils.c

index f25070d..4273d25 100644 (file)
@@ -149,6 +149,11 @@ void ast_store_lock_info(enum ast_lock_type type, const char *filename,
 void ast_mark_lock_acquired(void);
 
 /*!
+ * \brief Mark the last lock as failed (trylock)
+ */
+void ast_mark_lock_failed(void);
+
+/*!
  * \brief remove lock info for the current thread
  *
  * this gets called by ast_mutex_unlock so that information on the lock can
@@ -165,6 +170,7 @@ static inline int __ast_pthread_mutex_init_attr(int track, const char *filename,
                                                const char *mutex_name, ast_mutex_t *t,
                                                pthread_mutexattr_t *attr) 
 {
+       int i;
 #ifdef AST_MUTEX_INIT_W_CONSTRUCTORS
        int canlog = strcmp(filename, "logger.c");
 
@@ -180,10 +186,12 @@ static inline int __ast_pthread_mutex_init_attr(int track, const char *filename,
        }
 #endif
 
-       t->file[0] = filename;
-       t->lineno[0] = lineno;
-       t->func[0] = func;
-       t->thread[0]  = 0;
+       for (i = 0; i < AST_MAX_REENTRANCY; i++) {
+               t->file[i] = NULL;
+               t->lineno[i] = 0;
+               t->func[i] = NULL;
+               t->thread[i]  = 0;
+       }
        t->reentrancy = 0;
        t->track = track;
 
index 9d8fd0d..9cdf052 100644 (file)
@@ -2110,6 +2110,7 @@ static void ast_read_generator_actions(struct ast_channel *chan, struct ast_fram
 static struct ast_frame *__ast_read(struct ast_channel *chan, int dropaudio)
 {
        struct ast_frame *f = NULL;     /* the return value */
+       struct ast_channel *base = NULL;
        int blah;
        int prestate;
 
@@ -2133,6 +2134,23 @@ static struct ast_frame *__ast_read(struct ast_channel *chan, int dropaudio)
        }
        prestate = chan->_state;
 
+       /* Check if there's an underlying channel */
+       if (chan->tech->get_base_channel && (base = chan->tech->get_base_channel(chan)) != chan) {
+               int count = 0;
+               while (!base || ast_mutex_trylock(&base->lock)) {
+                       if (count++ > 10) {
+                               f = &ast_null_frame;
+                               goto done;
+                       }
+                       ast_mutex_unlock(&chan->lock);
+                       usleep(1);
+                       ast_mutex_lock(&chan->lock);
+                       base = chan->tech->get_base_channel(chan);
+               }
+               ast_mutex_unlock(&chan->lock);
+               chan = base;
+       }
+
        if (!ast_test_flag(chan, AST_FLAG_DEFER_DTMF | AST_FLAG_EMULATE_DTMF | AST_FLAG_IN_DTMF) && 
            !ast_strlen_zero(chan->dtmfq) && 
                (ast_tvzero(chan->dtmf_tv) || ast_tvdiff_ms(ast_tvnow(), chan->dtmf_tv) > AST_MIN_DTMF_GAP) ) {
@@ -2869,7 +2887,22 @@ int ast_write(struct ast_channel *chan, struct ast_frame *fr)
                                        ast_log(LOG_WARNING, "Failed to write data to channel monitor write stream\n");
                        }
                }
-               res = f ? chan->tech->write(chan, f) : 0;
+
+               if (f) {
+                       struct ast_channel *base = NULL;
+                       if (!chan->tech->get_base_channel || chan == chan->tech->get_base_channel(chan))
+                               res = chan->tech->write(chan, f);
+                       else {
+                               while (chan->tech->get_base_channel && (((base = chan->tech->get_base_channel(chan)) && ast_mutex_trylock(&base->lock)) || base == NULL)) {
+                                       ast_mutex_unlock(&chan->lock);
+                                       usleep(1);
+                                       ast_mutex_lock(&chan->lock);
+                               }
+                               res = base->tech->write(base, f);
+                               ast_mutex_unlock(&base->lock);
+                       }
+               } else
+                       res = 0;
                break;
        case AST_FRAME_NULL:
        case AST_FRAME_IAX:
index 0038f01..a4b0a45 100644 (file)
@@ -549,7 +549,7 @@ struct thr_lock_info {
                int times_locked;
                enum ast_lock_type type;
                /*! This thread is waiting on this lock */
-               unsigned int pending:1;
+               int pending:2;
        } locks[AST_MAX_LOCKS];
        /*! This is the number of locks currently held by this thread.
         *  The index (num_locks - 1) has the info on the last one in the
@@ -645,6 +645,19 @@ void ast_mark_lock_acquired(void)
        pthread_mutex_unlock(&lock_info->lock);
 }
 
+void ast_mark_lock_failed(void)
+{
+       struct thr_lock_info *lock_info;
+
+       if (!(lock_info = ast_threadstorage_get(&thread_lock_info, sizeof(*lock_info))))
+               return;
+
+       pthread_mutex_lock(&lock_info->lock);
+       lock_info->locks[lock_info->num_locks - 1].pending = -1;
+       lock_info->locks[lock_info->num_locks - 1].times_locked--;
+       pthread_mutex_unlock(&lock_info->lock);
+}
+
 void ast_remove_lock_info(void *lock_addr)
 {
        struct thr_lock_info *lock_info;
@@ -730,7 +743,7 @@ static char *handle_show_locks(struct ast_cli_entry *e, int cmd, struct ast_cli_
                pthread_mutex_lock(&lock_info->lock);
                for (i = 0; i < lock_info->num_locks; i++) {
                        ast_cli(a->fd, "=== ---> %sLock #%d (%s): %s %d %s %s %p (%d)\n", 
-                               lock_info->locks[i].pending ? "Waiting for " : "", i,
+                               lock_info->locks[i].pending > 0 ? "Waiting for " : lock_info->locks[i].pending < 0 ? "Tried and failed to get " : "", i,
                                lock_info->locks[i].file, 
                                locktype2str(lock_info->locks[i].type),
                                lock_info->locks[i].line_num,