Avoid a deadlock with ALL of the locks in the masquerade function, not just the

pairs of channels.  (Closes issue #10406)


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@84049 65c4cc65-6c06-0410-ace0-fbb531ad65f3
This commit is contained in:
Tilghman Lesher
2007-09-28 05:30:22 +00:00
parent 7c4e477fde
commit 253a34b756

View File

@@ -3410,7 +3410,11 @@ int ast_channel_make_compatible(struct ast_channel *chan, struct ast_channel *pe
int ast_channel_masquerade(struct ast_channel *original, struct ast_channel *clone)
{
int res = -1;
struct ast_channel *final_orig = original, *final_clone = clone;
struct ast_channel *final_orig, *final_clone;
retrymasq:
final_orig = original;
final_clone = clone;
ast_channel_lock(original);
while (ast_channel_trylock(clone)) {
@@ -3428,11 +3432,19 @@ int ast_channel_masquerade(struct ast_channel *original, struct ast_channel *clo
final_clone = clone->_bridge;
if ((final_orig != original) || (final_clone != clone)) {
ast_channel_lock(final_orig);
while (ast_channel_trylock(final_clone)) {
/* Lots and lots of deadlock avoidance. The main one we're competing with
* is ast_write(), which locks channels recursively, when working with a
* proxy channel. */
if (ast_channel_trylock(final_orig)) {
ast_channel_unlock(clone);
ast_channel_unlock(original);
goto retrymasq;
}
if (ast_channel_trylock(final_clone)) {
ast_channel_unlock(final_orig);
usleep(1);
ast_channel_lock(final_orig);
ast_channel_unlock(clone);
ast_channel_unlock(original);
goto retrymasq;
}
ast_channel_unlock(clone);
ast_channel_unlock(original);