diff options
Diffstat (limited to 'misc/thread_tools.c')
-rw-r--r-- | misc/thread_tools.c | 39 |
1 files changed, 17 insertions, 22 deletions
diff --git a/misc/thread_tools.c b/misc/thread_tools.c index ecf6bc2381..91b774eb93 100644 --- a/misc/thread_tools.c +++ b/misc/thread_tools.c @@ -105,12 +105,7 @@ static void cancel_destroy(void *p) assert(!c->slaves.head); // API user error - // We can access c->parent without synchronization, because: - // - since c is being destroyed, nobody can explicitly remove it as slave - // at the same time - // - c->parent needs to stay valid as long as the slave exists - if (c->parent) - mp_cancel_remove_slave(c->parent, c); + mp_cancel_set_parent(c, NULL); if (c->wakeup_pipe[0] >= 0) { close(c->wakeup_pipe[0]); @@ -225,25 +220,25 @@ void mp_cancel_set_cb(struct mp_cancel *c, void (*cb)(void *ctx), void *ctx) pthread_mutex_unlock(&c->lock); } -void mp_cancel_add_slave(struct mp_cancel *c, struct mp_cancel *slave) -{ - pthread_mutex_lock(&c->lock); - assert(!slave->parent); - slave->parent = c; - LL_APPEND(siblings, &c->slaves, slave); - retrigger_locked(c); - pthread_mutex_unlock(&c->lock); -} - -void mp_cancel_remove_slave(struct mp_cancel *c, struct mp_cancel *slave) +void mp_cancel_set_parent(struct mp_cancel *slave, struct mp_cancel *parent) { - pthread_mutex_lock(&c->lock); + // We can access c->parent without synchronization, because: + // - concurrent mp_cancel_set_parent() calls to slave are not allowed + // - slave->parent needs to stay valid as long as the slave exists + if (slave->parent == parent) + return; if (slave->parent) { - assert(slave->parent == c); - slave->parent = NULL; - LL_REMOVE(siblings, &c->slaves, slave); + pthread_mutex_lock(&slave->parent->lock); + LL_REMOVE(siblings, &slave->parent->slaves, slave); + pthread_mutex_unlock(&slave->parent->lock); + } + slave->parent = parent; + if (slave->parent) { + pthread_mutex_lock(&slave->parent->lock); + LL_APPEND(siblings, &slave->parent->slaves, slave); + retrigger_locked(slave->parent); + pthread_mutex_unlock(&slave->parent->lock); } - pthread_mutex_unlock(&c->lock); } int mp_cancel_get_fd(struct mp_cancel *c) |