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Release the SIGCHLD watch when the last process event goes #217

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Merged
EdmondDantes merged 2 commits into from
Aug 4, 2026
Merged

Release the SIGCHLD watch when the last process event goes #217

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b992fb1
#216 Release the SIGCHLD watch when the last process event goes
EdmondDantes Aug 3, 2026
6ff1d29
#216 Trim the comments, keep the two fixes
EdmondDantes Aug 4, 2026
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76 changes: 52 additions & 24 deletions libuv_reactor.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1083,6 +1083,12 @@ static bool libuv_timer_start(zend_async_event_t *event)
return false;
}

// Hidden means "keeps firing, but is not a reason to stay alive": unref drops
// the timer out of uv_loop_alive() without stopping it.
if (ZEND_ASYNC_EVENT_IS_HIDDEN(event)) {
uv_unref((uv_handle_t *) &timer->uv_handle);
}

event->loop_ref_count++;
ZEND_ASYNC_INCREASE_EVENT_COUNT(event);
return true;
Expand Down Expand Up @@ -1655,6 +1661,8 @@ static void libuv_handle_process_events(void)
ZEND_ASYNC_CALLBACKS_NOTIFY(event, NULL, NULL);
// Process event will be removed when stopped
}
// ECHILD is not settled here: a notified event outlives this sweep, so a
// second sweep would overwrite its exit code with a made-up one.
#endif
}

Expand Down Expand Up @@ -1694,44 +1702,63 @@ static void libuv_add_process_event(zend_async_event_t *event)

/* }}} */

/* {{{ libuv_remove_process_event */
static void libuv_remove_process_event(zend_async_event_t *event)
/* {{{ libuv_release_process_watch
* Drops the SIGCHLD handler once the last process event is gone. Call from every
* path that empties the table. */
static void libuv_release_process_watch(void)
{
if (ASYNC_G(process_events) == NULL) {
if (ASYNC_G(process_events) == NULL || zend_hash_num_elements(ASYNC_G(process_events)) > 0) {
return;
}

// Get process handle from event to use as key
async_process_event_t *process_event = (async_process_event_t *) event;

zend_hash_index_del(ASYNC_G(process_events), (uintptr_t) process_event->event.process);
bool has_sigchld_signal_events = false;

// Only remove SIGCHLD handler if no more process events AND no regular signal events for SIGCHLD
if (zend_hash_num_elements(ASYNC_G(process_events)) == 0) {
bool has_sigchld_signal_events = false;

// Check if there are regular signal events for SIGCHLD
if (ASYNC_G(signal_events) != NULL) {
HashTable *sigchld_events = zend_hash_index_find_ptr(ASYNC_G(signal_events), SIGCHLD);
if (sigchld_events != NULL && zend_hash_num_elements(sigchld_events) > 0) {
has_sigchld_signal_events = true;
}
// Check if there are regular signal events for SIGCHLD
if (ASYNC_G(signal_events) != NULL) {
HashTable *sigchld_events = zend_hash_index_find_ptr(ASYNC_G(signal_events), SIGCHLD);
if (sigchld_events != NULL && zend_hash_num_elements(sigchld_events) > 0) {
has_sigchld_signal_events = true;
}
}

// Only remove handler if no signal events exist for SIGCHLD
if (!has_sigchld_signal_events && ASYNC_G(signal_handlers) != NULL) {
uv_signal_t *handler = zend_hash_index_find_ptr(ASYNC_G(signal_handlers), SIGCHLD);
if (handler != NULL) {
// Only remove handler if no signal events exist for SIGCHLD
if (!has_sigchld_signal_events && ASYNC_G(signal_handlers) != NULL) {
uv_signal_t *handler = zend_hash_index_find_ptr(ASYNC_G(signal_handlers), SIGCHLD);
if (handler != NULL) {
if ((bool) (uintptr_t) handler->data) {
// pcntl still needs delivery; closing reverts the OS disposition.
uv_unref((uv_handle_t *) handler);
} else {
uv_signal_stop(handler);
#ifdef ZEND_SIGNALS
libuv_restore_signal_handler(SIGCHLD);
#endif
uv_close((uv_handle_t *) handler, libuv_signal_close_cb);
zend_hash_index_del(ASYNC_G(signal_handlers), SIGCHLD);
}
}
}

zend_hash_destroy(ASYNC_G(process_events));
pefree(ASYNC_G(process_events), 0);
ASYNC_G(process_events) = NULL;
zend_hash_destroy(ASYNC_G(process_events));
pefree(ASYNC_G(process_events), 0);
ASYNC_G(process_events) = NULL;
}

/* }}} */

/* {{{ libuv_remove_process_event */
static void libuv_remove_process_event(zend_async_event_t *event)
{
if (ASYNC_G(process_events) == NULL) {
return;
}

// Get process handle from event to use as key
async_process_event_t *process_event = (async_process_event_t *) event;

zend_hash_index_del(ASYNC_G(process_events), (uintptr_t) process_event->event.process);

libuv_release_process_watch();
}

/* }}} */
Expand Down Expand Up @@ -2170,6 +2197,7 @@ static bool libuv_process_event_dispose(zend_async_event_t *event)
const zend_process_t proc_handle = ((zend_async_process_event_t *) event)->process;
if ((uintptr_t) proc_handle != 0 && ASYNC_G(process_events) != NULL) {
zend_hash_index_del(ASYNC_G(process_events), (zend_ulong) (uintptr_t) proc_handle);
libuv_release_process_watch();
}

#ifdef PHP_WIN32
Expand Down
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