fix(sync): let is_done handle delayed tasks on shutdown

Instead of explicitly discarding delayed tasks in worker_thread,
teach sentry__bgworker_is_done to treat pending delayed tasks as
done when !running. Remaining tasks are cleaned up by decref.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: jpnurmi

src/sentry_sync.c

@@ -226,7 +226,9 @@ sentry__bgworker_get_state(sentry_bgworker_t *bgw)
 static bool
 sentry__bgworker_is_done(sentry_bgworker_t *bgw)
 {
-    return !bgw->first_task && !sentry__atomic_fetch(&bgw->running);
+    return (!bgw->first_task
+               || sentry__monotonic_time() < bgw->first_task->execute_after)
+        && !sentry__atomic_fetch(&bgw->running);
 }
 
 SENTRY_THREAD_FN
@@ -265,16 +267,6 @@ worker_thread(void *data)
         {
             uint64_t now = sentry__monotonic_time();
             if (now < task->execute_after) {
-                // discard delayed tasks submitted after shutdown pruning
-                if (!sentry__atomic_fetch(&bgw->running)) {
-                    while (bgw->first_task) {
-                        sentry_bgworker_task_t *t = bgw->first_task;
-                        bgw->first_task = t->next_task;
-                        sentry__task_decref(t);
-                    }
-                    bgw->last_task = NULL;
-                    continue;
-                }
                 sentry__cond_wait_timeout(&bgw->submit_signal, &bgw->task_lock,
                     (uint32_t)(task->execute_after - now));
                 continue;

tests/unit/test_sync.c

@@ -344,13 +344,13 @@ SENTRY_TEST(bgworker_delayed_shutdown)
     sentry__bgworker_submit(bgw, record_order_task, NULL, (void *)2);
     sentry__bgworker_submit(bgw, record_order_task, NULL, (void *)3);
 
-    // delayed tasks are discarded on shutdown unless already ready
-    sentry__bgworker_submit_delayed(
-        bgw, record_order_task, NULL, (void *)4, 50);
-    sentry__bgworker_submit_delayed(
-        bgw, record_order_task, NULL, (void *)5, 5000);
-    sentry__bgworker_submit_delayed(
-        bgw, record_order_task, NULL, (void *)6, 5000);
+    // pending delayed tasks are discarded on shutdown
+    sentry__bgworker_submit_at(
+        bgw, record_order_task, NULL, (void *)4, UINT64_MAX);
+    sentry__bgworker_submit_at(
+        bgw, record_order_task, NULL, (void *)5, UINT64_MAX);
+    sentry__bgworker_submit_at(
+        bgw, record_order_task, NULL, (void *)6, UINT64_MAX);
 
     sentry__bgworker_start(bgw);
     TEST_CHECK_INT_EQUAL(sentry__bgworker_shutdown(bgw, 1000), 0);