Simplify

Author: kleisauke

system/lib/pthread/pthread_create.c

@@ -315,24 +315,18 @@ void _emscripten_thread_exit(void* result) {
   // Call into the musl function that runs destructors of all thread-specific data.
   __pthread_tsd_run_dtors();
 
-  // This atomic potentially competes with a concurrent pthread_detach
-  // call; the loser is responsible for freeing thread resources.
-  int state = a_cas(&self->detach_state, DT_JOINABLE, DT_EXITING);
-
-  // The thread list lock must be AS-safe.
-  __tl_lock();
-
-  // If this is the only thread in the list, don't proceed with
-  // termination of the thread, but restore the previous lock to
-  // prepare for exit to call atexit handlers.
-  if (self->next == self) {
-    __tl_unlock();
-    self->detach_state = state;
+  // If this is the main runtime thread, don't proceed with
+  // termination of the thread, but prepare for exit to call
+  // atexit handlers.
+  if (emscripten_is_main_runtime_thread()) {
     exit(0);
   }
 
   // At this point we are committed to thread termination.
 
+  // The thread list lock must be AS-safe.
+  __tl_lock();
+
   // Process robust list in userspace to handle non-pshared mutexes
   // and the detached thread case where the robust list head will
   // be invalid when the kernel would process it.
@@ -367,6 +361,10 @@ void _emscripten_thread_exit(void* result) {
   // Not hosting a pthread anymore in this worker set __pthread_self to NULL
   __set_thread_state(NULL, 0, 0, 1);
 
+  // This atomic potentially competes with a concurrent pthread_detach
+  // call; the loser is responsible for freeing thread resources.
+  int state = a_cas(&self->detach_state, DT_JOINABLE, DT_EXITING);
+
   if (state == DT_DETACHED) {
     _emscripten_thread_cleanup(self);
   } else {

test/codesize/test_codesize_minimal_pthreads.json

@@ -1,10 +1,10 @@
 {
   "a.out.js": 7372,
   "a.out.js.gz": 3594,
-  "a.out.nodebug.wasm": 19055,
-  "a.out.nodebug.wasm.gz": 8798,
-  "total": 26427,
-  "total_gz": 12392,
+  "a.out.nodebug.wasm": 19037,
+  "a.out.nodebug.wasm.gz": 8787,
+  "total": 26409,
+  "total_gz": 12381,
   "sent": [
     "a (memory)",
     "b (exit)",

test/codesize/test_codesize_minimal_pthreads_memgrowth.json

@@ -1,10 +1,10 @@
 {
   "a.out.js": 7781,
   "a.out.js.gz": 3797,
-  "a.out.nodebug.wasm": 19056,
-  "a.out.nodebug.wasm.gz": 8799,
-  "total": 26837,
-  "total_gz": 12596,
+  "a.out.nodebug.wasm": 19038,
+  "a.out.nodebug.wasm.gz": 8789,
+  "total": 26819,
+  "total_gz": 12586,
   "sent": [
     "a (memory)",
     "b (exit)",