Avoid requiring EXIT_RUNTIME when running threaded programs under node

Prior to this change the thread calling `exit()` would itself keep
the runtime alive.

This change makes it easy to run arbitrary tests under
`PROXY_TO_PTHREAD` without also needing to remember to add
`EXIT_RUNTIME`

src/library.js

@@ -85,6 +85,7 @@ addToLibrary({
 #endif
 #if PTHREADS
     '$exitOnMainThread',
+    '_emscripten_thread_cleanup',
 #endif
 #if PTHREADS_DEBUG
     '$runtimeKeepaliveCounter',
@@ -111,6 +112,17 @@ addToLibrary({
       // The pthread may have decided not to exit its own runtime, for example
       // because it runs a main loop, but that doesn't affect the main thread.
       exitOnMainThread(status);
+#if !EXIT_RUNTIME
+      // When EXIT_RUNTIME is enabled the main thread will take care of shutting
+      // down the runtime, and killing all the workers/threads.
+      // However when EXIT_RUNTIME is no enabled we don't want the existance
+      // of this running thread to prevent node from exiting, do we use
+      // `__emscripten_thread_cleanup` to take outselves out of the list of
+      // running threads, but without making outselves joinable.
+      if (!keepRuntimeAlive()) {
+        __emscripten_thread_cleanup(_pthread_self())
+      }
+#endif
       throw 'unwind';
     }
 #if PTHREADS_DEBUG
@@ -127,7 +139,7 @@ addToLibrary({
 #if ASSERTIONS
     // if exit() was called explicitly, warn the user if the runtime isn't actually being shut down
     if (keepRuntimeAlive() && !implicit) {
-      var msg = `program exited (with status: ${status}), but keepRuntimeAlive() is set (counter=${runtimeKeepaliveCounter}) due to an async operation, so halting execution but not exiting the runtime or preventing further async execution (you can use emscripten_force_exit, if you want to force a true shutdown)`;
+      var msg = `program exited (with status: ${status}), but keepRuntimeAlive() is set (counter=${runtimeKeepaliveCounter}), so halting execution but not exiting the runtime or preventing further async execution (you can use emscripten_force_exit, if you want to force a true shutdown)`;
 #if MODULARIZE
       readyPromiseReject(msg);
 #endif // MODULARIZE
@@ -2207,7 +2219,7 @@ addToLibrary({
     }
 #endif
 #if RUNTIME_DEBUG
-    dbg(`maybeExit: user callback done: runtimeKeepaliveCounter=${runtimeKeepaliveCounter}`);
+    dbg(`maybeExit: runtimeKeepaliveCounter=${runtimeKeepaliveCounter}`);
 #endif
     if (!keepRuntimeAlive()) {
 #if RUNTIME_DEBUG

src/library_pthread.js

@@ -582,6 +582,7 @@ var LibraryPThread = {
 #if PTHREADS_DEBUG
     dbg(`cleanupThread: ${ptrToString(pthread_ptr)}`)
 #endif
+    if (!PThread.pthreads[pthread_ptr]) return;
 #if ASSERTIONS
     assert(!ENVIRONMENT_IS_PTHREAD, 'Internal Error! cleanupThread() can only ever be called from main application thread!');
     assert(pthread_ptr, 'Internal Error! Null pthread_ptr in cleanupThread!');
@@ -1138,11 +1139,8 @@ var LibraryPThread = {
       // emscripten_unwind_to_js_event_loop() in the pthread body.
       __emscripten_thread_exit(result);
 #else
-      if (keepRuntimeAlive()) {
-        EXITSTATUS = result;
-      } else {
-        __emscripten_thread_exit(result);
-      }
+      EXITSTATUS = result;
+      maybeExit();
 #endif
     }
 #if ASYNCIFY == 2

src/preamble.js

@@ -553,7 +553,7 @@ function makeAbortWrapper(original) {
         || e === Infinity // EXCEPTION_STACK_TRACES=0 will throw Infinity
 #endif // EXCEPTION_STACK_TRACES
 #endif
-        || e === 'unwind'
+        || (e instanceof ExitStatus || e == 'unwind')
       ) {
         throw e;
       }

src/runtime_pthread.js

@@ -216,7 +216,7 @@ if (ENVIRONMENT_IS_PTHREAD) {
             throw ex;
           }
 #if RUNTIME_DEBUG
-          dbg(`worker: Pthread 0x${_pthread_self().toString(16)} completed its main entry point with an 'unwind', keeping the worker alive for asynchronous operation.`);
+          dbg(`worker: pthread completed its main entry point with an 'unwind'`);
 #endif
         }
       } else if (cmd === 'cancel') { // Main thread is asking for a pthread_cancel() on this thread.

test/other/codesize/test_codesize_minimal_pthreads.gzsize

@@ -1 +1 @@
-5103
+5118

test/other/codesize/test_codesize_minimal_pthreads.jssize

@@ -1 +1 @@
-11028
+11064

test/other/test_unoptimized_code_size.js.size

@@ -1 +1 @@
-54682
+54656

test/other/test_unoptimized_code_size_strict.js.size

@@ -1 +1 @@
-53633
+53607

test/test_core.py

@@ -388,7 +388,6 @@ def test_hello_argc(self):
   @node_pthreads
   def test_hello_argc_pthreads(self):
     self.set_setting('PROXY_TO_PTHREAD')
-    self.set_setting('EXIT_RUNTIME')
     self.do_core_test('test_hello_argc.c', args=['hello', 'world'])
 
   @only_wasm2js('test shifts etc. on 64-bit integers')
@@ -1300,7 +1299,8 @@ def test_exceptions_uncaught_2(self):
   def test_exceptions_typed(self):
     # Depends on static destructors running
     self.set_setting('EXIT_RUNTIME')
-    self.clear_setting('SAFE_HEAP') # Throwing null will cause an ignorable null pointer access.
+    if self.get_setting('SAFE_HEAP'):
+      self.skipTest('Throwing null will cause an ignorable null pointer access')
     self.do_core_test('test_exceptions_typed.cpp')
 
   @with_all_eh_sjlj
@@ -1318,7 +1318,8 @@ def test_exceptions_multi(self):
 
   @with_all_eh_sjlj
   def test_exceptions_std(self):
-    self.clear_setting('SAFE_HEAP')
+    if self.get_setting('SAFE_HEAP'):
+      self.skipTest('Fails under SAFE_HEAP')
     self.do_core_test('test_exceptions_std.cpp')
 
   @with_all_eh_sjlj
@@ -1871,7 +1872,7 @@ def test_em_asm_2(self):
   # they will also get tested in MAIN_THREAD_EM_ASM form.
   @parameterized({
     '': ([],),
-    'pthread': (['-pthread', '-sPROXY_TO_PTHREAD', '-sEXIT_RUNTIME'],),
+    'pthread': (['-pthread', '-sPROXY_TO_PTHREAD'],),
   })
   def test_main_thread_em_asm(self, args):
     if args:
@@ -1933,8 +1934,8 @@ def test_em_asm_side_module(self):
 
   @parameterized({
     '': ([], False),
-    'pthreads': (['-pthread', '-sPROXY_TO_PTHREAD', '-sEXIT_RUNTIME'], False),
-    'pthreads_dylink': (['-pthread', '-sPROXY_TO_PTHREAD', '-sEXIT_RUNTIME', '-sMAIN_MODULE=2', '-Wno-experimental'], False),
+    'pthreads': (['-pthread', '-sPROXY_TO_PTHREAD'], False),
+    'pthreads_dylink': (['-pthread', '-sPROXY_TO_PTHREAD', '-sMAIN_MODULE=2', '-Wno-experimental'], False),
     'c': ([], True),
     'dylink': (['-sMAIN_MODULE=2'], False),
     'dylink_c': (['-sMAIN_MODULE=2'], True),
@@ -2500,7 +2501,6 @@ def test_pthread_proxying_canceled_work(self):
   @node_pthreads
   @flaky('https://github.com/emscripten-core/emscripten/issues/19795')
   def test_pthread_proxying_refcount(self):
-    self.set_setting('EXIT_RUNTIME')
     self.set_setting('PTHREAD_POOL_SIZE=1')
     self.set_setting('ASSERTIONS=0')
     self.do_run_in_out_file_test('pthread/test_pthread_proxying_refcount.c')
@@ -2524,7 +2524,6 @@ def test_pthread_nested_work_queue(self):
   @node_pthreads
   def test_pthread_thread_local_storage(self):
     self.set_setting('PROXY_TO_PTHREAD')
-    self.set_setting('EXIT_RUNTIME')
     if not self.has_changed_setting('INITIAL_MEMORY'):
       self.set_setting('INITIAL_MEMORY', '300mb')
     self.do_run_in_out_file_test('pthread/test_pthread_thread_local_storage.cpp')
@@ -2574,7 +2573,6 @@ def test_pthread_abort_interrupt(self):
   def test_pthread_emmalloc(self):
     self.emcc_args += ['-fno-builtin']
     self.set_setting('PROXY_TO_PTHREAD')
-    self.set_setting('EXIT_RUNTIME')
     self.set_setting('ASSERTIONS', 2)
     self.set_setting('MALLOC', 'emmalloc')
     self.do_core_test('test_emmalloc.c')
@@ -2589,7 +2587,6 @@ def test_pthread_stdout_after_main(self):
   @node_pthreads
   def test_pthread_proxy_to_pthread(self):
     self.set_setting('PROXY_TO_PTHREAD')
-    self.set_setting('EXIT_RUNTIME')
     self.do_run_in_out_file_test('pthread/test_pthread_proxy_to_pthread.c')
 
   @node_pthreads
@@ -2606,7 +2603,6 @@ def test_pthread_run_script(self):
     # Run the test again with PROXY_TO_PTHREAD
     self.setup_node_pthreads()
     self.set_setting('PROXY_TO_PTHREAD')
-    self.set_setting('EXIT_RUNTIME')
     self.do_runf('pthread/test_pthread_run_script.c')
 
   @node_pthreads
@@ -2903,7 +2899,7 @@ def test_dlfcn_missing(self):
   @needs_dylink
   @parameterized({
     '': ([],),
-    'pthreads': (['-pthread', '-sEXIT_RUNTIME', '-sPROXY_TO_PTHREAD', '-Wno-experimental'],),
+    'pthreads': (['-pthread', '-sPROXY_TO_PTHREAD', '-Wno-experimental'],),
   })
   def test_dlfcn_basic(self, args):
     if args:
@@ -6470,7 +6466,6 @@ def test_mmap_anon_pthreads(self):
     # Same test with threading enabled so give is some basic sanity
     # checks of the locking on the internal data structures.
     self.set_setting('PROXY_TO_PTHREAD')
-    self.set_setting('EXIT_RUNTIME')
     if not self.has_changed_setting('INITIAL_MEMORY'):
       self.set_setting('INITIAL_MEMORY', '64mb')
     self.do_core_test('test_mmap_anon.c')
@@ -7363,7 +7358,7 @@ def test_embind_2(self):
     self.emcc_args += [
       '-lembind', '--post-js', 'post.js',
       # for extra coverage, test using pthreads
-      '-pthread', '-sPROXY_TO_PTHREAD', '-sEXIT_RUNTIME'
+      '-pthread', '-sPROXY_TO_PTHREAD'
     ]
     create_file('post.js', '''
       function printLerp() {
@@ -8313,7 +8308,6 @@ def test_pthread_join_and_asyncify(self):
     self.require_jspi()
     self.do_runf('core/test_pthread_join_and_asyncify.c', 'joining thread!\njoined thread!',
                  emcc_args=['-sJSPI_EXPORTS=run_thread',
-                            '-sEXIT_RUNTIME=1',
                             '-pthread', '-sPROXY_TO_PTHREAD'])
 
   @no_asan('asyncify stack operations confuse asan')
@@ -9118,7 +9112,7 @@ def test_pthread_create(self):
   @parameterized({
     '': ([],),
     'pooled': (['-sPTHREAD_POOL_SIZE=1'],),
-    'proxied': (['-sPROXY_TO_PTHREAD', '-sEXIT_RUNTIME'],),
+    'proxied': (['-sPROXY_TO_PTHREAD'],),
   })
   def test_pthread_c11_threads(self, args):
     self.emcc_args += args
@@ -9164,7 +9158,6 @@ def test_pthread_create_pool(self):
   def test_pthread_create_proxy(self):
     # with PROXY_TO_PTHREAD, we can synchronously depend on workers being available
     self.set_setting('PROXY_TO_PTHREAD')
-    self.set_setting('EXIT_RUNTIME')
     self.emcc_args += ['-DALLOW_SYNC']
     self.do_run_in_out_file_test('core/pthread/create.c')
 
@@ -9215,7 +9208,6 @@ def test_pthread_unhandledrejection(self):
   @no_wasm2js('wasm2js does not support PROXY_TO_PTHREAD (custom section support)')
   def test_pthread_offset_converter(self):
     self.set_setting('PROXY_TO_PTHREAD')
-    self.set_setting('EXIT_RUNTIME')
     self.set_setting('USE_OFFSET_CONVERTER')
     if '-g' in self.emcc_args:
       self.emcc_args += ['-DDEBUG']
@@ -9225,7 +9217,6 @@ def test_pthread_offset_converter(self):
   @no_wasm2js('wasm2js does not support PROXY_TO_PTHREAD (custom section support)')
   def test_pthread_offset_converter_modularize(self):
     self.set_setting('PROXY_TO_PTHREAD')
-    self.set_setting('EXIT_RUNTIME')
     self.set_setting('USE_OFFSET_CONVERTER')
     self.set_setting('MODULARIZE')
     self.set_setting('EXPORT_NAME', 'foo')
@@ -9259,7 +9250,6 @@ def test_stdio_locking(self):
   def test_pthread_dylink_basics(self):
     self.emcc_args.append('-Wno-experimental')
     self.set_setting('PROXY_TO_PTHREAD')
-    self.set_setting('EXIT_RUNTIME')
     self.do_basic_dylink_test()
 
   @needs_dylink
@@ -9302,6 +9292,7 @@ def test_pthread_dlopen(self):
 
     self.emcc_args += ['--embed-file', '[email protected]']
     self.prep_dlfcn_main()
+    # Test depends on atexit()
     self.set_setting('EXIT_RUNTIME')
     self.set_setting('PROXY_TO_PTHREAD')
     self.do_runf('core/pthread/test_pthread_dlopen.c',
@@ -9321,6 +9312,7 @@ def test_pthread_dlopen_many(self):
       shutil.copyfile('liblib.so', f'liblib{i}.so')
 
     self.prep_dlfcn_main()
+    # Test depends on atexit()
     self.set_setting('EXIT_RUNTIME')
     self.set_setting('PROXY_TO_PTHREAD')
     self.set_setting('DEFAULT_LIBRARY_FUNCS_TO_INCLUDE', 'jslib_func')
@@ -9343,7 +9335,6 @@ def test_pthread_dlsym(self):
     self.build_dlfcn_lib(test_file('core/pthread/test_pthread_dlsym_side.c'))
 
     self.prep_dlfcn_main()
-    self.set_setting('EXIT_RUNTIME')
     self.set_setting('PROXY_TO_PTHREAD')
     self.do_runf('core/pthread/test_pthread_dlsym.c')
 
@@ -9370,7 +9361,7 @@ def test_pthread_dylink_main_module_1(self):
 
   @parameterized({
     '': ([],),
-    'pthreads': (['-sPROXY_TO_PTHREAD', '-sEXIT_RUNTIME', '-pthread', '-Wno-experimental'],)
+    'pthreads': (['-sPROXY_TO_PTHREAD', '-pthread', '-Wno-experimental'],)
   })
   @with_dylink_reversed
   def test_Module_dynamicLibraries(self, args):
@@ -9532,7 +9523,6 @@ def test_abort_on_exceptions_main(self):
   def test_abort_on_exceptions_pthreads(self):
     self.set_setting('ABORT_ON_WASM_EXCEPTIONS')
     self.set_setting('PROXY_TO_PTHREAD')
-    self.set_setting('EXIT_RUNTIME')
     self.do_core_test('test_hello_world.c')
 
   @needs_dylink