emscripten-core · sbc100 · Jun 18, 2021 · Jan 7, 2021
diff --git a/emcc.py b/emcc.py
@@ -1883,6 +1883,7 @@ def default_setting(name, new_default):
       '_emscripten_tls_init',
       '_pthread_self',
       '_pthread_testcancel',
+      '_pthread_self',
     ]
     # Some of these symbols are using by worker.js but otherwise unreferenced.
     # Because emitDCEGraph only considered the main js file, and not worker.js
@@ -1926,9 +1927,8 @@ def default_setting(name, new_default):
   if settings.USE_PTHREADS:
     # memalign is used to ensure allocated thread stacks are aligned.
     settings.EXPORTED_FUNCTIONS += ['_memalign']
-
-    if settings.MINIMAL_RUNTIME:
-      building.user_requested_exports.add('exit')
+    # _exit is called to shutdown the process
+    settings.EXPORTED_FUNCTIONS += ['_exit']
 
     if settings.PROXY_TO_PTHREAD:
       settings.EXPORTED_FUNCTIONS += ['_emscripten_proxy_main']
@@ -2209,6 +2209,9 @@ def check_memory_setting(setting):
     # enables the --post-emscripten pass
     settings.GLOBAL_BASE = 1024
 
+  if settings.EXIT_RUNTIME and not settings.STANDALONE_WASM:
+    settings.EXPORTED_FUNCTIONS += ['_exit']
+
   # various settings require malloc/free support from JS
   if settings.RELOCATABLE or \
      settings.BUILD_AS_WORKER or \

diff --git a/src/library.js b/src/library.js
@@ -155,20 +155,6 @@ LibraryManager.library = {
     return -1;
   },
 
-  exit__sig: 'vi',
-#if MINIMAL_RUNTIME
-  // minimal runtime doesn't do any exit cleanup handling so just
-  // map exit directly to the lower-level proc_exit syscall.
-  exit: 'proc_exit',
-  $exit: 'exit',
-#else
-  exit: function(status) {
-    // void _exit(int status);
-    // http://pubs.opengroup.org/onlinepubs/000095399/functions/exit.html
-    exit(status);
-  },
-#endif
-
   // fork, spawn, etc. all return an error as we don't support multiple
   // processes.
   fork__deps: ['$setErrNo'],
@@ -426,22 +412,6 @@ LibraryManager.library = {
   // stdlib.h
   // ==========================================================================
 
-#if MINIMAL_RUNTIME && !EXIT_RUNTIME
-  atexit__sig: 'v', // atexit unsupported in MINIMAL_RUNTIME
-  atexit: function(){},
-  __cxa_atexit: function(){},
-#else
-  atexit__proxy: 'sync',
-  atexit__sig: 'iii',
-  atexit: function(func, arg) {
-#if EXIT_RUNTIME
-    __ATEXIT__.unshift({ func: func, arg: arg });
-#endif
-  },
-  __cxa_atexit: 'atexit',
-
-#endif
-
   // TODO: There are currently two abort() functions that get imported to asm module scope: the built-in runtime function abort(),
   // and this function _abort(). Remove one of these, importing two functions for the same purpose is wasteful.
   abort__sig: 'v',
@@ -3579,9 +3549,13 @@ LibraryManager.library = {
     throw 'unwind';
   },
 
-#if MINIMAL_RUNTIME
-  emscripten_force_exit__deps: ['exit'],
+  emscripten_force_exit__deps: [
+#if MINIMAL_RUNTIME || hasExportedFunction('_exit')
+    'exit',
+#else
+    'proc_exit'
 #endif
+  ],
   emscripten_force_exit__proxy: 'sync',
   emscripten_force_exit__sig: 'vi',
   emscripten_force_exit: function(status) {
@@ -3595,7 +3569,10 @@ LibraryManager.library = {
 #else
     noExitRuntime = false;
     runtimeKeepaliveCounter = 0;
-    exit(status);
+#if hasExportedFunction('_exit')
+    _exit(status);
+#else
+    _proc_exit(status);
 #endif
   },
 
@@ -3684,7 +3661,13 @@ LibraryManager.library = {
         if (ENVIRONMENT_IS_PTHREAD) __emscripten_thread_exit(EXITSTATUS);
         else
 #endif
+#if EXIT_RUNTIME
+        //console.error("calling C exit");
         _exit(EXITSTATUS);
+#else
+        //console.error("bypassing C exit");
+        procExit(EXITSTATUS);
+#endif
       } catch (e) {
         handleException(e);
       }

diff --git a/src/library_async.js b/src/library_async.js
@@ -30,7 +30,6 @@ mergeInto(LibraryManager.library, {
       Normal: 0,
       Unwinding: 1,
       Rewinding: 2,
-      Disabled: 3,
     },
     state: 0,
     StackSize: {{{ ASYNCIFY_STACK_SIZE }}},
@@ -210,9 +209,6 @@ mergeInto(LibraryManager.library, {
     },
 
     handleSleep: function(startAsync) {
-#if ASSERTIONS
-      assert(Asyncify.state !== Asyncify.State.Disabled, 'Asyncify cannot be done during or after the runtime exits');
-#endif
       if (ABORT) return;
 #if ASYNCIFY_DEBUG
       err('ASYNCIFY: handleSleep ' + Asyncify.state);

diff --git a/src/library_pthread.js b/src/library_pthread.js
@@ -60,7 +60,6 @@ var LibraryPThread = {
     },
     // Maps pthread_t to pthread info objects
     pthreads: {},
-    threadExitHandlers: [], // An array of C functions to run when this thread exits.
 
 #if PTHREADS_PROFILING
     createProfilerBlock: function(pthreadPtr) {
@@ -303,7 +302,7 @@ var LibraryPThread = {
           err("exitProcess requested by worker");
 #endif
           try {
-            exit(d['returnCode']);
+            {{{ exportedAsmFunc('_exit') }}}(d['returnCode']);
           } catch (e) {
             handleException(e);
           }
@@ -928,13 +927,6 @@ var LibraryPThread = {
     postMessage({ 'cmd': 'exit' });
   },
 
-  __cxa_thread_atexit__sig: 'vii',
-  __cxa_thread_atexit: function(routine, arg) {
-    PThread.threadExitHandlers.push(function() { {{{ makeDynCall('vi', 'routine') }}}(arg) });
-  },
-  __cxa_thread_atexit_impl: '__cxa_thread_atexit',
-
-
   // Returns 0 on success, or one of the values -ETIMEDOUT, -EWOULDBLOCK or -EINVAL on error.
   emscripten_futex_wait__deps: ['emscripten_main_thread_process_queued_calls'],
   emscripten_futex_wait: function(addr, val, timeout) {

diff --git a/src/library_pthread_stub.js b/src/library_pthread_stub.js
@@ -26,9 +26,6 @@ var LibraryPThreadStub = {
       // Do nothing.
     }
   },
-
-  __cxa_thread_atexit: 'atexit',
-  __cxa_thread_atexit_impl: 'atexit',
 };
 
 mergeInto(LibraryManager.library, LibraryPThreadStub);
diff --git a/src/library_wasi.js b/src/library_wasi.js
@@ -11,7 +11,9 @@ var WasiLibrary = {
 #if MINIMAL_RUNTIME
     throw 'exit(' + code + ')';
 #else
+    //out('proc_exit');
     procExit(code);
+    //out('proc_exit done');
 #endif
   },
 

diff --git a/src/postamble.js b/src/postamble.js
@@ -103,6 +103,7 @@ function ExitStatus(status) {
 }
 
 var calledMain = false;
+var implicitExit = false;
 
 #if STANDALONE_WASM && MAIN_READS_PARAMS
 var mainArgs = undefined;
@@ -190,8 +191,19 @@ function callMain(args) {
     assert(ret == 0, '_emscripten_proxy_main failed to start proxy thread: ' + ret);
 #endif
 #else
-    // if we're not running an evented main loop, it's time to exit
-    exit(ret, /* implicit = */ true);
+    //console.error("implicitExit!");
+    implicitExit = true;
+#if EXIT_RUNTIME
+    if (!keepRuntimeAlive()) {
+      // Perform a full C _exit which will end up calling procExit.
+      //console.error("calling C exit");
+      _exit(ret);
+      // unreachable
+    }
+#endif
+    //console.error("bypassing C exit");
+    procExit(ret);
+    // unreachable
   }
   catch (e) {
     // Certain exception types we do not treat as errors since they are used for
@@ -212,6 +224,7 @@ function callMain(args) {
 #endif // !PROXY_TO_PTHREAD
   } finally {
     calledMain = true;
+    implicitExit = false;
 
 #if ABORT_ON_WASM_EXCEPTIONS
     // See abortWrapperDepth in preamble.js!
@@ -407,21 +420,20 @@ function checkUnflushedContent() {
 #endif // EXIT_RUNTIME
 #endif // ASSERTIONS
 
-/** @param {boolean|number=} implicit */
-function exit(status, implicit) {
+function procExit(status) {
+  //console.error('procExit');
   EXITSTATUS = status;
-
 #if ASSERTIONS
 #if EXIT_RUNTIME == 0
   checkUnflushedContent();
 #endif // EXIT_RUNTIME
 #endif // ASSERTIONS
 
 #if USE_PTHREADS
-  if (!implicit) {
+  if (!implicitExit) {
     if (ENVIRONMENT_IS_PTHREAD) {
 #if ASSERTIONS
-      err('Pthread 0x' + _pthread_self().toString(16) + ' called exit(), posting exitProcess.');
+      err('Pthread 0x' + _pthread_self().toString(16) + ' called procExit(), posting exitProcess.');
 #endif
       // When running in a pthread we propagate the exit back to the main thread
       // where it can decide if the whole process should be shut down or not.
@@ -431,16 +443,16 @@ function exit(status, implicit) {
       throw new ExitStatus(status);
     } else {
 #if ASSERTIONS
-      err('main thread called exit: keepRuntimeAlive=' + keepRuntimeAlive() + ' (counter=' + runtimeKeepaliveCounter + ')');
+      err('main thread called procExit: keepRuntimeAlive=' + keepRuntimeAlive() + ' (counter=' + runtimeKeepaliveCounter + ')');
 #endif
     }
   }
 #endif
 
   if (keepRuntimeAlive()) {
 #if ASSERTIONS
-    // if exit() was called, we may warn the user if the runtime isn't actually being shut down
-    if (!implicit) {
+    // if procExit() was called, we may warn the user if the runtime isn't actually being shut down
+    if (!implicitExit) {
 #if EXIT_RUNTIME == 0
       var msg = 'program exited (with status: ' + status + '), but EXIT_RUNTIME is not set, so halting execution but not exiting the runtime or preventing further async execution (build with EXIT_RUNTIME=1, if you want a true shutdown)';
 #else
@@ -473,6 +485,8 @@ function procExit(code) {
 #endif
     ABORT = true;
   }
+
+  //console.error('calling quit_');
   quit_(code, new ExitStatus(code));
 }
 

diff --git a/src/preamble.js b/src/preamble.js
@@ -401,18 +401,16 @@ function preMain() {
 #endif
 
 function exitRuntime() {
-#if ASYNCIFY && ASSERTIONS
-  // ASYNCIFY cannot be used once the runtime starts shutting down.
-  Asyncify.state = Asyncify.State.Disabled;
-#endif
 #if STACK_OVERFLOW_CHECK
   checkStackCookie();
 #endif
 #if USE_PTHREADS
   if (ENVIRONMENT_IS_PTHREAD) return; // PThreads reuse the runtime from the main thread.
 #endif
 #if EXIT_RUNTIME
+  //console.error(__ATEXIT__);
   callRuntimeCallbacks(__ATEXIT__);
+  //console.error('done exit callbacks');
   <<< ATEXITS >>>
 #endif
   runtimeExited = true;

diff --git a/system/lib/libc/musl/src/stdio/__stdio_exit.c b/system/lib/libc/musl/src/stdio/__stdio_exit.c
@@ -15,6 +15,7 @@ static void close_file(FILE *f)
 
 void __stdio_exit(void)
 {
+  //puts("__stdio_exit");
 	FILE *f;
 	for (f=*__ofl_lock(); f; f=f->next) close_file(f);
 	close_file(__stdin_used);

diff --git a/system/lib/libc/musl/src/thread/pthread_key_create.c b/system/lib/libc/musl/src/thread/pthread_key_create.c
@@ -40,10 +40,9 @@ int __pthread_key_delete(pthread_key_t k)
 }
 
 #ifdef __EMSCRIPTEN__
-void EMSCRIPTEN_KEEPALIVE __pthread_tsd_run_dtors()
-#else
-void __pthread_tsd_run_dtors()
+EMSCRIPTEN_KEEPALIVE
 #endif
+void __pthread_tsd_run_dtors()
 {
 	pthread_t self = __pthread_self();
 	int i, j, not_finished = self->tsd_used;

diff --git a/system/lib/libcxxabi/include/cxxabi.h b/system/lib/libcxxabi/include/cxxabi.h
@@ -164,7 +164,7 @@ __cxa_decrement_exception_refcount(void *primary_exception) _NOEXCEPT;
 extern _LIBCXXABI_FUNC_VIS bool __cxa_uncaught_exception() _NOEXCEPT;
 extern _LIBCXXABI_FUNC_VIS unsigned int __cxa_uncaught_exceptions() _NOEXCEPT;
 
-#if defined(__linux__) || defined(__Fuchsia__)
+#if defined(__linux__) || defined(__Fuchsia__) || defined(__EMSCRIPTEN__)
 // Linux and Fuchsia TLS support. Not yet an official part of the Itanium ABI.
 // https://sourceware.org/glibc/wiki/Destructor%20support%20for%20thread_local%20variables
 extern _LIBCXXABI_FUNC_VIS int __cxa_thread_atexit(void (*)(void *), void *,