Move most of pthread_kill to native code. NFC (#17041)

Author: sbc100

src/library_pthread.js

@@ -795,27 +795,12 @@ var LibraryPThread = {
 #endif
   },
 
-  pthread_kill__deps: ['emscripten_main_browser_thread_id'],
-  pthread_kill: function(thread, signal) {
-    if (signal < 0 || signal >= 65/*_NSIG*/) return {{{ cDefine('EINVAL') }}};
-    if (thread === _emscripten_main_browser_thread_id()) {
-      if (signal == 0) return 0; // signal == 0 is a no-op.
-      err('Main thread (id=' + ptrToString(thread) + ') cannot be killed with pthread_kill!');
-      return {{{ cDefine('ESRCH') }}};
-    }
-    if (!thread) {
-      err('pthread_kill attempted on a null thread pointer!');
-      return {{{ cDefine('ESRCH') }}};
-    }
-    var self = {{{ makeGetValue('thread', C_STRUCTS.pthread.self, 'i32') }}};
-    if (self !== thread) {
-      err('pthread_kill attempted on thread ' + ptrToString(thread) + ', which does not point to a valid thread, or does not exist anymore!');
-      return {{{ cDefine('ESRCH') }}};
-    }
+  __pthread_kill_js__deps: ['emscripten_main_browser_thread_id'],
+  __pthread_kill_js: function(thread, signal) {
     if (signal === {{{ cDefine('SIGCANCEL') }}}) { // Used by pthread_cancel in musl
       if (!ENVIRONMENT_IS_PTHREAD) cancelThread(thread);
       else postMessage({ 'cmd': 'cancelThread', 'thread': thread });
-    } else if (signal != 0) {
+    } else {
       if (!ENVIRONMENT_IS_PTHREAD) killThread(thread);
       else postMessage({ 'cmd': 'killThread', 'thread': thread });
     }

system/lib/pthread/pthread_kill.c

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2022 The Emscripten Authors.  All rights reserved.
+ * Emscripten is available under two separate licenses, the MIT license and the
+ * University of Illinois/NCSA Open Source License.  Both these licenses can be
+ * found in the LICENSE file.
+ */
+
+#include <emscripten/threading.h>
+
+#include "pthread_impl.h"
+#include "lock.h"
+
+int __pthread_kill_js(pthread_t t, int sig);
+
+int pthread_kill(pthread_t t, int sig) {
+  if (sig < 0 || sig >= _NSIG) {
+    return EINVAL;
+  }
+  if (t == emscripten_main_browser_thread_id()) {
+    if (sig == 0) return 0; // signal == 0 is a no-op.
+    return ESRCH;
+  }
+  if (!t || !_emscripten_thread_is_valid(t)) {
+    return ESRCH;
+  }
+  if (sig == 0) return 0; // signal == 0 is a no-op.
+  return __pthread_kill_js(t, sig);
+}

tools/system_libs.py

@@ -861,6 +861,7 @@ def get_files(self):
           'library_pthread.c',
           'proxying.c',
           'pthread_create.c',
+          'pthread_kill.c',
           'emscripten_proxy_main.c',
           'emscripten_thread_init.c',
           'emscripten_thread_state.S',