Fixing POSIX testsuite pthread test fails

This patch aims for fixing failures in pthread related POSIX test from
clone of http://posixtest.sourceforge.net/

Following problems are addressed:
1. pthread_cond_wait/2-3 test hang
  - Disabling recursive thread cancellation.
  - Allowing __timedwait_cp to be true cancellation point as _cp
    suffix suggests
2. pthread_getschedparam/1-3 test hangs sometimes:
   In pthread_barrier_wait adding check if lock is held by main thread
   and waiting on futex in small slices of time there, to check if
   there is some work to do on behalf of Worker Threads.

Signed-off-by: Adam Bujalski <[email protected]>

src/library_pthread.js

@@ -177,21 +177,31 @@ var LibraryPThread = {
 #endif
 
     runExitHandlers: function() {
+      console.log('thread exit handlers count: ' + PThread.threadExitHandlers.length);
       while (PThread.threadExitHandlers.length > 0) {
         PThread.threadExitHandlers.pop()();
       }
 
       // Call into the musl function that runs destructors of all thread-specific data.
-      if (ENVIRONMENT_IS_PTHREAD && _pthread_self()) ___pthread_tsd_run_dtors();
+      if (ENVIRONMENT_IS_PTHREAD && _pthread_self()) {
+        console.log('Running ___pthread_tsd_run_dtors');
+        ___pthread_tsd_run_dtors();
+      } else {
+        console.log('Not running musl code ENVIRONMENT_IS_PTHREAD: ' + ENVIRONMENT_IS_PTHREAD
+          + ' _pthread_self(): ' + _pthread_self());
+      }
     },
 
     onThreadExit: function(tb, exitCode) {
+        console.log('onThreadExit: tb: ' + tb + ' code: ' + exitCode + ' ENVIRONMENT_IS_PTHREAD: ' + ENVIRONMENT_IS_PTHREAD);
         // Disable all cancellation so that executing the cleanup handlers won't trigger another JS
         // canceled exception to be thrown.
         Atomics.store(HEAPU32, (tb + {{{ C_STRUCTS.pthread.canceldisable }}} ) >> 2, 1/*PTHREAD_CANCEL_DISABLE*/);
         Atomics.store(HEAPU32, (tb + {{{ C_STRUCTS.pthread.cancelasync }}} ) >> 2, 0/*PTHREAD_CANCEL_DEFERRED*/);
         PThread.runExitHandlers();
 
+        console.log('onThreadExit: clean-up handlers run...');
+
         Atomics.store(HEAPU32, (tb + {{{ C_STRUCTS.pthread.threadExitCode }}} ) >> 2, exitCode);
         // When we publish this, the main thread is free to deallocate the thread object and we are done.
         // Therefore set _pthread_self = 0; above to 'release' the object in this worker thread.
@@ -207,6 +217,7 @@ var LibraryPThread = {
     // by programmer, or implicitly when leaving the thread main function.
     threadExit: function(exitCode) {
       var tb = _pthread_self();
+      console.log('Thread exit: tb: ' + tb);
       if (tb) { // If we haven't yet exited?
 #if ASSERTIONS
         err('Pthread 0x' + tb.toString(16) + ' exited.');
@@ -226,7 +237,9 @@ var LibraryPThread = {
     },
 
     threadCancel: function() {
-      PThread.onThreadExit(_pthread_self(), -1/*PTHREAD_CANCELED*/);
+      console.log('threadCancel: Thread cancelled...: ' + _pthread_self());
+      var tb = _pthread_self();
+      PThread.onThreadExit(tb, -1/*PTHREAD_CANCELED*/);
       postMessage({ 'cmd': 'cancelDone' });
     },
 
@@ -321,6 +334,8 @@ var LibraryPThread = {
           return;
         }
 
+        console.log('cmd: ' + cmd);
+
         if (cmd === 'processQueuedMainThreadWork') {
           // TODO: Must post message to main Emscripten thread in PROXY_TO_WORKER mode.
           _emscripten_main_thread_process_queued_calls();
@@ -483,6 +498,7 @@ var LibraryPThread = {
   },
 
   $cancelThread: function(pthread_ptr) {
+    console.log('cancelThread tid: ' + pthread_ptr);
     if (ENVIRONMENT_IS_PTHREAD) throw 'Internal Error! cancelThread() can only ever be called from main application thread!';
     if (!pthread_ptr) throw 'Internal Error! Null pthread_ptr in cancelThread!';
     var pthread = PThread.pthreads[pthread_ptr];
@@ -944,6 +960,7 @@ var LibraryPThread = {
 
   pthread_cancel__deps: ['$cancelThread', 'emscripten_main_browser_thread_id'],
   pthread_cancel: function(thread) {
+    console.log('pthread_cancel Canceling thread: ' + thread);
     if (thread === _emscripten_main_browser_thread_id()) {
       err('Main thread (id=' + thread + ') cannot be canceled!');
       return ERRNO_CODES.ESRCH;

system/lib/libc/musl/src/thread/__timedwait.c

@@ -45,7 +45,9 @@ int __timedwait_cp(volatile int *addr, int val,
 	// cp suffix in the function name means "cancellation point", so this wait can be cancelled
 	// by the users unless current threads cancelability is set to PTHREAD_CANCEL_DISABLE
 	// which may be either done by the user of __timedwait() function.
-	if (is_main_thread || pthread_self()->canceldisable != PTHREAD_CANCEL_DISABLE) {
+	if (is_main_thread || 
+			pthread_self()->canceldisable != PTHREAD_CANCEL_DISABLE ||
+			pthread_self()->cancelasync == PTHREAD_CANCEL_ASYNCHRONOUS) {
 		double sleepUntilTime = emscripten_get_now() + msecsToSleep;
 		do {
 			if (_pthread_isduecanceled(pthread_self())) {

tests/test_posixtest.py

@@ -54,10 +54,7 @@ def get_pthread_tests():
 disabled = {
   'test_pthread_create_11_1': 'never returns',
   'test_pthread_barrier_wait_2_1': 'never returns',
-  'test_pthread_cond_timedwait_2_6': 'never returns',
-  'test_pthread_cond_timedwait_4_3': 'never returns',
   'test_pthread_attr_setscope_5_1': 'internally skipped (PTS_UNTESTED)',
-  'test_pthread_cond_wait_2_3': 'never returns',
   'test_pthread_create_5_1': 'never returns',
   'test_pthread_exit_1_2': 'never returns',
   'test_pthread_exit_2_2': 'never returns',