From 866676b3f3507738d902d3f150a8e8fb6cb5fad0 Mon Sep 17 00:00:00 2001
From: "Alon Zakai (kripken)" <alonzakai@gmail.com>
Date: Sat, 11 May 2019 13:38:34 -0700
Subject: [PATCH 01/25] horrible wip [ci skip]

---
 src/library_pthread.js |  9 +++++++
 src/shell.js           | 23 ++++++++++++++---
 src/worker.js          | 58 +++++++++++++++++++++++++++++++++++++-----
 3 files changed, 81 insertions(+), 9 deletions(-)

diff --git a/src/library_pthread.js b/src/library_pthread.js
index 24f36596645e..7c42b2b82ca0 100644
--- a/src/library_pthread.js
+++ b/src/library_pthread.js
@@ -275,6 +275,7 @@ var LibraryPThread = {
 
         (function(worker) {
           worker.onmessage = function(e) {
+console.log('parent got message ' + e);
             var d = e.data;
             // Sometimes we need to backproxy events to the calling thread (e.g. HTML5 DOM events handlers such as emscripten_set_mousemove_callback()), so keep track in a globally accessible variable about the thread that initiated the proxying.
             if (worker.pthread) PThread.currentProxiedOperationCallerThread = worker.pthread.threadInfoStruct;
@@ -344,6 +345,14 @@ var LibraryPThread = {
           worker.onerror = function(e) {
             err('pthread sent an error! ' + e.filename + ':' + e.lineno + ': ' + e.message);
           };
+
+          if (ENVIRONMENT_IS_NODE) {
+console.log('library_pthread worker on ' + [typeof worker.onmessage, typeof worker.onerror]);
+            worker.on('message', function(data) {
+              worker.onmessage({ data: data });
+            });
+            // note: adding onerror seems to only hurt on node.js
+          }
         }(worker));
 
         // Allocate tempDoublePtr for the worker. This is done here on the worker's behalf, since we may need to do this statically
diff --git a/src/shell.js b/src/shell.js
index 4c73ccde75df..65f05d0b7bd9 100644
--- a/src/shell.js
+++ b/src/shell.js
@@ -82,6 +82,10 @@ if (Module['ENVIRONMENT']) {
 // In MODULARIZE mode _scriptDir needs to be captured already at the very top of the page immediately when the page is parsed, so it is generated there
 // before the page load. In non-MODULARIZE modes generate it here.
 var _scriptDir = (typeof document !== 'undefined' && document.currentScript) ? document.currentScript.src : undefined;
+if (ENVIRONMENT_IS_NODE) {
+  _scriptDir = __filename;
+}
+console.log('_scriptDir: ' + _scriptDir);
 #endif
 
 // `/` should be present at the end if `scriptDirectory` is not empty
@@ -164,6 +168,22 @@ if (ENVIRONMENT_IS_NODE) {
   };
 
   Module['inspect'] = function () { return '[Emscripten Module object]'; };
+
+#if USE_PTHREADS
+  var nodeWorkerThreads = require('worker_threads');
+  Worker = nodeWorkerThreads.Worker;
+
+  // Polyfill the performance object, which emscripten pthreads support
+  // depends on for good timing.
+  if (typeof performance === 'undefined') {
+    performance = {
+      now: function() {
+        return Date.now();
+      }
+    };
+  }
+#endif
+
 } else
 #endif // ENVIRONMENT_MAY_BE_NODE
 #if ENVIRONMENT_MAY_BE_SHELL
@@ -343,9 +363,6 @@ assert(typeof Module['memoryInitializerPrefixURL'] === 'undefined', 'Module.memo
 assert(typeof Module['pthreadMainPrefixURL'] === 'undefined', 'Module.pthreadMainPrefixURL option was removed, use Module.locateFile instead');
 assert(typeof Module['cdInitializerPrefixURL'] === 'undefined', 'Module.cdInitializerPrefixURL option was removed, use Module.locateFile instead');
 assert(typeof Module['filePackagePrefixURL'] === 'undefined', 'Module.filePackagePrefixURL option was removed, use Module.locateFile instead');
-#if USE_PTHREADS
-assert(ENVIRONMENT_IS_WEB || ENVIRONMENT_IS_WORKER, 'Pthreads do not work in non-browser environments yet (need Web Workers, or an alternative to them)');
-#endif // USE_PTHREADS
 #endif // ASSERTIONS
 
 {{BODY}}
diff --git a/src/worker.js b/src/worker.js
index 7d35202ebd6f..2aadac548ce2 100644
--- a/src/worker.js
+++ b/src/worker.js
@@ -44,13 +44,16 @@ function assert(condition, text) {
 
 // When error objects propagate from Web Worker to main thread, they lose helpful call stack and thread ID information, so print out errors early here,
 // before that happens.
-this.addEventListener('error', function(e) {
-  if (e.message.indexOf('SimulateInfiniteLoop') != -1) return e.preventDefault();
+// Note that addEventListener may not exist on some environments, like node.
+if (typeof addEventListener === 'function') {
+  addEventListener('error', function(e) {
+    if (e.message.indexOf('SimulateInfiniteLoop') != -1) return e.preventDefault();
 
-  var errorSource = ' in ' + e.filename + ':' + e.lineno + ':' + e.colno;
-  console.error('Pthread ' + selfThreadId + ' uncaught exception' + (e.filename || e.lineno || e.colno ? errorSource : "") + ': ' + e.message + '. Error object:');
-  console.error(e.error);
-});
+    var errorSource = ' in ' + e.filename + ':' + e.lineno + ':' + e.colno;
+    console.error('Pthread ' + selfThreadId + ' uncaught exception' + (e.filename || e.lineno || e.colno ? errorSource : "") + ': ' + e.message + '. Error object:');
+    console.error(e.error);
+  });
+}
 
 function threadPrint() {
   var text = Array.prototype.slice.call(arguments).join(' ');
@@ -85,6 +88,7 @@ var wasmModule;
 var wasmMemory;
 
 this.onmessage = function(e) {
+  console.log('gottt ' + [e, JSON.stringify(e), typeof e.data.urlOrBlob, e.data.urlOrBlob]);
   try {
     if (e.data.cmd === 'load') { // Preload command that is called once per worker to parse and load the Emscripten code.
       // Initialize the thread-local field(s):
@@ -230,3 +234,45 @@ this.onmessage = function(e) {
     throw e;
   }
 }
+
+// Node.js support
+if (typeof require === 'function') {
+  // Create as web-worker-like an environment as we can.
+  self = {
+    location: {
+      href: __filename // XXX wat
+    }
+  };
+
+  var onmessage = this.onmessage;
+
+  var nodeWorkerThreads = require('worker_threads');
+
+  Worker = nodeWorkerThreads.Worker;
+
+  var parentPort = nodeWorkerThreads.parentPort;
+
+  parentPort.on('message', function(data) {
+    onmessage({ data: data });
+  });
+
+  var nodeFS = require('fs');
+
+  var nodeRead = function(filename) {
+    // TODO: convert to absolute path?
+    return nodeFS.readFileSync(filename).toString();
+  };
+
+  function globalEval(x) {
+    eval.call(null, x);
+  }
+
+  importScripts = function(f) {
+    globalEval(nodeRead(f));
+  };
+
+  postMessage = function(msg) {
+    parentPort.postMessage(msg);
+  };
+}
+

From 5e80c1fe36d15ff295c2515865887f5ad1f0c88d Mon Sep 17 00:00:00 2001
From: "Alon Zakai (kripken)" <alonzakai@gmail.com>
Date: Sat, 11 May 2019 15:33:32 -0700
Subject: [PATCH 02/25] bad wip exploration [ci skip]

---
 src/library_pthread.js                |  25 ++++-
 src/postamble.js                      |   5 +
 src/shell.js                          |   2 +-
 src/worker.js                         |  27 ++++-
 tests/pthread/test_pthread_create.cpp | 156 ++++++++++++++------------
 5 files changed, 140 insertions(+), 75 deletions(-)

diff --git a/src/library_pthread.js b/src/library_pthread.js
index 7c42b2b82ca0..0aca06c47beb 100644
--- a/src/library_pthread.js
+++ b/src/library_pthread.js
@@ -275,7 +275,7 @@ var LibraryPThread = {
 
         (function(worker) {
           worker.onmessage = function(e) {
-console.log('parent got message ' + e);
+console.log('parent got message ' + [e, JSON.stringify(e)]);
             var d = e.data;
             // Sometimes we need to backproxy events to the calling thread (e.g. HTML5 DOM events handlers such as emscripten_set_mousemove_callback()), so keep track in a globally accessible variable about the thread that initiated the proxying.
             if (worker.pthread) PThread.currentProxiedOperationCallerThread = worker.pthread.threadInfoStruct;
@@ -311,7 +311,9 @@ console.log('parent got message ' + e);
                 delete worker.runPthread;
               }
               ++numWorkersLoaded;
+console.log('loaded a warker');
               if (numWorkersLoaded === numWorkers && onFinishedLoading) {
+console.log('ALL WARKERS LADED! ' + onFinishedLoading);
                 onFinishedLoading();
               }
             } else if (d.cmd === 'print') {
@@ -347,10 +349,23 @@ console.log('parent got message ' + e);
           };
 
           if (ENVIRONMENT_IS_NODE) {
+            worker.ref(); // XXX FIXME wat
 console.log('library_pthread worker on ' + [typeof worker.onmessage, typeof worker.onerror]);
             worker.on('message', function(data) {
               worker.onmessage({ data: data });
             });
+            worker.on('close', function(data) {
+              console.log('worker closed ..!?');
+            });
+            worker.on('error', function(data) {
+              console.log('worker errored :(');
+            });
+            worker.on('exit', function(data) {
+              console.log('werker exited');
+            });
+            worker.on('online', function(data) {
+              console.log('workerah is online!!!1!');
+            });
             // note: adding onerror seems to only hurt on node.js
           }
         }(worker));
@@ -434,6 +449,8 @@ console.log('library_pthread worker on ' + [typeof worker.onmessage, typeof work
     if (ENVIRONMENT_IS_PTHREAD) throw 'Internal Error! _spawn_thread() can only ever be called from main application thread!';
 
     var worker = PThread.getNewWorker();
+console.log('spaewn ' + worker);
+
     if (worker.pthread !== undefined) throw 'Internal error!';
     if (!threadParams.pthread_ptr) throw 'Internal error, no pthread ptr!';
     PThread.runningWorkers.push(worker);
@@ -495,6 +512,7 @@ console.log('library_pthread worker on ' + [typeof worker.onmessage, typeof work
     worker.runPthread = function() {
       // Ask the worker to start executing its pthread entry point function.
       msg.time = performance.now();
+console.log('..tell child to run');
       worker.postMessage(msg, threadParams.transferList);
     };
     if (worker.loaded) {
@@ -521,6 +539,7 @@ console.log('library_pthread worker on ' + [typeof worker.onmessage, typeof work
 
   pthread_create__deps: ['_spawn_thread', 'pthread_getschedparam', 'pthread_self'],
   pthread_create: function(pthread_ptr, attr, start_routine, arg) {
+console.log('create a thradd');
     if (typeof SharedArrayBuffer === 'undefined') {
       err('Current environment does not support SharedArrayBuffer, pthreads are not available!');
       return {{{ cDefine('EAGAIN') }}};
@@ -623,6 +642,7 @@ console.log('library_pthread worker on ' + [typeof worker.onmessage, typeof work
 
     // If on the main thread, and accessing Canvas/OffscreenCanvas failed, abort with the detected error.
     if (error) return error;
+console.log('..moar1');
 
     var stackSize = 0;
     var stackBase = 0;
@@ -733,6 +753,7 @@ console.log('library_pthread worker on ' + [typeof worker.onmessage, typeof work
 
   pthread_join__deps: ['_cleanup_thread', '_pthread_testcancel_js', 'emscripten_main_thread_process_queued_calls'],
   pthread_join: function(thread, status) {
+console.log('joinn ' + [thread, status]);
     if (!thread) {
       err('pthread_join attempted on a null thread pointer!');
       return ERRNO_CODES.ESRCH;
@@ -756,6 +777,7 @@ console.log('library_pthread worker on ' + [typeof worker.onmessage, typeof work
       err('Attempted to join thread ' + thread + ', which was already detached!');
       return ERRNO_CODES.EINVAL; // The thread is already detached, can no longer join it!
     }
+console.log('3joinn loop');
     for (;;) {
       var threadStatus = Atomics.load(HEAPU32, (thread + {{{ C_STRUCTS.pthread.threadStatus }}} ) >> 2);
       if (threadStatus == 1) { // Exited?
@@ -765,6 +787,7 @@ console.log('library_pthread worker on ' + [typeof worker.onmessage, typeof work
 
         if (!ENVIRONMENT_IS_PTHREAD) __cleanup_thread(thread);
         else postMessage({ cmd: 'cleanupThread', thread: thread});
+console.log('4joinn stahp');
         return 0;
       }
       // TODO HACK! Replace the _js variant with just _pthread_testcancel:
diff --git a/src/postamble.js b/src/postamble.js
index 1134ab744487..4026632f6760 100644
--- a/src/postamble.js
+++ b/src/postamble.js
@@ -164,6 +164,7 @@ dependenciesFulfilled = function runCaller() {
 
 #if HAS_MAIN
 Module['callMain'] = function callMain(args) {
+console.log('callMain! ' + ENVIRONMENT_IS_NODE);
 #if ASSERTIONS
   assert(runDependencies == 0, 'cannot call main when async dependencies remain! (listen on Module["onRuntimeInitialized"])');
   assert(__ATPRERUN__.length == 0, 'cannot call main when preRun functions remain to be called');
@@ -195,7 +196,9 @@ Module['callMain'] = function callMain(args) {
     // that will call the user's real main() for the application.
     var ret = Module['_proxy_main'](argc, argv, 0);
 #else
+console.log('calle maienne! ' + ENVIRONMENT_IS_NODE);
     var ret = Module['_main'](argc, argv, 0);
+console.log('called off');
 #endif
 
 #if BENCHMARK
@@ -244,6 +247,7 @@ Module['callMain'] = function callMain(args) {
 
 /** @type {function(Array=)} */
 function run(args) {
+console.log('run! ' + ENVIRONMENT_IS_NODE);
   args = args || Module['arguments'];
 
   if (runDependencies > 0) {
@@ -263,6 +267,7 @@ function run(args) {
   if (Module['calledRun']) return; // run may have just been called through dependencies being fulfilled just in this very frame
 
   function doRun() {
+console.log('doRun! ' + ENVIRONMENT_IS_NODE);
     if (Module['calledRun']) return; // run may have just been called while the async setStatus time below was happening
     Module['calledRun'] = true;
 
diff --git a/src/shell.js b/src/shell.js
index 65f05d0b7bd9..f7629c8561fb 100644
--- a/src/shell.js
+++ b/src/shell.js
@@ -82,10 +82,10 @@ if (Module['ENVIRONMENT']) {
 // In MODULARIZE mode _scriptDir needs to be captured already at the very top of the page immediately when the page is parsed, so it is generated there
 // before the page load. In non-MODULARIZE modes generate it here.
 var _scriptDir = (typeof document !== 'undefined' && document.currentScript) ? document.currentScript.src : undefined;
+
 if (ENVIRONMENT_IS_NODE) {
   _scriptDir = __filename;
 }
-console.log('_scriptDir: ' + _scriptDir);
 #endif
 
 // `/` should be present at the end if `scriptDirectory` is not empty
diff --git a/src/worker.js b/src/worker.js
index 2aadac548ce2..77fdab8f21f7 100644
--- a/src/worker.js
+++ b/src/worker.js
@@ -88,7 +88,7 @@ var wasmModule;
 var wasmMemory;
 
 this.onmessage = function(e) {
-  console.log('gottt ' + [e, JSON.stringify(e), typeof e.data.urlOrBlob, e.data.urlOrBlob]);
+  console.log('child gottt ' + [e, JSON.stringify(e), typeof e.data.urlOrBlob, e.data.urlOrBlob]);
   try {
     if (e.data.cmd === 'load') { // Preload command that is called once per worker to parse and load the Emscripten code.
       // Initialize the thread-local field(s):
@@ -237,6 +237,15 @@ this.onmessage = function(e) {
 
 // Node.js support
 if (typeof require === 'function') {
+
+  console.log('child wants to live forever ' + typeof setInterval);
+  setInterval(function() {
+    console.log('time in worker...');
+    throw 55;
+  }, 2000);
+
+
+
   // Create as web-worker-like an environment as we can.
   self = {
     location: {
@@ -252,9 +261,24 @@ if (typeof require === 'function') {
 
   var parentPort = nodeWorkerThreads.parentPort;
 
+  parentPort.ref(); // stay alive XXX?
+//process.exit(); XXX at the right time
+
   parentPort.on('message', function(data) {
     onmessage({ data: data });
   });
+            parentPort.on('close', function(data) {
+              console.log('parentPort closed ..!?');
+            });
+            parentPort.on('error', function(data) {
+              console.log('parentPort errored :(');
+            });
+            parentPort.on('exit', function(data) {
+              console.log('werker exited');
+            });
+            parentPort.on('online', function(data) {
+              console.log('parentPortah is online!!!1!');
+            });
 
   var nodeFS = require('fs');
 
@@ -275,4 +299,5 @@ if (typeof require === 'function') {
     parentPort.postMessage(msg);
   };
 }
+console.log('workers first event loop is going away now');
 
diff --git a/tests/pthread/test_pthread_create.cpp b/tests/pthread/test_pthread_create.cpp
index e52f11d0ad6d..727b15786a17 100644
--- a/tests/pthread/test_pthread_create.cpp
+++ b/tests/pthread/test_pthread_create.cpp
@@ -10,49 +10,51 @@
 #include <emscripten/threading.h>
 #include <assert.h>
 
-#define NUM_THREADS 8
+#define NUM_THREADS 1
 
 int fib(int n)
 {
-	if (n <= 0) return 0;
-	if (n == 1) return 1;
-	return fib(n-1) + fib(n-2);
+  if (n <= 0) return 0;
+  if (n == 1) return 1;
+  return fib(n-1) + fib(n-2);
 }
 
 unsigned int global_shared_data[NUM_THREADS];
 
 void *ThreadMain(void *arg)
 {
-	int idx = (int)arg;
-	unsigned int param = global_shared_data[idx];
+printf("ThreadMain! %d\n", (int)arg);
+
+  int idx = (int)arg;
+  unsigned int param = global_shared_data[idx];
 
 #define N 100
 
-	EM_ASM(err('Thread idx '+$0+': sorting ' + $1 + ' numbers with param ' + $2 + '.'), idx, N, param);
-
-	unsigned int n[N];
-	for(unsigned int i = 0; i < N; ++i)
-		n[i] = (i + param) % N; // Create a shifted increasing sequence of numbers [0, N-1[
-
-	// Sort the sequence to ordered [0, N[
-	for(unsigned int i = 0; i < N; ++i)
-		for(unsigned int j = i; j < N; ++j)
-		{
-			if (n[i] > n[j])
-			{
-				unsigned int t = n[i];
-				n[i] = n[j];
-				n[j] = t;
-			}
-		}
-	// Ensure all elements are in place.
-	int numGood = 0;
-	for(unsigned int i = 0; i < N; ++i)
-		if (n[i] == i) ++numGood;
-		else EM_ASM(err('n['+$0+']='+$1), i, n[i]);
-
-	EM_ASM(out('Thread idx ' + $0 + ' with param '+$1+': all done with result '+$2+'.'), idx, param, numGood);
-	pthread_exit((void*)numGood);
+  EM_ASM(err('Thread idx '+$0+': sorting ' + $1 + ' numbers with param ' + $2 + '.'), idx, N, param);
+
+  unsigned int n[N];
+  for(unsigned int i = 0; i < N; ++i)
+    n[i] = (i + param) % N; // Create a shifted increasing sequence of numbers [0, N-1[
+
+  // Sort the sequence to ordered [0, N[
+  for(unsigned int i = 0; i < N; ++i)
+    for(unsigned int j = i; j < N; ++j)
+    {
+      if (n[i] > n[j])
+      {
+        unsigned int t = n[i];
+        n[i] = n[j];
+        n[j] = t;
+      }
+    }
+  // Ensure all elements are in place.
+  int numGood = 0;
+  for(unsigned int i = 0; i < N; ++i)
+    if (n[i] == i) ++numGood;
+    else EM_ASM(err('n['+$0+']='+$1), i, n[i]);
+
+  EM_ASM(out('Thread idx ' + $0 + ' with param '+$1+': all done with result '+$2+'.'), idx, param, numGood);
+  pthread_exit((void*)numGood);
 }
 
 pthread_t thread[NUM_THREADS];
@@ -61,54 +63,64 @@ int numThreadsToCreate = 1000;
 
 void CreateThread(int i)
 {
-	pthread_attr_t attr;
-	pthread_attr_init(&attr);
-	pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
-	static int counter = 1;
-	global_shared_data[i] = (counter++ * 12141231) & 0x7FFFFFFF; // Arbitrary random'ish data for perturbing the sort for this thread task.
-//	EM_ASM(out('Main: Creating thread idx ' + $0 + ' (param ' + $1 + ')'), i, global_shared_data[i]);
-	int rc = pthread_create(&thread[i], &attr, ThreadMain, (void*)i);
-	assert(rc == 0);
-	pthread_attr_destroy(&attr);
+  pthread_attr_t attr;
+  pthread_attr_init(&attr);
+  pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
+  static int counter = 1;
+  global_shared_data[i] = (counter++ * 12141231) & 0x7FFFFFFF; // Arbitrary random'ish data for perturbing the sort for this thread task.
+//  EM_ASM(out('Main: Creating thread idx ' + $0 + ' (param ' + $1 + ')'), i, global_shared_data[i]);
+  int rc = pthread_create(&thread[i], &attr, ThreadMain, (void*)i);
+  assert(rc == 0);
+  pthread_attr_destroy(&attr);
 }
 
 int main()
 {
-	if (!emscripten_has_threading_support())
-	{
+printf("mainne1\n");
+  if (!emscripten_has_threading_support())
+  {
 #ifdef REPORT_RESULT
-		REPORT_RESULT(0);
+    REPORT_RESULT(0);
 #endif
-		printf("Skipped: Threading is not supported.\n");
-		return 0;
-	}
-
-	// Create initial threads.
-	for(int i = 0; i < NUM_THREADS; ++i)
-		CreateThread(i);
-
-	// Join all threads and create more.
-        while (numThreadsToCreate > 0)
+    printf("Skipped: Threading is not supported.\n");
+    return 0;
+  }
+printf("mainne2\n");
+
+  // Create initial threads.
+  for(int i = 0; i < NUM_THREADS; ++i) {
+printf("mainne3\n");
+    CreateThread(i);
+  }
+printf("mainne4\n");
+
+  // Join all threads and create more.
+  while (numThreadsToCreate > 0)
+  {
+printf("mainne5\n");
+    for(int i = 0; i < NUM_THREADS; ++i)
+    {
+printf("mainne6\n");
+      if (thread[i])
+      {
+printf("mainne7\n");
+        int status;
+// synchronous blocking here maybe is what prevents node from sending the thread creation postMessages :(
+        int rc = pthread_join(thread[i], (void**)&status);
+printf("mainne8\n");
+        assert(rc == 0);
+        EM_ASM(err('Main: Joined thread idx ' + $0 + ' (param ' + $1 + ') with status ' + $2), i, global_shared_data[i], (int)status);
+        assert(status == N);
+        thread[i] = 0;
+        if (numThreadsToCreate > 0)
         {
-		for(int i = 0; i < NUM_THREADS; ++i)
-		{
-			if (thread[i])
-			{
-				int status;
-				int rc = pthread_join(thread[i], (void**)&status);
-				assert(rc == 0);
-				EM_ASM(err('Main: Joined thread idx ' + $0 + ' (param ' + $1 + ') with status ' + $2), i, global_shared_data[i], (int)status);
-				assert(status == N);
-				thread[i] = 0;
-				if (numThreadsToCreate > 0)
-				{
-					--numThreadsToCreate;
-					CreateThread(i);
-				}
-			}
-		}
-	}
+          --numThreadsToCreate;
+          CreateThread(i);
+        }
+      }
+    }
+  }
 #ifdef REPORT_RESULT
-	REPORT_RESULT(0);
+  REPORT_RESULT(0);
 #endif
 }

From 6c427c7ba615f258f9501c5a513bd4cc3cd85d5b Mon Sep 17 00:00:00 2001
From: "Alon Zakai (kripken)" <alonzakai@gmail.com>
Date: Sat, 11 May 2019 19:31:39 -0700
Subject: [PATCH 03/25] note the issue [ci skip]

---
 src/library_pthread.js                |  3 ---
 src/worker.js                         |  8 ++++++
 tests/pthread/test_pthread_create.cpp | 37 ++++++---------------------
 3 files changed, 16 insertions(+), 32 deletions(-)

diff --git a/src/library_pthread.js b/src/library_pthread.js
index 0aca06c47beb..c80caddafd4e 100644
--- a/src/library_pthread.js
+++ b/src/library_pthread.js
@@ -357,9 +357,6 @@ console.log('library_pthread worker on ' + [typeof worker.onmessage, typeof work
             worker.on('close', function(data) {
               console.log('worker closed ..!?');
             });
-            worker.on('error', function(data) {
-              console.log('worker errored :(');
-            });
             worker.on('exit', function(data) {
               console.log('werker exited');
             });
diff --git a/src/worker.js b/src/worker.js
index 77fdab8f21f7..f403edc07925 100644
--- a/src/worker.js
+++ b/src/worker.js
@@ -298,6 +298,14 @@ if (typeof require === 'function') {
   postMessage = function(msg) {
     parentPort.postMessage(msg);
   };
+
+  if (typeof performance === 'undefined') {
+    performance = {
+      now: function() {
+        return Date.now();
+      }
+    };
+  }
 }
 console.log('workers first event loop is going away now');
 
diff --git a/tests/pthread/test_pthread_create.cpp b/tests/pthread/test_pthread_create.cpp
index 727b15786a17..a123ac28a472 100644
--- a/tests/pthread/test_pthread_create.cpp
+++ b/tests/pthread/test_pthread_create.cpp
@@ -74,6 +74,10 @@ void CreateThread(int i)
   pthread_attr_destroy(&attr);
 }
 
+void mainn() {
+  printf("main iter\n");
+}
+
 int main()
 {
 printf("mainne1\n");
@@ -94,33 +98,8 @@ printf("mainne3\n");
   }
 printf("mainne4\n");
 
-  // Join all threads and create more.
-  while (numThreadsToCreate > 0)
-  {
-printf("mainne5\n");
-    for(int i = 0; i < NUM_THREADS; ++i)
-    {
-printf("mainne6\n");
-      if (thread[i])
-      {
-printf("mainne7\n");
-        int status;
-// synchronous blocking here maybe is what prevents node from sending the thread creation postMessages :(
-        int rc = pthread_join(thread[i], (void**)&status);
-printf("mainne8\n");
-        assert(rc == 0);
-        EM_ASM(err('Main: Joined thread idx ' + $0 + ' (param ' + $1 + ') with status ' + $2), i, global_shared_data[i], (int)status);
-        assert(status == N);
-        thread[i] = 0;
-        if (numThreadsToCreate > 0)
-        {
-          --numThreadsToCreate;
-          CreateThread(i);
-        }
-      }
-    }
-  }
-#ifdef REPORT_RESULT
-  REPORT_RESULT(0);
-#endif
+  // synchronous here would not let the worker start -
+  // the postMessage is only sent at the end of the event
+  // loop it seems :(
+  emscripten_set_main_loop(mainn, 1, 1);
 }

From 3604163d363dd767738f614eb1551439086fcf54 Mon Sep 17 00:00:00 2001
From: Alon Zakai <azakai@google.com>
Date: Mon, 8 Jul 2019 11:26:42 -0700
Subject: [PATCH 04/25] wip [ci skip]

---
 src/library_pthread.js | 11 -----------
 src/postamble.js       |  5 -----
 2 files changed, 16 deletions(-)

diff --git a/src/library_pthread.js b/src/library_pthread.js
index c80caddafd4e..87a1311c417b 100644
--- a/src/library_pthread.js
+++ b/src/library_pthread.js
@@ -275,7 +275,6 @@ var LibraryPThread = {
 
         (function(worker) {
           worker.onmessage = function(e) {
-console.log('parent got message ' + [e, JSON.stringify(e)]);
             var d = e.data;
             // Sometimes we need to backproxy events to the calling thread (e.g. HTML5 DOM events handlers such as emscripten_set_mousemove_callback()), so keep track in a globally accessible variable about the thread that initiated the proxying.
             if (worker.pthread) PThread.currentProxiedOperationCallerThread = worker.pthread.threadInfoStruct;
@@ -311,9 +310,7 @@ console.log('parent got message ' + [e, JSON.stringify(e)]);
                 delete worker.runPthread;
               }
               ++numWorkersLoaded;
-console.log('loaded a warker');
               if (numWorkersLoaded === numWorkers && onFinishedLoading) {
-console.log('ALL WARKERS LADED! ' + onFinishedLoading);
                 onFinishedLoading();
               }
             } else if (d.cmd === 'print') {
@@ -350,7 +347,6 @@ console.log('ALL WARKERS LADED! ' + onFinishedLoading);
 
           if (ENVIRONMENT_IS_NODE) {
             worker.ref(); // XXX FIXME wat
-console.log('library_pthread worker on ' + [typeof worker.onmessage, typeof worker.onerror]);
             worker.on('message', function(data) {
               worker.onmessage({ data: data });
             });
@@ -446,7 +442,6 @@ console.log('library_pthread worker on ' + [typeof worker.onmessage, typeof work
     if (ENVIRONMENT_IS_PTHREAD) throw 'Internal Error! _spawn_thread() can only ever be called from main application thread!';
 
     var worker = PThread.getNewWorker();
-console.log('spaewn ' + worker);
 
     if (worker.pthread !== undefined) throw 'Internal error!';
     if (!threadParams.pthread_ptr) throw 'Internal error, no pthread ptr!';
@@ -509,7 +504,6 @@ console.log('spaewn ' + worker);
     worker.runPthread = function() {
       // Ask the worker to start executing its pthread entry point function.
       msg.time = performance.now();
-console.log('..tell child to run');
       worker.postMessage(msg, threadParams.transferList);
     };
     if (worker.loaded) {
@@ -536,7 +530,6 @@ console.log('..tell child to run');
 
   pthread_create__deps: ['_spawn_thread', 'pthread_getschedparam', 'pthread_self'],
   pthread_create: function(pthread_ptr, attr, start_routine, arg) {
-console.log('create a thradd');
     if (typeof SharedArrayBuffer === 'undefined') {
       err('Current environment does not support SharedArrayBuffer, pthreads are not available!');
       return {{{ cDefine('EAGAIN') }}};
@@ -639,7 +632,6 @@ console.log('create a thradd');
 
     // If on the main thread, and accessing Canvas/OffscreenCanvas failed, abort with the detected error.
     if (error) return error;
-console.log('..moar1');
 
     var stackSize = 0;
     var stackBase = 0;
@@ -750,7 +742,6 @@ console.log('..moar1');
 
   pthread_join__deps: ['_cleanup_thread', '_pthread_testcancel_js', 'emscripten_main_thread_process_queued_calls'],
   pthread_join: function(thread, status) {
-console.log('joinn ' + [thread, status]);
     if (!thread) {
       err('pthread_join attempted on a null thread pointer!');
       return ERRNO_CODES.ESRCH;
@@ -774,7 +765,6 @@ console.log('joinn ' + [thread, status]);
       err('Attempted to join thread ' + thread + ', which was already detached!');
       return ERRNO_CODES.EINVAL; // The thread is already detached, can no longer join it!
     }
-console.log('3joinn loop');
     for (;;) {
       var threadStatus = Atomics.load(HEAPU32, (thread + {{{ C_STRUCTS.pthread.threadStatus }}} ) >> 2);
       if (threadStatus == 1) { // Exited?
@@ -784,7 +774,6 @@ console.log('3joinn loop');
 
         if (!ENVIRONMENT_IS_PTHREAD) __cleanup_thread(thread);
         else postMessage({ cmd: 'cleanupThread', thread: thread});
-console.log('4joinn stahp');
         return 0;
       }
       // TODO HACK! Replace the _js variant with just _pthread_testcancel:
diff --git a/src/postamble.js b/src/postamble.js
index 4026632f6760..1134ab744487 100644
--- a/src/postamble.js
+++ b/src/postamble.js
@@ -164,7 +164,6 @@ dependenciesFulfilled = function runCaller() {
 
 #if HAS_MAIN
 Module['callMain'] = function callMain(args) {
-console.log('callMain! ' + ENVIRONMENT_IS_NODE);
 #if ASSERTIONS
   assert(runDependencies == 0, 'cannot call main when async dependencies remain! (listen on Module["onRuntimeInitialized"])');
   assert(__ATPRERUN__.length == 0, 'cannot call main when preRun functions remain to be called');
@@ -196,9 +195,7 @@ console.log('callMain! ' + ENVIRONMENT_IS_NODE);
     // that will call the user's real main() for the application.
     var ret = Module['_proxy_main'](argc, argv, 0);
 #else
-console.log('calle maienne! ' + ENVIRONMENT_IS_NODE);
     var ret = Module['_main'](argc, argv, 0);
-console.log('called off');
 #endif
 
 #if BENCHMARK
@@ -247,7 +244,6 @@ console.log('called off');
 
 /** @type {function(Array=)} */
 function run(args) {
-console.log('run! ' + ENVIRONMENT_IS_NODE);
   args = args || Module['arguments'];
 
   if (runDependencies > 0) {
@@ -267,7 +263,6 @@ console.log('run! ' + ENVIRONMENT_IS_NODE);
   if (Module['calledRun']) return; // run may have just been called through dependencies being fulfilled just in this very frame
 
   function doRun() {
-console.log('doRun! ' + ENVIRONMENT_IS_NODE);
     if (Module['calledRun']) return; // run may have just been called while the async setStatus time below was happening
     Module['calledRun'] = true;
 

From a90fc1b6509dc86972a663ff17aa7271b61b3ab6 Mon Sep 17 00:00:00 2001
From: Alon Zakai <azakai@google.com>
Date: Tue, 24 Sep 2019 14:06:13 -0700
Subject: [PATCH 05/25] wip [ci skip]

---
 src/node_shell_read.js          |  30 ++++++++++
 src/runtime_init_memory.js      |   1 +
 src/shell.js                    | 100 ++++----------------------------
 src/web_or_worker_shell_read.js |  63 ++++++++++++++++++++
 4 files changed, 105 insertions(+), 89 deletions(-)
 create mode 100644 src/node_shell_read.js
 create mode 100644 src/web_or_worker_shell_read.js

diff --git a/src/node_shell_read.js b/src/node_shell_read.js
new file mode 100644
index 000000000000..6045597c43e6
--- /dev/null
+++ b/src/node_shell_read.js
@@ -0,0 +1,30 @@
+  // Expose functionality in the same simple way that the shells work
+  // Note that we pollute the global namespace here, otherwise we break in node
+  var nodeFS;
+  var nodePath;
+
+  read_ = function shell_read(filename, binary) {
+    var ret;
+#if SUPPORT_BASE64_EMBEDDING
+    ret = tryParseAsDataURI(filename);
+    if (!ret) {
+#endif
+      if (!nodeFS) nodeFS = require('fs');
+      if (!nodePath) nodePath = require('path');
+      filename = nodePath['normalize'](filename);
+      ret = nodeFS['readFileSync'](filename);
+#if SUPPORT_BASE64_EMBEDDING
+    }
+#endif
+    return binary ? ret : ret.toString();
+  };
+
+  readBinary = function readBinary(filename) {
+    var ret = read_(filename, true);
+    if (!ret.buffer) {
+      ret = new Uint8Array(ret);
+    }
+    assert(ret.buffer);
+    return ret;
+  };
+
diff --git a/src/runtime_init_memory.js b/src/runtime_init_memory.js
index 0289bbae47b7..a157114c6220 100644
--- a/src/runtime_init_memory.js
+++ b/src/runtime_init_memory.js
@@ -36,6 +36,7 @@ if (ENVIRONMENT_IS_PTHREAD) {
     });
 #if USE_PTHREADS
     assert(wasmMemory.buffer instanceof SharedArrayBuffer, 'requested a shared WebAssembly.Memory but the returned buffer is not a SharedArrayBuffer, indicating that while the browser has SharedArrayBuffer it does not have WebAssembly threads support - you may need to set a flag');
+    // e.g. on node: --experimental-wasm-threads --experimental-wasm-bulk-memory
 #endif
   }
 
diff --git a/src/shell.js b/src/shell.js
index 2e654a861fa2..5bb5065e3cfd 100644
--- a/src/shell.js
+++ b/src/shell.js
@@ -128,35 +128,7 @@ if (ENVIRONMENT_IS_NODE) {
 #endif
   scriptDirectory = __dirname + '/';
 
-  // Expose functionality in the same simple way that the shells work
-  // Note that we pollute the global namespace here, otherwise we break in node
-  var nodeFS;
-  var nodePath;
-
-  read_ = function shell_read(filename, binary) {
-    var ret;
-#if SUPPORT_BASE64_EMBEDDING
-    ret = tryParseAsDataURI(filename);
-    if (!ret) {
-#endif
-      if (!nodeFS) nodeFS = require('fs');
-      if (!nodePath) nodePath = require('path');
-      filename = nodePath['normalize'](filename);
-      ret = nodeFS['readFileSync'](filename);
-#if SUPPORT_BASE64_EMBEDDING
-    }
-#endif
-    return binary ? ret : ret.toString();
-  };
-
-  readBinary = function readBinary(filename) {
-    var ret = read_(filename, true);
-    if (!ret.buffer) {
-      ret = new Uint8Array(ret);
-    }
-    assert(ret.buffer);
-    return ret;
-  };
+#include "node_shell_read.js"
 
   if (process['argv'].length > 1) {
     thisProgram = process['argv'][1].replace(/\\/g, '/');
@@ -295,68 +267,18 @@ if (ENVIRONMENT_IS_WEB || ENVIRONMENT_IS_WORKER) {
 #endif
 #endif
 
-  read_ = function shell_read(url) {
-#if SUPPORT_BASE64_EMBEDDING
-    try {
-#endif
-      var xhr = new XMLHttpRequest();
-      xhr.open('GET', url, false);
-      xhr.send(null);
-      return xhr.responseText;
-#if SUPPORT_BASE64_EMBEDDING
-    } catch (err) {
-      var data = tryParseAsDataURI(url);
-      if (data) {
-        return intArrayToString(data);
-      }
-      throw err;
-    }
-#endif
-  };
+  // Differentiate the Web Worker from the Node Worker case, as reading must
+  // be done differently.
+  if (!ENVIRONMENT_HAS_NODE) {
+
+#include "web_or_worker_shell_read.js"
+
+  } else {
+
+#include "node_shell_read.js"
 
-  if (ENVIRONMENT_IS_WORKER) {
-    readBinary = function readBinary(url) {
-#if SUPPORT_BASE64_EMBEDDING
-      try {
-#endif
-        var xhr = new XMLHttpRequest();
-        xhr.open('GET', url, false);
-        xhr.responseType = 'arraybuffer';
-        xhr.send(null);
-        return new Uint8Array(xhr.response);
-#if SUPPORT_BASE64_EMBEDDING
-      } catch (err) {
-        var data = tryParseAsDataURI(url);
-        if (data) {
-          return data;
-        }
-        throw err;
-      }
-#endif
-    };
   }
 
-  readAsync = function readAsync(url, onload, onerror) {
-    var xhr = new XMLHttpRequest();
-    xhr.open('GET', url, true);
-    xhr.responseType = 'arraybuffer';
-    xhr.onload = function xhr_onload() {
-      if (xhr.status == 200 || (xhr.status == 0 && xhr.response)) { // file URLs can return 0
-        onload(xhr.response);
-        return;
-      }
-#if SUPPORT_BASE64_EMBEDDING
-      var data = tryParseAsDataURI(url);
-      if (data) {
-        onload(data.buffer);
-        return;
-      }
-#endif
-      onerror();
-    };
-    xhr.onerror = onerror;
-    xhr.send(null);
-  };
 
   setWindowTitle = function(title) { document.title = title };
 } else
@@ -407,7 +329,7 @@ assert(typeof Module['setWindowTitle'] === 'undefined', 'Module.setWindowTitle o
 // TODO: add when SDL2 is fixed {{{ makeRemovedModuleAPIAssert('setWindowTitle') }}}
 
 #if USE_PTHREADS
-assert(ENVIRONMENT_IS_WEB || ENVIRONMENT_IS_WORKER, 'Pthreads do not work in non-browser environments yet (need Web Workers, or an alternative to them)');
+assert(ENVIRONMENT_IS_WEB || ENVIRONMENT_IS_WORKER || ENVIRONMENT_IS_NODE, 'Pthreads do not work in this environment yet (need Web Workers, or an alternative to them)');
 #endif // USE_PTHREADS
 #endif // ASSERTIONS
 
diff --git a/src/web_or_worker_shell_read.js b/src/web_or_worker_shell_read.js
new file mode 100644
index 000000000000..6c7c0560aa26
--- /dev/null
+++ b/src/web_or_worker_shell_read.js
@@ -0,0 +1,63 @@
+  read_ = function shell_read(url) {
+#if SUPPORT_BASE64_EMBEDDING
+    try {
+#endif
+      var xhr = new XMLHttpRequest();
+      xhr.open('GET', url, false);
+      xhr.send(null);
+      return xhr.responseText;
+#if SUPPORT_BASE64_EMBEDDING
+    } catch (err) {
+      var data = tryParseAsDataURI(url);
+      if (data) {
+        return intArrayToString(data);
+      }
+      throw err;
+    }
+#endif
+  };
+
+  if (ENVIRONMENT_IS_WORKER) {
+    readBinary = function readBinary(url) {
+#if SUPPORT_BASE64_EMBEDDING
+      try {
+#endif
+        var xhr = new XMLHttpRequest();
+        xhr.open('GET', url, false);
+        xhr.responseType = 'arraybuffer';
+        xhr.send(null);
+        return new Uint8Array(xhr.response);
+#if SUPPORT_BASE64_EMBEDDING
+      } catch (err) {
+        var data = tryParseAsDataURI(url);
+        if (data) {
+          return data;
+        }
+        throw err;
+      }
+#endif
+    };
+  }
+
+  readAsync = function readAsync(url, onload, onerror) {
+    var xhr = new XMLHttpRequest();
+    xhr.open('GET', url, true);
+    xhr.responseType = 'arraybuffer';
+    xhr.onload = function xhr_onload() {
+      if (xhr.status == 200 || (xhr.status == 0 && xhr.response)) { // file URLs can return 0
+        onload(xhr.response);
+        return;
+      }
+#if SUPPORT_BASE64_EMBEDDING
+      var data = tryParseAsDataURI(url);
+      if (data) {
+        onload(data.buffer);
+        return;
+      }
+#endif
+      onerror();
+    };
+    xhr.onerror = onerror;
+    xhr.send(null);
+  };
+

From 7a3716d7ccbbc472282016a7df6a2aa1636b8ff0 Mon Sep 17 00:00:00 2001
From: Alon Zakai <azakai@google.com>
Date: Thu, 26 Sep 2019 15:23:28 -0700
Subject: [PATCH 06/25] more logging [ci skip]

---
 src/library_pthread.js | 3 +++
 src/worker.js          | 4 ++++
 2 files changed, 7 insertions(+)

diff --git a/src/library_pthread.js b/src/library_pthread.js
index d226e19fe36f..419d6e03d3ac 100644
--- a/src/library_pthread.js
+++ b/src/library_pthread.js
@@ -506,10 +506,13 @@ var LibraryPThread = {
         offscreenCanvases: threadParams.offscreenCanvases,
 #endif
       };
+console.log('parent ready to run pthread');
     worker.runPthread = function() {
       // Ask the worker to start executing its pthread entry point function.
+console.log('  posting to run pthread');
       msg.time = performance.now();
       worker.postMessage(msg, threadParams.transferList);
+console.log('  postedded');
     };
     if (worker.loaded) {
       worker.runPthread();
diff --git a/src/worker.js b/src/worker.js
index 77ffefb4f2b4..a5c7876fa2e2 100644
--- a/src/worker.js
+++ b/src/worker.js
@@ -119,6 +119,7 @@ var wasmOffsetData;
 this.onmessage = function(e) {
   console.log('child gottt ' + [e, JSON.stringify(e), typeof e.data.urlOrBlob, e.data.urlOrBlob]);
   try {
+console.log('child command:', e.data.cmd);
     if (e.data.cmd === 'load') { // Preload command that is called once per worker to parse and load the Emscripten code.
 #if !WASM_BACKEND
       // Initialize the thread-local field(s):
@@ -183,7 +184,9 @@ this.onmessage = function(e) {
       });
 #else
       if (typeof e.data.urlOrBlob === 'string') {
+console.log('child loading scripts');
         importScripts(e.data.urlOrBlob);
+console.log('child loaded scripts');
       } else {
         var objectUrl = URL.createObjectURL(e.data.urlOrBlob);
         importScripts(objectUrl);
@@ -365,6 +368,7 @@ if (typeof require === 'function') {
   };
 
   function globalEval(x) {
+    global.require = require;
     eval.call(null, x);
   }
 

From 257b02baeb077e978856d930e283295438abe6a1 Mon Sep 17 00:00:00 2001
From: Alon Zakai <azakai@google.com>
Date: Thu, 26 Sep 2019 15:43:43 -0700
Subject: [PATCH 07/25] more [ci skip]

---
 src/settings.js | 5 +++++
 src/worker.js   | 1 +
 2 files changed, 6 insertions(+)

diff --git a/src/settings.js b/src/settings.js
index c0313efffcd4..8e824a1480bd 100644
--- a/src/settings.js
+++ b/src/settings.js
@@ -1662,3 +1662,8 @@ var LEGACY_SETTINGS = [
   ['ERROR_ON_MISSING_LIBRARIES', [1], 'missing libraries are always an error now'],
   ['EMITTING_JS', [1], 'The new STANDALONE_WASM flag replaces this (replace EMITTING_JS=0 with STANDALONE_WASM=1)'],
 ];
+
+
+// ./emcc tests/pthread/test_pthread_create.cpp -s USE_PTHREADS -s PTHREAD_POOL_SIZE=1 -g
+// ~/Downloads/node-v13.0.0-nightly20190924e078e482c5-linux-x64/bin/node --experimental-wasm-threads --experimental-wasm-bulk-memory a.out.js
+
diff --git a/src/worker.js b/src/worker.js
index a5c7876fa2e2..66ea883f6141 100644
--- a/src/worker.js
+++ b/src/worker.js
@@ -369,6 +369,7 @@ if (typeof require === 'function') {
 
   function globalEval(x) {
     global.require = require;
+    global.Module = Module;
     eval.call(null, x);
   }
 

From 5a8c86db5d955d45ff54b6b73d7d02e79b314f95 Mon Sep 17 00:00:00 2001
From: Alon Zakai <azakai@google.com>
Date: Wed, 30 Oct 2019 14:27:22 -0700
Subject: [PATCH 08/25] exit pthread properly on node [ci skip]

---
 src/library_pthread.js | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/library_pthread.js b/src/library_pthread.js
index aa67261e500c..571a3c3f1b45 100644
--- a/src/library_pthread.js
+++ b/src/library_pthread.js
@@ -937,6 +937,11 @@ console.log('  postedded');
     else PThread.threadExit(status);
 #if WASM_BACKEND
     // pthread_exit is marked noReturn, so we must not return from it.
+    if (ENVIRONMENT_HAS_NODE) {
+      // exit the pthread properly on node, as a normal JS exception will halt
+      // the entire application.
+      process.exit(status);
+    }
     throw 'pthread_exit';
 #endif
   },

From 4120e71bdb44936be19a2e88d6673d8667089d92 Mon Sep 17 00:00:00 2001
From: Alon Zakai <azakai@google.com>
Date: Wed, 30 Oct 2019 14:45:06 -0700
Subject: [PATCH 09/25] frist test

---
 tests/core/pthread/create.cpp | 62 +++++++++++++++++++++++++++++++++++
 tests/core/pthread/create.txt |  1 +
 tests/test_core.py            | 12 +++++++
 3 files changed, 75 insertions(+)
 create mode 100644 tests/core/pthread/create.cpp
 create mode 100644 tests/core/pthread/create.txt

diff --git a/tests/core/pthread/create.cpp b/tests/core/pthread/create.cpp
new file mode 100644
index 000000000000..0cfc1a4eb60e
--- /dev/null
+++ b/tests/core/pthread/create.cpp
@@ -0,0 +1,62 @@
+// Copyright 2019 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 <stdio.h>
+#include <stdlib.h>
+#include <pthread.h>
+#include <assert.h>
+#include <emscripten.h>
+
+#include <atomic>
+
+#define NUM_THREADS 2
+#define TOTAL 100
+
+static std::atomic<int> sum;
+
+void *ThreadMain(void *arg) {
+  for (int i = 0; i < TOTAL; i++) {
+    sum++;
+    // wait for a change, so we see interleaved processing.
+    int last = sum.load();
+    while (sum.load() == last) {}
+  }
+  pthread_exit((void*)TOTAL);
+}
+
+pthread_t thread[NUM_THREADS];
+
+void CreateThread(int i)
+{
+  pthread_attr_t attr;
+  pthread_attr_init(&attr);
+  pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
+  static int counter = 1;
+  int rc = pthread_create(&thread[i], &attr, ThreadMain, (void*)i);
+  assert(rc == 0);
+  pthread_attr_destroy(&attr);
+}
+
+void mainn() {
+  static int main_adds = 0;
+  int worker_adds = sum.load() - main_adds;
+  sum++;
+  main_adds++;
+  printf("main iter %d : %d\n", main_adds, worker_adds);
+  if (worker_adds == NUM_THREADS * TOTAL) {
+    emscripten_cancel_main_loop();
+    printf("done!\n");
+  }
+}
+
+int main() {
+  // Create initial threads.
+  for(int i = 0; i < NUM_THREADS; ++i) {
+    CreateThread(i);
+  }
+
+  // Node.js requires the event loop to be reached for the worker to start up.
+  emscripten_set_main_loop(mainn, 0, 0);
+}
diff --git a/tests/core/pthread/create.txt b/tests/core/pthread/create.txt
new file mode 100644
index 000000000000..3b17e24adf23
--- /dev/null
+++ b/tests/core/pthread/create.txt
@@ -0,0 +1 @@
+done!
diff --git a/tests/test_core.py b/tests/test_core.py
index f79efeebada3..89f27293b830 100644
--- a/tests/test_core.py
+++ b/tests/test_core.py
@@ -150,6 +150,13 @@ def decorated(self):
   return decorated
 
 
+def node_pthreads(f):
+  def decorated(self):
+    self.set_setting('USE_PTHREADS', 1)
+    f(self, js_engines=[NODE_JS + ['--experimental-wasm-threads', '--experimental-wasm-bulk-memory']])
+  return decorated
+
+
 # A simple check whether the compiler arguments cause optimization.
 def is_optimizing(args):
   return '-O' in str(args) and '-O0' not in args
@@ -8364,6 +8371,11 @@ def test_fpic_static(self):
     self.emcc_args.remove('-Werror')
     self.do_run_in_out_file_test('tests', 'core', 'test_hello_world')
 
+  @node_pthreads
+  def test_pthreads_hello(self, js_engines):
+    self.do_run_in_out_file_test('tests', 'core', 'pthread', 'create',
+                                 js_engines=js_engines)
+
 
 # Generate tests for everything
 def make_run(name, emcc_args, settings=None, env=None):

From 1d85ac00ef7a504512cb8b931267caa514323a98 Mon Sep 17 00:00:00 2001
From: Alon Zakai <azakai@google.com>
Date: Wed, 30 Oct 2019 14:45:44 -0700
Subject: [PATCH 10/25] TODO [ci skip]

---
 src/library_pthread.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/library_pthread.js b/src/library_pthread.js
index 571a3c3f1b45..8dca6fdcae89 100644
--- a/src/library_pthread.js
+++ b/src/library_pthread.js
@@ -434,7 +434,7 @@ var LibraryPThread = {
           };
 
           if (ENVIRONMENT_IS_NODE) {
-            worker.ref(); // XXX FIXME wat
+            worker.ref(); // XXX FIXME wat?
             worker.on('message', function(data) {
               worker.onmessage({ data: data });
             });

From b6003c2e9fd21ecc1a2a74150944411ebb786d69 Mon Sep 17 00:00:00 2001
From: Alon Zakai <azakai@google.com>
Date: Wed, 30 Oct 2019 14:47:26 -0700
Subject: [PATCH 11/25] testing

---
 tests/test_core.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tests/test_core.py b/tests/test_core.py
index 89f27293b830..24768cccf8de 100644
--- a/tests/test_core.py
+++ b/tests/test_core.py
@@ -153,6 +153,10 @@ def decorated(self):
 def node_pthreads(f):
   def decorated(self):
     self.set_setting('USE_PTHREADS', 1)
+    if not self.is_wasm_backend():
+      self.skipTest('node pthreads only supported on wasm backend')
+    if not self.get_setting('WASM'):
+      self.skipTest("pthreads doesn't work in non-wasm yet")
     f(self, js_engines=[NODE_JS + ['--experimental-wasm-threads', '--experimental-wasm-bulk-memory']])
   return decorated
 

From 9619833b794eeff620eaa52357f3a79e2b3cfa53 Mon Sep 17 00:00:00 2001
From: Alon Zakai <azakai@google.com>
Date: Wed, 30 Oct 2019 14:54:53 -0700
Subject: [PATCH 12/25] cleanups

---
 src/library_pthread.js     | 17 ++---------------
 src/runtime_init_memory.js |  9 +++++++--
 src/settings.js            |  5 -----
 src/worker.js              | 23 +----------------------
 4 files changed, 10 insertions(+), 44 deletions(-)

diff --git a/src/library_pthread.js b/src/library_pthread.js
index 8dca6fdcae89..a46249d9330a 100644
--- a/src/library_pthread.js
+++ b/src/library_pthread.js
@@ -433,21 +433,11 @@ var LibraryPThread = {
             err('pthread sent an error! ' + e.filename + ':' + e.lineno + ': ' + e.message);
           };
 
-          if (ENVIRONMENT_IS_NODE) {
-            worker.ref(); // XXX FIXME wat?
+          if (ENVIRONMENT_HAS_NODE) {
+            //worker.ref(); // TODO: investigate when we need this
             worker.on('message', function(data) {
               worker.onmessage({ data: data });
             });
-            worker.on('close', function(data) {
-              console.log('worker closed ..!?');
-            });
-            worker.on('exit', function(data) {
-              console.log('werker exited');
-            });
-            worker.on('online', function(data) {
-              console.log('workerah is online!!!1!');
-            });
-            // note: adding onerror seems to only hurt on node.js
           }
         }(worker));
       }  // for each worker
@@ -581,13 +571,10 @@ var LibraryPThread = {
         'offscreenCanvases': threadParams.offscreenCanvases,
 #endif
       };
-console.log('parent ready to run pthread');
     worker.runPthread = function() {
       // Ask the worker to start executing its pthread entry point function.
-console.log('  posting to run pthread');
       msg.time = performance.now();
       worker.postMessage(msg, threadParams.transferList);
-console.log('  postedded');
     };
     if (worker.loaded) {
       worker.runPthread();
diff --git a/src/runtime_init_memory.js b/src/runtime_init_memory.js
index d9645417d8ad..dfbcd92c46d2 100644
--- a/src/runtime_init_memory.js
+++ b/src/runtime_init_memory.js
@@ -31,8 +31,13 @@ if (ENVIRONMENT_IS_PTHREAD) {
 #endif
     });
 #if USE_PTHREADS
-    assert(wasmMemory.buffer instanceof SharedArrayBuffer, 'requested a shared WebAssembly.Memory but the returned buffer is not a SharedArrayBuffer, indicating that while the browser has SharedArrayBuffer it does not have WebAssembly threads support - you may need to set a flag');
-    // e.g. on node: --experimental-wasm-threads --experimental-wasm-bulk-memory
+    if (!(wasmMemory.buffer instanceof SharedArrayBuffer)) {
+      err('requested a shared WebAssembly.Memory but the returned buffer is not a SharedArrayBuffer, indicating that while the browser has SharedArrayBuffer it does not have WebAssembly threads support - you may need to set a flag');
+      if (ENVIRONMENT_HAS_NODE) {
+        console.log('(on node you may need: --experimental-wasm-threads --experimental-wasm-bulk-memory and also use a recent version)');
+      }
+      throw Error('bad memory');
+    }
 #endif
   }
 
diff --git a/src/settings.js b/src/settings.js
index a8f509d94f44..6401f0d5df96 100644
--- a/src/settings.js
+++ b/src/settings.js
@@ -1653,8 +1653,3 @@ var LEGACY_SETTINGS = [
   ['EMITTING_JS', [1], 'The new STANDALONE_WASM flag replaces this (replace EMITTING_JS=0 with STANDALONE_WASM=1)'],
   ['SKIP_STACK_IN_SMALL', [0, 1], 'SKIP_STACK_IN_SMALL is no longer needed as the backend can optimize it directly'],
 ];
-
-
-// ./emcc tests/pthread/test_pthread_create.cpp -s USE_PTHREADS -s PTHREAD_POOL_SIZE=1 -g
-// ~/Downloads/node-v13.0.0-nightly20190924e078e482c5-linux-x64/bin/node --experimental-wasm-threads --experimental-wasm-bulk-memory a.out.js
-
diff --git a/src/worker.js b/src/worker.js
index 155c52fb8e13..5c08c502f02c 100644
--- a/src/worker.js
+++ b/src/worker.js
@@ -39,19 +39,6 @@ function assert(condition, text) {
 }
 #endif
 
-// When error objects propagate from Web Worker to main thread, they lose helpful call stack and thread ID information, so print out errors early here,
-// before that happens.
-// Note that addEventListener may not exist on some environments, like node.
-if (typeof addEventListener === 'function') {
-  addEventListener('error', function(e) {
-    if (e.message.indexOf('SimulateInfiniteLoop') != -1) return e.preventDefault();
-
-    var errorSource = ' in ' + e.filename + ':' + e.lineno + ':' + e.colno;
-    console.error('Pthread ' + selfThreadId + ' uncaught exception' + (e.filename || e.lineno || e.colno ? errorSource : "") + ': ' + e.message + '. Error object:');
-    console.error(e.error);
-  });
-}
-
 function threadPrintErr() {
   var text = Array.prototype.slice.call(arguments).join(' ');
   console.error(text);
@@ -105,7 +92,6 @@ var wasmOffsetData;
 this.onmessage = function(e) {
   console.log('child gottt ' + [e, JSON.stringify(e), typeof e.data.urlOrBlob, e.data.urlOrBlob]);
   try {
-console.log('child command:', e.data.cmd);
     if (e.data.cmd === 'load') { // Preload command that is called once per worker to parse and load the Emscripten code.
 #if !WASM_BACKEND
       // Initialize the thread-local field(s):
@@ -158,9 +144,7 @@ console.log('child command:', e.data.cmd);
       });
 #else
       if (typeof e.data.urlOrBlob === 'string') {
-console.log('child loading scripts');
         importScripts(e.data.urlOrBlob);
-console.log('child loaded scripts');
       } else {
         var objectUrl = URL.createObjectURL(e.data.urlOrBlob);
         importScripts(objectUrl);
@@ -283,16 +267,13 @@ console.log('child loaded scripts');
 };
 
 // Node.js support
-if (typeof require === 'function') {
-
+if (typeof process === 'object' && typeof process.versions === 'object' && typeof process.versions.node === 'string') {
   console.log('child wants to live forever ' + typeof setInterval);
   setInterval(function() {
     console.log('time in worker...');
     throw 55;
   }, 2000);
 
-
-
   // Create as web-worker-like an environment as we can.
   self = {
     location: {
@@ -356,5 +337,3 @@ if (typeof require === 'function') {
     };
   }
 }
-console.log('workers first event loop is going away now');
-

From fb605f0677dcc03f46a97f9ec8fad286dbf5a14a Mon Sep 17 00:00:00 2001
From: Alon Zakai <azakai@google.com>
Date: Wed, 30 Oct 2019 14:56:47 -0700
Subject: [PATCH 13/25] more cleanup

---
 src/library_pthread.js |  2 +-
 src/worker.js          | 15 +--------------
 2 files changed, 2 insertions(+), 15 deletions(-)

diff --git a/src/library_pthread.js b/src/library_pthread.js
index a46249d9330a..49e769830cff 100644
--- a/src/library_pthread.js
+++ b/src/library_pthread.js
@@ -434,7 +434,7 @@ var LibraryPThread = {
           };
 
           if (ENVIRONMENT_HAS_NODE) {
-            //worker.ref(); // TODO: investigate when we need this
+            worker.ref(); // TODO: investigate when we need this
             worker.on('message', function(data) {
               worker.onmessage({ data: data });
             });
diff --git a/src/worker.js b/src/worker.js
index 5c08c502f02c..83faad96f2c7 100644
--- a/src/worker.js
+++ b/src/worker.js
@@ -289,24 +289,11 @@ if (typeof process === 'object' && typeof process.versions === 'object' && typeo
 
   var parentPort = nodeWorkerThreads.parentPort;
 
-  parentPort.ref(); // stay alive XXX?
-//process.exit(); XXX at the right time
+  parentPort.ref(); // TODO: investigate when we need this
 
   parentPort.on('message', function(data) {
     onmessage({ data: data });
   });
-            parentPort.on('close', function(data) {
-              console.log('parentPort closed ..!?');
-            });
-            parentPort.on('error', function(data) {
-              console.log('parentPort errored :(');
-            });
-            parentPort.on('exit', function(data) {
-              console.log('werker exited');
-            });
-            parentPort.on('online', function(data) {
-              console.log('parentPortah is online!!!1!');
-            });
 
   var nodeFS = require('fs');
 

From 1e2e871c6f736dbc6236ee1d17749106208222d1 Mon Sep 17 00:00:00 2001
From: Alon Zakai <azakai@google.com>
Date: Wed, 30 Oct 2019 14:57:47 -0700
Subject: [PATCH 14/25] revert

---
 tests/pthread/test_pthread_create.cpp | 141 ++++++++++++++------------
 1 file changed, 75 insertions(+), 66 deletions(-)

diff --git a/tests/pthread/test_pthread_create.cpp b/tests/pthread/test_pthread_create.cpp
index a123ac28a472..e52f11d0ad6d 100644
--- a/tests/pthread/test_pthread_create.cpp
+++ b/tests/pthread/test_pthread_create.cpp
@@ -10,51 +10,49 @@
 #include <emscripten/threading.h>
 #include <assert.h>
 
-#define NUM_THREADS 1
+#define NUM_THREADS 8
 
 int fib(int n)
 {
-  if (n <= 0) return 0;
-  if (n == 1) return 1;
-  return fib(n-1) + fib(n-2);
+	if (n <= 0) return 0;
+	if (n == 1) return 1;
+	return fib(n-1) + fib(n-2);
 }
 
 unsigned int global_shared_data[NUM_THREADS];
 
 void *ThreadMain(void *arg)
 {
-printf("ThreadMain! %d\n", (int)arg);
-
-  int idx = (int)arg;
-  unsigned int param = global_shared_data[idx];
+	int idx = (int)arg;
+	unsigned int param = global_shared_data[idx];
 
 #define N 100
 
-  EM_ASM(err('Thread idx '+$0+': sorting ' + $1 + ' numbers with param ' + $2 + '.'), idx, N, param);
-
-  unsigned int n[N];
-  for(unsigned int i = 0; i < N; ++i)
-    n[i] = (i + param) % N; // Create a shifted increasing sequence of numbers [0, N-1[
-
-  // Sort the sequence to ordered [0, N[
-  for(unsigned int i = 0; i < N; ++i)
-    for(unsigned int j = i; j < N; ++j)
-    {
-      if (n[i] > n[j])
-      {
-        unsigned int t = n[i];
-        n[i] = n[j];
-        n[j] = t;
-      }
-    }
-  // Ensure all elements are in place.
-  int numGood = 0;
-  for(unsigned int i = 0; i < N; ++i)
-    if (n[i] == i) ++numGood;
-    else EM_ASM(err('n['+$0+']='+$1), i, n[i]);
-
-  EM_ASM(out('Thread idx ' + $0 + ' with param '+$1+': all done with result '+$2+'.'), idx, param, numGood);
-  pthread_exit((void*)numGood);
+	EM_ASM(err('Thread idx '+$0+': sorting ' + $1 + ' numbers with param ' + $2 + '.'), idx, N, param);
+
+	unsigned int n[N];
+	for(unsigned int i = 0; i < N; ++i)
+		n[i] = (i + param) % N; // Create a shifted increasing sequence of numbers [0, N-1[
+
+	// Sort the sequence to ordered [0, N[
+	for(unsigned int i = 0; i < N; ++i)
+		for(unsigned int j = i; j < N; ++j)
+		{
+			if (n[i] > n[j])
+			{
+				unsigned int t = n[i];
+				n[i] = n[j];
+				n[j] = t;
+			}
+		}
+	// Ensure all elements are in place.
+	int numGood = 0;
+	for(unsigned int i = 0; i < N; ++i)
+		if (n[i] == i) ++numGood;
+		else EM_ASM(err('n['+$0+']='+$1), i, n[i]);
+
+	EM_ASM(out('Thread idx ' + $0 + ' with param '+$1+': all done with result '+$2+'.'), idx, param, numGood);
+	pthread_exit((void*)numGood);
 }
 
 pthread_t thread[NUM_THREADS];
@@ -63,43 +61,54 @@ int numThreadsToCreate = 1000;
 
 void CreateThread(int i)
 {
-  pthread_attr_t attr;
-  pthread_attr_init(&attr);
-  pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
-  static int counter = 1;
-  global_shared_data[i] = (counter++ * 12141231) & 0x7FFFFFFF; // Arbitrary random'ish data for perturbing the sort for this thread task.
-//  EM_ASM(out('Main: Creating thread idx ' + $0 + ' (param ' + $1 + ')'), i, global_shared_data[i]);
-  int rc = pthread_create(&thread[i], &attr, ThreadMain, (void*)i);
-  assert(rc == 0);
-  pthread_attr_destroy(&attr);
-}
-
-void mainn() {
-  printf("main iter\n");
+	pthread_attr_t attr;
+	pthread_attr_init(&attr);
+	pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
+	static int counter = 1;
+	global_shared_data[i] = (counter++ * 12141231) & 0x7FFFFFFF; // Arbitrary random'ish data for perturbing the sort for this thread task.
+//	EM_ASM(out('Main: Creating thread idx ' + $0 + ' (param ' + $1 + ')'), i, global_shared_data[i]);
+	int rc = pthread_create(&thread[i], &attr, ThreadMain, (void*)i);
+	assert(rc == 0);
+	pthread_attr_destroy(&attr);
 }
 
 int main()
 {
-printf("mainne1\n");
-  if (!emscripten_has_threading_support())
-  {
+	if (!emscripten_has_threading_support())
+	{
+#ifdef REPORT_RESULT
+		REPORT_RESULT(0);
+#endif
+		printf("Skipped: Threading is not supported.\n");
+		return 0;
+	}
+
+	// Create initial threads.
+	for(int i = 0; i < NUM_THREADS; ++i)
+		CreateThread(i);
+
+	// Join all threads and create more.
+        while (numThreadsToCreate > 0)
+        {
+		for(int i = 0; i < NUM_THREADS; ++i)
+		{
+			if (thread[i])
+			{
+				int status;
+				int rc = pthread_join(thread[i], (void**)&status);
+				assert(rc == 0);
+				EM_ASM(err('Main: Joined thread idx ' + $0 + ' (param ' + $1 + ') with status ' + $2), i, global_shared_data[i], (int)status);
+				assert(status == N);
+				thread[i] = 0;
+				if (numThreadsToCreate > 0)
+				{
+					--numThreadsToCreate;
+					CreateThread(i);
+				}
+			}
+		}
+	}
 #ifdef REPORT_RESULT
-    REPORT_RESULT(0);
+	REPORT_RESULT(0);
 #endif
-    printf("Skipped: Threading is not supported.\n");
-    return 0;
-  }
-printf("mainne2\n");
-
-  // Create initial threads.
-  for(int i = 0; i < NUM_THREADS; ++i) {
-printf("mainne3\n");
-    CreateThread(i);
-  }
-printf("mainne4\n");
-
-  // synchronous here would not let the worker start -
-  // the postMessage is only sent at the end of the event
-  // loop it seems :(
-  emscripten_set_main_loop(mainn, 1, 1);
 }

From fed61a364e69fd1253654b225909ab338729d5df Mon Sep 17 00:00:00 2001
From: Alon Zakai <azakai@google.com>
Date: Wed, 30 Oct 2019 16:04:45 -0700
Subject: [PATCH 15/25] fix closure

---
 src/node_shell_read.js | 5 -----
 src/shell.js           | 5 +++++
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/node_shell_read.js b/src/node_shell_read.js
index 6045597c43e6..6a1c07872a54 100644
--- a/src/node_shell_read.js
+++ b/src/node_shell_read.js
@@ -1,8 +1,3 @@
-  // Expose functionality in the same simple way that the shells work
-  // Note that we pollute the global namespace here, otherwise we break in node
-  var nodeFS;
-  var nodePath;
-
   read_ = function shell_read(filename, binary) {
     var ret;
 #if SUPPORT_BASE64_EMBEDDING
diff --git a/src/shell.js b/src/shell.js
index 2e5bbdb2609d..9008720d2e2b 100644
--- a/src/shell.js
+++ b/src/shell.js
@@ -121,6 +121,11 @@ var read_,
     readBinary,
     setWindowTitle;
 
+#if ENVIRONMENT_MAY_BE_NODE
+var nodeFS;
+var nodePath;
+#endif
+
 #if ENVIRONMENT_MAY_BE_NODE
 if (ENVIRONMENT_IS_NODE) {
 #if ENVIRONMENT

From 399e9ca7a0f81d1714a396e3727544dd301b02b5 Mon Sep 17 00:00:00 2001
From: Alon Zakai <azakai@google.com>
Date: Wed, 30 Oct 2019 16:48:50 -0700
Subject: [PATCH 16/25] fix

---
 src/shell.js | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/src/shell.js b/src/shell.js
index 9008720d2e2b..b4baa9371209 100644
--- a/src/shell.js
+++ b/src/shell.js
@@ -276,17 +276,19 @@ if (ENVIRONMENT_IS_WEB || ENVIRONMENT_IS_WORKER) {
 
   // Differentiate the Web Worker from the Node Worker case, as reading must
   // be done differently.
-  if (!ENVIRONMENT_HAS_NODE) {
+#if USE_PTHREADS
+  if (ENVIRONMENT_HAS_NODE) {
 
-#include "web_or_worker_shell_read.js"
+#include "node_shell_read.js"
 
-  } else {
+  } else
+#endif
+  {
 
-#include "node_shell_read.js"
+#include "web_or_worker_shell_read.js"
 
   }
 
-
   setWindowTitle = function(title) { document.title = title };
 } else
 #endif // ENVIRONMENT_MAY_BE_WEB || ENVIRONMENT_MAY_BE_WORKER

From b5245d0026f4f5a5339f5b0fe7c1c681e156eb29 Mon Sep 17 00:00:00 2001
From: Alon Zakai <azakai@google.com>
Date: Wed, 30 Oct 2019 17:11:01 -0700
Subject: [PATCH 17/25] fix

---
 src/compiler.js | 7 ++++++-
 src/shell.js    | 4 ++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/compiler.js b/src/compiler.js
index 253336ec87b8..99f942bca29a 100644
--- a/src/compiler.js
+++ b/src/compiler.js
@@ -193,10 +193,15 @@ Runtime.QUANTUM_SIZE = 4;
 
 var ENVIRONMENTS = ENVIRONMENT.split(',');
 ENVIRONMENT_MAY_BE_WEB    = !ENVIRONMENT || ENVIRONMENTS.indexOf('web') >= 0;
-ENVIRONMENT_MAY_BE_WORKER = !ENVIRONMENT || ENVIRONMENTS.indexOf('worker') >= 0;
 ENVIRONMENT_MAY_BE_NODE   = !ENVIRONMENT || ENVIRONMENTS.indexOf('node') >= 0;
 ENVIRONMENT_MAY_BE_SHELL  = !ENVIRONMENT || ENVIRONMENTS.indexOf('shell') >= 0;
 
+// The worker case also includes Node.js workers when pthreads are
+// enabled and Node.js is being built for. Node.js workers are detected as
+// a combination of ENVIRONMENT_IS_WORKER and ENVIRONMENT_HAS_NODE.
+ENVIRONMENT_MAY_BE_WORKER = !ENVIRONMENT || ENVIRONMENTS.indexOf('worker') >= 0 ||
+                            (ENVIRONMENT_MAY_BE_NODE && USE_PTHREADS);
+
 if (ENVIRONMENT && !(ENVIRONMENT_MAY_BE_WEB || ENVIRONMENT_MAY_BE_WORKER || ENVIRONMENT_MAY_BE_NODE || ENVIRONMENT_MAY_BE_SHELL)) {
   throw 'Invalid environment specified in "ENVIRONMENT": ' + ENVIRONMENT + '. Should be one of: web, worker, node, shell.';
 }
diff --git a/src/shell.js b/src/shell.js
index b4baa9371209..9c41d68b5997 100644
--- a/src/shell.js
+++ b/src/shell.js
@@ -244,6 +244,10 @@ if (ENVIRONMENT_IS_SHELL) {
   }
 } else
 #endif // ENVIRONMENT_MAY_BE_SHELL
+
+// Note that this includes Node.js workers when relevant (pthreads is enabled).
+// Node.js workers are detected as a combination of ENVIRONMENT_IS_WORKER and
+// ENVIRONMENT_HAS_NODE.
 #if ENVIRONMENT_MAY_BE_WEB || ENVIRONMENT_MAY_BE_WORKER
 if (ENVIRONMENT_IS_WEB || ENVIRONMENT_IS_WORKER) {
   if (ENVIRONMENT_IS_WORKER) { // Check worker, not web, since window could be polyfilled

From 43c180a8b0f873dd2212aa718acef79b8d9a266b Mon Sep 17 00:00:00 2001
From: Alon Zakai <azakai@google.com>
Date: Wed, 30 Oct 2019 17:23:27 -0700
Subject: [PATCH 18/25] cleanup

---
 src/worker.js | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/src/worker.js b/src/worker.js
index 83faad96f2c7..6ecba1b8f159 100644
--- a/src/worker.js
+++ b/src/worker.js
@@ -90,7 +90,6 @@ var wasmOffsetData;
 #endif
 
 this.onmessage = function(e) {
-  console.log('child gottt ' + [e, JSON.stringify(e), typeof e.data.urlOrBlob, e.data.urlOrBlob]);
   try {
     if (e.data.cmd === 'load') { // Preload command that is called once per worker to parse and load the Emscripten code.
 #if !WASM_BACKEND
@@ -266,18 +265,13 @@ this.onmessage = function(e) {
   }
 };
 
+#if ENVIRONMENT_MAY_BE_NODE
 // Node.js support
 if (typeof process === 'object' && typeof process.versions === 'object' && typeof process.versions.node === 'string') {
-  console.log('child wants to live forever ' + typeof setInterval);
-  setInterval(function() {
-    console.log('time in worker...');
-    throw 55;
-  }, 2000);
-
   // Create as web-worker-like an environment as we can.
   self = {
     location: {
-      href: __filename // XXX wat
+      href: __filename
     }
   };
 
@@ -298,7 +292,6 @@ if (typeof process === 'object' && typeof process.versions === 'object' && typeo
   var nodeFS = require('fs');
 
   var nodeRead = function(filename) {
-    // TODO: convert to absolute path?
     return nodeFS.readFileSync(filename).toString();
   };
 
@@ -324,3 +317,4 @@ if (typeof process === 'object' && typeof process.versions === 'object' && typeo
     };
   }
 }
+#endif // ENVIRONMENT_MAY_BE_NODE

From da9d89eb8668d608023c41def1cfd41204e96980 Mon Sep 17 00:00:00 2001
From: Alon Zakai <azakai@google.com>
Date: Thu, 31 Oct 2019 15:20:52 -0700
Subject: [PATCH 19/25] feedback

---
 ChangeLog.md           | 1 +
 src/library_pthread.js | 1 -
 src/worker.js          | 2 --
 3 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/ChangeLog.md b/ChangeLog.md
index 605820c5e28a..304c4b2463ba 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -24,6 +24,7 @@ Current Trunk
    `ALLOW_BLOCKING_ON_MAIN_THREAD` is unset then the warning is an error.
  - Add `pthread_tryjoin_np`, which is a POSIX API similar to `pthread_join`
    but without blocking.
+ - Add support for pthreads in Node.js, using Node Workers. See #9745
 
 v1.39.1: 10/30/2019
 -------------------
diff --git a/src/library_pthread.js b/src/library_pthread.js
index 8cc0b23e3cf3..6e18e64d0f2b 100644
--- a/src/library_pthread.js
+++ b/src/library_pthread.js
@@ -434,7 +434,6 @@ var LibraryPThread = {
           };
 
           if (ENVIRONMENT_HAS_NODE) {
-            worker.ref(); // TODO: investigate when we need this
             worker.on('message', function(data) {
               worker.onmessage({ data: data });
             });
diff --git a/src/worker.js b/src/worker.js
index 6ecba1b8f159..48f6f0a55437 100644
--- a/src/worker.js
+++ b/src/worker.js
@@ -283,8 +283,6 @@ if (typeof process === 'object' && typeof process.versions === 'object' && typeo
 
   var parentPort = nodeWorkerThreads.parentPort;
 
-  parentPort.ref(); // TODO: investigate when we need this
-
   parentPort.on('message', function(data) {
     onmessage({ data: data });
   });

From ec991f8256d0fb5dbdce7327d92b44dcc49c37bc Mon Sep 17 00:00:00 2001
From: Alon Zakai <azakai@google.com>
Date: Thu, 31 Oct 2019 15:33:08 -0700
Subject: [PATCH 20/25] Nicer warning

---
 src/shell.js | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/shell.js b/src/shell.js
index 9c41d68b5997..6ae65ede4028 100644
--- a/src/shell.js
+++ b/src/shell.js
@@ -171,7 +171,13 @@ if (ENVIRONMENT_IS_NODE) {
   Module['inspect'] = function () { return '[Emscripten Module object]'; };
 
 #if USE_PTHREADS
-  var nodeWorkerThreads = require('worker_threads');
+  var nodeWorkerThreads;
+  try {
+    nodeWorkerThreads = require('worker_threads');
+  } catch (e) {
+    console.error('The "worker_threads" module is not supported in this node.js build - perhaps a newer version is needed?');
+    throw e;
+  }
   Worker = nodeWorkerThreads.Worker;
 
   // Polyfill the performance object, which emscripten pthreads support

From b6cbb22e9415d2fd4e7c41869664fffe160069d3 Mon Sep 17 00:00:00 2001
From: Alon Zakai <azakai@google.com>
Date: Thu, 31 Oct 2019 15:39:23 -0700
Subject: [PATCH 21/25] More event handling

---
 src/library_pthread.js | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/library_pthread.js b/src/library_pthread.js
index 6e18e64d0f2b..522914e47c29 100644
--- a/src/library_pthread.js
+++ b/src/library_pthread.js
@@ -437,6 +437,12 @@ var LibraryPThread = {
             worker.on('message', function(data) {
               worker.onmessage({ data: data });
             });
+            worker.on('error', function(data) {
+              worker.onerror(data.err);
+            });
+            worker.on('exit', function(data) {
+              console.log('worker exited - TODO: update the worker queue?');
+            });
           }
         }(worker));
       }  // for each worker

From 1073fa595b01f11db84727a114f98ac057799da9 Mon Sep 17 00:00:00 2001
From: Alon Zakai <azakai@google.com>
Date: Thu, 31 Oct 2019 16:29:31 -0700
Subject: [PATCH 22/25] feedback

---
 src/shell.js                  |  2 --
 tests/core/pthread/create.cpp | 12 ++++++++++--
 tests/test_core.py            | 12 +++++++++---
 3 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/src/shell.js b/src/shell.js
index 6ae65ede4028..fe772f9551b6 100644
--- a/src/shell.js
+++ b/src/shell.js
@@ -124,9 +124,7 @@ var read_,
 #if ENVIRONMENT_MAY_BE_NODE
 var nodeFS;
 var nodePath;
-#endif
 
-#if ENVIRONMENT_MAY_BE_NODE
 if (ENVIRONMENT_IS_NODE) {
 #if ENVIRONMENT
 #if ASSERTIONS
diff --git a/tests/core/pthread/create.cpp b/tests/core/pthread/create.cpp
index 0cfc1a4eb60e..b65de1e560e4 100644
--- a/tests/core/pthread/create.cpp
+++ b/tests/core/pthread/create.cpp
@@ -46,8 +46,12 @@ void mainn() {
   main_adds++;
   printf("main iter %d : %d\n", main_adds, worker_adds);
   if (worker_adds == NUM_THREADS * TOTAL) {
-    emscripten_cancel_main_loop();
     printf("done!\n");
+#ifndef POOL
+    emscripten_cancel_main_loop();
+#else
+    exit(0);
+#endif
   }
 }
 
@@ -57,6 +61,10 @@ int main() {
     CreateThread(i);
   }
 
-  // Node.js requires the event loop to be reached for the worker to start up.
+  // Without a pool, the event loop must be reached for the worker to start up.
+#ifndef POOL
   emscripten_set_main_loop(mainn, 0, 0);
+#else
+  while (1) mainn();
+#endif
 }
diff --git a/tests/test_core.py b/tests/test_core.py
index 00ee08f353e7..93ff610888b3 100644
--- a/tests/test_core.py
+++ b/tests/test_core.py
@@ -8392,10 +8392,16 @@ def test_fpic_static(self):
     self.do_run_in_out_file_test('tests', 'core', 'test_hello_world')
 
   @node_pthreads
-  def test_pthreads_hello(self, js_engines):
-    self.do_run_in_out_file_test('tests', 'core', 'pthread', 'create',
-                                 js_engines=js_engines)
+  def test_pthreads_create(self, js_engines):
+    def test():
+      self.do_run_in_out_file_test('tests', 'core', 'pthread', 'create',
+                                   js_engines=js_engines)
+    test()
 
+    # with a pool, we can synchronously depend on workers being available
+    self.set_setting('PTHREAD_POOL_SIZE', '2')
+    self.emcc_args += ['-DPOOL']
+    test()
 
 # Generate tests for everything
 def make_run(name, emcc_args, settings=None, env=None):

From 8354dff73d08d1e32ce1c600fd71d6b2d6f7fbf8 Mon Sep 17 00:00:00 2001
From: Alon Zakai <azakai@google.com>
Date: Thu, 31 Oct 2019 16:51:43 -0700
Subject: [PATCH 23/25] flake8

---
 tests/test_core.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tests/test_core.py b/tests/test_core.py
index 93ff610888b3..53bfd7261da0 100644
--- a/tests/test_core.py
+++ b/tests/test_core.py
@@ -8403,6 +8403,7 @@ def test():
     self.emcc_args += ['-DPOOL']
     test()
 
+
 # Generate tests for everything
 def make_run(name, emcc_args, settings=None, env=None):
   if env is None:

From fe6edc9b86d165338e3083ac8f145f9e737fc33b Mon Sep 17 00:00:00 2001
From: Alon Zakai <azakai@google.com>
Date: Fri, 1 Nov 2019 13:39:31 -0700
Subject: [PATCH 24/25] text

---
 src/compiler.js | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/compiler.js b/src/compiler.js
index 99f942bca29a..3babfb7b99e7 100644
--- a/src/compiler.js
+++ b/src/compiler.js
@@ -197,8 +197,9 @@ ENVIRONMENT_MAY_BE_NODE   = !ENVIRONMENT || ENVIRONMENTS.indexOf('node') >= 0;
 ENVIRONMENT_MAY_BE_SHELL  = !ENVIRONMENT || ENVIRONMENTS.indexOf('shell') >= 0;
 
 // The worker case also includes Node.js workers when pthreads are
-// enabled and Node.js is being built for. Node.js workers are detected as
-// a combination of ENVIRONMENT_IS_WORKER and ENVIRONMENT_HAS_NODE.
+// enabled and Node.js is one of the supported environments for the build to
+// run on. Node.js workers are detected as a combination of
+// ENVIRONMENT_IS_WORKER and ENVIRONMENT_HAS_NODE.
 ENVIRONMENT_MAY_BE_WORKER = !ENVIRONMENT || ENVIRONMENTS.indexOf('worker') >= 0 ||
                             (ENVIRONMENT_MAY_BE_NODE && USE_PTHREADS);
 

From 485832442b9556077b89df012f99c699e3a50ba1 Mon Sep 17 00:00:00 2001
From: Alon Zakai <azakai@google.com>
Date: Fri, 1 Nov 2019 13:39:49 -0700
Subject: [PATCH 25/25] use perf_hooks.performance, and use it for all threads

---
 src/shell.js | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/src/shell.js b/src/shell.js
index fe772f9551b6..75a81a683dcc 100644
--- a/src/shell.js
+++ b/src/shell.js
@@ -177,16 +177,6 @@ if (ENVIRONMENT_IS_NODE) {
     throw e;
   }
   Worker = nodeWorkerThreads.Worker;
-
-  // Polyfill the performance object, which emscripten pthreads support
-  // depends on for good timing.
-  if (typeof performance === 'undefined') {
-    performance = {
-      now: function() {
-        return Date.now();
-      }
-    };
-  }
 #endif
 
 } else
@@ -306,6 +296,16 @@ if (ENVIRONMENT_IS_WEB || ENVIRONMENT_IS_WORKER) {
 #endif // ASSERTIONS
 }
 
+#if ENVIRONMENT_MAY_BE_NODE && USE_PTHREADS
+if (ENVIRONMENT_HAS_NODE) {
+  // Polyfill the performance object, which emscripten pthreads support
+  // depends on for good timing.
+  if (typeof performance === 'undefined') {
+    performance = require('perf_hooks').performance;
+  }
+}
+#endif
+
 // Set up the out() and err() hooks, which are how we can print to stdout or
 // stderr, respectively.
 {{{ makeModuleReceiveWithVar('out', 'print',    'console.log.bind(console)',  true) }}}