Pthreads support in node environemnt

[hlolli]

I see that a comment on pthread issue has been removed so I will describe what I'm struggling with

So I'm compiling with this command

emcc -v -O3 -g4 -DINIT_STATIC_MODULES=0 -s USE_PTHREADS=1 -s PTHREAD_POOL_SIZE=16  -s WASM=1 -s ASSERTIONS=1 -s "BINARYEN_METHOD='native-wasm'" -s RESERVED_FUNCTION_POINTERS=1 -s TOTAL_MEMORY=268435456 -s NO_EXIT_RUNTIME=0 -s EXTRA_EXPORTED_RUNTIME_METHODS="['FS', 'cwrap', 'ccall']" -s EXPORTED_FUNCTIONS="['_strlen', '_CsoundObj_closeAudioOut', '_CsoundObj_compileCSD', '_CsoundObj_compileOrc', '_CsoundObj_destroy', '_CsoundObj_evaluateCode', '_CsoundObj_getControlChannel', '_CsoundObj_getInputBuffer', '_CsoundObj_getInputChannelCount', '_CsoundObj_getKsmps', '_CsoundObj_getOutputBuffer', '_CsoundObj_getOutputChannelCount', '_CsoundObj_getTable', '_CsoundObj_getTableLength', '_CsoundObj_getZerodBFS', '_CsoundObj_new', '_CsoundObj_openAudioOut', '_CsoundObj_pause', '_CsoundObj_performKsmps', '_CsoundObj_play', '_CsoundObj_prepareRT', '_CsoundObj_pushMidiMessage', '_CsoundObj_readScore' , '_CsoundObj_inputMessage', '_CsoundObj_inputMessageAsync', '_CsoundObj_render' , '_CsoundObj_reset', '_CsoundObj_setControlChannel', '_CsoundObj_setMidiCallbacks', '_CsoundObj_setOption', '_CsoundObj_setOutputChannelCallback', '_CsoundObj_getScoreTime', '_CsoundObj_setStringChannel', '_CsoundObj_setTable']" CsoundObj.bc FileList.bc libcsound.a ../deps/libsndfile-1.0.25/libsndfile-wasm.a -o libcsound.js

when running this output I get

TypeError: [object Uint32Array] is not an integer shared typed array.
    at Atomics.store (<anonymous>)
    at Object.initMainThreadBlock (/home/hlolli/csound/csound-wasm/node_modules/libcsound/libcsound.js:1828:17)
    at Object.<anonymous> (/home/hlolli/csound/csound-wasm/node_modules/libcsound/libcsound.js:7673:38)
    at Module._compile (module.js:662:30)
    at Object.Module._extensions..js (module.js:673:10)
    at Module.load (module.js:575:32)
    at tryModuleLoad (module.js:515:12)
    at Function.Module._load (module.js:507:3)
    at Module.require (module.js:606:17)
    at require (internal/module.js:11:18)

what's happening is that the buffer given to the Uint32Array is not of type SharedArrayBuffer, so when ensureing that

function updateGlobalBufferViews() {
  if (!(buffer instanceof SharedArrayBuffer)) {
    buffer = new SharedArrayBuffer(buffer.byteLength );
  }
  Module['HEAP8'] = HEAP8 = new Int8Array(buffer);
  Module['HEAP16'] = HEAP16 = new Int16Array(buffer);
  Module['HEAP32'] = HEAP32 = new Int32Array(buffer);
  Module['HEAPU8'] = HEAPU8 = new Uint8Array(buffer);
  Module['HEAPU16'] = HEAPU16 = new Uint16Array(buffer);
  Module['HEAPU32'] = HEAPU32 = new Uint32Array(buffer);
  Module['HEAPF32'] = HEAPF32 = new Float32Array(buffer);
  Module['HEAPF64'] = HEAPF64 = new Float64Array(buffer);
}

I'm welcomed with another error

failed to asynchronously prepare wasm: CompileError: WasmCompile: Compiling wasm function #4442:_sbrk failed: invalid block arity > 1 @+2443509
CompileError: WasmCompile: Compiling wasm function #4442:_sbrk failed: invalid block arity > 1 @+2443509
    at /home/hlolli/csound/csound-wasm/node_modules/libcsound/libcsound.js:1612:28
    at <anonymous>
    at process._tickCallback (internal/process/next_tick.js:160:7)
    at Function.Module.runMain (module.js:705:11)
    at startup (bootstrap_node.js:193:16)
    at bootstrap_node.js:665:3
CompileError: WasmCompile: Compiling wasm function #4442:_sbrk failed: invalid block arity > 1 @+2443509
    at /home/hlolli/csound/csound-wasm/node_modules/libcsound/libcsound.js:1612:28
    at <anonymous>
    at process._tickCallback (internal/process/next_tick.js:160:7)
    at Function.Module.runMain (module.js:705:11)
    at startup (bootstrap_node.js:193:16)
    at bootstrap_node.js:665:3
node.js exiting due to unhandled promise rejection

I'm running on node v9.6.1, emsdk incoming compiled yesterday
add that this all works great then -s USE_PTHREADS=1 is not present. I'm hopeful to see pthread support available in coming days/weeks.

[dschuff]

Pthread support is currently built on top of web workers and SharedArrayBuffer. As far as I know, nodejs does not support SharedArrayBuffer, or any other mechanism to share memory. Do you know if I'm wrong about that, or if it's on the roadmap?

[hlolli]

@dschuff Nodejs 9x supports atomics and SharedArrayBuffer by default, workers even longer.

ps. workers would be in node the cluster api to be accurate.

[timkerchmar]

WebAssembly/binaryen#1419 is related, depending upon whether or not one uses USE_PTHREAD=1 or USE_PTHREAD=2

Tested on Chrome Version 66.0.3359.181 (Official Build) (64-bit) OSX 10.13.4 (17E202) with SharedArrayBuffers enabled.

[kripken]

Closing as this appears to be the same as #6567 and there is more discussion there.