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chromium / external / github.com / emscripten-core / emscripten.git / b7267b58da559aadd9670237ec7f2626bfed1108 / . / src / library_pthread.js
blob: 4bd28bd6fecd9220fd66951790ce52b0135de71e [file] [log] [blame]
/**
* @license
* Copyright 2015 The Emscripten Authors
* SPDX-License-Identifier: MIT
*/
var LibraryPThread = {
$PThread__postset: 'if (!ENVIRONMENT_IS_PTHREAD) PThread.initMainThreadBlock();',
$PThread__deps: ['_emscripten_thread_init',
'emscripten_register_main_browser_thread_id',
'$ERRNO_CODES', 'emscripten_futex_wake', '$killThread',
'$cancelThread', '$cleanupThread',
#if USE_ASAN || USE_LSAN
, '$withBuiltinMalloc'
#endif
],
$PThread: {
// Contains all Workers that are idle/unused and not currently hosting an
// executing pthread. Unused Workers can either be pooled up before page
// startup, but also when a pthread quits, its hosting Worker is not
// terminated, but is returned to this pool as an optimization so that
// starting the next thread is faster.
unusedWorkers: [],
// Contains all Workers that are currently hosting an active pthread.
runningWorkers: [],
tlsInitFunctions: [],
initMainThreadBlock: function() {
#if ASSERTIONS
assert(!ENVIRONMENT_IS_PTHREAD);
#endif
#if PTHREAD_POOL_SIZE
var pthreadPoolSize = {{{ PTHREAD_POOL_SIZE }}};
// Start loading up the Worker pool, if requested.
for (var i = 0; i < pthreadPoolSize; ++i) {
PThread.allocateUnusedWorker();
}
#endif
},
initRuntime: function() {
#if USE_ASAN || USE_LSAN
// When sanitizers are enabled, malloc is normally instrumented to call
// sanitizer code that checks some things about pthreads. As we are just
// setting up the main thread here, and are not ready for such calls,
// call malloc directly.
withBuiltinMalloc(function () {
#endif
var tb = _malloc({{{ C_STRUCTS.pthread.__size__ }}});
for (var i = 0; i < {{{ C_STRUCTS.pthread.__size__ }}}/4; ++i) HEAPU32[tb/4+i] = 0;
// The pthread struct has a field that points to itself - this is used as
// a magic ID to detect whether the pthread_t structure is 'alive'.
{{{ makeSetValue('tb', C_STRUCTS.pthread.self, 'tb', 'i32') }}};
// pthread struct robust_list head should point to itself.
var headPtr = tb + {{{ C_STRUCTS.pthread.robust_list }}};
{{{ makeSetValue('headPtr', 0, 'headPtr', 'i32') }}};
// Allocate memory for thread-local storage.
var tlsMemory = _malloc({{{ cDefine('PTHREAD_KEYS_MAX') * 4 }}});
for (var i = 0; i < {{{ cDefine('PTHREAD_KEYS_MAX') }}}; ++i) HEAPU32[tlsMemory/4+i] = 0;
Atomics.store(HEAPU32, (tb + {{{ C_STRUCTS.pthread.tsd }}} ) >> 2, tlsMemory); // Init thread-local-storage memory array.
Atomics.store(HEAPU32, (tb + {{{ C_STRUCTS.pthread.tid }}} ) >> 2, tb); // Main thread ID.
#if PTHREADS_PROFILING
PThread.createProfilerBlock(tb);
PThread.setThreadName(tb, "Browser main thread");
PThread.setThreadStatus(tb, {{{ cDefine('EM_THREAD_STATUS_RUNNING') }}});
#endif
// Pass the thread address to the native code where they stored in wasm
// globals which act as a form of TLS. Global constructors trying
// to access this value will read the wrong value, but that is UB anyway.
__emscripten_thread_init(tb, /*isMainBrowserThread=*/!ENVIRONMENT_IS_WORKER, /*isMainRuntimeThread=*/1);
_emscripten_register_main_browser_thread_id(tb);
#if ASSERTIONS
PThread.mainRuntimeThread = true;
#endif
#if USE_ASAN || USE_LSAN
});
#endif
},
initWorker: function() {
#if USE_CLOSURE_COMPILER
// worker.js is not compiled together with us, and must access certain
// things.
PThread['receiveObjectTransfer'] = PThread.receiveObjectTransfer;
PThread['threadInit'] = PThread.threadInit;
PThread['threadCancel'] = PThread.threadCancel;
PThread['threadExit'] = PThread.threadExit;
PThread['setExitStatus'] = PThread.setExitStatus;
#endif
},
// 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) {
var profilerBlock = _malloc({{{ C_STRUCTS.thread_profiler_block.__size__ }}});
Atomics.store(HEAPU32, (pthreadPtr + {{{ C_STRUCTS.pthread.profilerBlock }}} ) >> 2, profilerBlock);
// Zero fill contents at startup.
for (var i = 0; i < {{{ C_STRUCTS.thread_profiler_block.__size__ }}}; i += 4) Atomics.store(HEAPU32, (profilerBlock + i) >> 2, 0);
Atomics.store(HEAPU32, (profilerBlock + {{{ C_STRUCTS.thread_profiler_block.currentStatusStartTime }}} ) >> 2, performance.now());
},
// Sets the current thread status, but only if it was in the given expected state before. This is used
// to allow high-level control flow "override" the thread status before low-level (futex wait) operations set it.
setThreadStatusConditional: function(pthreadPtr, expectedStatus, newStatus) {
var profilerBlock = Atomics.load(HEAPU32, (pthreadPtr + {{{ C_STRUCTS.pthread.profilerBlock }}} ) >> 2);
if (!profilerBlock) return;
var prevStatus = Atomics.load(HEAPU32, (profilerBlock + {{{ C_STRUCTS.thread_profiler_block.threadStatus }}} ) >> 2);
if (prevStatus != newStatus && (prevStatus == expectedStatus || expectedStatus == -1)) {
var now = performance.now();
var startState = HEAPF64[(profilerBlock + {{{ C_STRUCTS.thread_profiler_block.currentStatusStartTime }}} ) >> 3];
var duration = now - startState;
HEAPF64[((profilerBlock + {{{ C_STRUCTS.thread_profiler_block.timeSpentInStatus }}} ) >> 3) + prevStatus] += duration;
Atomics.store(HEAPU32, (profilerBlock + {{{ C_STRUCTS.thread_profiler_block.threadStatus }}} ) >> 2, newStatus);
HEAPF64[(profilerBlock + {{{ C_STRUCTS.thread_profiler_block.currentStatusStartTime }}} ) >> 3] = now;
}
},
// Unconditionally sets the thread status.
setThreadStatus: function(pthreadPtr, newStatus) {
PThread.setThreadStatusConditional(pthreadPtr, -1, newStatus);
},
setThreadName: function(pthreadPtr, name) {
var profilerBlock = Atomics.load(HEAPU32, (pthreadPtr + {{{ C_STRUCTS.pthread.profilerBlock }}} ) >> 2);
if (!profilerBlock) return;
stringToUTF8(name, profilerBlock + {{{ C_STRUCTS.thread_profiler_block.name }}}, 32);
},
getThreadName: function(pthreadPtr) {
var profilerBlock = Atomics.load(HEAPU32, (pthreadPtr + {{{ C_STRUCTS.pthread.profilerBlock }}} ) >> 2);
if (!profilerBlock) return "";
return UTF8ToString(profilerBlock + {{{ C_STRUCTS.thread_profiler_block.name }}});
},
threadStatusToString: function(threadStatus) {
switch (threadStatus) {
case 0: return "not yet started";
case 1: return "running";
case 2: return "sleeping";
case 3: return "waiting for a futex";
case 4: return "waiting for a mutex";
case 5: return "waiting for a proxied operation";
case 6: return "finished execution";
default: return "unknown (corrupt?!)";
}
},
threadStatusAsString: function(pthreadPtr) {
var profilerBlock = Atomics.load(HEAPU32, (pthreadPtr + {{{ C_STRUCTS.pthread.profilerBlock }}} ) >> 2);
var status = (profilerBlock == 0) ? 0 : Atomics.load(HEAPU32, (profilerBlock + {{{ C_STRUCTS.thread_profiler_block.threadStatus }}} ) >> 2);
return PThread.threadStatusToString(status);
},
#else
setThreadStatus: function() {},
#endif
runExitHandlers: function() {
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();
},
runExitHandlersAndDeinitThread: function(tb, exitCode) {
#if PTHREADS_PROFILING
var profilerBlock = Atomics.load(HEAPU32, (tb + {{{ C_STRUCTS.pthread.profilerBlock }}} ) >> 2);
Atomics.store(HEAPU32, (tb + {{{ C_STRUCTS.pthread.profilerBlock }}} ) >> 2, 0);
_free(profilerBlock);
#endif
// 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();
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.
Atomics.store(HEAPU32, (tb + {{{ C_STRUCTS.pthread.threadStatus }}} ) >> 2, 1); // Mark the thread as no longer running.
_emscripten_futex_wake(tb + {{{ C_STRUCTS.pthread.threadStatus }}}, {{{ cDefine('INT_MAX') }}}); // wake all threads
// Not hosting a pthread anymore in this worker, reset the info structures to null.
__emscripten_thread_init(0, 0, 0); // Unregister the thread block inside the wasm module.
},
setExitStatus: function(status) {
EXITSTATUS = status;
},
// Called when we are performing a pthread_exit(), either explicitly called
// by programmer, or implicitly when leaving the thread main function.
threadExit: function(exitCode) {
var tb = _pthread_self();
if (tb) { // If we haven't yet exited?
#if ASSERTIONS
err('Pthread 0x' + tb.toString(16) + ' exited.');
#endif
PThread.runExitHandlersAndDeinitThread(tb, exitCode);
if (ENVIRONMENT_IS_PTHREAD) {
// Note: in theory we would like to return any offscreen canvases back to the main thread,
// but if we ever fetched a rendering context for them that would not be valid, so we don't try.
postMessage({ 'cmd': 'exit' });
}
}
},
threadCancel: function() {
PThread.runExitHandlersAndDeinitThread(_pthread_self(), -1/*PTHREAD_CANCELED*/);
postMessage({ 'cmd': 'cancelDone' });
},
terminateAllThreads: function() {
for (var t in PThread.pthreads) {
var pthread = PThread.pthreads[t];
if (pthread && pthread.worker) {
PThread.returnWorkerToPool(pthread.worker);
}
}
PThread.pthreads = {};
for (var i = 0; i < PThread.unusedWorkers.length; ++i) {
var worker = PThread.unusedWorkers[i];
#if ASSERTIONS
assert(!worker.pthread); // This Worker should not be hosting a pthread at this time.
#endif
worker.terminate();
}
PThread.unusedWorkers = [];
for (var i = 0; i < PThread.runningWorkers.length; ++i) {
var worker = PThread.runningWorkers[i];
var pthread = worker.pthread;
#if ASSERTIONS
assert(pthread, 'This Worker should have a pthread it is executing');
#endif
PThread.freeThreadData(pthread);
worker.terminate();
}
PThread.runningWorkers = [];
},
freeThreadData: function(pthread) {
if (!pthread) return;
if (pthread.threadInfoStruct) {
var tlsMemory = {{{ makeGetValue('pthread.threadInfoStruct', C_STRUCTS.pthread.tsd, 'i32') }}};
{{{ makeSetValue('pthread.threadInfoStruct', C_STRUCTS.pthread.tsd, 0, 'i32') }}};
_free(tlsMemory);
_free(pthread.threadInfoStruct);
}
pthread.threadInfoStruct = 0;
if (pthread.allocatedOwnStack && pthread.stackBase) _free(pthread.stackBase);
pthread.stackBase = 0;
if (pthread.worker) pthread.worker.pthread = null;
},
returnWorkerToPool: function(worker) {
// We don't want to run main thread queued calls here, since we are doing
// some operations that leave the worker queue in an invalid state until
// we are completely done (it would be bad if free() ends up calling a
// queued pthread_create which looks at the global data structures we are
// modifying).
PThread.runWithoutMainThreadQueuedCalls(function() {
delete PThread.pthreads[worker.pthread.threadInfoStruct];
//Note: worker is intentionally not terminated so the pool can dynamically grow.
PThread.unusedWorkers.push(worker);
PThread.runningWorkers.splice(PThread.runningWorkers.indexOf(worker), 1); // Not a running Worker anymore
PThread.freeThreadData(worker.pthread);
// Detach the worker from the pthread object, and return it to the worker pool as an unused worker.
worker.pthread = undefined;
});
},
// Runs a function with processing of queued calls to the main thread
// disabled. This is useful to avoid something like free() ending up waiting
// for a lock, then running processing events, and those events can end up
// doing things that interfere with what we were doing before (for example,
// if we are tearing down a thread, calling free to erase its data could
// end up calling a proxied pthread_create, which gets a free worker, and
// can interfere).
// This is only safe to call if we do not need queued calls to run. That is
// the case when doing something like free(), which just needs the malloc
// lock to be released.
runWithoutMainThreadQueuedCalls: function(func) {
#if ASSERTIONS
assert(PThread.mainRuntimeThread, 'runWithoutMainThreadQueuedCalls must be done on the main runtime thread');
assert(__emscripten_allow_main_runtime_queued_calls);
#endif
HEAP32[__emscripten_allow_main_runtime_queued_calls >> 2] = 0;
try {
func();
} finally {
HEAP32[__emscripten_allow_main_runtime_queued_calls >> 2] = 1;
}
},
receiveObjectTransfer: function(data) {
#if OFFSCREENCANVAS_SUPPORT
if (typeof GL !== 'undefined') {
for (var i in data.offscreenCanvases) {
GL.offscreenCanvases[i] = data.offscreenCanvases[i];
}
if (!Module['canvas'] && data.moduleCanvasId && GL.offscreenCanvases[data.moduleCanvasId]) {
Module['canvas'] = GL.offscreenCanvases[data.moduleCanvasId].offscreenCanvas;
Module['canvas'].id = data.moduleCanvasId;
}
}
#endif
},
// Called by worker.js each time a thread is started.
threadInit: function() {
#if PTHREADS_DEBUG
out("threadInit");
#endif
PThread.setThreadStatus(_pthread_self(), {{{ cDefine('EM_THREAD_STATUS_RUNNING') }}});
// Call thread init functions (these are the emscripten_tls_init for each
// module loaded.
for (var i in PThread.tlsInitFunctions) {
PThread.tlsInitFunctions[i]();
}
},
// Loads the WebAssembly module into the given list of Workers.
// onFinishedLoading: A callback function that will be called once all of
// the workers have been initialized and are
// ready to host pthreads.
loadWasmModuleToWorker: function(worker, onFinishedLoading) {
worker.onmessage = function(e) {
var d = e['data'];
var cmd = d['cmd'];
// 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;
// If this message is intended to a recipient that is not the main thread, forward it to the target thread.
if (d['targetThread'] && d['targetThread'] != _pthread_self()) {
var thread = PThread.pthreads[d.targetThread];
if (thread) {
thread.worker.postMessage(e.data, d['transferList']);
} else {
console.error('Internal error! Worker sent a message "' + cmd + '" to target pthread ' + d['targetThread'] + ', but that thread no longer exists!');
}
PThread.currentProxiedOperationCallerThread = undefined;
return;
}
if (cmd === 'processQueuedMainThreadWork') {
// TODO: Must post message to main Emscripten thread in PROXY_TO_WORKER mode.
_emscripten_main_thread_process_queued_calls();
} else if (cmd === 'spawnThread') {
spawnThread(e.data);
} else if (cmd === 'cleanupThread') {
cleanupThread(d['thread']);
} else if (cmd === 'killThread') {
killThread(d['thread']);
} else if (cmd === 'cancelThread') {
cancelThread(d['thread']);
} else if (cmd === 'loaded') {
worker.loaded = true;
if (onFinishedLoading) onFinishedLoading(worker);
// If this Worker is already pending to start running a thread, launch the thread now
if (worker.runPthread) {
worker.runPthread();
delete worker.runPthread;
}
} else if (cmd === 'print') {
out('Thread ' + d['threadId'] + ': ' + d['text']);
} else if (cmd === 'printErr') {
err('Thread ' + d['threadId'] + ': ' + d['text']);
} else if (cmd === 'alert') {
alert('Thread ' + d['threadId'] + ': ' + d['text']);
} else if (cmd === 'exit') {
var detached = worker.pthread && Atomics.load(HEAPU32, (worker.pthread.threadInfoStruct + {{{ C_STRUCTS.pthread.detached }}}) >> 2);
if (detached) {
PThread.returnWorkerToPool(worker);
}
} else if (cmd === 'exitProcess') {
// A pthread has requested to exit the whole application process (runtime).
#if ASSERTIONS
err("exitProcess requested by worker");
#endif
try {
exit(d['returnCode']);
} catch (e) {
if (e instanceof ExitStatus) return;
throw e;
}
} else if (cmd === 'cancelDone') {
PThread.returnWorkerToPool(worker);
} else if (cmd === 'objectTransfer') {
PThread.receiveObjectTransfer(e.data);
} else if (e.data.target === 'setimmediate') {
worker.postMessage(e.data); // Worker wants to postMessage() to itself to implement setImmediate() emulation.
} else {
err("worker sent an unknown command " + cmd);
}
PThread.currentProxiedOperationCallerThread = undefined;
};
worker.onerror = function(e) {
err('pthread sent an error! ' + e.filename + ':' + e.lineno + ': ' + e.message);
};
#if ENVIRONMENT_MAY_BE_NODE
if (ENVIRONMENT_IS_NODE) {
worker.on('message', function(data) {
worker.onmessage({ data: data });
});
worker.on('error', function(data) {
worker.onerror(data);
});
worker.on('exit', function(data) {
// TODO: update the worker queue?
// See: https://github.com/emscripten-core/emscripten/issues/9763
});
}
#endif
#if ASSERTIONS
assert(wasmMemory instanceof WebAssembly.Memory, 'WebAssembly memory should have been loaded by now!');
assert(wasmModule instanceof WebAssembly.Module, 'WebAssembly Module should have been loaded by now!');
#endif
// Ask the new worker to load up the Emscripten-compiled page. This is a heavy operation.
worker.postMessage({
'cmd': 'load',
// If the application main .js file was loaded from a Blob, then it is not possible
// to access the URL of the current script that could be passed to a Web Worker so that
// it could load up the same file. In that case, developer must either deliver the Blob
// object in Module['mainScriptUrlOrBlob'], or a URL to it, so that pthread Workers can
// independently load up the same main application file.
'urlOrBlob': Module['mainScriptUrlOrBlob'] || _scriptDir,
#if WASM2JS
// the polyfill WebAssembly.Memory instance has function properties,
// which will fail in postMessage, so just send a custom object with the
// property we need, the buffer
'wasmMemory': { 'buffer': wasmMemory.buffer },
#else // WASM2JS
'wasmMemory': wasmMemory,
#endif // WASM2JS
'wasmModule': wasmModule,
#if LOAD_SOURCE_MAP
'wasmSourceMap': wasmSourceMap,
#endif
#if USE_OFFSET_CONVERTER
'wasmOffsetConverter': wasmOffsetConverter,
#endif
#if MAIN_MODULE
'dynamicLibraries': Module['dynamicLibraries'],
#endif
});
},
// Creates a new web Worker and places it in the unused worker pool to wait for its use.
allocateUnusedWorker: function() {
#if MINIMAL_RUNTIME
var pthreadMainJs = Module['worker'];
#else
// Allow HTML module to configure the location where the 'worker.js' file will be loaded from,
// via Module.locateFile() function. If not specified, then the default URL 'worker.js' relative
// to the main html file is loaded.
var pthreadMainJs = locateFile('{{{ PTHREAD_WORKER_FILE }}}');
#endif
#if PTHREADS_DEBUG
out('Allocating a new web worker from ' + pthreadMainJs);
#endif
PThread.unusedWorkers.push(new Worker(pthreadMainJs));
},
getNewWorker: function() {
if (PThread.unusedWorkers.length == 0) {
#if !PROXY_TO_PTHREAD && PTHREAD_POOL_SIZE_STRICT
#if ASSERTIONS
err('Tried to spawn a new thread, but the thread pool is exhausted.\n' +
'This might result in a deadlock unless some threads eventually exit or the code explicitly breaks out to the event loop.\n' +
'If you want to increase the pool size, use setting `-s PTHREAD_POOL_SIZE=...`.'
#if PTHREAD_POOL_SIZE_STRICT == 1
+ '\nIf you want to throw an explicit error instead of the risk of deadlocking in those cases, use setting `-s PTHREAD_POOL_SIZE_STRICT=2`.'
#endif
);
#endif // ASSERTIONS
#if PTHREAD_POOL_SIZE_STRICT == 2
// Don't return a Worker, which will translate into an EAGAIN error.
return;
#endif
#endif
PThread.allocateUnusedWorker();
PThread.loadWasmModuleToWorker(PThread.unusedWorkers[0]);
}
return PThread.unusedWorkers.pop();
},
busySpinWait: function(msecs) {
var t = performance.now() + msecs;
while (performance.now() < t) {
;
}
}
},
$killThread: function(pthread_ptr) {
if (ENVIRONMENT_IS_PTHREAD) throw 'Internal Error! killThread() can only ever be called from main application thread!';
if (!pthread_ptr) throw 'Internal Error! Null pthread_ptr in killThread!';
{{{ makeSetValue('pthread_ptr', C_STRUCTS.pthread.self, 0, 'i32') }}};
var pthread = PThread.pthreads[pthread_ptr];
pthread.worker.terminate();
PThread.freeThreadData(pthread);
// The worker was completely nuked (not just the pthread execution it was hosting), so remove it from running workers
// but don't put it back to the pool.
PThread.runningWorkers.splice(PThread.runningWorkers.indexOf(pthread.worker), 1); // Not a running Worker anymore.
pthread.worker.pthread = undefined;
},
$cleanupThread: function(pthread_ptr) {
if (ENVIRONMENT_IS_PTHREAD) throw 'Internal Error! cleanupThread() can only ever be called from main application thread!';
if (!pthread_ptr) throw 'Internal Error! Null pthread_ptr in cleanupThread!';
var pthread = PThread.pthreads[pthread_ptr];
// If pthread has been removed from this map this also means that pthread_ptr points
// to already freed data. Such situation may occur in following circumstances:
// 1. Joining cancelled thread - in such situation it may happen that pthread data will
// already be removed by handling 'cancelDone' message.
// 2. Joining thread from non-main browser thread (this also includes thread running main()
// when compiled with `PROXY_TO_PTHREAD`) - in such situation it may happen that following
// code flow occur (MB - Main Browser Thread, S1, S2 - Worker Threads):
// S2: thread ends, 'exit' message is sent to MB
// S1: calls pthread_join(S2), this causes:
// a. S2 is marked as detached,
// b. 'cleanupThread' message is sent to MB.
// MB: handles 'exit' message, as thread is detached, so returnWorkerToPool()
// is called and all thread related structs are freed/released.
// MB: handles 'cleanupThread' message which calls this function.
if (pthread) {
{{{ makeSetValue('pthread_ptr', C_STRUCTS.pthread.self, 0, 'i32') }}};
var worker = pthread.worker;
PThread.returnWorkerToPool(worker);
}
},
$cancelThread: function(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];
pthread.worker.postMessage({ 'cmd': 'cancel' });
},
$spawnThread: function(threadParams) {
if (ENVIRONMENT_IS_PTHREAD) throw 'Internal Error! spawnThread() can only ever be called from main application thread!';
var worker = PThread.getNewWorker();
if (!worker) {
// No available workers in the PThread pool.
return {{{ cDefine('EAGAIN') }}};
}
if (worker.pthread !== undefined) throw 'Internal error!';
if (!threadParams.pthread_ptr) throw 'Internal error, no pthread ptr!';
PThread.runningWorkers.push(worker);
// Allocate memory for thread-local storage and initialize it to zero.
var tlsMemory = _malloc({{{ cDefine('PTHREAD_KEYS_MAX') }}} * 4);
for (var i = 0; i < {{{ cDefine('PTHREAD_KEYS_MAX') }}}; ++i) {
{{{ makeSetValue('tlsMemory', 'i*4', 0, 'i32') }}};
}
var stackHigh = threadParams.stackBase + threadParams.stackSize;
// Create a pthread info object to represent this thread.
var pthread = PThread.pthreads[threadParams.pthread_ptr] = {
worker: worker,
stackBase: threadParams.stackBase,
stackSize: threadParams.stackSize,
allocatedOwnStack: threadParams.allocatedOwnStack,
// Info area for this thread in Emscripten HEAP (shared)
threadInfoStruct: threadParams.pthread_ptr
};
var tis = pthread.threadInfoStruct >> 2;
// spawnThread is always called with a zero-initialized thread struct so
// no need to set any valudes to zero here.
Atomics.store(HEAPU32, tis + ({{{ C_STRUCTS.pthread.detached }}} >> 2), threadParams.detached);
Atomics.store(HEAPU32, tis + ({{{ C_STRUCTS.pthread.tsd }}} >> 2), tlsMemory); // Init thread-local-storage memory array.
Atomics.store(HEAPU32, tis + ({{{ C_STRUCTS.pthread.tid }}} >> 2), pthread.threadInfoStruct); // Main thread ID.
Atomics.store(HEAPU32, tis + ({{{ C_STRUCTS.pthread.stack_size }}} >> 2), threadParams.stackSize);
Atomics.store(HEAPU32, tis + ({{{ C_STRUCTS.pthread.stack }}} >> 2), stackHigh);
Atomics.store(HEAPU32, tis + ({{{ C_STRUCTS.pthread.attr }}} >> 2), threadParams.stackSize);
Atomics.store(HEAPU32, tis + ({{{ C_STRUCTS.pthread.attr }}} + 8 >> 2), stackHigh);
Atomics.store(HEAPU32, tis + ({{{ C_STRUCTS.pthread.attr }}} + 12 >> 2), threadParams.detached);
var global_libc = _emscripten_get_global_libc();
var global_locale = global_libc + {{{ C_STRUCTS.libc.global_locale }}};
Atomics.store(HEAPU32, tis + ({{{ C_STRUCTS.pthread.locale }}} >> 2), global_locale);
#if PTHREADS_PROFILING
PThread.createProfilerBlock(pthread.threadInfoStruct);
#endif
worker.pthread = pthread;
var msg = {
'cmd': 'run',
'start_routine': threadParams.startRoutine,
'arg': threadParams.arg,
'threadInfoStruct': threadParams.pthread_ptr,
'stackBase': threadParams.stackBase,
'stackSize': threadParams.stackSize
};
#if OFFSCREENCANVAS_SUPPORT
// Note that we do not need to quote these names because they are only used
// in this file, and not from the external worker.js.
msg.moduleCanvasId = threadParams.moduleCanvasId;
msg.offscreenCanvases = threadParams.offscreenCanvases;
#endif
worker.runPthread = function() {
// Ask the worker to start executing its pthread entry point function.
msg.time = performance.now();
worker.postMessage(msg, threadParams.transferList);
};
if (worker.loaded) {
worker.runPthread();
delete worker.runPthread;
}
return 0;
},
emscripten_has_threading_support: function() {
return typeof SharedArrayBuffer !== 'undefined';
},
emscripten_num_logical_cores: function() {
#if ENVIRONMENT_MAY_BE_NODE
if (ENVIRONMENT_IS_NODE) return require('os').cpus().length;
#endif
return navigator['hardwareConcurrency'];
},
{{{ USE_LSAN || USE_ASAN ? 'emscripten_builtin_' : '' }}}pthread_create__deps: ['$spawnThread', 'pthread_self', 'memalign', 'emscripten_sync_run_in_main_thread_4'],
{{{ USE_LSAN || USE_ASAN ? 'emscripten_builtin_' : '' }}}pthread_create: function(pthread_ptr, attr, start_routine, arg) {
if (typeof SharedArrayBuffer === 'undefined') {
err('Current environment does not support SharedArrayBuffer, pthreads are not available!');
return {{{ cDefine('EAGAIN') }}};
}
if (!pthread_ptr) {
err('pthread_create called with a null thread pointer!');
return {{{ cDefine('EINVAL') }}};
}
// List of JS objects that will transfer ownership to the Worker hosting the thread
var transferList = [];
var error = 0;
#if OFFSCREENCANVAS_SUPPORT
// Deduce which WebGL canvases (HTMLCanvasElements or OffscreenCanvases) should be passed over to the
// Worker that hosts the spawned pthread.
// Comma-delimited list of CSS selectors that must identify canvases by IDs: "#canvas1, #canvas2, ..."
var transferredCanvasNames = attr ? {{{ makeGetValue('attr', 36, 'i32') }}} : 0;
#if OFFSCREENCANVASES_TO_PTHREAD
// Proxied canvases string pointer -1 is used as a special token to fetch
// whatever canvases were passed to build in -s
// OFFSCREENCANVASES_TO_PTHREAD= command line.
if (transferredCanvasNames == -1) transferredCanvasNames = '{{{ OFFSCREENCANVASES_TO_PTHREAD }}}';
else
#endif
if (transferredCanvasNames) transferredCanvasNames = UTF8ToString(transferredCanvasNames).trim();
if (transferredCanvasNames) transferredCanvasNames = transferredCanvasNames.split(',');
#if GL_DEBUG
console.log('pthread_create: transferredCanvasNames="' + transferredCanvasNames + '"');
#endif
var offscreenCanvases = {}; // Dictionary of OffscreenCanvas objects we'll transfer to the created thread to own
var moduleCanvasId = Module['canvas'] ? Module['canvas'].id : '';
for (var i in transferredCanvasNames) {
var name = transferredCanvasNames[i].trim();
var offscreenCanvasInfo;
try {
if (name == '#canvas') {
if (!Module['canvas']) {
err('pthread_create: could not find canvas with ID "' + name + '" to transfer to thread!');
error = {{{ cDefine('EINVAL') }}};
break;
}
name = Module['canvas'].id;
}
#if ASSERTIONS
assert(typeof GL === 'object', 'OFFSCREENCANVAS_SUPPORT assumes GL is in use (you can force-include it with -s \'DEFAULT_LIBRARY_FUNCS_TO_INCLUDE=["$GL"]\')');
#endif
if (GL.offscreenCanvases[name]) {
offscreenCanvasInfo = GL.offscreenCanvases[name];
GL.offscreenCanvases[name] = null; // This thread no longer owns this canvas.
if (Module['canvas'] instanceof OffscreenCanvas && name === Module['canvas'].id) Module['canvas'] = null;
} else if (!ENVIRONMENT_IS_PTHREAD) {
var canvas = (Module['canvas'] && Module['canvas'].id === name) ? Module['canvas'] : document.querySelector(name);
if (!canvas) {
err('pthread_create: could not find canvas with ID "' + name + '" to transfer to thread!');
error = {{{ cDefine('EINVAL') }}};
break;
}
if (canvas.controlTransferredOffscreen) {
err('pthread_create: cannot transfer canvas with ID "' + name + '" to thread, since the current thread does not have control over it!');
error = {{{ cDefine('EPERM') }}}; // Operation not permitted, some other thread is accessing the canvas.
break;
}
if (canvas.transferControlToOffscreen) {
#if GL_DEBUG
err('pthread_create: canvas.transferControlToOffscreen(), transferring canvas by name "' + name + '" (DOM id="' + canvas.id + '") from main thread to pthread');
#endif
// Create a shared information block in heap so that we can control
// the canvas size from any thread.
if (!canvas.canvasSharedPtr) {
canvas.canvasSharedPtr = _malloc(12);
{{{ makeSetValue('canvas.canvasSharedPtr', 0, 'canvas.width', 'i32') }}};
{{{ makeSetValue('canvas.canvasSharedPtr', 4, 'canvas.height', 'i32') }}};
{{{ makeSetValue('canvas.canvasSharedPtr', 8, 0, 'i32') }}}; // pthread ptr to the thread that owns this canvas, filled in below.
}
offscreenCanvasInfo = {
offscreenCanvas: canvas.transferControlToOffscreen(),
canvasSharedPtr: canvas.canvasSharedPtr,
id: canvas.id
}
// After calling canvas.transferControlToOffscreen(), it is no
// longer possible to access certain operations on the canvas, such
// as resizing it or obtaining GL contexts via it.
// Use this field to remember that we have permanently converted
// this Canvas to be controlled via an OffscreenCanvas (there is no
// way to undo this in the spec)
canvas.controlTransferredOffscreen = true;
} else {
err('pthread_create: cannot transfer control of canvas "' + name + '" to pthread, because current browser does not support OffscreenCanvas!');
// If building with OFFSCREEN_FRAMEBUFFER=1 mode, we don't need to
// be able to transfer control to offscreen, but WebGL can be
// proxied from worker to main thread.
#if !OFFSCREEN_FRAMEBUFFER
err('pthread_create: Build with -s OFFSCREEN_FRAMEBUFFER=1 to enable fallback proxying of GL commands from pthread to main thread.');
return {{{ cDefine('ENOSYS') }}}; // Function not implemented, browser doesn't have support for this.
#endif
}
}
if (offscreenCanvasInfo) {
transferList.push(offscreenCanvasInfo.offscreenCanvas);
offscreenCanvases[offscreenCanvasInfo.id] = offscreenCanvasInfo;
}
} catch(e) {
err('pthread_create: failed to transfer control of canvas "' + name + '" to OffscreenCanvas! Error: ' + e);
return {{{ cDefine('EINVAL') }}}; // Hitting this might indicate an implementation bug or some other internal error
}
}
#endif
// Synchronously proxy the thread creation to main thread if possible. If we
// need to transfer ownership of objects, then proxy asynchronously via
// postMessage.
if (ENVIRONMENT_IS_PTHREAD && (transferList.length === 0 || error)) {
return _emscripten_sync_run_in_main_thread_4({{{ cDefine('EM_PROXIED_PTHREAD_CREATE') }}}, pthread_ptr, attr, start_routine, arg);
}
// If on the main thread, and accessing Canvas/OffscreenCanvas failed, abort
// with the detected error.
if (error) return error;
var stackSize = 0;
var stackBase = 0;
// Default thread attr is PTHREAD_CREATE_JOINABLE, i.e. start as not detached.
var detached = 0;
// When musl creates C11 threads it passes __ATTRP_C11_THREAD (-1) which
// treat as if it was NULL.
if (attr && attr != {{{ cDefine('__ATTRP_C11_THREAD') }}}) {
stackSize = {{{ makeGetValue('attr', 0, 'i32') }}};
// Musl has a convention that the stack size that is stored to the pthread
// attribute structure is always musl's #define DEFAULT_STACK_SIZE
// smaller than the actual created stack size. That is, stored stack size
// of 0 would mean a stack of DEFAULT_STACK_SIZE in size. All musl
// functions hide this impl detail, and offset the size transparently, so
// pthread_*() API user does not see this offset when operating with
// the pthread API. When reading the structure directly on JS side
// however, we need to offset the size manually here.
stackSize += 81920 /*DEFAULT_STACK_SIZE*/;
stackBase = {{{ makeGetValue('attr', 8, 'i32') }}};
detached = {{{ makeGetValue('attr', 12/*_a_detach*/, 'i32') }}} !== 0/*PTHREAD_CREATE_JOINABLE*/;
} else {
// According to
// http://man7.org/linux/man-pages/man3/pthread_create.3.html, default
// stack size if not specified is 2 MB, so follow that convention.
stackSize = {{{ DEFAULT_PTHREAD_STACK_SIZE }}};
}
// If allocatedOwnStack == true, then the pthread impl maintains the stack allocation.
var allocatedOwnStack = stackBase == 0;
if (allocatedOwnStack) {
// Allocate a stack if the user doesn't want to place the stack in a
// custom memory area.
stackBase = _memalign({{{ STACK_ALIGN }}}, stackSize);
} else {
// Musl stores the stack base address assuming stack grows downwards, so
// adjust it to Emscripten convention that the
// stack grows upwards instead.
stackBase -= stackSize;
assert(stackBase > 0);
}
// Allocate thread block (pthread_t structure).
var threadInfoStruct = _malloc({{{ C_STRUCTS.pthread.__size__ }}});
// zero-initialize thread structure.
for (var i = 0; i < {{{ C_STRUCTS.pthread.__size__ }}} >> 2; ++i) HEAPU32[(threadInfoStruct>>2) + i] = 0;
{{{ makeSetValue('pthread_ptr', 0, 'threadInfoStruct', 'i32') }}};
// The pthread struct has a field that points to itself - this is used as a
// magic ID to detect whether the pthread_t structure is 'alive'.
{{{ makeSetValue('threadInfoStruct', C_STRUCTS.pthread.self, 'threadInfoStruct', 'i32') }}};
// pthread struct robust_list head should point to itself.
var headPtr = threadInfoStruct + {{{ C_STRUCTS.pthread.robust_list }}};
{{{ makeSetValue('headPtr', 0, 'headPtr', 'i32') }}};
#if OFFSCREENCANVAS_SUPPORT
// Register for each of the transferred canvases that the new thread now
// owns the OffscreenCanvas.
for (var i in offscreenCanvases) {
// pthread ptr to the thread that owns this canvas.
{{{ makeSetValue('offscreenCanvases[i].canvasSharedPtr', 8, 'threadInfoStruct', 'i32') }}};
}
#endif
var threadParams = {
stackBase: stackBase,
stackSize: stackSize,
allocatedOwnStack: allocatedOwnStack,
detached: detached,
startRoutine: start_routine,
pthread_ptr: threadInfoStruct,
arg: arg,
#if OFFSCREENCANVAS_SUPPORT
moduleCanvasId: moduleCanvasId,
offscreenCanvases: offscreenCanvases,
#endif
transferList: transferList
};
if (ENVIRONMENT_IS_PTHREAD) {
// The prepopulated pool of web workers that can host pthreads is stored
// in the main JS thread. Therefore if a pthread is attempting to spawn a
// new thread, the thread creation must be deferred to the main JS thread.
threadParams.cmd = 'spawnThread';
postMessage(threadParams, transferList);
// When we defer thread creation this way, we have no way to detect thread
// creation synchronously today, so we have to assume success and return 0.
return 0;
}
// We are the main thread, so we have the pthread warmup pool in this
// thread and can fire off JS thread creation directly ourselves.
return spawnThread(threadParams);
},
// TODO HACK! Remove this function, it is a JS side copy of the function
// pthread_testcancel() in library_pthread.c. Just call pthread_testcancel()
// everywhere.
_pthread_testcancel_js: function() {
if (!ENVIRONMENT_IS_PTHREAD) return;
var tb = _pthread_self();
if (!tb) return;
var cancelDisabled = Atomics.load(HEAPU32, (tb + {{{ C_STRUCTS.pthread.canceldisable }}} ) >> 2);
if (cancelDisabled) return;
var canceled = Atomics.load(HEAPU32, (tb + {{{ C_STRUCTS.pthread.threadStatus }}} ) >> 2);
if (canceled == 2) throw 'Canceled!';
},
#if MINIMAL_RUNTIME
emscripten_check_blocking_allowed__deps: ['$warnOnce'],
#endif
emscripten_check_blocking_allowed: function() {
#if ASSERTIONS || IN_TEST_HARNESS || !MINIMAL_RUNTIME || !ALLOW_BLOCKING_ON_MAIN_THREAD
#if ENVIRONMENT_MAY_BE_NODE
if (ENVIRONMENT_IS_NODE) return;
#endif
if (ENVIRONMENT_IS_WORKER) return; // Blocking in a worker/pthread is fine.
warnOnce('Blocking on the main thread is very dangerous, see https://emscripten.org/docs/porting/pthreads.html#blocking-on-the-main-browser-thread');
#if !ALLOW_BLOCKING_ON_MAIN_THREAD
abort('Blocking on the main thread is not allowed by default. See https://emscripten.org/docs/porting/pthreads.html#blocking-on-the-main-browser-thread');
#endif
#endif
},
_emscripten_do_pthread_join__deps: ['$cleanupThread', '_pthread_testcancel_js', 'emscripten_main_thread_process_queued_calls', 'emscripten_futex_wait', 'pthread_self', 'emscripten_main_browser_thread_id',
#if ASSERTIONS || IN_TEST_HARNESS || !MINIMAL_RUNTIME || !ALLOW_BLOCKING_ON_MAIN_THREAD
'emscripten_check_blocking_allowed'
#endif
],
_emscripten_do_pthread_join: function(thread, status, block) {
if (!thread) {
err('pthread_join attempted on a null thread pointer!');
return ERRNO_CODES.ESRCH;
}
if (ENVIRONMENT_IS_PTHREAD && _pthread_self() == thread) {
err('PThread ' + thread + ' is attempting to join to itself!');
return ERRNO_CODES.EDEADLK;
}
else if (!ENVIRONMENT_IS_PTHREAD && _emscripten_main_browser_thread_id() == thread) {
err('Main thread ' + thread + ' is attempting to join to itself!');
return ERRNO_CODES.EDEADLK;
}
var self = {{{ makeGetValue('thread', C_STRUCTS.pthread.self, 'i32') }}};
if (self !== thread) {
err('pthread_join attempted on thread ' + thread + ', which does not point to a valid thread, or does not exist anymore!');
return ERRNO_CODES.ESRCH;
}
var detached = Atomics.load(HEAPU32, (thread + {{{ C_STRUCTS.pthread.detached }}} ) >> 2);
if (detached) {
err('Attempted to join thread ' + thread + ', which was already detached!');
return ERRNO_CODES.EINVAL; // The thread is already detached, can no longer join it!
}
#if ASSERTIONS || IN_TEST_HARNESS || !MINIMAL_RUNTIME || !ALLOW_BLOCKING_ON_MAIN_THREAD
if (block) {
_emscripten_check_blocking_allowed();
}
#endif
for (;;) {
var threadStatus = Atomics.load(HEAPU32, (thread + {{{ C_STRUCTS.pthread.threadStatus }}} ) >> 2);
if (threadStatus == 1) { // Exited?
var threadExitCode = Atomics.load(HEAPU32, (thread + {{{ C_STRUCTS.pthread.threadExitCode }}} ) >> 2);
if (status) {{{ makeSetValue('status', 0, 'threadExitCode', 'i32') }}};
Atomics.store(HEAPU32, (thread + {{{ C_STRUCTS.pthread.detached }}} ) >> 2, 1); // Mark the thread as detached.
if (!ENVIRONMENT_IS_PTHREAD) cleanupThread(thread);
else postMessage({ 'cmd': 'cleanupThread', 'thread': thread });
return 0;
}
if (!block) {
return ERRNO_CODES.EBUSY;
}
// TODO HACK! Replace the _js variant with just _pthread_testcancel:
//_pthread_testcancel();
__pthread_testcancel_js();
// In main runtime thread (the thread that initialized the Emscripten C
// runtime and launched main()), assist pthreads in performing operations
// that they need to access the Emscripten main runtime for.
if (!ENVIRONMENT_IS_PTHREAD) _emscripten_main_thread_process_queued_calls();
_emscripten_futex_wait(thread + {{{ C_STRUCTS.pthread.threadStatus }}}, threadStatus, ENVIRONMENT_IS_PTHREAD ? 100 : 1);
}
},
{{{ USE_LSAN ? 'emscripten_builtin_' : '' }}}pthread_join__deps: ['_emscripten_do_pthread_join'],
{{{ USE_LSAN ? 'emscripten_builtin_' : '' }}}pthread_join: function(thread, status) {
return __emscripten_do_pthread_join(thread, status, true);
},
pthread_tryjoin_np__deps: ['_emscripten_do_pthread_join'],
pthread_tryjoin_np: function(thread, status) {
return __emscripten_do_pthread_join(thread, status, false);
},
pthread_kill__deps: ['$killThread', 'emscripten_main_browser_thread_id'],
pthread_kill: function(thread, signal) {
if (signal < 0 || signal >= 65/*_NSIG*/) return ERRNO_CODES.EINVAL;
if (thread === _emscripten_main_browser_thread_id()) {
if (signal == 0) return 0; // signal == 0 is a no-op.
err('Main thread (id=' + thread + ') cannot be killed with pthread_kill!');
return ERRNO_CODES.ESRCH;
}
if (!thread) {
err('pthread_kill attempted on a null thread pointer!');
return ERRNO_CODES.ESRCH;
}
var self = {{{ makeGetValue('thread', C_STRUCTS.pthread.self, 'i32') }}};
if (self !== thread) {
err('pthread_kill attempted on thread ' + thread + ', which does not point to a valid thread, or does not exist anymore!');
return ERRNO_CODES.ESRCH;
}
if (signal != 0) {
if (!ENVIRONMENT_IS_PTHREAD) killThread(thread);
else postMessage({ 'cmd': 'killThread', 'thread': thread});
}
return 0;
},
pthread_cancel__deps: ['$cancelThread', 'emscripten_main_browser_thread_id'],
pthread_cancel: function(thread) {
if (thread === _emscripten_main_browser_thread_id()) {
err('Main thread (id=' + thread + ') cannot be canceled!');
return ERRNO_CODES.ESRCH;
}
if (!thread) {
err('pthread_cancel attempted on a null thread pointer!');
return ERRNO_CODES.ESRCH;
}
var self = {{{ makeGetValue('thread', C_STRUCTS.pthread.self, 'i32') }}};
if (self !== thread) {
err('pthread_cancel attempted on thread ' + thread + ', which does not point to a valid thread, or does not exist anymore!');
return ERRNO_CODES.ESRCH;
}
Atomics.compareExchange(HEAPU32, (thread + {{{ C_STRUCTS.pthread.threadStatus }}} ) >> 2, 0, 2); // Signal the thread that it needs to cancel itself.
if (!ENVIRONMENT_IS_PTHREAD) cancelThread(thread);
else postMessage({ 'cmd': 'cancelThread', 'thread': thread});
return 0;
},
pthread_detach__sig: 'vi',
pthread_detach: function(thread) {
if (!thread) {
err('pthread_detach attempted on a null thread pointer!');
return ERRNO_CODES.ESRCH;
}
var self = {{{ makeGetValue('thread', C_STRUCTS.pthread.self, 'i32') }}};
if (self !== thread) {
err('pthread_detach attempted on thread ' + thread + ', which does not point to a valid thread, or does not exist anymore!');
return ERRNO_CODES.ESRCH;
}
// Follow musl convention: detached:0 means not detached, 1 means the thread
// was created as detached, and 2 means that the thread was detached via
// pthread_detach.
var wasDetached = Atomics.compareExchange(HEAPU32, (thread + {{{ C_STRUCTS.pthread.detached }}} ) >> 2, 0, 2);
return wasDetached ? ERRNO_CODES.EINVAL : 0;
},
// C11 threads function.
// TODO: remove this in favor or compiling musl/src/thread/pthread_detach.c
thrd_detach: 'pthread_detach',
pthread_exit__deps: ['exit'],
pthread_exit: function(status) {
if (!ENVIRONMENT_IS_PTHREAD) _exit(status);
else PThread.threadExit(status);
// pthread_exit is marked noReturn, so we must not return from it.
if (ENVIRONMENT_IS_NODE) {
// exit the pthread properly on node, as a normal JS exception will halt
// the entire application.
process.exit(status);
}
throw 'unwind';
},
pthread_cleanup_push__sig: 'vii',
pthread_cleanup_push: function(routine, arg) {
PThread.threadExitHandlers.push(function() { {{{ makeDynCall('vi', 'routine') }}}(arg) });
},
pthread_cleanup_pop: function(execute) {
var routine = PThread.threadExitHandlers.pop();
if (execute) routine();
},
// 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) {
if (addr <= 0 || addr > HEAP8.length || addr&3 != 0) return -{{{ cDefine('EINVAL') }}};
// We can do a normal blocking wait anywhere but on the main browser thread.
if (!ENVIRONMENT_IS_WEB) {
#if PTHREADS_PROFILING
PThread.setThreadStatusConditional(_pthread_self(), {{{ cDefine('EM_THREAD_STATUS_RUNNING') }}}, {{{ cDefine('EM_THREAD_STATUS_WAITFUTEX') }}});
#endif
var ret = Atomics.wait(HEAP32, addr >> 2, val, timeout);
#if PTHREADS_PROFILING
PThread.setThreadStatusConditional(_pthread_self(), {{{ cDefine('EM_THREAD_STATUS_WAITFUTEX') }}}, {{{ cDefine('EM_THREAD_STATUS_RUNNING') }}});
#endif
if (ret === 'timed-out') return -{{{ cDefine('ETIMEDOUT') }}};
if (ret === 'not-equal') return -{{{ cDefine('EWOULDBLOCK') }}};
if (ret === 'ok') return 0;
throw 'Atomics.wait returned an unexpected value ' + ret;
} else {
// First, check if the value is correct for us to wait on.
if (Atomics.load(HEAP32, addr >> 2) != val) {
return -{{{ cDefine('EWOULDBLOCK') }}};
}
// Atomics.wait is not available in the main browser thread, so simulate it via busy spinning.
var tNow = performance.now();
var tEnd = tNow + timeout;
#if PTHREADS_PROFILING
PThread.setThreadStatusConditional(_pthread_self(), {{{ cDefine('EM_THREAD_STATUS_RUNNING') }}}, {{{ cDefine('EM_THREAD_STATUS_WAITFUTEX') }}});
#endif
// Register globally which address the main thread is simulating to be
// waiting on. When zero, the main thread is not waiting on anything, and on
// nonzero, the contents of the address pointed by __emscripten_main_thread_futex
// tell which address the main thread is simulating its wait on.
// We need to be careful of recursion here: If we wait on a futex, and
// then call _emscripten_main_thread_process_queued_calls() below, that
// will call code that takes the proxying mutex - which can once more
// reach this code in a nested call. To avoid interference between the
// two (there is just a single __emscripten_main_thread_futex at a time), unmark
// ourselves before calling the potentially-recursive call. See below for
// how we handle the case of our futex being notified during the time in
// between when we are not set as the value of __emscripten_main_thread_futex.
#if ASSERTIONS
assert(__emscripten_main_thread_futex > 0);
#endif
var lastAddr = Atomics.exchange(HEAP32, __emscripten_main_thread_futex >> 2, addr);
#if ASSERTIONS
// We must not have already been waiting.
assert(lastAddr == 0);
#endif
while (1) {
// Check for a timeout.
tNow = performance.now();
if (tNow > tEnd) {
#if PTHREADS_PROFILING
PThread.setThreadStatusConditional(_pthread_self(), {{{ cDefine('EM_THREAD_STATUS_RUNNING') }}}, {{{ cDefine('EM_THREAD_STATUS_WAITFUTEX') }}});
#endif
// We timed out, so stop marking ourselves as waiting.
lastAddr = Atomics.exchange(HEAP32, __emscripten_main_thread_futex >> 2, 0);
#if ASSERTIONS
// The current value must have been our address which we set, or
// in a race it was set to 0 which means another thread just allowed
// us to run, but (tragically) that happened just a bit too late.
assert(lastAddr == addr || lastAddr == 0);
#endif
return -{{{ cDefine('ETIMEDOUT') }}};
}
// We are performing a blocking loop here, so we must handle proxied
// events from pthreads, to avoid deadlocks.
// Note that we have to do so carefully, as we may take a lock while
// doing so, which can recurse into this function; stop marking
// ourselves as waiting while we do so.
lastAddr = Atomics.exchange(HEAP32, __emscripten_main_thread_futex >> 2, 0);
#if ASSERTIONS
assert(lastAddr == addr || lastAddr == 0);
#endif
if (lastAddr == 0) {
// We were told to stop waiting, so stop.
break;
}
_emscripten_main_thread_process_queued_calls();
// Check the value, as if we were starting the futex all over again.
// This handles the following case:
//
// * wait on futex A
// * recurse into emscripten_main_thread_process_queued_calls(),
// which waits on futex B. that sets the __emscripten_main_thread_futex address to
// futex B, and there is no longer any mention of futex A.
// * a worker is done with futex A. it checks __emscripten_main_thread_futex but does
// not see A, so it does nothing special for the main thread.
// * a worker is done with futex B. it flips mainThreadMutex from B
// to 0, ending the wait on futex B.
// * we return to the wait on futex A. __emscripten_main_thread_futex is 0, but that
// is because of futex B being done - we can't tell from
// __emscripten_main_thread_futex whether A is done or not. therefore, check the
// memory value of the futex.
//
// That case motivates the design here. Given that, checking the memory
// address is also necessary for other reasons: we unset and re-set our
// address in __emscripten_main_thread_futex around calls to
// emscripten_main_thread_process_queued_calls(), and a worker could
// attempt to wake us up right before/after such times.
//
// Note that checking the memory value of the futex is valid to do: we
// could easily have been delayed (relative to the worker holding on
// to futex A), which means we could be starting all of our work at the
// later time when there is no need to block. The only "odd" thing is
// that we may have caused side effects in that "delay" time. But the
// only side effects we can have are to call
// emscripten_main_thread_process_queued_calls(). That is always ok to
// do on the main thread (it's why it is ok for us to call it in the
// middle of this function, and elsewhere). So if we check the value
// here and return, it's the same is if what happened on the main thread
// was the same as calling emscripten_main_thread_process_queued_calls()
// a few times times before calling emscripten_futex_wait().
if (Atomics.load(HEAP32, addr >> 2) != val) {
return -{{{ cDefine('EWOULDBLOCK') }}};
}
// Mark us as waiting once more, and continue the loop.
lastAddr = Atomics.exchange(HEAP32, __emscripten_main_thread_futex >> 2, addr);
#if ASSERTIONS
assert(lastAddr == 0);
#endif
}
#if PTHREADS_PROFILING
PThread.setThreadStatusConditional(_pthread_self(), {{{ cDefine('EM_THREAD_STATUS_RUNNING') }}}, {{{ cDefine('EM_THREAD_STATUS_WAITFUTEX') }}});
#endif
return 0;
}
},
// Returns the number of threads (>= 0) woken up, or the value -EINVAL on error.
// Pass count == INT_MAX to wake up all threads.
emscripten_futex_wake: function(addr, count) {
if (addr <= 0 || addr > HEAP8.length || addr&3 != 0 || count < 0) return -{{{ cDefine('EINVAL') }}};
if (count == 0) return 0;
// Waking (at least) INT_MAX waiters is defined to mean wake all callers.
// For Atomics.notify() API Infinity is to be passed in that case.
if (count >= {{{ cDefine('INT_MAX') }}}) count = Infinity;
// See if main thread is waiting on this address? If so, wake it up by resetting its wake location to zero.
// Note that this is not a fair procedure, since we always wake main thread first before any workers, so
// this scheme does not adhere to real queue-based waiting.
#if ASSERTIONS
assert(__emscripten_main_thread_futex > 0);
#endif
var mainThreadWaitAddress = Atomics.load(HEAP32, __emscripten_main_thread_futex >> 2);
var mainThreadWoken = 0;
if (mainThreadWaitAddress == addr) {
#if ASSERTIONS
// We only use __emscripten_main_thread_futex on the main browser thread, where we
// cannot block while we wait. Therefore we should only see it set from
// other threads, and not on the main thread itself. In other words, the
// main thread must never try to wake itself up!
assert(!ENVIRONMENT_IS_WEB);
#endif
var loadedAddr = Atomics.compareExchange(HEAP32, __emscripten_main_thread_futex >> 2, mainThreadWaitAddress, 0);
if (loadedAddr == mainThreadWaitAddress) {
--count;
mainThreadWoken = 1;
if (count <= 0) return 1;
}
}
// Wake any workers waiting on this address.
var ret = Atomics.notify(HEAP32, addr >> 2, count);
if (ret >= 0) return ret + mainThreadWoken;
throw 'Atomics.notify returned an unexpected value ' + ret;
},
__atomic_is_lock_free: function(size, ptr) {
return size <= 4 && (size & (size-1)) == 0 && (ptr&(size-1)) == 0;
},
__call_main: function(argc, argv) {
var returnCode = {{{ exportedAsmFunc('_main') }}}(argc, argv);
#if EXIT_RUNTIME
if (!keepRuntimeAlive()) {
// exitRuntime enabled, proxied main() finished in a pthread, shut down the process.
#if ASSERTIONS
out('Proxied main thread 0x' + _pthread_self().toString(16) + ' finished with return code ' + returnCode + '. EXIT_RUNTIME=1 set, quitting process.');
#endif
postMessage({ 'cmd': 'exitProcess', 'returnCode': returnCode });
return returnCode;
}
#else
// EXIT_RUNTIME==0 set on command line, keeping main thread alive.
#if ASSERTIONS
out('Proxied main thread 0x' + _pthread_self().toString(16) + ' finished with return code ' + returnCode + '. EXIT_RUNTIME=0 set, so keeping main thread alive for asynchronous event operations.');
#endif
#endif
},
emscripten_conditional_set_current_thread_status_js: function(expectedStatus, newStatus) {
#if PTHREADS_PROFILING
PThread.setThreadStatusConditional(_pthread_self(), expectedStatus, newStatus);
#endif
},
emscripten_set_current_thread_status_js: function(newStatus) {
#if PTHREADS_PROFILING
PThread.setThreadStatus(_pthread_self(), newStatus);
#endif
},
// The profiler setters are defined twice, here in asm.js so that they can be #if'ed out
// without having to pay the impact of a FFI transition for a no-op in non-profiling builds.
emscripten_conditional_set_current_thread_status__asm: true,
emscripten_conditional_set_current_thread_status__sig: 'vii',
emscripten_conditional_set_current_thread_status__deps: ['emscripten_conditional_set_current_thread_status_js'],
emscripten_conditional_set_current_thread_status: function(expectedStatus, newStatus) {
#if PTHREADS_PROFILING
expectedStatus = expectedStatus|0;
newStatus = newStatus|0;
_emscripten_conditional_set_current_thread_status_js(expectedStatus|0, newStatus|0);
#endif
},
emscripten_set_current_thread_status__asm: true,
emscripten_set_current_thread_status__sig: 'vi',
emscripten_set_current_thread_status__deps: ['emscripten_set_current_thread_status_js'],
emscripten_set_current_thread_status: function(newStatus) {
#if PTHREADS_PROFILING
newStatus = newStatus|0;
_emscripten_set_current_thread_status_js(newStatus|0);
#endif
},
emscripten_set_thread_name__asm: true,
emscripten_set_thread_name__sig: 'vii',
emscripten_set_thread_name: function(threadId, name) {
#if PTHREADS_PROFILING
threadId = threadId|0;
name = name|0;
PThread.setThreadName(threadId, UTF8ToString(name));
#endif
},
emscripten_proxy_to_main_thread_js__deps: ['emscripten_run_in_main_runtime_thread_js'],
emscripten_proxy_to_main_thread_js__docs: '/** @type{function(number, (number|boolean), ...(number|boolean))} */',
emscripten_proxy_to_main_thread_js: function(index, sync) {
// Additional arguments are passed after those two, which are the actual
// function arguments.
// The serialization buffer contains the number of call params, and then
// all the args here.
// We also pass 'sync' to C separately, since C needs to look at it.
var numCallArgs = arguments.length - 2;
#if ASSERTIONS
if (numCallArgs > {{{ cDefine('EM_QUEUED_JS_CALL_MAX_ARGS') }}}-1) throw 'emscripten_proxy_to_main_thread_js: Too many arguments ' + numCallArgs + ' to proxied function idx=' + index + ', maximum supported is ' + ({{{ cDefine('EM_QUEUED_JS_CALL_MAX_ARGS') }}}-1) + '!';
#endif
// Allocate a buffer, which will be copied by the C code.
var stack = stackSave();
// First passed parameter specifies the number of arguments to the function.
// When BigInt support is enabled, we must handle types in a more complex
// way, detecting at runtime if a value is a BigInt or not (as we have no
// type info here). To do that, add a "prefix" before each value that
// indicates if it is a BigInt, which effectively doubles the number of
// values we serialize for proxying. TODO: pack this?
var serializedNumCallArgs = numCallArgs {{{ WASM_BIGINT ? "* 2" : "" }}};
var args = stackAlloc(serializedNumCallArgs * 8);
var b = args >> 3;
for (var i = 0; i < numCallArgs; i++) {
var arg = arguments[2 + i];
#if WASM_BIGINT
if (typeof arg === 'bigint') {
// The prefix is non-zero to indicate a bigint.
HEAP64[b + 2*i] = BigInt(1);
HEAP64[b + 2*i + 1] = arg;
} else {
// The prefix is zero to indicate a JS Number.
HEAP64[b + 2*i] = BigInt(0);
HEAPF64[b + 2*i + 1] = arg;
}
#else
HEAPF64[b + i] = arg;
#endif
}
var ret = _emscripten_run_in_main_runtime_thread_js(index, serializedNumCallArgs, args, sync);
stackRestore(stack);
return ret;
},
emscripten_receive_on_main_thread_js_callArgs: '=[]',
emscripten_receive_on_main_thread_js__deps: [
'emscripten_proxy_to_main_thread_js',
'emscripten_receive_on_main_thread_js_callArgs',
'$readAsmConstArgs'],
emscripten_receive_on_main_thread_js: function(index, numCallArgs, args) {
#if WASM_BIGINT
numCallArgs /= 2;
#endif
_emscripten_receive_on_main_thread_js_callArgs.length = numCallArgs;
var b = args >> 3;
for (var i = 0; i < numCallArgs; i++) {
#if WASM_BIGINT
if (HEAP64[b + 2*i]) {
// It's a BigInt.
_emscripten_receive_on_main_thread_js_callArgs[i] = HEAP64[b + 2*i + 1];
} else {
// It's a Number.
_emscripten_receive_on_main_thread_js_callArgs[i] = HEAPF64[b + 2*i + 1];
}
#else
_emscripten_receive_on_main_thread_js_callArgs[i] = HEAPF64[b + i];
#endif
}
// Proxied JS library funcs are encoded as positive values, and
// EM_ASMs as negative values (see include_asm_consts)
var isEmAsmConst = index < 0;
var func = !isEmAsmConst ? proxiedFunctionTable[index] : ASM_CONSTS[-index - 1];
#if ASSERTIONS
assert(func.length == numCallArgs, 'Call args mismatch in emscripten_receive_on_main_thread_js');
#endif
return func.apply(null, _emscripten_receive_on_main_thread_js_callArgs);
},
$establishStackSpace: function(stackTop, stackMax) {
_emscripten_stack_set_limits(stackTop, stackMax);
#if STACK_OVERFLOW_CHECK >= 2
___set_stack_limits(_emscripten_stack_get_base(), _emscripten_stack_get_end());
#endif
// Call inside wasm module to set up the stack frame for this pthread in wasm module scope
stackRestore(stackTop);
#if STACK_OVERFLOW_CHECK
// Write the stack cookie last, after we have set up the proper bounds and
// current position of the stack.
writeStackCookie();
#endif
},
$invokeEntryPoint: function(ptr, arg) {
return {{{ makeDynCall('ii', 'ptr') }}}(arg);
},
// This function is called internally to notify target thread ID that it has messages it needs to
// process in its message queue inside the Wasm heap. As a helper, the caller must also pass the
// ID of the main browser thread to this function, to avoid needlessly ping-ponging between JS and
// Wasm boundaries.
_emscripten_notify_thread_queue: function(targetThreadId, mainThreadId) {
if (targetThreadId == mainThreadId) {
postMessage({'cmd' : 'processQueuedMainThreadWork'});
} else if (ENVIRONMENT_IS_PTHREAD) {
postMessage({'targetThread': targetThreadId, 'cmd': 'processThreadQueue'});
} else {
var pthread = PThread.pthreads[targetThreadId];
var worker = pthread && pthread.worker;
if (!worker) {
#if ASSERTIONS
err('Cannot send message to thread with ID ' + targetThreadId + ', unknown thread ID!');
#endif
return /*0*/;
}
worker.postMessage({'cmd' : 'processThreadQueue'});
}
return 1;
}
};
autoAddDeps(LibraryPThread, '$PThread');
mergeInto(LibraryManager.library, LibraryPThread);