Enable growable array buffers (#24684)

Currently this is still behind a flag so we never turn it on by default.
    
Fixes: #24287

Author: sbc100

.circleci/config.yml

@@ -320,7 +320,7 @@ commands:
             CHROME_FLAGS_BASE: "--no-first-run -start-maximized --no-sandbox --use-gl=swiftshader --user-data-dir=/tmp/chrome-emscripten-profile --enable-experimental-web-platform-features --enable-features=JavaScriptSourcePhaseImports"
             # Increase the window size to avoid flaky sdl tests see #24236.
             CHROME_FLAGS_HEADLESS: "--headless=new --window-size=1024,768 --remote-debugging-port=1234"
-            CHROME_FLAGS_WASM: "--enable-experimental-webassembly-features --js-flags=\"--experimental-wasm-stack-switching --experimental-wasm-type-reflection\""
+            CHROME_FLAGS_WASM: "--enable-experimental-webassembly-features --js-flags=\"--experimental-wasm-stack-switching --experimental-wasm-type-reflection --experimental-wasm-rab-integration\""
             CHROME_FLAGS_NOCACHE: "--disk-cache-dir=/dev/null --disk-cache-size=1 --media-cache-size=1 --disable-application-cache --incognito"
             # The runners lack sound hardware so fallback to a dummy device (and
             # bypass the user gesture so audio tests work without interaction)
@@ -820,6 +820,7 @@ jobs:
             other.test_gen_struct_info
             other.test_native_call_before_init
             other.test_node_unhandled_rejection
+            other.test_*growable_arraybuffers
             core2.test_hello_world
             core2.test_esm_integration*
             core0.test_esm_integration*
@@ -1023,6 +1024,7 @@ jobs:
             skip:browser.test_webgl_offscreen_canvas_in_pthread
             skip:browser.test_webgl_offscreen_canvas_in_mainthread_after_pthread
             skip:browser.test_glut_glutget
+            skip:browser.test_*_growable_arraybuffers
             "
   test-browser-firefox-wasm64:
     executor: focal

site/source/docs/tools_reference/settings_reference.rst

@@ -3343,6 +3343,19 @@ or chrome.
 
 Default value: false
 
+.. _growable_arraybuffers:
+
+GROWABLE_ARRAYBUFFERS
+=====================
+
+Enable support for GrowableSharedArrayBuffer.
+This features is only available behind a flag in recent versions of
+node/chrome.
+
+.. note:: This is an experimental setting
+
+Default value: false
+
 .. _wasm_js_types:
 
 WASM_JS_TYPES

src/lib/libcore.js

@@ -182,7 +182,9 @@ addToLibrary({
     try {
       // round size grow request up to wasm page size (fixed 64KB per spec)
       wasmMemory.grow({{{ toIndexType('pages') }}}); // .grow() takes a delta compared to the previous size
+#if !GROWABLE_ARRAYBUFFERS
       updateMemoryViews();
+#endif
 #if MEMORYPROFILER
       if (typeof emscriptenMemoryProfiler != 'undefined') {
         emscriptenMemoryProfiler.onMemoryResize(oldHeapSize, wasmMemory.buffer.byteLength);
@@ -320,6 +322,7 @@ addToLibrary({
 #endif // ALLOW_MEMORY_GROWTH
   },
 
+#if !GROWABLE_ARRAYBUFFERS
   // Called after wasm grows memory. At that time we need to update the views.
   // Without this notification, we'd need to check the buffer in JS every time
   // we return from any wasm, which adds overhead. See
@@ -330,6 +333,7 @@ addToLibrary({
 #endif
     updateMemoryViews();
   },
+#endif
 
   _emscripten_system: (command) => {
 #if ENVIRONMENT_MAY_BE_NODE
@@ -2415,7 +2419,7 @@ function wrapSyscallFunction(x, library, isWasi) {
 
   library[x + '__deps'] ??= [];
 
-#if PURE_WASI
+#if PURE_WASI && !GROWABLE_ARRAYBUFFERS
   // In PURE_WASI mode we can't assume the wasm binary was built by emscripten
   // and politely notify us on memory growth.  Instead we have to check for
   // possible memory growth on each syscall.

src/runtime_common.js

@@ -12,7 +12,7 @@
 #include "runtime_safe_heap.js"
 #endif
 
-#if SHARED_MEMORY && ALLOW_MEMORY_GROWTH
+#if SHARED_MEMORY && ALLOW_MEMORY_GROWTH && !GROWABLE_ARRAYBUFFERS
 #include "growableHeap.js"
 #endif
 
@@ -132,7 +132,11 @@ var runtimeExited = false;
 }}}
 
 function updateMemoryViews() {
+#if GROWABLE_ARRAYBUFFERS
+  var b = wasmMemory.toResizableBuffer();
+#else
   var b = wasmMemory.buffer;
+#endif
   {{{ maybeExportHeap('HEAP8')   }}}HEAP8 = new Int8Array(b);
   {{{ maybeExportHeap('HEAP16')  }}}HEAP16 = new Int16Array(b);
   {{{ maybeExportHeap('HEAPU8')  }}}HEAPU8 = new Uint8Array(b);

src/settings.js

@@ -2184,6 +2184,13 @@ var WASM_ESM_INTEGRATION = false;
 // [link]
 var JS_BASE64_API = false;
 
+// Enable support for GrowableSharedArrayBuffer.
+// This features is only available behind a flag in recent versions of
+// node/chrome.
+// [experimental]
+// [link]
+var GROWABLE_ARRAYBUFFERS = false;
+
 // Experimental support for WebAssembly js-types proposal.
 // It's currently only available under a flag in certain browsers,
 // so we disable it by default to save on code size.

test/test_browser.py

@@ -4739,17 +4739,21 @@ def test_minimal_runtime_hello_thread(self, opts):
   # Tests memory growth in pthreads mode, but still on the main thread.
   @parameterized({
     '': ([], 1),
+    'growable_arraybuffers': (['-sGROWABLE_ARRAYBUFFERS', '-Wno-experimental'], 1),
     'proxy': (['-sPROXY_TO_PTHREAD', '-sEXIT_RUNTIME'], 2),
   })
   @no_2gb('uses INITIAL_MEMORY')
   @no_4gb('uses INITIAL_MEMORY')
   def test_pthread_growth_mainthread(self, cflags, pthread_pool_size):
     self.set_setting('PTHREAD_POOL_SIZE', pthread_pool_size)
-    self.btest_exit('pthread/test_pthread_memory_growth_mainthread.c', cflags=['-Wno-pthreads-mem-growth', '-pthread', '-sALLOW_MEMORY_GROWTH', '-sINITIAL_MEMORY=32MB', '-sMAXIMUM_MEMORY=256MB'] + cflags)
+    if '-sGROWABLE_ARRAYBUFFERS' not in cflags:
+      self.cflags.append('-Wno-pthreads-mem-growth')
+    self.btest_exit('pthread/test_pthread_memory_growth_mainthread.c', cflags=['-pthread', '-sALLOW_MEMORY_GROWTH', '-sINITIAL_MEMORY=32MB', '-sMAXIMUM_MEMORY=256MB'] + cflags)
 
   # Tests memory growth in a pthread.
   @parameterized({
     '': ([],),
+    'growable_arraybuffers': (['-sGROWABLE_ARRAYBUFFERS', '-Wno-experimental'],),
     'assert': (['-sASSERTIONS'],),
     'proxy': (['-sPROXY_TO_PTHREAD'], 2),
     'minimal': (['-sMINIMAL_RUNTIME', '-sMODULARIZE', '-sEXPORT_NAME=MyModule'],),
@@ -4758,7 +4762,9 @@ def test_pthread_growth_mainthread(self, cflags, pthread_pool_size):
   @no_4gb('uses INITIAL_MEMORY')
   def test_pthread_growth(self, cflags, pthread_pool_size = 1):
     self.set_setting('PTHREAD_POOL_SIZE', pthread_pool_size)
-    self.btest_exit('pthread/test_pthread_memory_growth.c', cflags=['-Wno-pthreads-mem-growth', '-pthread', '-sALLOW_MEMORY_GROWTH', '-sINITIAL_MEMORY=32MB', '-sMAXIMUM_MEMORY=256MB'] + cflags)
+    if '-sGROWABLE_ARRAYBUFFERS' not in cflags:
+      self.cflags.append('-Wno-pthreads-mem-growth')
+    self.btest_exit('pthread/test_pthread_memory_growth.c', cflags=['-pthread', '-sALLOW_MEMORY_GROWTH', '-sINITIAL_MEMORY=32MB', '-sMAXIMUM_MEMORY=256MB'] + cflags)
 
   # Tests that time in a pthread is relative to the main thread, so measurements
   # on different threads are still monotonic, as if checking a single central

test/test_other.py

@@ -14282,23 +14282,52 @@ def test_pthread_kill(self):
   @node_pthreads
   @parameterized({
     '': ([], 1),
+    'growable_arraybuffers': (['-sGROWABLE_ARRAYBUFFERS', '-Wno-experimental'], 1),
     'proxy': (['-sPROXY_TO_PTHREAD', '-sEXIT_RUNTIME'], 2),
   })
   def test_pthread_growth_mainthread(self, cflags, pthread_pool_size):
+    if '-sGROWABLE_ARRAYBUFFERS' in cflags:
+      self.node_args.append('--experimental-wasm-rab-integration')
+      self.v8_args.append('--experimental-wasm-rab-integration')
+      self.require_node_canary()
+    else:
+      self.cflags.append('-Wno-pthreads-mem-growth')
     self.set_setting('PTHREAD_POOL_SIZE', pthread_pool_size)
-    self.do_runf('pthread/test_pthread_memory_growth_mainthread.c', cflags=['-Wno-pthreads-mem-growth', '-pthread', '-sALLOW_MEMORY_GROWTH', '-sINITIAL_MEMORY=32MB', '-sMAXIMUM_MEMORY=256MB'] + cflags)
+    self.do_runf('pthread/test_pthread_memory_growth_mainthread.c', cflags=['-pthread', '-sALLOW_MEMORY_GROWTH', '-sINITIAL_MEMORY=32MB', '-sMAXIMUM_MEMORY=256MB'] + cflags)
+
+  @requires_node_canary
+  def test_growable_arraybuffers(self):
+    self.node_args.append('--experimental-wasm-rab-integration')
+    self.v8_args.append('--experimental-wasm-rab-integration')
+    self.do_runf('hello_world.c',
+                 cflags=['-O2', '-pthread', '-sALLOW_MEMORY_GROWTH', '-sGROWABLE_ARRAYBUFFERS', '-Wno-experimental'],
+                 output_basename='growable')
+    self.do_runf('hello_world.c',
+                 cflags=['-O2', '-pthread', '-sALLOW_MEMORY_GROWTH', '-Wno-pthreads-mem-growth'],
+                 output_basename='no_growable')
+    growable_size = os.path.getsize('growable.js')
+    no_growable_size = os.path.getsize('no_growable.js')
+    print('growable:', growable_size, 'no_growable:', no_growable_size)
+    self.assertLess(growable_size, no_growable_size)
 
   # Tests memory growth in a pthread.
   @node_pthreads
   @parameterized({
     '': ([],),
+    'growable_arraybuffers': (['-sGROWABLE_ARRAYBUFFERS', '-Wno-experimental'],),
     'assert': (['-sASSERTIONS'],),
     'proxy': (['-sPROXY_TO_PTHREAD', '-sEXIT_RUNTIME'], 2),
     'minimal': (['-sMINIMAL_RUNTIME', '-sMODULARIZE', '-sEXPORT_NAME=MyModule'],),
   })
   def test_pthread_growth(self, cflags, pthread_pool_size = 1):
     self.set_setting('PTHREAD_POOL_SIZE', pthread_pool_size)
-    self.do_runf('pthread/test_pthread_memory_growth.c', cflags=['-Wno-pthreads-mem-growth', '-pthread', '-sALLOW_MEMORY_GROWTH', '-sINITIAL_MEMORY=32MB', '-sMAXIMUM_MEMORY=256MB'] + cflags)
+    if '-sGROWABLE_ARRAYBUFFERS' in cflags:
+      self.node_args.append('--experimental-wasm-rab-integration')
+      self.v8_args.append('--experimental-wasm-rab-integration')
+      self.require_node_canary()
+    else:
+      self.cflags.append('-Wno-pthreads-mem-growth')
+    self.do_runf('pthread/test_pthread_memory_growth.c', cflags=['-pthread', '-sALLOW_MEMORY_GROWTH', '-sINITIAL_MEMORY=32MB', '-sMAXIMUM_MEMORY=256MB'] + cflags)
 
   @node_pthreads
   def test_emscripten_set_interval(self):

tools/building.py

@@ -1059,6 +1059,7 @@ def little_endian_heap(js_file):
 
 
 def apply_wasm_memory_growth(js_file):
+  assert not settings.GROWABLE_ARRAYBUFFERS
   logger.debug('supporting wasm memory growth with pthreads')
   return acorn_optimizer(js_file, ['growableHeap'])
 

tools/link.py

@@ -509,7 +509,7 @@ def setup_pthreads():
       diagnostics.warning('experimental', '-sMAIN_MODULE + pthreads is experimental')
     elif settings.LINKABLE:
       diagnostics.warning('experimental', '-sLINKABLE + pthreads is experimental')
-  if settings.ALLOW_MEMORY_GROWTH:
+  if settings.ALLOW_MEMORY_GROWTH and not settings.GROWABLE_ARRAYBUFFERS:
     diagnostics.warning('pthreads-mem-growth', '-pthread + ALLOW_MEMORY_GROWTH may run non-wasm code slowly, see https://github.com/WebAssembly/design/issues/1271')
 
   default_setting('DEFAULT_PTHREAD_STACK_SIZE', settings.STACK_SIZE)
@@ -795,6 +795,9 @@ def phase_linker_setup(options, linker_args):  # noqa: C901, PLR0912, PLR0915
   if settings.JS_BASE64_API:
     diagnostics.warning('experimental', '-sJS_BASE64_API is still experimental and not yet supported in browsers')
 
+  if settings.GROWABLE_ARRAYBUFFERS:
+    diagnostics.warning('experimental', '-sGROWABLE_ARRAYBUFFERS is still experimental and not yet supported in browsers')
+
   if settings.SOURCE_PHASE_IMPORTS:
     if not settings.EXPORT_ES6:
       exit_with_error('SOURCE_PHASE_IMPORTS requires EXPORT_ES6')
@@ -2330,7 +2333,7 @@ def phase_binaryen(target, options, wasm_target):
     # unsigning pass.
     # we also must do this after the asan or safe_heap instrumentation, as they
     # wouldn't be able to recognize patterns produced by the growth pass.
-    if settings.SHARED_MEMORY and settings.ALLOW_MEMORY_GROWTH:
+    if settings.SHARED_MEMORY and settings.ALLOW_MEMORY_GROWTH and not settings.GROWABLE_ARRAYBUFFERS:
       with ToolchainProfiler.profile_block('apply_wasm_memory_growth'):
         final_js = building.apply_wasm_memory_growth(final_js)
 

tools/system_libs.py

@@ -2229,7 +2229,7 @@ def vary_on(cls):
   def get_default_variation(cls, **kwargs):
     return super().get_default_variation(
       is_mem_grow=settings.ALLOW_MEMORY_GROWTH,
-      is_pure=settings.PURE_WASI,
+      is_pure=settings.PURE_WASI or settings.GROWABLE_ARRAYBUFFERS,
       nocatch=settings.DISABLE_EXCEPTION_CATCHING and not settings.WASM_EXCEPTIONS,
       **kwargs,
     )