Allow SHARED_MEMORY flag to be used independently.

system/lib/compiler-rt/stack_limits.S

@@ -15,14 +15,17 @@
 #endif
 
 .globaltype __stack_pointer, PTR
+.globl __stack_pointer
 
 .section .globals,"",@
 
 # TODO(sbc): It would be nice if these we initialized directly
 # using PTR.const rather than using the `emscripten_stack_init`
 .globaltype __stack_end, PTR
 __stack_end:
+.globl __stack_end
 .globaltype __stack_base, PTR
+.globl __stack_base
 __stack_base:
 
 .section .text,"",@
@@ -82,57 +85,6 @@ emscripten_stack_get_free:
   PTR.sub
   end_function
 
-#ifdef __EMSCRIPTEN_WASM_WORKERS__
-# TODO: Relocate the following to its own file wasm_worker.S, but need to figure out how to reference
-# __stack_base and __stack_end globals from a separate file as externs in order for that to work.
-.globl _emscripten_wasm_worker_initialize
-_emscripten_wasm_worker_initialize:
-  .functype _emscripten_wasm_worker_initialize (PTR /*stackLowestAddress*/, i32 /*stackSize*/) -> ()
-
-  // __stack_end = stackLowestAddress + (__builtin_wasm_tls_size() + 15) & -16;
-  local.get 0
-  .globaltype __tls_size, PTR, immutable
-  global.get __tls_size
-  PTR.add
-  PTR.const 0xf
-  PTR.add
-  PTR.const -0x10
-  PTR.and
-  global.set __stack_end
-
-  // __stack_base = stackLowestAddress + stackSize;
-  local.get 0
-  local.get 1
-#ifdef __wasm64__
-  i64.extend_i32_u
-#endif
-  PTR.add
-  global.set __stack_base
-
-// TODO: We'd like to do this here to avoid JS side calls to __set_stack_limits.
-//       (or even better, we'd like to avoid duplicate versions of the stack variables)
-// See https://github.com/emscripten-core/emscripten/issues/16496
-//  global.get __stack_base
-//  global.get __stack_end
-//  .functype __set_stack_limits (PTR, PTR) -> ()
-//  call __set_stack_limits
-
-  // __wasm_init_tls(stackLowestAddress);
-  local.get 0
-  .functype __wasm_init_tls (PTR) -> ()
-  call __wasm_init_tls
-
-  // N.b. The function __wasm_init_tls above does not need
-  // __stack_pointer initialized, and it destroys the value it was set to.
-  // So we must initialize __stack_pointer only *after* completing __wasm_init_tls:
-
-  // __stack_pointer = __stack_base;
-  global.get __stack_base
-  global.set __stack_pointer
-
-  end_function
-#endif
-
 # Add emscripten_stack_init to static ctors
 .section .init_array.1,"",@
 .p2align ALIGN

system/lib/dlmalloc.c

@@ -21,13 +21,12 @@
 /* XXX Emscripten Tracing API. This defines away the code if tracing is disabled. */
 #include <emscripten/trace.h>
 
-#ifdef __EMSCRIPTEN_WASM_WORKERS__
+#ifdef __EMSCRIPTEN_SHARED_MEMORY__
 #define USE_LOCKS 1
 #endif
 
 /* Make malloc() and free() threadsafe by securing the memory allocations with pthread mutexes. */
 #if __EMSCRIPTEN_PTHREADS__
-#define USE_LOCKS 1
 #define USE_SPIN_LOCKS 0 // Ensure we use pthread_mutex_t.
 #endif
 

system/lib/wasm_worker/wasm_worker.S

@@ -0,0 +1,64 @@
+.extern __stack_pointer
+.extern __stack_base
+.extern __stack_end
+
+#ifdef __wasm64__
+#define PTR i64
+#define ALIGN 3
+#define PTRSTORE .int64
+#else
+#define PTR i32
+#define ALIGN 2
+#define PTRSTORE .int32
+#endif
+
+.globaltype __stack_pointer, PTR
+.globaltype __stack_end, PTR
+.globaltype __stack_base, PTR
+
+.globl _emscripten_wasm_worker_initialize
+_emscripten_wasm_worker_initialize:
+  .functype _emscripten_wasm_worker_initialize (PTR /*stackLowestAddress*/, i32 /*stackSize*/) -> ()
+
+  // __stack_end = stackLowestAddress + (__builtin_wasm_tls_size() + 15) & -16;
+  local.get 0
+  .globaltype __tls_size, PTR, immutable
+  global.get __tls_size
+  PTR.add
+  PTR.const 0xf
+  PTR.add
+  PTR.const -0x10
+  PTR.and
+  global.set __stack_end
+
+  // __stack_base = stackLowestAddress + stackSize;
+  local.get 0
+  local.get 1
+#ifdef __wasm64__
+  i64.extend_i32_u
+#endif
+  PTR.add
+  global.set __stack_base
+
+// TODO: We'd like to do this here to avoid JS side calls to __set_stack_limits.
+//       (or even better, we'd like to avoid duplicate versions of the stack variables)
+// See https://github.com/emscripten-core/emscripten/issues/16496
+//  global.get __stack_base
+//  global.get __stack_end
+//  .functype __set_stack_limits (PTR, PTR) -> ()
+//  call __set_stack_limits
+
+  // __wasm_init_tls(stackLowestAddress);
+  local.get 0
+  .functype __wasm_init_tls (PTR) -> ()
+  call __wasm_init_tls
+
+  // N.b. The function __wasm_init_tls above does not need
+  // __stack_pointer initialized, and it destroys the value it was set to.
+  // So we must initialize __stack_pointer only *after* completing __wasm_init_tls:
+
+  // __stack_pointer = __stack_base;
+  global.get __stack_base
+  global.set __stack_pointer
+
+  end_function

test/core/test_dlfcn_self.exports

@@ -9,7 +9,9 @@ __progname_full
 __sig_actions
 __sig_pending
 __signgam
+__stack_base
 __stack_chk_guard
+__stack_end
 __threwValue
 __timezone
 __tzname

test/core/test_em_asm_unicode.out

@@ -1 +1 @@
-hello world…
+hello world…

test/core/test_longjmp.out

@@ -1,4 +1,4 @@
 first
 result: 1 1
 second
-result: 2 -1
+result: 2 -1

tools/link.py

@@ -1413,7 +1413,7 @@ def phase_linker_setup(options, state, newargs):
       'removeRunDependency',
     ]
 
-  if settings.SHARED_MEMORY or settings.RELOCATABLE or settings.ASYNCIFY_LAZY_LOAD_CODE:
+  if settings.PTHREADS or settings.WASM_WORKERS or settings.RELOCATABLE or settings.ASYNCIFY_LAZY_LOAD_CODE:
     settings.IMPORTED_MEMORY = 1
 
   set_initial_memory()

tools/system_libs.py

@@ -725,7 +725,7 @@ def get_cflags(self):
     if self.is_mt:
       cflags += ['-pthread', '-sWASM_WORKERS']
     if self.is_ww:
-      cflags += ['-sWASM_WORKERS']
+      cflags += ['-sSHARED_MEMORY=1']
     return cflags
 
   def get_base_name(self):
@@ -742,12 +742,17 @@ def vary_on(cls):
 
   @classmethod
   def get_default_variation(cls, **kwargs):
-    return super().get_default_variation(is_mt=settings.PTHREADS, is_ww=settings.WASM_WORKERS and not settings.PTHREADS, **kwargs)
+    return super().get_default_variation(
+      is_mt=settings.PTHREADS,
+      is_ww=settings.SHARED_MEMORY and not settings.PTHREADS,
+      **kwargs
+    )
 
   @classmethod
   def variations(cls):
     combos = super(MTLibrary, cls).variations()
-    # To save on # of variations, pthreads and Wasm workers when used together, just use pthreads variation.
+
+    # These are mutually exclusive, only one flag will be set at any give time.
     return [combo for combo in combos if not combo['is_mt'] or not combo['is_ww']]
 
 
@@ -1420,6 +1425,8 @@ def __init__(self, **kwargs):
 
   def get_cflags(self):
     cflags = super().get_cflags()
+    if self.is_ww:
+      cflags += ['-sWASM_WORKERS']
     if self.debug:
       cflags += ['-D_DEBUG']
       # library_wasm_worker.c contains an assert that a nonnull parameter
@@ -1452,9 +1459,19 @@ def get_default_variation(cls, **kwargs):
     return super().get_default_variation(debug=settings.ASSERTIONS >= 1, **kwargs)
 
   def get_files(self):
+    files = []
+    if self.is_ww:
+      files = [
+        'library_wasm_worker.c',
+        'wasm_worker.S',
+      ]
+    else:
+      files = [
+        'library_wasm_worker_stub.c'
+      ]
     return files_in_path(
         path='system/lib/wasm_worker',
-        filenames=['library_wasm_worker.c' if self.is_ww or self.is_mt else 'library_wasm_worker_stub.c'])
+        filenames=files)
 
   def can_use(self):
     # see src/library_wasm_worker.js