[wasi] Implement TODO in mono-threads-wasi.S (#101337)

src/mono/mono/utils/CMakeLists.txt

@@ -17,7 +17,7 @@ if(HOST_WIN32 AND HOST_AMD64)
     set(CMAKE_ASM_MASM_COMPILE_OPTIONS_MSVC_RUNTIME_LIBRARY_MultiThreadedDebugDLL "")
 
     list(APPEND utils_win32_sources win64.asm)
-elseif(HOST_WASI)
+elseif(HOST_WASM)
     set (CMAKE_ASM_COMPILER_VERSION "${CMAKE_C_COMPILER_VERSION}")
     set (CMAKE_ASM_COMPILER_TARGET "${CMAKE_C_COMPILER_TARGET}")
     enable_language(ASM)
@@ -30,8 +30,8 @@ set(utils_unix_sources
 
 if(HOST_WIN32)
     set(utils_platform_sources ${utils_win32_sources})
-elseif(HOST_WASI)
-    set(utils_platform_sources ${utils_unix_sources} mono-threads-wasi.S)
+elseif(HOST_WASM)
+    set(utils_platform_sources ${utils_unix_sources} mono-threads-wasm.S)
 else()
     set(utils_platform_sources ${utils_unix_sources})
 endif()

src/mono/mono/utils/mono-threads-wasm.S

@@ -0,0 +1,17 @@
+.globl get_wasm_stack_low
+.globl get_wasm_stack_high
+
+get_wasm_stack_low:
+  .functype get_wasm_stack_low () -> (i32)
+  global.get __stack_low@GOT
+  // align up to 16 bytes
+  i32.const 0xF
+  i32.add
+  i32.const -0x10
+  i32.and
+  end_function
+
+get_wasm_stack_high:
+  .functype get_wasm_stack_high () -> (i32)
+  global.get __stack_high@GOT
+  end_function

src/mono/mono/utils/mono-threads-wasm.c

@@ -20,74 +20,46 @@
 #include <mono/utils/mono-threads-wasm.h>
 
 #include <emscripten.h>
-#include <emscripten/stack.h>
 #ifndef DISABLE_THREADS
 #include <emscripten/threading.h>
 #include <mono/metadata/threads-types.h>
 #endif
 
+#endif
 
-#define round_down(addr, val) ((void*)((addr) & ~((val) - 1)))
-
-EMSCRIPTEN_KEEPALIVE
-static int
-wasm_get_stack_base (void)
-{
-	// wasm-mt: add MONO_ENTER_GC_UNSAFE / MONO_EXIT_GC_UNSAFE if this function becomes more complex
-	return emscripten_stack_get_end ();
-}
-
-EMSCRIPTEN_KEEPALIVE
-static int
-wasm_get_stack_size (void)
-{
-	// wasm-mt: add MONO_ENTER_GC_UNSAFE / MONO_EXIT_GC_UNSAFE if this function becomes more complex
-	return (guint8*)emscripten_stack_get_base () - (guint8*)emscripten_stack_get_end ();
-}
-
-#else /* HOST_BROWSER -> WASI */
-
-// TODO after https://github.com/llvm/llvm-project/commit/1532be98f99384990544bd5289ba339bca61e15b
-// use __stack_low && __stack_high
-// see mono-threads-wasi.S
-uintptr_t get_wasm_heap_base(void);
-uintptr_t get_wasm_data_end(void);
+uintptr_t get_wasm_stack_high(void);
+uintptr_t get_wasm_stack_low(void);
 
 static int
 wasm_get_stack_size (void)
 {
+#if defined(HOST_WASI) && !defined(DISABLE_THREADS)
+	// TODO: this will need changes for WASI multithreading as the stack will be allocated per thread at different addresses
+	g_assert_not_reached ();
+#else
 	/*
 	 * | -- increasing address ---> |
-	 * | data (data_end)| stack |(heap_base) heap |
+	 * | data |(stack low) stack (stack high)| heap |
 	 */
-	size_t heap_base = get_wasm_heap_base();
-	size_t data_end = get_wasm_data_end();
-	size_t max_stack_size = heap_base - data_end;
-
-	g_assert (data_end > 0);
-	g_assert (heap_base > data_end);
+	size_t stack_high = get_wasm_stack_high();
+	size_t stack_low = get_wasm_stack_low();
+	size_t max_stack_size = stack_high - stack_low;
 
-	// this is the max available stack size size,
-	// return a 16-byte aligned smaller size
-	return max_stack_size & ~0xF;
-}
+	g_assert (stack_low >= 0);
+	g_assert (stack_high > stack_low);
+	g_assert (max_stack_size >= 64 * 1024);
 
-static int
-wasm_get_stack_base (void)
-{
-	return get_wasm_data_end();
-	// this will need further change for multithreading as the stack will allocated be per thread at different addresses
+	// this is the max available stack size size
+	return max_stack_size;
+#endif
 }
 
-#endif /* HOST_BROWSER */
-
 int
 mono_thread_info_get_system_max_stack_size (void)
 {
 	return wasm_get_stack_size ();
 }
 
-
 void
 mono_threads_suspend_init_signals (void)
 {
@@ -226,12 +198,13 @@ mono_threads_platform_get_stack_bounds (guint8 **staddr, size_t *stsize)
 	if (G_UNLIKELY (res != 0))
 		g_error ("%s: pthread_attr_destroy failed with \"%s\" (%d)", __func__, g_strerror (res), res);
 
-	if (*staddr == NULL) {
-		*staddr = (guint8*)wasm_get_stack_base ();
-		*stsize = wasm_get_stack_size ();
-	}
+	g_assert (*staddr != NULL);
+	g_assert (*stsize != (size_t)-1);
+#elif defined(HOST_WASI) && !defined(DISABLE_THREADS)
+	// TODO: this will need changes for WASI multithreading as the stack will be allocated per thread at different addresses
+	g_assert_not_reached ();
 #else
-	*staddr = (guint8*)wasm_get_stack_base ();
+	*staddr = (guint8*)get_wasm_stack_low ();
 	*stsize = wasm_get_stack_size ();
 #endif