Add support for WASI threads

Author: Milek7

eng/native/gen-buildsys.cmd

@@ -22,6 +22,7 @@ set __Arch=%4
 set __Os=%5
 set __CmakeGenerator=Visual Studio
 set __UseEmcmake=0
+set __Pthreads=0
 if /i "%__Ninja%" == "1" (
     set __CmakeGenerator=Ninja
 ) else (
@@ -37,6 +38,14 @@ if /i "%__Ninja%" == "1" (
     )
 )
 
+:loop
+if [%6] == [] goto end_loop
+if ""%6"" == """-DCMAKE_USE_PTHREADS=1""" set __Pthreads=1
+set __ExtraCmakeParams=%__ExtraCmakeParams% %6
+shift
+goto loop
+:end_loop
+
 if /i "%__Arch%" == "wasm" (
 
     if "%__Os%" == "" (
@@ -72,19 +81,16 @@ if /i "%__Arch%" == "wasm" (
         set "WASI_SDK_PATH=!WASI_SDK_PATH:\=/!"
         if not "!WASI_SDK_PATH:~-1!" == "/" set "WASI_SDK_PATH=!WASI_SDK_PATH!/"
         set __CmakeGenerator=Ninja
-        set __ExtraCmakeParams=%__ExtraCmakeParams% -DCLR_CMAKE_TARGET_OS=wasi -DCLR_CMAKE_TARGET_ARCH=wasm "-DWASI_SDK_PREFIX=!WASI_SDK_PATH!" "-DCMAKE_TOOLCHAIN_FILE=!WASI_SDK_PATH!/share/cmake/wasi-sdk.cmake" "-DCMAKE_SYSROOT=!WASI_SDK_PATH!/share/wasi-sysroot"
+        if "%__Pthreads%" == "1" (
+            set __ExtraCmakeParams=%__ExtraCmakeParams% -DCLR_CMAKE_TARGET_OS=wasi -DCLR_CMAKE_TARGET_ARCH=wasm "-DWASI_SDK_PREFIX=!WASI_SDK_PATH!" "-DCMAKE_TOOLCHAIN_FILE=!WASI_SDK_PATH!/share/cmake/wasi-sdk-pthread.cmake" "-DCMAKE_SYSROOT=!WASI_SDK_PATH!/share/wasi-sysroot"
+        ) else (
+            set __ExtraCmakeParams=%__ExtraCmakeParams% -DCLR_CMAKE_TARGET_OS=wasi -DCLR_CMAKE_TARGET_ARCH=wasm "-DWASI_SDK_PREFIX=!WASI_SDK_PATH!" "-DCMAKE_TOOLCHAIN_FILE=!WASI_SDK_PATH!/share/cmake/wasi-sdk.cmake" "-DCMAKE_SYSROOT=!WASI_SDK_PATH!/share/wasi-sysroot"
+        )
     )
 ) else (
     set __ExtraCmakeParams=%__ExtraCmakeParams%  "-DCMAKE_SYSTEM_VERSION=10.0"
 )
 
-:loop
-if [%6] == [] goto end_loop
-set __ExtraCmakeParams=%__ExtraCmakeParams% %6
-shift
-goto loop
-:end_loop
-
 set __ExtraCmakeParams="-DCMAKE_INSTALL_PREFIX=%__CMakeBinDir%" "-DCLR_CMAKE_HOST_ARCH=%__Arch%" %__ExtraCmakeParams%
 
 set __CmdLineOptionsUpToDateFile=%__IntermediatesDir%\cmake_cmd_line.txt

src/mono/CMakeLists.txt

@@ -154,6 +154,10 @@ if(NOT AOT_TARGET_TRIPLE STREQUAL "")
   elseif(AOT_TARGET_TRIPLE STREQUAL "wasm32-unknown-wasi")
     set(TARGET_SYSTEM_NAME "wasi")
     set(TARGET_ARCH "wasm")
+  elseif(AOT_TARGET_TRIPLE STREQUAL "wasm32-unknown-wasi-threads")
+    set(TARGET_SYSTEM_NAME "wasi")
+    set(TARGET_SYSTEM_VARIANT "threads")
+    set(TARGET_ARCH "wasm")
   elseif(AOT_TARGET_TRIPLE STREQUAL "x86_64-none-linux-android")
     set(TARGET_SYSTEM_NAME "android")
     set(TARGET_ARCH "x86_64")
@@ -181,11 +185,17 @@ endif()
 # HOST OS CHECKS
 ######################################
 
+if("${triple}" STREQUAL "wasm32-wasi-threads")
+  set(CMAKE_SYSTEM_VARIANT "threads")
+endif()
+
 message ("CMAKE_SYSTEM_NAME=${CMAKE_SYSTEM_NAME}")
 message ("CMAKE_SYSTEM_VARIANT=${CMAKE_SYSTEM_VARIANT}")
 
 set(CLR_CMAKE_HOST_OS ${CMAKE_SYSTEM_NAME})
-string(TOLOWER ${CLR_CMAKE_HOST_OS} CLR_CMAKE_HOST_OS)
+set(CLR_CMAKE_HOST_VARIANT ${CMAKE_SYSTEM_VARIANT})
+string(TOLOWER "${CLR_CMAKE_HOST_OS}" CLR_CMAKE_HOST_OS)
+string(TOLOWER "${CLR_CMAKE_HOST_VARIANT}" CLR_CMAKE_HOST_VARIANT)
 
 # TODO: check if we can enable this on more platforms
 # set(MONO_KEYWORD_THREAD "__thread")
@@ -196,7 +206,7 @@ if(CLR_CMAKE_HOST_OS STREQUAL "darwin")
   set(HOST_OSX 1)
   set(PTHREAD_POINTER_ID 1)
   set(USE_MACH_SEMA 1)
-  if(CMAKE_SYSTEM_VARIANT STREQUAL "maccatalyst")
+  if(CLR_CMAKE_HOST_VARIANT STREQUAL "maccatalyst")
     set(HOST_MACCAT 1)
   endif()
 elseif(CLR_CMAKE_HOST_OS STREQUAL "ios" OR CLR_CMAKE_HOST_OS STREQUAL "tvos")
@@ -312,14 +322,15 @@ endif()
 
 if(NOT TARGET_SYSTEM_NAME)
   set(TARGET_SYSTEM_NAME "${CLR_CMAKE_HOST_OS}")
+  set(TARGET_SYSTEM_VARIANT "${CLR_CMAKE_HOST_VARIANT}")
 endif()
 
 if(TARGET_SYSTEM_NAME STREQUAL "darwin")
   set(TARGET_UNIX 1)
   set(TARGET_MACH 1)
   set(TARGET_OSX 1)
   set(TARGET_DARWIN 1)
-  if(CMAKE_SYSTEM_VARIANT STREQUAL "maccatalyst")
+  if(TARGET_SYSTEM_VARIANT STREQUAL "maccatalyst")
     set(TARGET_MACCAT 1)
   endif()
 elseif(TARGET_SYSTEM_NAME STREQUAL "ios" OR TARGET_SYSTEM_NAME STREQUAL "tvos")
@@ -353,7 +364,9 @@ elseif(TARGET_SYSTEM_NAME STREQUAL "emscripten")
   endif()
 elseif(TARGET_SYSTEM_NAME STREQUAL "wasi")
   set(TARGET_WASI 1)
-  set(DISABLE_THREADS 1)
+  if (NOT (TARGET_SYSTEM_VARIANT STREQUAL "threads"))
+    set(DISABLE_THREADS 1)
+  endif()
   if (CMAKE_BUILD_TYPE STREQUAL "Release")
     add_compile_options(-Os)
   endif()

src/mono/mono.proj

@@ -59,6 +59,7 @@
   <PropertyGroup>
     <MonoThreadSuspend Condition="'$(TargetswatchOS)' == 'true' and '$(MonoThreadSuspend)' == ''">coop</MonoThreadSuspend>
     <MonoThreadSuspend Condition="'$(TargetsBrowser)' == 'true' and '$(WasmEnableThreads)' == 'true' and '$(MonoThreadSuspend)' == ''">coop</MonoThreadSuspend>
+    <MonoThreadSuspend Condition="'$(TargetsWasi)' == 'true' and '$(WasmEnableThreads)' == 'true' and '$(MonoThreadSuspend)' == ''">coop</MonoThreadSuspend>
     <!-- wasm isn't really preemptive, but we don't want safepoints -->
     <MonoThreadSuspend Condition="( '$(TargetsBrowser)' == 'true' or '$(TargetsWasi)' == 'true' ) and '$(MonoThreadSuspend)' == ''">preemptive</MonoThreadSuspend>
     <!-- all other platforms -->
@@ -619,7 +620,8 @@
       <_MonoCMakeConfigureCommand>cmake @(_MonoCMakeArgs, ' ') $(MonoCMakeExtraArgs) &quot;$(MonoProjectRoot.TrimEnd('\/'))&quot;</_MonoCMakeConfigureCommand>
       <_MonoCMakeConfigureCommand Condition="'$(TargetsBrowser)' != 'true' and '$(TargetsWasi)' != 'true' and '$(_MonoSkipInitCompiler)' != 'true' and '$(HostOS)' != 'windows'">sh -c 'build_arch=&quot;$(_CompilerTargetArch)&quot; compiler=&quot;$(MonoCCompiler)&quot; . &quot;$(RepositoryEngineeringCommonDir)native/init-compiler.sh&quot; &amp;&amp; @(_MonoBuildEnv, ' ') $(_MonoCMakeConfigureCommand)'</_MonoCMakeConfigureCommand>
       <_MonoCMakeConfigureCommand Condition="'$(TargetsBrowser)' != 'true' and '$(TargetsWasi)' != 'true' and '$(_MonoSkipInitCompiler)' == 'true' and '$(HostOS)' != 'windows'">$(_MonoCCOption) $(_MonoCXXOption) @(_MonoBuildEnv, ' ') $(_MonoCMakeConfigureCommand)</_MonoCMakeConfigureCommand>
-      <_MonoCMakeConfigureCommand Condition="'$(TargetsWasi)' == 'true'">$(_MonoCMakeConfigureCommand) -DWASI_SDK_PREFIX=$(WASI_SDK_PATH) -DCMAKE_SYSROOT=$(WASI_SDK_PATH)share/wasi-sysroot -DCMAKE_TOOLCHAIN_FILE=$(WASI_SDK_PATH)share/cmake/wasi-sdk.cmake -DCMAKE_CXX_FLAGS="--sysroot=$(WASI_SDK_PATH)share/wasi-sysroot"</_MonoCMakeConfigureCommand>
+      <_MonoCMakeConfigureCommand Condition="'$(TargetsWasi)' == 'true' and '$(WasmEnableThreads)' != 'true'">$(_MonoCMakeConfigureCommand) -DWASI_SDK_PREFIX=$(WASI_SDK_PATH) -DCMAKE_SYSROOT=$(WASI_SDK_PATH)share/wasi-sysroot -DCMAKE_TOOLCHAIN_FILE=$(WASI_SDK_PATH)share/cmake/wasi-sdk.cmake -DCMAKE_CXX_FLAGS="--sysroot=$(WASI_SDK_PATH)share/wasi-sysroot"</_MonoCMakeConfigureCommand>
+      <_MonoCMakeConfigureCommand Condition="'$(TargetsWasi)' == 'true' and '$(WasmEnableThreads)' == 'true'">$(_MonoCMakeConfigureCommand) -DWASI_SDK_PREFIX=$(WASI_SDK_PATH) -DCMAKE_SYSROOT=$(WASI_SDK_PATH)share/wasi-sysroot -DCMAKE_TOOLCHAIN_FILE=$(WASI_SDK_PATH)share/cmake/wasi-sdk-pthread.cmake -DCMAKE_CXX_FLAGS="--sysroot=$(WASI_SDK_PATH)share/wasi-sysroot"</_MonoCMakeConfigureCommand>
 
       <_MonoCMakeConfigureCommand Condition="'$(TargetsBrowser)' != 'true' and '$(TargetsWasi)' != 'true' and '$(HostOS)' == 'windows'">call &quot;$(RepositoryEngineeringDir)native\init-vs-env.cmd&quot; $(_CompilerTargetArch) &amp;&amp; cd /D &quot;$(MonoObjDir)&quot; &amp;&amp; @(_MonoBuildEnv, ' ') $(_MonoCMakeConfigureCommand)</_MonoCMakeConfigureCommand>
       <_MonoCMakeConfigureCommand Condition="'$(TargetsBrowser)' == 'true' and '$(HostOS)' != 'windows'">bash -c 'source $(EMSDK_PATH)/emsdk_env.sh 2>&amp;1 &amp;&amp; emcmake $(_MonoCMakeConfigureCommand)'</_MonoCMakeConfigureCommand>
@@ -741,7 +743,8 @@
     <PropertyGroup Condition="'$(TargetsBrowser)' == 'true' or '$(TargetsWasi)' == 'true'">
       <MonoUseCrossTool>true</MonoUseCrossTool>
       <MonoAotAbi Condition="'$(TargetsBrowser)' == 'true'">wasm32-unknown-none</MonoAotAbi>
-      <MonoAotAbi Condition="'$(TargetsWasi)' == 'true'">wasm32-unknown-wasi</MonoAotAbi>
+      <MonoAotAbi Condition="'$(TargetsWasi)' == 'true' and $(WasmEnableThreads) != 'true'">wasm32-unknown-wasi</MonoAotAbi>
+      <MonoAotAbi Condition="'$(TargetsWasi)' == 'true' and $(WasmEnableThreads) == 'true'">wasm32-unknown-wasi-threads</MonoAotAbi>
       <MonoAotOffsetsFile>$(MonoObjCrossDir)offsets-wasm32-unknown-none.h</MonoAotOffsetsFile>
       <MonoLibClang Condition="$([MSBuild]::IsOSPlatform('OSX'))">$(MonoLLVMDir)/$(BuildArchitecture)/lib/libclang.dylib</MonoLibClang>
       <MonoLibClang Condition="$([MSBuild]::IsOSPlatform('Linux'))">$(MonoLLVMDir)/$(BuildArchitecture)/lib/libclang.so</MonoLibClang>

src/mono/mono/component/diagnostics_server.c

@@ -7,7 +7,7 @@
 #include <mono/utils/mono-publib.h>
 #include <mono/utils/mono-compiler.h>
 #include <eventpipe/ds-server.h>
-#if defined (HOST_WASM) && !defined(HOST_WASI)
+#if defined(HOST_BROWSER)
 #include <eventpipe/ep-ipc-stream.h>
 #include <mono/component/event_pipe-wasm.h>
 #include <mono/utils/mono-coop-semaphore.h>
@@ -19,7 +19,7 @@
 static bool
 diagnostics_server_available (void);
 
-#if !defined (HOST_WASM) || defined (DISABLE_THREADS)
+#if !defined(HOST_BROWSER) || defined (DISABLE_THREADS)
 static MonoComponentDiagnosticsServer fn_table = {
 	{ MONO_COMPONENT_ITF_VERSION, &diagnostics_server_available },
 	&ds_server_init,
@@ -349,7 +349,7 @@ wasm_ipc_stream_close (void *self)
 	return r == 0;
 }
 
-#endif /* !defined (HOST_WASM) || defined (DISABLE_THREADS) */
+#endif /* !defined (HOST_BROWSER) || defined (DISABLE_THREADS) */
 
 static bool
 diagnostics_server_available (void)

src/mono/mono/metadata/gc.c

@@ -691,7 +691,7 @@ mono_gc_finalize_notify (void)
 	if (mono_gc_is_null ())
 		return;
 
-#if defined(HOST_WASI)
+#if defined(HOST_WASI) && defined(DISABLE_THREADS)
 	// TODO: Schedule the background job on WASI. Threads aren't yet supported in this build.
 #elif defined(HOST_WASM) && defined(DISABLE_THREADS)
 	mono_main_thread_schedule_background_job (mono_runtime_do_background_work);

src/mono/mono/metadata/sgen-mono.c

@@ -2893,7 +2893,7 @@ sgen_client_binary_protocol_collection_end (int minor_gc_count, int generation,
 	MONO_PROFILER_RAISE (gc_event, (MONO_GC_EVENT_END, generation, generation == GENERATION_OLD && sgen_concurrent_collection_in_progress));
 }
 
-#if defined(HOST_WASM) && defined(DISABLE_THREADS)
+#if defined(HOST_BROWSER) && defined(DISABLE_THREADS)
 void
 sgen_client_schedule_background_job (void (*cb)(void))
 {

src/mono/mono/metadata/threads.c

@@ -1286,8 +1286,11 @@ start_wrapper (gpointer data)
 	}
 
 	mono_thread_info_exit (res);
-
+#ifdef HOST_WASI
+	return (mono_thread_start_return_t)res;
+#else
 	g_assert_not_reached ();
+#endif
 }
 
 static void
@@ -1754,6 +1757,8 @@ mono_thread_exit (void)
 		exit (mono_environment_exitcode_get ());
 
 	mono_thread_info_exit (0);
+
+	g_assert_not_reached ();
 }
 
 MonoThread *
@@ -2889,6 +2894,8 @@ mono_threads_set_shutting_down (void)
 
 		/* Wake up other threads potentially waiting for us */
 		mono_thread_info_exit (0);
+
+		g_assert_not_reached ();
 	} else {
 		shutting_down = TRUE;
 

src/mono/mono/mini/mini-wasm.h

@@ -91,8 +91,10 @@ typedef struct {
 #define MONO_ARCH_HAS_REGISTER_ICALL 1
 #define MONO_ARCH_HAVE_SDB_TRAMPOLINES 1
 #define MONO_ARCH_LLVM_TARGET_LAYOUT "e-m:e-p:32:32-i64:64-n32:64-S128"
-#ifdef TARGET_WASI
+#if defined(TARGET_WASI) && defined(DISABLE_THREADS)
 #define MONO_ARCH_LLVM_TARGET_TRIPLE "wasm32-unknown-wasi"
+#elif defined(TARGET_WASI)
+#define MONO_ARCH_LLVM_TARGET_TRIPLE "wasm32-unknown-wasi-threads"
 #else
 #define MONO_ARCH_LLVM_TARGET_TRIPLE "wasm32-unknown-emscripten"
 #endif

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

@@ -32,7 +32,7 @@
 
 #include <errno.h>
 
-#if defined(_POSIX_VERSION) && !defined (HOST_WASM)
+#if defined(_POSIX_VERSION) && !defined (USE_WASM_BACKEND)
 
 #include <pthread.h>
 
@@ -127,11 +127,13 @@ mono_threads_platform_yield (void)
 	return sched_yield () == 0;
 }
 
+#ifndef USE_PTHREAD_WASM_BACKEND
 void
 mono_threads_platform_exit (gsize exit_code)
 {
 	pthread_exit ((gpointer) exit_code);
 }
+#endif
 
 gboolean
 mono_thread_platform_external_eventloop_keepalive_check (void)
@@ -142,7 +144,7 @@ mono_thread_platform_external_eventloop_keepalive_check (void)
 	return FALSE;
 }
 
-#if HOST_FUCHSIA
+#if defined(HOST_FUCHSIA) || !defined(HAVE_GETRLIMIT)
 int
 mono_thread_info_get_system_max_stack_size (void)
 {

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

@@ -13,3 +13,16 @@ get_wasm_heap_base:
   .functype get_wasm_heap_base () -> (i32)
   global.get __heap_base@GOT
   end_function
+
+.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
+  end_function
+
+get_wasm_stack_high:
+  .functype get_wasm_stack_high () -> (i32)
+  global.get __stack_high@GOT
+  end_function