[vm] Use _setjmp instead of setjmp on MacOS/iOS

alexmarkov · Commit Queue · commit ebb7e1061ce9 · 2025-02-26T14:01:44.000-08:00
setjmp is extremely expensive on MacOS/iOS as it always saves signal mask. Introduce DART_SETJMP / DART_LONGJMP macros to use _setjmp instead of setjmp on MacOS/iOS. DeltaBlue on Mac/arm64 on the interpreter: 179585.3 us -> 58347.9 us. (3x faster) TEST=ci Issue: #60205 Change-Id: I2122f2eb4d5de66ae2ef904a7034af1ed09f1d07 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/412320 Reviewed-by: Ryan Macnak <rmacnak@google.com> Commit-Queue: Alexander Markov <alexmarkov@google.com>
diff --git a/runtime/platform/globals.h b/runtime/platform/globals.h
@@ -297,6 +297,15 @@ struct simd128_value_t {
 #error Automatic compiler detection failed.
 #endif
 
+#if defined(__APPLE__)
+// Avoid expensive saving of sigmask in setjmp/longjmp.
+#define DART_SETJMP _setjmp
+#define DART_LONGJMP _longjmp
+#else
+#define DART_SETJMP setjmp
+#define DART_LONGJMP longjmp
+#endif
+
 #if !defined(TARGET_ARCH_ARM) && !defined(TARGET_ARCH_X64) &&                  \
     !defined(TARGET_ARCH_IA32) && !defined(TARGET_ARCH_ARM64) &&               \
     !defined(TARGET_ARCH_RISCV32) && !defined(TARGET_ARCH_RISCV64)
diff --git a/runtime/vm/allocation_test.cc b/runtime/vm/allocation_test.cc
@@ -92,7 +92,7 @@ static void StackAllocatedLongJumpHelper(int* ptr, LongJumpScope* jump) {
 ISOLATE_UNIT_TEST_CASE(StackAllocatedLongJump) {
   LongJumpScope jump;
   int data = 1;
-  if (setjmp(*jump.Set()) == 0) {
+  if (DART_SETJMP(*jump.Set()) == 0) {
     StackAllocatedLongJumpHelper(&data, &jump);
     UNREACHABLE();
   } else {
@@ -145,7 +145,7 @@ ISOLATE_UNIT_TEST_CASE(StackResourceLongJump) {
   {
     LongJumpScope jump;
     int data = 1;
-    if (setjmp(*jump.Set()) == 0) {
+    if (DART_SETJMP(*jump.Set()) == 0) {
       StackResourceLongJumpHelper(&data, &jump);
       UNREACHABLE();
     } else {
diff --git a/runtime/vm/bootstrap.cc b/runtime/vm/bootstrap.cc
@@ -114,7 +114,7 @@ static ErrorPtr BootstrapFromKernelSingleProgram(
     std::unique_ptr<kernel::Program> program) {
   Zone* zone = thread->zone();
   LongJumpScope jump;
-  if (setjmp(*jump.Set()) == 0) {
+  if (DART_SETJMP(*jump.Set()) == 0) {
     kernel::KernelLoader loader(program.get(), /*uri_to_source_table=*/nullptr);
 
     auto isolate_group = thread->isolate_group();
diff --git a/runtime/vm/class_finalizer.cc b/runtime/vm/class_finalizer.cc
@@ -199,7 +199,7 @@ bool ClassFinalizer::ProcessPendingClasses() {
   }
 
   LongJumpScope jump;
-  if (setjmp(*jump.Set()) == 0) {
+  if (DART_SETJMP(*jump.Set()) == 0) {
     GrowableObjectArray& class_array = GrowableObjectArray::Handle();
     class_array = object_store->pending_classes();
     ASSERT(!class_array.IsNull());
@@ -827,7 +827,7 @@ ErrorPtr ClassFinalizer::LoadClassMembers(const Class& cls) {
   ASSERT(!cls.is_finalized());
 
   LongJumpScope jump;
-  if (setjmp(*jump.Set()) == 0) {
+  if (DART_SETJMP(*jump.Set()) == 0) {
     cls.EnsureDeclarationLoaded();
     ASSERT(cls.is_type_finalized());
     ClassFinalizer::FinalizeClass(cls);
diff --git a/runtime/vm/compiler/aot/precompiler.cc b/runtime/vm/compiler/aot/precompiler.cc
@@ -364,7 +364,7 @@ static void Jump(const Error& error) {
 
 ErrorPtr Precompiler::CompileAll() {
   LongJumpScope jump;
-  if (setjmp(*jump.Set()) == 0) {
+  if (DART_SETJMP(*jump.Set()) == 0) {
     Precompiler precompiler(Thread::Current());
     precompiler.DoCompileAll();
     precompiler.ReportStats();
@@ -3486,7 +3486,7 @@ bool PrecompileParsedFunctionHelper::GenerateCode(FlowGraph* flow_graph) {
 
   while (!done) {
     LongJumpScope jump;
-    const intptr_t val = setjmp(*jump.Set());
+    const intptr_t val = DART_SETJMP(*jump.Set());
     if (val == 0) {
       // Even in bare instructions mode we don't directly add objects into
       // the global object pool because code generation can bail out
diff --git a/runtime/vm/compiler/backend/inliner.cc b/runtime/vm/compiler/backend/inliner.cc
@@ -1278,7 +1278,7 @@ class CallSiteInliner : public ValueObject {
 
       // Install bailout jump.
       LongJumpScope jump;
-      if (setjmp(*jump.Set()) == 0) {
+      if (DART_SETJMP(*jump.Set()) == 0) {
         // Load IC data for the callee.
         ZoneGrowableArray<const ICData*>* ic_data_array =
             new (Z) ZoneGrowableArray<const ICData*>();
diff --git a/runtime/vm/compiler/jit/compiler.cc b/runtime/vm/compiler/jit/compiler.cc
@@ -498,7 +498,7 @@ CodePtr CompileParsedFunctionHelper::Compile() {
   while (!done) {
     *result = Code::null();
     LongJumpScope jump;
-    if (setjmp(*jump.Set()) == 0) {
+    if (DART_SETJMP(*jump.Set()) == 0) {
       FlowGraph* flow_graph = nullptr;
       ZoneGrowableArray<const ICData*>* ic_data_array = nullptr;
 
@@ -673,7 +673,7 @@ static ObjectPtr CompileFunctionHelper(const Function& function,
   ASSERT(!FLAG_precompiled_mode);
   ASSERT(!optimized || function.WasCompiled() || function.ForceOptimize());
   LongJumpScope jump;
-  if (setjmp(*jump.Set()) == 0) {
+  if (DART_SETJMP(*jump.Set()) == 0) {
     StackZone stack_zone(thread);
     Zone* const zone = stack_zone.GetZone();
     const bool trace_compiler =
@@ -889,7 +889,7 @@ void Compiler::ComputeLocalVarDescriptors(const Code& code) {
   Zone* zone = thread->zone();
   CompilerState state(thread, /*is_aot=*/false, /*is_optimizing=*/false);
   LongJumpScope jump;
-  if (setjmp(*jump.Set()) == 0) {
+  if (DART_SETJMP(*jump.Set()) == 0) {
     ParsedFunction* parsed_function =
         new ParsedFunction(thread, Function::ZoneHandle(zone, function.ptr()));
     ZoneGrowableArray<const ICData*>* ic_data_array =
diff --git a/runtime/vm/exceptions.cc b/runtime/vm/exceptions.cc
@@ -671,7 +671,7 @@ NO_SANITIZE_SAFE_STACK  // This function manipulates the safestack pointer.
     tsan_utils->exception_pc = program_counter;
     tsan_utils->exception_sp = stack_pointer;
     tsan_utils->exception_fp = frame_pointer;
-    longjmp(*(tsan_utils->setjmp_buffer), 1);
+    DART_LONGJMP(*(tsan_utils->setjmp_buffer), 1);
   }
 #endif  // defined(USING_THREAD_SANITIZER)
 
diff --git a/runtime/vm/heap/scavenger.cc b/runtime/vm/heap/scavenger.cc
@@ -282,7 +282,7 @@ class ScavengerVisitorBase : public ObjectPointerVisitor,
     page_space_->AcquireLock(freelist_);
 
     LongJumpScope jump(thread_);
-    if (setjmp(*jump.Set()) == 0) {
+    if (DART_SETJMP(*jump.Set()) == 0) {
       scavenger_->IterateRoots(this);
     } else {
       ASSERT(scavenger_->abort_);
@@ -291,7 +291,7 @@ class ScavengerVisitorBase : public ObjectPointerVisitor,
 
   void ProcessSurvivors() {
     LongJumpScope jump(thread_);
-    if (setjmp(*jump.Set()) == 0) {
+    if (DART_SETJMP(*jump.Set()) == 0) {
       // Iterate until all work has been drained.
       do {
         ProcessToSpace();
@@ -305,7 +305,7 @@ class ScavengerVisitorBase : public ObjectPointerVisitor,
   void ProcessAll() {
     TIMELINE_FUNCTION_GC_DURATION(thread_, "ProcessToSpace");
     LongJumpScope jump(thread_);
-    if (setjmp(*jump.Set()) == 0) {
+    if (DART_SETJMP(*jump.Set()) == 0) {
       do {
         do {
           ProcessToSpace();
@@ -320,7 +320,7 @@ class ScavengerVisitorBase : public ObjectPointerVisitor,
 
   void ProcessWeakProperties() {
     LongJumpScope jump(thread_);
-    if (setjmp(*jump.Set()) == 0) {
+    if (DART_SETJMP(*jump.Set()) == 0) {
       ProcessWeakPropertiesScoped();
     } else {
       ASSERT(scavenger_->abort_);
diff --git a/runtime/vm/interpreter.cc b/runtime/vm/interpreter.cc
@@ -51,7 +51,7 @@ class InterpreterSetjmpBuffer {
   void Longjmp() {
     // "This" is now the last setjmp buffer.
     interpreter_->set_last_setjmp_buffer(this);
-    longjmp(buffer_, 1);
+    DART_LONGJMP(buffer_, 1);
   }
 
   explicit InterpreterSetjmpBuffer(Interpreter* interpreter) {
@@ -532,7 +532,7 @@ static DART_NOINLINE bool InvokeRuntime(Thread* thread,
                                         RuntimeFunction drt,
                                         const NativeArguments& args) {
   InterpreterSetjmpBuffer buffer(interpreter);
-  if (!setjmp(buffer.buffer_)) {
+  if (!DART_SETJMP(buffer.buffer_)) {
     thread->set_vm_tag(reinterpret_cast<uword>(drt));
     drt(args);
     thread->set_vm_tag(VMTag::kDartInterpretedTagId);
@@ -581,7 +581,7 @@ DART_NOINLINE bool Interpreter::InvokeCompiled(Thread* thread,
   Exit(thread, *FP, call_top + 1, *pc);
   {
     InterpreterSetjmpBuffer buffer(this);
-    if (!setjmp(buffer.buffer_)) {
+    if (!DART_SETJMP(buffer.buffer_)) {
 #if defined(USING_SIMULATOR)
       // We need to beware that bouncing between the interpreter and the
       // simulator may exhaust the C stack before exhausting either the
diff --git a/runtime/vm/isolate_reload.cc b/runtime/vm/isolate_reload.cc
@@ -1218,7 +1218,7 @@ ObjectPtr ProgramReloadContext::ReloadPhase2LoadKernel(
   Thread* thread = Thread::Current();
 
   LongJumpScope jump;
-  if (setjmp(*jump.Set()) == 0) {
+  if (DART_SETJMP(*jump.Set()) == 0) {
     const Object& tmp = kernel::KernelLoader::LoadEntireProgram(program);
     if (tmp.IsError()) {
       return tmp.ptr();
diff --git a/runtime/vm/kernel.cc b/runtime/vm/kernel.cc
@@ -382,7 +382,7 @@ ObjectPtr EvaluateStaticConstFieldInitializer(const Field& field) {
   ASSERT(field.is_static() && field.is_const());
 
   LongJumpScope jump;
-  if (setjmp(*jump.Set()) == 0) {
+  if (DART_SETJMP(*jump.Set()) == 0) {
     Thread* thread = Thread::Current();
     Zone* zone = thread->zone();
     TranslationHelper helper(thread);
@@ -468,7 +468,7 @@ ObjectPtr EvaluateMetadata(const Library& library,
                            intptr_t kernel_offset,
                            bool is_annotations_offset) {
   LongJumpScope jump;
-  if (setjmp(*jump.Set()) == 0) {
+  if (DART_SETJMP(*jump.Set()) == 0) {
     Thread* thread = Thread::Current();
     Zone* zone = thread->zone();
     TranslationHelper helper(thread);
@@ -572,7 +572,7 @@ ObjectPtr ParameterDescriptorBuilder::BuildParameterDescriptor(
 
 ObjectPtr BuildParameterDescriptor(const Function& function) {
   LongJumpScope jump;
-  if (setjmp(*jump.Set()) == 0) {
+  if (DART_SETJMP(*jump.Set()) == 0) {
     Thread* thread = Thread::Current();
     Zone* zone = thread->zone();
 
diff --git a/runtime/vm/kernel_loader.cc b/runtime/vm/kernel_loader.cc
@@ -526,7 +526,7 @@ ObjectPtr KernelLoader::LoadProgram(bool process_pending_classes) {
   }
 
   LongJumpScope jump;
-  if (setjmp(*jump.Set()) == 0) {
+  if (DART_SETJMP(*jump.Set()) == 0) {
     // Note that `problemsAsJson` on Component is implicitly skipped.
     const intptr_t length = program_->library_count();
     for (intptr_t i = 0; i < length; i++) {
@@ -652,7 +652,7 @@ void KernelLoader::FindModifiedLibraries(Program* program,
                                          intptr_t* p_num_procedures) {
   LongJumpScope jump;
   Zone* zone = Thread::Current()->zone();
-  if (setjmp(*jump.Set()) == 0) {
+  if (DART_SETJMP(*jump.Set()) == 0) {
     if (force_reload) {
       // If a reload is being forced we mark all libraries as having
       // been modified.
diff --git a/runtime/vm/longjump.cc b/runtime/vm/longjump.cc
@@ -38,7 +38,7 @@ void LongJumpScope::Jump(int value) {
 
   // Destruct all the active StackResource objects.
   StackResource::UnwindAbove(thread, top_);
-  longjmp(environment_, value);
+  DART_LONGJMP(environment_, value);
   UNREACHABLE();
 }
 
diff --git a/runtime/vm/longjump_test.cc b/runtime/vm/longjump_test.cc
@@ -19,7 +19,7 @@ ISOLATE_UNIT_TEST_CASE(LongJump) {
   LongJumpScope* base = Thread::Current()->long_jump_base();
   {
     LongJumpScope jump;
-    if (setjmp(*jump.Set()) == 0) {
+    if (DART_SETJMP(*jump.Set()) == 0) {
       LongJumpHelper(&jump);
       UNREACHABLE();
     } else {
diff --git a/runtime/vm/message_snapshot.cc b/runtime/vm/message_snapshot.cc
@@ -3483,7 +3483,7 @@ ObjectPtr ReadMessage(Thread* thread, Message* message) {
   } else {
     RELEASE_ASSERT(message->IsSnapshot());
     LongJumpScope jump(thread);
-    if (setjmp(*jump.Set()) == 0) {
+    if (DART_SETJMP(*jump.Set()) == 0) {
       MessageDeserializer deserializer(thread, message);
       return deserializer.Deserialize();
     } else {
diff --git a/runtime/vm/object_graph_copy.cc b/runtime/vm/object_graph_copy.cc
@@ -2441,7 +2441,7 @@ class ObjectGraphCopier : public StackResource {
 
     {
       LongJumpScope jump;  // e.g. for OOMs.
-      if (setjmp(*jump.Set()) == 0) {
+      if (DART_SETJMP(*jump.Set()) == 0) {
         result = CopyObjectGraphInternal(root, &exception_msg);
         // Any allocated external typed data must have finalizers attached so
         // memory will get free()ed.
diff --git a/runtime/vm/simulator_arm.cc b/runtime/vm/simulator_arm.cc
@@ -55,7 +55,7 @@ class SimulatorSetjmpBuffer {
   void Longjmp() {
     // "This" is now the last setjmp buffer.
     simulator_->set_last_setjmp_buffer(this);
-    longjmp(buffer_, 1);
+    DART_LONGJMP(buffer_, 1);
   }
 
   explicit SimulatorSetjmpBuffer(Simulator* sim) {
@@ -1416,7 +1416,7 @@ void Simulator::SupervisorCall(Instr* instr) {
     case Instr::kSimulatorRedirectCode: {
       SimulatorSetjmpBuffer buffer(this);
 
-      if (!setjmp(buffer.buffer_)) {
+      if (!DART_SETJMP(buffer.buffer_)) {
         int32_t saved_lr = get_register(LR);
         Redirection* redirection = Redirection::FromSvcInstruction(instr);
         uword external = redirection->external_function();
diff --git a/runtime/vm/simulator_arm64.cc b/runtime/vm/simulator_arm64.cc
@@ -58,7 +58,7 @@ class SimulatorSetjmpBuffer {
   void Longjmp() {
     // "This" is now the last setjmp buffer.
     simulator_->set_last_setjmp_buffer(this);
-    longjmp(buffer_, 1);
+    DART_LONGJMP(buffer_, 1);
   }
 
   explicit SimulatorSetjmpBuffer(Simulator* sim) {
@@ -1677,7 +1677,7 @@ void Simulator::DoRedirectedCall(Instr* instr) {
   memory_.FlushAll();
 
   SimulatorSetjmpBuffer buffer(this);
-  if (!setjmp(buffer.buffer_)) {
+  if (!DART_SETJMP(buffer.buffer_)) {
     int64_t saved_lr = get_register(LR);
     Redirection* redirection = Redirection::FromHltInstruction(instr);
     uword external = redirection->external_function();
diff --git a/runtime/vm/simulator_riscv.cc b/runtime/vm/simulator_riscv.cc
@@ -43,7 +43,7 @@ class SimulatorSetjmpBuffer {
   void Longjmp() {
     // "This" is now the last setjmp buffer.
     simulator_->set_last_setjmp_buffer(this);
-    longjmp(buffer_, 1);
+    DART_LONGJMP(buffer_, 1);
   }
 
   explicit SimulatorSetjmpBuffer(Simulator* sim) {
@@ -2109,7 +2109,7 @@ void Simulator::InterpretECALL(Instr instr) {
   memory_.FlushAll();
 
   SimulatorSetjmpBuffer buffer(this);
-  if (!setjmp(buffer.buffer_)) {
+  if (!DART_SETJMP(buffer.buffer_)) {
     uintx_t saved_ra = get_xreg(RA);
     Redirection* redirection = Redirection::FromECallInstruction(pc_);
     uword external = redirection->external_function();
diff --git a/runtime/vm/thread.h b/runtime/vm/thread.h
@@ -321,7 +321,7 @@ struct TsanUtils {
   // implementation.
   // -> See https://dartbug.com/47472#issuecomment-948235479 for details.
 #if defined(USING_THREAD_SANITIZER)
-  void* setjmp_function = reinterpret_cast<void*>(&setjmp);
+  void* setjmp_function = reinterpret_cast<void*>(&DART_SETJMP);
 #else
   // MSVC (on Windows) is not happy with getting address of purely intrinsic.
   void* setjmp_function = nullptr;
diff --git a/runtime/vm/thread_test.cc b/runtime/vm/thread_test.cc
@@ -1034,7 +1034,7 @@ static void RunLockerWithLongJumpTest() {
   LockType lock;
   for (intptr_t i = 0; i < kNumIterations; ++i) {
     LongJumpScope jump;
-    if (setjmp(*jump.Set()) == 0) {
+    if (DART_SETJMP(*jump.Set()) == 0) {
       LockerType locker(Thread::Current(), &lock);
       execution_count = execution_count + 1;
       Thread::Current()->long_jump_base()->Jump(
diff --git a/runtime/vm/type_testing_stubs.cc b/runtime/vm/type_testing_stubs.cc
@@ -223,7 +223,7 @@ static CodePtr RetryCompilationWithFarBranches(
   volatile intptr_t far_branch_level = 0;
   while (true) {
     LongJumpScope jump;
-    if (setjmp(*jump.Set()) == 0) {
+    if (DART_SETJMP(*jump.Set()) == 0) {
       // To use the already-defined __ Macro !
       compiler::Assembler assembler(nullptr, far_branch_level);
       return fun(assembler);
diff --git a/runtime/vm/unit_test.h b/runtime/vm/unit_test.h
@@ -103,7 +103,7 @@
     volatile intptr_t far_branch_level = 0;                                    \
     while (true) {                                                             \
       LongJumpScope jump(thread);                                              \
-      if (setjmp(*jump.Set()) == 0) {                                          \
+      if (DART_SETJMP(*jump.Set()) == 0) {                                     \
         compiler::ObjectPoolBuilder object_pool_builder;                       \
         compiler::Assembler assembler(&object_pool_builder, far_branch_level); \
         AssemblerTest test("" #name, &assembler, thread->zone());              \

Original file line number	Diff line number	Diff line change
`@@ -671,7 +671,7 @@ NO_SANITIZE_SAFE_STACK // This function manipulates the safestack pointer.`
`671`	`671`	`tsan_utils->exception_pc = program_counter;`
`672`	`672`	`tsan_utils->exception_sp = stack_pointer;`
`673`	`673`	`tsan_utils->exception_fp = frame_pointer;`
`674`		`- longjmp(*(tsan_utils->setjmp_buffer), 1);`
	`674`	`+ DART_LONGJMP(*(tsan_utils->setjmp_buffer), 1);`
`675`	`675`	`}`
`676`	`676`	`#endif // defined(USING_THREAD_SANITIZER)`
`677`	`677`