[execution] Move v8::Locker::WasEverUsed() flag into Isolate

So far this flag was process-global, so if one isolate used v8::Locker
all isolates were forced to use v8::Locker. With the shared isolate
now being a thing that routinely gets migrated between different
threads, all users of the shared isolate would be forced to use
v8::Locker. So we now store that flag on the isolate such that using
v8::Locker for the shared isolate does not affect other isolates.

Deprecate v8::Locker::WasEverUsed() at the same time.

Bug: v8:11708
Change-Id: I60531f084cc1b1b113620c46f5bed20511f52c26
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3401595Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/main@{#78712}

include/v8-locker.h

@@ -127,6 +127,7 @@ class V8_EXPORT Locker {
    * The current implementation is quite confusing and leads to unexpected
    * results if anybody uses v8::Locker in the current process.
    */
+  V8_DEPRECATE_SOON("This method will be removed.")
   static bool WasEverUsed();
   V8_DEPRECATED("Use WasEverUsed instead")
   static bool IsActive();

src/api/api.cc

@@ -961,7 +961,7 @@ void HandleScope::Initialize(Isolate* isolate) {
   // We make an exception if the serializer is enabled, which means that the
   // Isolate is exclusively used to create a snapshot.
   Utils::ApiCheck(
-      !v8::Locker::WasEverUsed() ||
+      !internal_isolate->was_locker_ever_used() ||
           internal_isolate->thread_manager()->IsLockedByCurrentThread() ||
           internal_isolate->serializer_enabled(),
       "HandleScope::HandleScope",
@@ -9306,7 +9306,7 @@ void Isolate::IsolateInBackgroundNotification() {
 void Isolate::MemoryPressureNotification(MemoryPressureLevel level) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(this);
   bool on_isolate_thread =
-      v8::Locker::WasEverUsed()
+      isolate->was_locker_ever_used()
           ? isolate->thread_manager()->IsLockedByCurrentThread()
           : i::ThreadId::Current() == isolate->thread_id();
   isolate->heap()->MemoryPressureNotification(level, on_isolate_thread);

src/execution/isolate.h

@@ -1484,6 +1484,13 @@ class V8_EXPORT_PRIVATE Isolate final : private HiddenFactory {
 
   int id() const { return id_; }
 
+  bool was_locker_ever_used() const {
+    return was_locker_ever_used_.load(std::memory_order_relaxed);
+  }
+  void set_was_locker_ever_used() {
+    was_locker_ever_used_.store(true, std::memory_order_relaxed);
+  }
+
   CompilationStatistics* GetTurboStatistics();
   CodeTracer* GetCodeTracer();
 
@@ -2056,6 +2063,7 @@ class V8_EXPORT_PRIVATE Isolate final : private HiddenFactory {
   const int id_;
   EntryStackItem* entry_stack_ = nullptr;
   int stack_trace_nesting_level_ = 0;
+  std::atomic<bool> was_locker_ever_used_{false};
   StringStream* incomplete_message_ = nullptr;
   Address isolate_addresses_[kIsolateAddressCount + 1] = {};
   Bootstrapper* bootstrapper_ = nullptr;

src/execution/v8threads.cc

@@ -31,8 +31,11 @@ void Locker::Initialize(v8::Isolate* isolate) {
   has_lock_ = false;
   top_level_ = true;
   isolate_ = reinterpret_cast<i::Isolate*>(isolate);
+
   // Record that the Locker has been used at least once.
   base::Relaxed_Store(&g_locker_was_ever_used_, 1);
+  isolate_->set_was_locker_ever_used();
+
   // Get the big lock if necessary.
   if (!isolate_->thread_manager()->IsLockedByCurrentThread()) {
     isolate_->thread_manager()->Lock();

src/logging/log.cc

@@ -944,7 +944,7 @@ class Ticker : public sampler::Sampler {
   void SampleStack(const v8::RegisterState& state) override {
     if (!profiler_) return;
     Isolate* isolate = reinterpret_cast<Isolate*>(this->isolate());
-    if (v8::Locker::WasEverUsed() &&
+    if (isolate->was_locker_ever_used() &&
         (!isolate->thread_manager()->IsLockedByThread(
              perThreadData_->thread_id()) ||
          perThreadData_->thread_state() != nullptr))

src/profiler/cpu-profiler.cc

@@ -40,7 +40,7 @@ class CpuSampler : public sampler::Sampler {
 
   void SampleStack(const v8::RegisterState& regs) override {
     Isolate* isolate = reinterpret_cast<Isolate*>(this->isolate());
-    if (v8::Locker::WasEverUsed() &&
+    if (isolate->was_locker_ever_used() &&
         (!isolate->thread_manager()->IsLockedByThread(
              perThreadData_->thread_id()) ||
          perThreadData_->thread_state() != nullptr)) {

test/cctest/cctest.cc

@@ -122,7 +122,7 @@ void CcTest::Run() {
   DCHECK_EQ(active_isolates, i::Isolate::non_disposed_isolates());
 #endif  // DEBUG
   if (initialize_) {
-    if (v8::Locker::WasEverUsed()) {
+    if (i_isolate()->was_locker_ever_used()) {
       v8::Locker locker(isolate_);
       EmptyMessageQueues(isolate_);
     } else {