[compiler] Park main thread while awaiting compile tasks

Currently a deadlock can result on heap teardown during the shared heap
verification which performs a global safepoint. The heap teardown awaits
compile tasks, while the compile helper thread is waiting on a
global safepoint.

Bug: v8:11708
Change-Id: I8328a4b142cb9045bfaf592ac4f4dd259ba0d397
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3820354
Commit-Queue: Shu-yu Guo <syg@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/main@{#82364}

src/compiler-dispatcher/optimizing-compile-dispatcher.cc

@@ -139,8 +139,12 @@ void OptimizingCompileDispatcher::FlushInputQueue() {
 
 void OptimizingCompileDispatcher::AwaitCompileTasks() {
   {
+    AllowGarbageCollection allow_before_parking;
+    ParkedScope parked_scope(isolate_->main_thread_local_isolate());
     base::MutexGuard lock_guard(&ref_count_mutex_);
-    while (ref_count_ > 0) ref_count_zero_.Wait(&ref_count_mutex_);
+    while (ref_count_ > 0) {
+      ref_count_zero_.ParkedWait(parked_scope, &ref_count_mutex_);
+    }
   }
 
 #ifdef DEBUG
@@ -152,10 +156,7 @@ void OptimizingCompileDispatcher::AwaitCompileTasks() {
 void OptimizingCompileDispatcher::FlushQueues(
     BlockingBehavior blocking_behavior, bool restore_function_code) {
   FlushInputQueue();
-  if (blocking_behavior == BlockingBehavior::kBlock) {
-    base::MutexGuard lock_guard(&ref_count_mutex_);
-    while (ref_count_ > 0) ref_count_zero_.Wait(&ref_count_mutex_);
-  }
+  if (blocking_behavior == BlockingBehavior::kBlock) AwaitCompileTasks();
   FlushOutputQueue(restore_function_code);
 }
 

src/compiler-dispatcher/optimizing-compile-dispatcher.h

@@ -12,6 +12,7 @@
 #include "src/base/platform/mutex.h"
 #include "src/common/globals.h"
 #include "src/flags/flags.h"
+#include "src/heap/parked-scope.h"
 #include "src/utils/allocation.h"
 
 namespace v8 {
@@ -98,7 +99,7 @@ class V8_EXPORT_PRIVATE OptimizingCompileDispatcher {
 
   std::atomic<int> ref_count_;
   base::Mutex ref_count_mutex_;
-  base::ConditionVariable ref_count_zero_;
+  ParkingConditionVariable ref_count_zero_;
 
   // Copy of FLAG_concurrent_recompilation_delay that will be used from the
   // background thread.

src/heap/parked-scope.h

@@ -119,6 +119,7 @@ class V8_NODISCARD ParkedSharedMutexGuardIf final {
 class V8_NODISCARD ParkingConditionVariable final
     : public base::ConditionVariable {
  public:
+  ParkingConditionVariable() = default;
   ParkingConditionVariable(const ParkingConditionVariable&) = delete;
   ParkingConditionVariable& operator=(const ParkingConditionVariable&) = delete;