deps: cherry-pick 22858cb from V8 upstream

Original commit message:
  Only flush not yet started and finished compile jobs from gc

  We shouldn't block during GC for arbitrarily long intervals.

  BUG=chromium:686153,chromium:642532
  R=verwaest@chromium.org,hpayer@chromium.org

  Review-Url: https://codereview.chromium.org/2658313002
  Cr-Commit-Position: refs/heads/master@{#42761}

PR-URL: #11998
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

deps/v8/src/compiler-dispatcher/optimizing-compile-dispatcher.cc

@@ -134,7 +134,23 @@ void OptimizingCompileDispatcher::FlushOutputQueue(bool restore_function_code) {
   }
 }
 
-void OptimizingCompileDispatcher::Flush() {
+void OptimizingCompileDispatcher::Flush(BlockingBehavior blocking_behavior) {
+  if (FLAG_block_concurrent_recompilation) Unblock();
+  if (blocking_behavior == BlockingBehavior::kDontBlock) {
+    base::LockGuard<base::Mutex> access_input_queue_(&input_queue_mutex_);
+    while (input_queue_length_ > 0) {
+      CompilationJob* job = input_queue_[InputQueueIndex(0)];
+      DCHECK_NOT_NULL(job);
+      input_queue_shift_ = InputQueueIndex(1);
+      input_queue_length_--;
+      DisposeCompilationJob(job, true);
+    }
+    FlushOutputQueue(true);
+    if (FLAG_trace_concurrent_recompilation) {
+      PrintF("  ** Flushed concurrent recompilation queues (not blocking).\n");
+    }
+    return;
+  }
   base::Release_Store(&mode_, static_cast<base::AtomicWord>(FLUSH));
   if (FLAG_block_concurrent_recompilation) Unblock();
   {

deps/v8/src/compiler-dispatcher/optimizing-compile-dispatcher.h

@@ -22,6 +22,8 @@ class SharedFunctionInfo;
 
 class OptimizingCompileDispatcher {
  public:
+  enum class BlockingBehavior { kBlock, kDontBlock };
+
   explicit OptimizingCompileDispatcher(Isolate* isolate)
       : isolate_(isolate),
         input_queue_capacity_(FLAG_concurrent_recompilation_queue_length),
@@ -38,7 +40,7 @@ class OptimizingCompileDispatcher {
 
   void Run();
   void Stop();
-  void Flush();
+  void Flush(BlockingBehavior blocking_behavior);
   void QueueForOptimization(CompilationJob* job);
   void Unblock();
   void InstallOptimizedFunctions();

deps/v8/src/debug/debug.cc

@@ -1264,7 +1264,8 @@ bool Debug::PrepareFunctionForBreakPoints(Handle<SharedFunctionInfo> shared) {
   DCHECK(shared->is_compiled());
 
   if (isolate_->concurrent_recompilation_enabled()) {
-    isolate_->optimizing_compile_dispatcher()->Flush();
+    isolate_->optimizing_compile_dispatcher()->Flush(
+        OptimizingCompileDispatcher::BlockingBehavior::kBlock);
   }
 
   List<Handle<JSFunction> > functions;

deps/v8/src/heap/heap.cc

@@ -862,7 +862,8 @@ void Heap::CollectAllAvailableGarbage(GarbageCollectionReason gc_reason) {
   if (isolate()->concurrent_recompilation_enabled()) {
     // The optimizing compiler may be unnecessarily holding on to memory.
     DisallowHeapAllocation no_recursive_gc;
-    isolate()->optimizing_compile_dispatcher()->Flush();
+    isolate()->optimizing_compile_dispatcher()->Flush(
+        OptimizingCompileDispatcher::BlockingBehavior::kDontBlock);
   }
   isolate()->ClearSerializerData();
   set_current_gc_flags(kMakeHeapIterableMask | kReduceMemoryFootprintMask);
@@ -1056,7 +1057,8 @@ int Heap::NotifyContextDisposed(bool dependant_context) {
   }
   if (isolate()->concurrent_recompilation_enabled()) {
     // Flush the queued recompilation tasks.
-    isolate()->optimizing_compile_dispatcher()->Flush();
+    isolate()->optimizing_compile_dispatcher()->Flush(
+        OptimizingCompileDispatcher::BlockingBehavior::kDontBlock);
   }
   AgeInlineCaches();
   number_of_disposed_maps_ = retained_maps()->Length();
@@ -4457,7 +4459,8 @@ void Heap::CheckMemoryPressure() {
     if (isolate()->concurrent_recompilation_enabled()) {
       // The optimizing compiler may be unnecessarily holding on to memory.
       DisallowHeapAllocation no_recursive_gc;
-      isolate()->optimizing_compile_dispatcher()->Flush();
+      isolate()->optimizing_compile_dispatcher()->Flush(
+          OptimizingCompileDispatcher::BlockingBehavior::kDontBlock);
     }
   }
   if (memory_pressure_level_.Value() == MemoryPressureLevel::kCritical) {