Add memory pressure interrupt for memory pressure notification

src/execution.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/execution.h"
 
 #include "src/bootstrapper.h"
 #include "src/codegen.h"
 #include "src/isolate-inl.h"
 #include "src/messages.h"
@@ skipping 434 matching lines @@
   }
 }
 
 
 Object* StackGuard::HandleInterrupts() {
   if (FLAG_verify_predictable) {
     // Advance synthetic time by making a time request.
     isolate_->heap()->MonotonicallyIncreasingTimeInMs();
   }
 
-  if (CheckAndClearInterrupt(GC_REQUEST)) {
-    isolate_->heap()->HandleGCRequest();
+  if (CheckAndClearInterrupt(MEMORY_PRESSURE_INTERRUPT)) {
+    isolate_->heap()->CollectAllAvailableGarbage("low memory notification");
+    CheckAndClearInterrupt(GC_REQUEST);
+  } else {
+    if (CheckAndClearInterrupt(GC_REQUEST)) {
+      isolate_->heap()->HandleGCRequest();
+    }
   }
 
   if (CheckDebugBreak() || CheckDebugCommand()) {
     isolate_->debug()->HandleDebugBreak();
   }
 
   if (CheckAndClearInterrupt(TERMINATE_EXECUTION)) {
     return isolate_->TerminateExecution();
   }
 
@@ skipping 11 matching lines @@
     isolate_->InvokeApiInterruptCallbacks();
   }
 
   isolate_->counters()->stack_interrupts()->Increment();
   isolate_->counters()->runtime_profiler_ticks()->Increment();
   isolate_->runtime_profiler()->MarkCandidatesForOptimization();
 
   return isolate_->heap()->undefined_value();
 }
 
+bool StackGuard::NeedMemoryPressureGC() {
+  return CheckInterrupt(MEMORY_PRESSURE_INTERRUPT);
+}
+
+void StackGuard::MemoryPressureGCDone() {
+  CheckAndClearInterrupt(MEMORY_PRESSURE_INTERRUPT);
+}
+
 }  // namespace internal
 }  // namespace v8