A64: Synchronize with r15358.

src/optimizing-compiler-thread.cc

Index: src/optimizing-compiler-thread.cc
diff --git a/src/optimizing-compiler-thread.cc b/src/optimizing-compiler-thread.cc
index b2abc813abb63e52a191ae789352b79962264e19..b9ff7d83eca369c0b194ab2cd40ccdec5c9379be 100644
--- a/src/optimizing-compiler-thread.cc
+++ b/src/optimizing-compiler-thread.cc
@@ -89,8 +89,9 @@ void OptimizingCompilerThread::CompileNext() {
   ASSERT(status != OptimizingCompiler::FAILED);
 
   // The function may have already been optimized by OSR.  Simply continue.
-  // Mark it for installing before queuing so that we can be sure of the write
-  // order: marking first and (after being queued) installing code second.
+  // Use a mutex to make sure that functions marked for install
+  // are always also queued.
+  ScopedLock mark_and_queue(install_mutex_);
   { Heap::RelocationLock relocation_lock(isolate_->heap());
     AllowHandleDereference ahd;
     optimizing_compiler->info()->closure()->MarkForInstallingRecompiledCode();
@@ -106,12 +107,15 @@ void OptimizingCompilerThread::Stop() {
   stop_semaphore_->Wait();
 
   if (FLAG_parallel_recompilation_delay != 0) {
-    InstallOptimizedFunctions();
     // Barrier when loading queue length is not necessary since the write
     // happens in CompileNext on the same thread.
-    while (NoBarrier_Load(&queue_length_) > 0) {
-      CompileNext();
-      InstallOptimizedFunctions();
+    while (NoBarrier_Load(&queue_length_) > 0) CompileNext();
+    InstallOptimizedFunctions();
+  } else {
+    OptimizingCompiler* optimizing_compiler;
+    while (input_queue_.Dequeue(&optimizing_compiler)) {
+      // The optimizing compiler is allocated in the CompilationInfo's zone.
+      delete optimizing_compiler->info();
     }
   }
 
@@ -127,12 +131,13 @@ void OptimizingCompilerThread::Stop() {
 void OptimizingCompilerThread::InstallOptimizedFunctions() {
   ASSERT(!IsOptimizerThread());
   HandleScope handle_scope(isolate_);
-  int functions_installed = 0;
-  while (!output_queue_.IsEmpty()) {
-    OptimizingCompiler* compiler;
-    output_queue_.Dequeue(&compiler);
+  OptimizingCompiler* compiler;
+  while (true) {
+    { // Memory barrier to ensure marked functions are queued.
+      ScopedLock marked_and_queued(install_mutex_);
+      if (!output_queue_.Dequeue(&compiler)) return;
+    }
     Compiler::InstallOptimizedCode(compiler);
-    functions_installed++;
   }
 }