Parallel recompilation: fix concurrency issues.

src/compiler.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 928 matching lines @@
       info->SaveHandles();
 
       if (Rewriter::Rewrite(*info) && Scope::Analyze(*info)) {
         OptimizingCompiler* compiler =
             new(info->zone()) OptimizingCompiler(*info);
         OptimizingCompiler::Status status = compiler->CreateGraph();
         if (status == OptimizingCompiler::SUCCEEDED) {
           // Do a scavenge to put off the next scavenge as far as possible.
           // This may ease the issue that GVN blocks the next scavenge.
           isolate->heap()->CollectGarbage(NEW_SPACE, "parallel recompile");
-          closure->MarkInRecompileQueue();
           shared->code()->set_profiler_ticks(0);
           info.Detach();
           isolate->optimizing_compiler_thread()->QueueForOptimization(compiler);
         } else if (status == OptimizingCompiler::BAILED_OUT) {
           isolate->clear_pending_exception();
           InstallFullCode(*info);
         }
       }
     }
   }
@@ skipping 11 matching lines @@
                                       *check_code,
                                       *replacement_code);
   }
 
   if (isolate->has_pending_exception()) isolate->clear_pending_exception();
 }
 
 
 void Compiler::InstallOptimizedCode(OptimizingCompiler* optimizing_compiler) {
   SmartPointer<CompilationInfo> info(optimizing_compiler->info());
-  ASSERT(info->closure()->IsMarkedForInstallingRecompiledCode());
-  // While waiting for the optimizer thread, OSR may have already done all
-  // the work and disabled optimization of this function for some reason.
+  // The function may have already been optimized by OSR.  Simply continue.
+  // Except when OSR already disabled optimization for some reason.
   if (info->shared_info()->optimization_disabled()) {
     info->SetCode(Handle<Code>(info->shared_info()->code()));
     InstallFullCode(*info);
+    if (FLAG_trace_parallel_recompilation) {
+      PrintF("  ** aborting optimization for ");
+      info->closure()->PrintName();
+      PrintF(" as it has been disabled.\n");
+    }
+    ASSERT(!info->closure()->IsMarkedForInstallingRecompiledCode());
     return;
   }
 
   Isolate* isolate = info->isolate();
   VMState state(isolate, PARALLEL_COMPILER);
   Logger::TimerEventScope timer(
       isolate, Logger::TimerEventScope::v8_recompile_synchronous);
   // If crankshaft succeeded, install the optimized code else install
   // the unoptimized code.
   OptimizingCompiler::Status status = optimizing_compiler->last_status();
@@ skipping 21 matching lines @@
       info->closure()->PrintName();
       PrintF(" installed.\n");
     }
   } else {
     info->SetCode(Handle<Code>(info->shared_info()->code()));
     InstallFullCode(*info);
   }
   // Optimized code is finally replacing unoptimized code.  Reset the latter's
   // profiler ticks to prevent too soon re-opt after a deopt.
   info->shared_info()->code()->set_profiler_ticks(0);
+  ASSERT(!info->closure()->IsMarkedForInstallingRecompiledCode());
 }
 
 
 Handle<SharedFunctionInfo> Compiler::BuildFunctionInfo(FunctionLiteral* literal,
                                                        Handle<Script> script) {
   // Precondition: code has been parsed and scopes have been analyzed.
   CompilationInfoWithZone info(script);
   info.SetFunction(literal);
   info.SetScope(literal->scope());
   info.SetLanguageMode(literal->scope()->language_mode());
@@ skipping 114 matching lines @@
     }
   }
 
   GDBJIT(AddCode(Handle<String>(shared->DebugName()),
                  Handle<Script>(info->script()),
                  Handle<Code>(info->code()),
                  info));
 }
 
 } }  // namespace v8::internal