[compiler] Properly canonicalize handles even with concurrent recompilation.

src/compiler.cc

 // Copyright 2012 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/compiler.h"
 
 #include <algorithm>
 #include <memory>
 
 #include "src/asmjs/asm-js.h"
@@ skipping 640 matching lines @@
   bool passes_turbo_filter = shared->PassesFilter(FLAG_turbo_filter);
 
   return is_turbofanable_asm || is_unsupported_by_crankshaft_but_turbofanable ||
          passes_turbo_filter;
 }
 
 bool GetOptimizedCodeNow(CompilationJob* job) {
   CompilationInfo* info = job->info();
   Isolate* isolate = info->isolate();
 
+  // All handles below this point will be canonicalized.
+  CanonicalHandleScope canonical(isolate);
+
   // Parsing is not required when optimizing from existing bytecode.
   if (!info->is_optimizing_from_bytecode()) {
     if (!Compiler::ParseAndAnalyze(info->parse_info())) return false;
     EnsureFeedbackMetadata(info);
   }
 
   JSFunction::EnsureLiterals(info->closure());
 
+  // Reopen handles in the new CompilationHandleScope.
+  info->ReopenHandlesInNewHandleScope();
+  info->parse_info()->ReopenHandlesInNewHandleScope();
+
   TimerEventScope<TimerEventRecompileSynchronous> timer(isolate);
   RuntimeCallTimerScope runtimeTimer(isolate,
                                      &RuntimeCallStats::RecompileSynchronous);
   TRACE_EVENT_RUNTIME_CALL_STATS_TRACING_SCOPED(
       isolate, &tracing::TraceEventStatsTable::RecompileSynchronous);
 
   if (job->PrepareJob() != CompilationJob::SUCCEEDED ||
       job->ExecuteJob() != CompilationJob::SUCCEEDED ||
       job->FinalizeJob() != CompilationJob::SUCCEEDED) {
     if (FLAG_trace_opt) {
@@ skipping 27 matching lines @@
 
   if (isolate->heap()->HighMemoryPressure()) {
     if (FLAG_trace_concurrent_recompilation) {
       PrintF("  ** High memory pressure, will retry optimizing ");
       info->closure()->ShortPrint();
       PrintF(" later.\n");
     }
     return false;
   }
 
-  // All handles below this point will be allocated in a deferred handle scope
-  // that is detached and handed off to the background thread when we return.
+  // All handles below this point will be canonicalized and allocated in a
+  // deferred handle scope that is detached and handed off to the background
+  // thread when we return.
   CompilationHandleScope handle_scope(info);
+  CanonicalHandleScope canonical(isolate);
 
   // Parsing is not required when optimizing from existing bytecode.
   if (!info->is_optimizing_from_bytecode()) {
     if (!Compiler::ParseAndAnalyze(info->parse_info())) return false;
     EnsureFeedbackMetadata(info);
   }
 
   JSFunction::EnsureLiterals(info->closure());
 
   // Reopen handles in the new CompilationHandleScope.
@@ skipping 72 matching lines @@
   }
 
   // Limit the number of times we try to optimize functions.
   const int kMaxOptCount =
       FLAG_deopt_every_n_times == 0 ? FLAG_max_opt_count : 1000;
   if (info->shared_info()->opt_count() > kMaxOptCount) {
     info->AbortOptimization(kOptimizedTooManyTimes);
     return MaybeHandle<Code>();
   }
 
-  CanonicalHandleScope canonical(isolate);
   TimerEventScope<TimerEventOptimizeCode> optimize_code_timer(isolate);
   RuntimeCallTimerScope runtimeTimer(isolate, &RuntimeCallStats::OptimizeCode);
   TRACE_EVENT_RUNTIME_CALL_STATS_TRACING_SCOPED(
       isolate, &tracing::TraceEventStatsTable::OptimizeCode);
 
   // TurboFan can optimize directly from existing bytecode.
   if (FLAG_turbo_from_bytecode && use_turbofan && ShouldUseIgnition(info)) {
     if (!Compiler::EnsureBytecode(info)) {
       if (isolate->has_pending_exception()) isolate->clear_pending_exception();
       return MaybeHandle<Code>();
@@ skipping 1155 matching lines @@
     DCHECK(shared->is_compiled());
     function->set_literals(cached.literals);
   } else if (shared->is_compiled()) {
     // TODO(mvstanton): pass pretenure flag to EnsureLiterals.
     JSFunction::EnsureLiterals(function);
   }
 }
 
 }  // namespace internal
 }  // namespace v8