Add more tests for compiler-dispatcher

src/compiler-dispatcher/compiler-dispatcher.cc

 // Copyright 2016 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-dispatcher/compiler-dispatcher.h"
 
 #include "include/v8-platform.h"
 #include "include/v8.h"
 #include "src/base/platform/time.h"
 #include "src/cancelable-task.h"
 #include "src/compiler-dispatcher/compiler-dispatcher-job.h"
 #include "src/compiler-dispatcher/compiler-dispatcher-tracer.h"
 #include "src/objects-inl.h"
 
 namespace v8 {
 namespace internal {
 
 namespace {
 
 enum class ExceptionHandling { kSwallow, kThrow };
 
 bool DoNextStepOnMainThread(Isolate* isolate, CompilerDispatcherJob* job,
                             ExceptionHandling exception_handling) {
   DCHECK(ThreadId::Current().Equals(isolate->thread_id()));
-  v8::TryCatch try_catch(reinterpret_cast<v8::Isolate*>(isolate));

[jochen (gone - plz use gerrit), 2017/01/04 08:23:22]

turns out that we only create a pending exception, but don't schedule it, so the
trycatch did nothing

   switch (job->status()) {
     case CompileJobStatus::kInitial:
       job->PrepareToParseOnMainThread();
       break;
 
     case CompileJobStatus::kReadyToParse:
       job->Parse();
       break;
 
     case CompileJobStatus::kParsed:
@@ skipping 10 matching lines @@
 
     case CompileJobStatus::kCompiled:
       job->FinalizeCompilingOnMainThread();
       break;
 
     case CompileJobStatus::kFailed:
     case CompileJobStatus::kDone:
       break;
   }
 
-  if (exception_handling == ExceptionHandling::kThrow &&
-      try_catch.HasCaught()) {
-    DCHECK(job->status() == CompileJobStatus::kFailed);
-    try_catch.ReThrow();
+  if (job->status() == CompileJobStatus::kFailed) {
+    DCHECK(isolate->has_pending_exception());
+    if (exception_handling == ExceptionHandling::kSwallow) {
+      isolate->clear_pending_exception();
+    }
+  } else {
+    DCHECK(!isolate->has_pending_exception());
   }

[vogelheim, 2017/01/04 10:08:49]

nitpick: Hmm... How about:

DCHECK_EQ(job->status() == CompileJobStatus::kFailed,
          isolate->has_pending_exception());
if (ob->status() == CompileJobStatus::kFailed
    && exception_handling == ExceptionHandling::kSwallow)
  isolate->clear_pending_exception();

[jochen (gone - plz use gerrit), 2017/01/04 10:23:18]

will do in a follow-up

   return job->status() != CompileJobStatus::kFailed;
 }
 
 bool IsFinished(CompilerDispatcherJob* job) {
   return job->status() == CompileJobStatus::kDone ||
          job->status() == CompileJobStatus::kFailed;
 }
 
 bool CanRunOnAnyThread(CompilerDispatcherJob* job) {
   return (job->status() == CompileJobStatus::kReadyToParse &&
@@ skipping 308 matching lines @@
       lock.reset();
       DoNextStepOnMainThread(isolate_, job->second.get(),
                              ExceptionHandling::kSwallow);
     }
   }
   if (jobs_.size() > too_long_jobs) ScheduleIdleTaskIfNeeded();
 }
 
 }  // namespace internal
 }  // namespace v8