Hewlett-Packard Development Company, LP
Igalia, S.L.
Joyent, Inc.
+Bloomberg Finance L.P.
Akinori MUSHA <knu@FreeBSD.org>
Alexander Botero-Lowry <alexbl@FreeBSD.org>
static bool IsExecutionTerminating(Isolate* isolate = NULL);
/**
+ * Resume execution capability in the given isolate, whose execution
+ * was previously forcefully terminated using TerminateExecution().
+ *
+ * When execution is forcefully terminated using TerminateExecution(),
+ * the isolate can not resume execution until all JavaScript frames
+ * have propagated the uncatchable exception which is generated. This
+ * method allows the program embedding the engine to handle the
+ * termination event and resume execution capability, even if
+ * JavaScript frames remain on the stack.
+ *
+ * This method can be used by any thread even if that thread has not
+ * acquired the V8 lock with a Locker object.
+ *
+ * \param isolate The isolate in which to resume execution capability.
+ */
+ static void CancelTerminateExecution(Isolate* isolate);
+
+ /**
* Releases any resources used by v8 and stops any utility threads
* that may be running. Note that disposing v8 is permanent, it
* cannot be reinitialized.
bool HasCaught() const;
/**
- * For certain types of exceptions, it makes no sense to continue
- * execution.
- *
- * Currently, the only type of exception that can be caught by a
- * TryCatch handler and for which it does not make sense to continue
- * is termination exception. Such exceptions are thrown when the
- * TerminateExecution methods are called to terminate a long-running
- * script.
+ * For certain types of exceptions, it makes no sense to continue execution.
*
- * If CanContinue returns false, the correct action is to perform
- * any C++ cleanup needed and then return.
+ * If CanContinue returns false, the correct action is to perform any C++
+ * cleanup needed and then return. If CanContinue returns false and
+ * HasTerminated returns true, it is possible to call
+ * CancelTerminateExecution in order to continue calling into the engine.
*/
bool CanContinue() const;
/**
+ * Returns true if an exception has been caught due to script execution
+ * being terminated.
+ *
+ * There is no JavaScript representation of an execution termination
+ * exception. Such exceptions are thrown when the TerminateExecution
+ * methods are called to terminate a long-running script.
+ *
+ * If such an exception has been thrown, HasTerminated will return true,
+ * indicating that it is possible to call CancelTerminateExecution in order
+ * to continue calling into the engine.
+ */
+ bool HasTerminated() const;
+
+ /**
* Throws the exception caught by this TryCatch in a way that avoids
* it being caught again by this same TryCatch. As with ThrowException
* it is illegal to execute any JavaScript operations after calling
bool can_continue_ : 1;
bool capture_message_ : 1;
bool rethrow_ : 1;
+ bool has_terminated_ : 1;
friend class v8::internal::Isolate;
};
is_verbose_(false),
can_continue_(true),
capture_message_(true),
- rethrow_(false) {
+ rethrow_(false),
+ has_terminated_(false) {
isolate_->RegisterTryCatchHandler(this);
}
}
+bool v8::TryCatch::HasTerminated() const {
+ return has_terminated_;
+}
+
+
v8::Handle<v8::Value> v8::TryCatch::ReThrow() {
if (!HasCaught()) return v8::Local<v8::Value>();
rethrow_ = true;
}
+void V8::CancelTerminateExecution(Isolate* isolate) {
+ i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
+ i_isolate->stack_guard()->CancelTerminateExecution();
+}
+
+
Isolate* Isolate::GetCurrent() {
i::Isolate* isolate = i::Isolate::UncheckedCurrent();
return reinterpret_cast<Isolate*>(isolate);
}
+void StackGuard::CancelTerminateExecution() {
+ ExecutionAccess access(isolate_);
+ Continue(TERMINATE);
+ isolate_->CancelTerminateExecution();
+}
+
+
void StackGuard::TerminateExecution() {
ExecutionAccess access(isolate_);
thread_local_.interrupt_flags_ |= TERMINATE;
void Interrupt();
bool IsTerminateExecution();
void TerminateExecution();
+ void CancelTerminateExecution();
#ifdef ENABLE_DEBUGGER_SUPPORT
bool IsDebugBreak();
void DebugBreak();
}
+void Isolate::CancelTerminateExecution() {
+ if (try_catch_handler()) {
+ try_catch_handler()->has_terminated_ = false;
+ }
+ if (has_pending_exception() &&
+ pending_exception() == heap_.termination_exception()) {
+ thread_local_top()->external_caught_exception_ = false;
+ clear_pending_exception();
+ }
+ if (has_scheduled_exception() &&
+ scheduled_exception() == heap_.termination_exception()) {
+ thread_local_top()->external_caught_exception_ = false;
+ clear_scheduled_exception();
+ }
+}
+
+
Failure* Isolate::Throw(Object* exception, MessageLocation* location) {
DoThrow(exception, location);
return Failure::Exception();
} else if (thread_local_top_.pending_exception_ ==
heap()->termination_exception()) {
try_catch_handler()->can_continue_ = false;
+ try_catch_handler()->has_terminated_ = true;
try_catch_handler()->exception_ = heap()->null_value();
} else {
// At this point all non-object (failure) exceptions have
// been dealt with so this shouldn't fail.
ASSERT(!pending_exception()->IsFailure());
try_catch_handler()->can_continue_ = true;
+ try_catch_handler()->has_terminated_ = false;
try_catch_handler()->exception_ = pending_exception();
if (!thread_local_top_.pending_message_obj_->IsTheHole()) {
try_catch_handler()->message_ = thread_local_top_.pending_message_obj_;
// Out of resource exception helpers.
Failure* StackOverflow();
Failure* TerminateExecution();
+ void CancelTerminateExecution();
// Administration
void Iterate(ObjectVisitor* v);
"f()"))->Run()->IsTrue());
context.Dispose(context->GetIsolate());
}
+
+v8::Handle<v8::Value> DoLoopCancelTerminate(const v8::Arguments& args) {
+ v8::TryCatch try_catch;
+ CHECK(!v8::V8::IsExecutionTerminating());
+ v8::Script::Compile(v8::String::New("var term = true;"
+ "while(true) {"
+ " if (term) terminate();"
+ " term = false;"
+ "}"
+ "fail();"))->Run();
+ CHECK(try_catch.HasCaught());
+ CHECK(try_catch.Exception()->IsNull());
+ CHECK(try_catch.Message().IsEmpty());
+ CHECK(!try_catch.CanContinue());
+ CHECK(v8::V8::IsExecutionTerminating());
+ CHECK(try_catch.HasTerminated());
+ v8::V8::CancelTerminateExecution(v8::Isolate::GetCurrent());
+ CHECK(!v8::V8::IsExecutionTerminating());
+ return v8::Undefined();
+}
+
+// Test that a single thread of JavaScript execution can terminate
+// itself and then resume execution.
+TEST(TerminateCancelTerminateFromThreadItself) {
+ v8::HandleScope scope;
+ v8::Handle<v8::ObjectTemplate> global =
+ CreateGlobalTemplate(TerminateCurrentThread, DoLoopCancelTerminate);
+ v8::Persistent<v8::Context> context = v8::Context::New(NULL, global);
+ v8::Context::Scope context_scope(context);
+ CHECK(!v8::V8::IsExecutionTerminating());
+ v8::Handle<v8::String> source =
+ v8::String::New("try { doloop(); } catch(e) { fail(); } 'completed';");
+ // Check that execution completed with correct return value.
+ CHECK(v8::Script::Compile(source)->Run()->Equals(v8_str("completed")));
+ context.Dispose(context->GetIsolate());
+}
+