Add IsExecutionTerminating api method.

IsExecutionTerminating returns true if a termination exception is
currently being propagated.  C++ code should not reenter V8 when
IsExecutionTerminating returns true.

Review URL: http://codereview.chromium.org/668052

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4016 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

diff --git a/include/v8.h b/include/v8.h
index 92e1bb6..238dddd 100644 (file)
--- a/include/v8.h
+++ b/include/v8.h
@@ -2464,6 +2464,16 @@ class V8EXPORT V8 {
   static void TerminateExecution();
 
   /**
+   * Is V8 terminating JavaScript execution.
+   *
+   * Returns true if JavaScript execution is currently terminating
+   * because of a call to TerminateExecution.  In that case there are
+   * still JavaScript frames on the stack and the termination
+   * exception is still active.
+   */
+  static bool IsExecutionTerminating();
+
+  /**
    * 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.

diff --git a/src/api.cc b/src/api.cc
index 4d193c3..f479f5c 100644 (file)
--- a/src/api.cc
+++ b/src/api.cc
@@ -3615,6 +3615,15 @@ void V8::TerminateExecution() {
 }
 
 
+bool V8::IsExecutionTerminating() {
+  if (!i::V8::IsRunning()) return false;
+  if (i::Top::has_scheduled_exception()) {
+    return i::Top::scheduled_exception() == i::Heap::termination_exception();
+  }
+  return false;
+}
+
+
 String::Utf8Value::Utf8Value(v8::Handle<v8::Value> obj) {
   EnsureInitialized("v8::String::Utf8Value::Utf8Value()");
   if (obj.IsEmpty()) {

diff --git a/test/cctest/test-thread-termination.cc b/test/cctest/test-thread-termination.cc
index 1e8102e..83a1e19 100644 (file)
--- a/test/cctest/test-thread-termination.cc
+++ b/test/cctest/test-thread-termination.cc
@@ -40,6 +40,7 @@ v8::Handle<v8::Value> Signal(const v8::Arguments& args) {
 
 
 v8::Handle<v8::Value> TerminateCurrentThread(const v8::Arguments& args) {
+  CHECK(!v8::V8::IsExecutionTerminating());
   v8::V8::TerminateExecution();
   return v8::Undefined();
 }
@@ -52,15 +53,19 @@ v8::Handle<v8::Value> Fail(const v8::Arguments& args) {
 
 
 v8::Handle<v8::Value> Loop(const v8::Arguments& args) {
+  CHECK(!v8::V8::IsExecutionTerminating());
   v8::Handle<v8::String> source =
       v8::String::New("try { doloop(); fail(); } catch(e) { fail(); }");
-  v8::Script::Compile(source)->Run();
+  v8::Handle<v8::Value> result = v8::Script::Compile(source)->Run();
+  CHECK(result.IsEmpty());
+  CHECK(v8::V8::IsExecutionTerminating());
   return v8::Undefined();
 }
 
 
 v8::Handle<v8::Value> DoLoop(const v8::Arguments& args) {
   v8::TryCatch try_catch;
+  CHECK(!v8::V8::IsExecutionTerminating());
   v8::Script::Compile(v8::String::New("function f() {"
                                       "  var term = true;"
                                       "  try {"
@@ -78,12 +83,14 @@ v8::Handle<v8::Value> DoLoop(const v8::Arguments& args) {
   CHECK(try_catch.Exception()->IsNull());
   CHECK(try_catch.Message().IsEmpty());
   CHECK(!try_catch.CanContinue());
+  CHECK(v8::V8::IsExecutionTerminating());
   return v8::Undefined();
 }
 
 
 v8::Handle<v8::Value> DoLoopNoCall(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();"
@@ -93,6 +100,7 @@ v8::Handle<v8::Value> DoLoopNoCall(const v8::Arguments& args) {
   CHECK(try_catch.Exception()->IsNull());
   CHECK(try_catch.Message().IsEmpty());
   CHECK(!try_catch.CanContinue());
+  CHECK(v8::V8::IsExecutionTerminating());
   return v8::Undefined();
 }
 
@@ -118,11 +126,13 @@ TEST(TerminateOnlyV8ThreadFromThreadItself) {
       CreateGlobalTemplate(TerminateCurrentThread, DoLoop);
   v8::Persistent<v8::Context> context = v8::Context::New(NULL, global);
   v8::Context::Scope context_scope(context);
+  CHECK(!v8::V8::IsExecutionTerminating());
   // Run a loop that will be infinite if thread termination does not work.
   v8::Handle<v8::String> source =
       v8::String::New("try { loop(); fail(); } catch(e) { fail(); }");
   v8::Script::Compile(source)->Run();
   // Test that we can run the code again after thread termination.
+  CHECK(!v8::V8::IsExecutionTerminating());
   v8::Script::Compile(source)->Run();
   context.Dispose();
 }
@@ -136,10 +146,12 @@ TEST(TerminateOnlyV8ThreadFromThreadItselfNoLoop) {
       CreateGlobalTemplate(TerminateCurrentThread, DoLoopNoCall);
   v8::Persistent<v8::Context> context = v8::Context::New(NULL, global);
   v8::Context::Scope context_scope(context);
+  CHECK(!v8::V8::IsExecutionTerminating());
   // Run a loop that will be infinite if thread termination does not work.
   v8::Handle<v8::String> source =
       v8::String::New("try { loop(); fail(); } catch(e) { fail(); }");
   v8::Script::Compile(source)->Run();
+  CHECK(!v8::V8::IsExecutionTerminating());
   // Test that we can run the code again after thread termination.
   v8::Script::Compile(source)->Run();
   context.Dispose();
@@ -149,6 +161,7 @@ TEST(TerminateOnlyV8ThreadFromThreadItselfNoLoop) {
 class TerminatorThread : public v8::internal::Thread {
   void Run() {
     semaphore->Wait();
+    CHECK(!v8::V8::IsExecutionTerminating());
     v8::V8::TerminateExecution();
   }
 };
@@ -165,6 +178,7 @@ TEST(TerminateOnlyV8ThreadFromOtherThread) {
   v8::Handle<v8::ObjectTemplate> global = CreateGlobalTemplate(Signal, DoLoop);
   v8::Persistent<v8::Context> context = v8::Context::New(NULL, global);
   v8::Context::Scope context_scope(context);
+  CHECK(!v8::V8::IsExecutionTerminating());
   // Run a loop that will be infinite if thread termination does not work.
   v8::Handle<v8::String> source =
       v8::String::New("try { loop(); fail(); } catch(e) { fail(); }");
@@ -187,6 +201,7 @@ class LoopingThread : public v8::internal::Thread {
         CreateGlobalTemplate(Signal, DoLoop);
     v8::Persistent<v8::Context> context = v8::Context::New(NULL, global);
     v8::Context::Scope context_scope(context);
+    CHECK(!v8::V8::IsExecutionTerminating());
     // Run a loop that will be infinite if thread termination does not work.
     v8::Handle<v8::String> source =
         v8::String::New("try { loop(); fail(); } catch(e) { fail(); }");
@@ -235,6 +250,7 @@ int call_count = 0;
 
 v8::Handle<v8::Value> TerminateOrReturnObject(const v8::Arguments& args) {
   if (++call_count == 10) {
+    CHECK(!v8::V8::IsExecutionTerminating());
     v8::V8::TerminateExecution();
     return v8::Undefined();
   }
@@ -246,6 +262,7 @@ v8::Handle<v8::Value> TerminateOrReturnObject(const v8::Arguments& args) {
 
 v8::Handle<v8::Value> LoopGetProperty(const v8::Arguments& args) {
   v8::TryCatch try_catch;
+  CHECK(!v8::V8::IsExecutionTerminating());
   v8::Script::Compile(v8::String::New("function f() {"
                                       "  try {"
                                       "    while(true) {"
@@ -261,6 +278,7 @@ v8::Handle<v8::Value> LoopGetProperty(const v8::Arguments& args) {
   CHECK(try_catch.Exception()->IsNull());
   CHECK(try_catch.Message().IsEmpty());
   CHECK(!try_catch.CanContinue());
+  CHECK(v8::V8::IsExecutionTerminating());
   return v8::Undefined();
 }
 
@@ -278,12 +296,14 @@ TEST(TerminateLoadICException) {
 
   v8::Persistent<v8::Context> context = v8::Context::New(NULL, global);
   v8::Context::Scope context_scope(context);
+  CHECK(!v8::V8::IsExecutionTerminating());
   // Run a loop that will be infinite if thread termination does not work.
   v8::Handle<v8::String> source =
       v8::String::New("try { loop(); fail(); } catch(e) { fail(); }");
   call_count = 0;
   v8::Script::Compile(source)->Run();
   // Test that we can run the code again after thread termination.
+  CHECK(!v8::V8::IsExecutionTerminating());
   call_count = 0;
   v8::Script::Compile(source)->Run();
   context.Dispose();