Automatic thread cleanup on non-Windows platforms.

runtime/vm/thread.cc

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/thread.h"
 
 #include "vm/isolate.h"
 #include "vm/os_thread.h"
 #include "vm/profiler.h"
 #include "vm/thread_interrupter.h"
 
 
 namespace dart {
 
 // The single thread local key which stores all the thread local data
 // for a thread.
 // TODO(koda): Can we merge this with ThreadInterrupter::thread_state_key_?
 ThreadLocalKey Thread::thread_key_ = OSThread::kUnsetThreadLocalKey;
 
 
+static void DeleteThread(void* thread) {
+  delete reinterpret_cast<Thread*>(thread);
+}
+
+
 void Thread::InitOnce() {
   ASSERT(thread_key_ == OSThread::kUnsetThreadLocalKey);
-  thread_key_ = OSThread::CreateThreadLocal();
+  thread_key_ = OSThread::CreateThreadLocal(DeleteThread);
   ASSERT(thread_key_ != OSThread::kUnsetThreadLocalKey);
 }
 
 
 void Thread::SetCurrent(Thread* current) {
   OSThread::SetThreadLocal(thread_key_, reinterpret_cast<uword>(current));
 }
 
 
 void Thread::EnsureInit() {
   if (Thread::Current() == NULL) {
     SetCurrent(new Thread());
   }
 }
 
 
+#if defined(TARGET_OS_WINDOWS)
 void Thread::CleanUp() {
   Thread* current = Current();
   if (current != NULL) {
     delete current;
   }
   SetCurrent(NULL);
 }
+#endif
 
 
 void Thread::EnterIsolate(Isolate* isolate) {
   EnsureInit();

[Ivan Posva, 2015/05/15 15:40:52]

How about initializing once in the thread pool and only asserting here? Then we
only need to ensure the thread is initialized when calling Dart_EnterIsolatem
(and friends) through the C API.

At the extreme you could have Thread::Current() assert that a thread is set. And
use a private Thread::CurrentNoCheck() to build the EnsureInit functionality.

[koda, 2015/05/15 17:30:04]

Done (but not to the extreme).

   Thread* thread = Thread::Current();
   ASSERT(thread->isolate() == NULL);
   ASSERT(isolate->mutator_thread() == NULL);
   isolate->set_mutator_thread(thread);
   // TODO(koda): Migrate thread_state_ and profile_data_ to Thread, to allow
   // helper threads concurrent with mutator.
   ASSERT(isolate->thread_state() == NULL);
   InterruptableThreadState* thread_state =
       ThreadInterrupter::GetCurrentThreadState();
 #if defined(DEBUG)
@@ skipping 19 matching lines @@
   }
   isolate->set_thread_state(NULL);
   Profiler::EndExecution(isolate);
   isolate->set_mutator_thread(NULL);
   thread->isolate_ = NULL;
   ASSERT(Isolate::Current() == NULL);
 }
 
 
 void Thread::EnterIsolateAsHelper(Isolate* isolate) {
   EnsureInit();

[Ivan Posva, 2015/05/15 15:40:52]

ditto

[koda, 2015/05/15 17:30:03]

Done.

   Thread* thread = Thread::Current();
   ASSERT(thread->isolate() == NULL);
   thread->isolate_ = isolate;
   // Do not update isolate->mutator_thread, but perform sanity check:
   // this thread should not be both the main mutator and helper.
   ASSERT(isolate->mutator_thread() != thread);
 }
 
 
 void Thread::ExitIsolateAsHelper() {
@@ skipping 10 matching lines @@
   return isolate_->cha_;
 }
 
 
 void Thread::set_cha(CHA* value) {
   ASSERT(isolate_ != NULL);
   isolate_->cha_ = value;
 }
 
 }  // namespace dart