Uses an open thread handle as the ThreadJoinId on Windows.

runtime/bin/thread_win.cc

Index: runtime/bin/thread_win.cc
diff --git a/runtime/bin/thread_win.cc b/runtime/bin/thread_win.cc
index db4119604000d64ae30868b7fb32514ae9e30212..b8b73dc442c8244310146e7fa4fab0a7646d07a5 100644
--- a/runtime/bin/thread_win.cc
+++ b/runtime/bin/thread_win.cc
@@ -104,23 +104,7 @@ ThreadId Thread::GetCurrentThreadId() {
 
 
 bool Thread::Join(ThreadId id) {
-  HANDLE handle = OpenThread(SYNCHRONIZE, false, id);
-
-  // TODO(zra): OSThread::Start() closes the handle to the thread. Thus, by the
-  // time we try to join the thread, its resources may have already been
-  // reclaimed, and joining will fail. This can be avoided in a couple of ways.
-  // First, GetCurrentThreadJoinId could call OpenThread and return a handle.
-  // This is bad, because each of those handles would have to be closed.
-  // Second OSThread could be refactored to no longer be AllStatic. Then the
-  // handle could be cached in the object by the Start method.
-  if (handle == NULL) {
-    return false;
-  }
-
-  DWORD res = WaitForSingleObject(handle, INFINITE);
-  CloseHandle(handle);
-  ASSERT(res == WAIT_OBJECT_0);
-  return true;
+  return false;
 }

[siva, 2016/05/16 17:59:27]

The Thread::Join function doesn't seem to be used anymore why not just delete
it.

[zra, 2016/05/16 20:32:54]

Done.