Bug 1296878 - Implement js::ThisThread::GetName for limited set of platforms, r=fitzgen

--HG--
extra : rebase_source : 43c3a5efd7e73e7b32728a58648f8606463b0147

js/src/threading/Thread.h

@@ -185,6 +185,12 @@ Thread::Id GetId();
 // nothing.
 void SetName(const char* name);
 
+// Get the current thread name. As with SetName, not available on all
+// platforms. On these platforms getName() will give back an empty string (by
+// storing NUL in nameBuffer[0]). 'len' is the bytes available to be written in
+// 'nameBuffer', including the terminating NUL.
+void GetName(char* nameBuffer, size_t len);
+
 } // namespace ThisThread
 
 namespace detail {

js/src/threading/posix/Thread.cpp

@@ -164,3 +164,25 @@ js::ThisThread::SetName(const char* name)
 #endif
   MOZ_RELEASE_ASSERT(!rv);
 }
+
+void
+js::ThisThread::GetName(char* nameBuffer, size_t len)
+{
+  // Using http://stackoverflow.com/questions/2369738/can-i-set-the-name-of-a-thread-in-pthreads-linux as a reference.
+
+  int rv;
+#ifdef XP_DARWIN
+  rv = pthread_getname_np(pthread_self(), nameBuffer, len);
+#elif defined(__DragonFly__) || defined(__FreeBSD__) || defined(__OpenBSD__)
+  pthread_get_name_np(pthread_self(), nameBuffer, len);
+  rv = 0;
+#elif defined(__NetBSD__)
+  rv = pthread_getname_np(pthread_self(), nameBuffer, len);
+#else
+  rv = pthread_getname_np(pthread_self(), nameBuffer, len);
+#endif
+
+  MOZ_RELEASE_ASSERT(len > 0);
+  if (rv)
+    nameBuffer[0] = '\0';
+}

js/src/threading/windows/Thread.cpp

@@ -155,3 +155,10 @@ js::ThisThread::SetName(const char* name)
   }
 #endif
 }
+
+void
+js::ThisThread::GetName(char* nameBuffer, size_t len)
+{
+  MOZ_RELEASE_ASSERT(len > 0);
+  *nameBuffer = '\0';
+}