Cloning a bunch of stuff from the native_client repository at r6528

ppapi/native_client/src/shared/ppapi_proxy/plugin_threading.cc

Index: ppapi/native_client/src/shared/ppapi_proxy/plugin_threading.cc
===================================================================
--- ppapi/native_client/src/shared/ppapi_proxy/plugin_threading.cc	(revision 0)
+++ ppapi/native_client/src/shared/ppapi_proxy/plugin_threading.cc	(revision 0)
@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2011 The Native Client Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include <pthread.h>
+
+#include "native_client/src/include/nacl_macros.h"
+#include "native_client/src/shared/ppapi_proxy/ppruntime.h"
+
+
+/*
+ * This provides a default definition that is overridden in the IRT.
+ * TODO(mseaborn): Remove this when PPAPI is only supported via the IRT.
+ * See http://code.google.com/p/nativeclient/issues/detail?id=1691
+ */
+
+static int thread_create(uintptr_t *tid,
+                         void (*func)(void *thread_argument),
+                         void *thread_argument) {
+  /*
+   * We know that newlib and glibc use a small pthread_t type, so we
+   * do not need to wrap pthread_t values.
+   */
+  NACL_COMPILE_TIME_ASSERT(sizeof(pthread_t) == sizeof(uintptr_t));
+
+  return pthread_create((pthread_t *) tid, NULL,
+                        (void *(*)(void *thread_argument)) func,
+                        thread_argument);
+}
+
+static int thread_join(uintptr_t tid) {
+  return pthread_join((pthread_t) tid, NULL);
+}
+
+const static struct PP_ThreadFunctions thread_funcs = {
+  thread_create,
+  thread_join
+};
+
+void PpapiPluginRegisterDefaultThreadCreator() {
+  PpapiPluginRegisterThreadCreator(&thread_funcs);
+}