Implement nacl_irt_thread and nacl_irt_tls for non-sfi mode.

components/nacl/loader/nonsfi/irt_thread.cc

Index: components/nacl/loader/nonsfi/irt_thread.cc
diff --git a/components/nacl/loader/nonsfi/irt_thread.cc b/components/nacl/loader/nonsfi/irt_thread.cc
new file mode 100644
index 0000000000000000000000000000000000000000..d0a181425c548fba1493e4ab648c337c7f403c6f
--- /dev/null
+++ b/components/nacl/loader/nonsfi/irt_thread.cc
@@ -0,0 +1,123 @@
+// Copyright 2014 The Chromium 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 <errno.h>
+#include <pthread.h>
+
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "components/nacl/loader/nonsfi/irt_interfaces.h"
+
+namespace nacl {
+namespace nonsfi {
+namespace {
+
+// We heuristically chose 1M for the stack size per thread.
+const int kStackSize = 1024 * 1024;
+
+// For RAII of pthread_attr_t.
+class ScopedPthreadAttrPtr {
+ public:
+  ScopedPthreadAttrPtr(pthread_attr_t* attr) : attr_(attr) {
+  }
+  ~ScopedPthreadAttrPtr() {
+    pthread_attr_destroy(attr_);
+  }
+
+ private:
+  pthread_attr_t* attr_;
+};
+
+struct ThreadContext {
+  void (*start_func)();
+  void* thread_ptr;
+};
+
+// A thread local pointer to support nacl_irt_tls.
+// This should be initialized at the beginning of ThreadMain, which is a thin
+// wrapper of a user function called on a newly created thread, and may be
+// reset via IrtTlsInit(). The pointer can be obtained via IrtTlsGet().
+__thread void* g_thread_ptr;
+
+void* ThreadMain(void *arg) {
+  ::scoped_ptr<ThreadContext> context(static_cast<ThreadContext*>(arg));
+  g_thread_ptr = context->thread_ptr;
+
+  // Release the memory of context before running start_func.
+  void (*start_func)() = context->start_func;
+  context.reset();
+
+  start_func();
+  return NULL;

[Mark Seaborn, 2014/01/15 19:06:39]

Can you call abort() instead?  The user's function is not supposed to return.

[hidehiko, 2014/01/16 03:17:44]

Done.

+}
+
+int IrtThreadCreate(void (*start_func)(), void* stack, void* thread_ptr) {
+  pthread_attr_t attr;
+  int error = pthread_attr_init(&attr);
+  if (error != 0)
+    return error;
+  ScopedPthreadAttrPtr scoped_attr_ptr(&attr);
+
+  // Note: Currently we ignore the argument stack.
+  error = pthread_attr_setstacksize(&attr, kStackSize);
+  if (error != 0)
+    return error;
+
+  error = pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
+  if (error != 0)
+    return error;
+
+  ::scoped_ptr<ThreadContext> context(new ThreadContext);
+  context->start_func = start_func;
+  context->thread_ptr = thread_ptr;
+
+  pthread_t tid;
+  error = pthread_create(&tid, &attr, ThreadMain, context.get());
+  if (error != 0)
+    return error;
+
+  // The ownership of the context is taken by the created thread. So, here we
+  // just manually release it.
+  ignore_result(context.release());
+  return 0;
+}
+
+void IrtThreadExit(int32_t* stack_flag) {
+  // As we actually don't use stack given to thread_create, it means that the
+  // memory can be released whenever.
+  if (stack_flag)
+    *stack_flag = 0;
+  pthread_exit(NULL);
+}
+
+int IrtThreadNice(const int nice) {
+  // TODO(https://code.google.com/p/nativeclient/issues/detail?id=3734):
+  // Implement this method.
+  return ENOSYS;

[Mark Seaborn, 2014/01/15 19:06:39]

Since 'nice' is just a hint, it would be better to return 0, so that this
doesn't break any programs that call this.

[hidehiko, 2014/01/16 03:17:44]

Done.

+}
+
+int IrtTlsInit(void* thread_ptr) {
+  g_thread_ptr = thread_ptr;
+  return 0;
+}
+
+void* IrtTlsGet() {
+  return g_thread_ptr;
+}
+
+}  // namespace
+
+const nacl_irt_thread kIrtThread = {
+  IrtThreadCreate,
+  IrtThreadExit,
+  IrtThreadNice,
+};
+
+const nacl_irt_tls kIrtTls = {
+  IrtTlsInit,
+  IrtTlsGet,
+};
+
+}  // namespace nonsfi
+}  // namespace nacl