// Copyright (c) 2006-2008 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 "base/platform_thread.h"

#include <errno.h>
#include <sched.h>

#if defined(XP_DARWIN)
#  include <mach/mach.h>
#elif defined(XP_NETBSD)
#  include <lwp.h>
#elif defined(XP_LINUX)
#  include <sys/syscall.h>
#  include <sys/prctl.h>
#endif

#if !defined(XP_DARWIN)
#  include <unistd.h>
#endif

#if (defined(__DragonFly__) || defined(XP_FREEBSD) || defined(XP_OPENBSD)) && \
    !defined(__GLIBC__)
#  include <pthread_np.h>
#endif

#include "nsThreadUtils.h"

#if defined(XP_DARWIN)
namespace base {
void InitThreading();
}  // namespace base
#endif

static void* ThreadFunc(void* closure) {
  PlatformThread::Delegate* delegate =
      static_cast<PlatformThread::Delegate*>(closure);
  delegate->ThreadMain();
  return nullptr;
}

// static
PlatformThreadId PlatformThread::CurrentId() {
  // Pthreads doesn't have the concept of a thread ID, so we have to reach down
  // into the kernel.
#if defined(XP_DARWIN)
  mach_port_t port = mach_thread_self();
  mach_port_deallocate(mach_task_self(), port);
  return port;
#elif defined(XP_LINUX)
  return syscall(__NR_gettid);
#elif defined(XP_OPENBSD) || defined(XP_SOLARIS) || defined(__GLIBC__)
  return (intptr_t)(pthread_self());
#elif defined(XP_NETBSD)
  return _lwp_self();
#elif defined(__DragonFly__)
  return lwp_gettid();
#elif defined(XP_FREEBSD)
  return pthread_getthreadid_np();
#endif
}

// static
void PlatformThread::YieldCurrentThread() { sched_yield(); }

// static
void PlatformThread::Sleep(int duration_ms) {
  struct timespec sleep_time, remaining;

  // Contains the portion of duration_ms >= 1 sec.
  sleep_time.tv_sec = duration_ms / 1000;
  duration_ms -= sleep_time.tv_sec * 1000;

  // Contains the portion of duration_ms < 1 sec.
  sleep_time.tv_nsec = duration_ms * 1000 * 1000;  // nanoseconds.

  while (nanosleep(&sleep_time, &remaining) == -1 && errno == EINTR)
    sleep_time = remaining;
}

#ifndef XP_DARWIN
// Mac is implemented in platform_thread_mac.mm.

// static
void PlatformThread::SetName(const char* name) {
  // On linux we can get the thread names to show up in the debugger by setting
  // the process name for the LWP.  We don't want to do this for the main
  // thread because that would rename the process, causing tools like killall
  // to stop working.
  if (PlatformThread::CurrentId() == getpid()) return;

  // Using NS_SetCurrentThreadName, as opposed to using platform APIs directly,
  // also sets the thread name on the PRThread wrapper, and allows us to
  // retrieve it using PR_GetThreadName.
  NS_SetCurrentThreadName(name);
}
#endif  // !XP_DARWIN

namespace {

bool CreateThread(size_t stack_size, bool joinable,
                  PlatformThread::Delegate* delegate,
                  PlatformThreadHandle* thread_handle) {
#if defined(XP_DARWIN)
  base::InitThreading();
#endif  // XP_DARWIN

  bool success = false;
  pthread_attr_t attributes;
  pthread_attr_init(&attributes);

  // Pthreads are joinable by default, so only specify the detached attribute if
  // the thread should be non-joinable.
  if (!joinable) {
    pthread_attr_setdetachstate(&attributes, PTHREAD_CREATE_DETACHED);
  }

  if (stack_size == 0) stack_size = nsIThreadManager::DEFAULT_STACK_SIZE;
  pthread_attr_setstacksize(&attributes, stack_size);

  success = !pthread_create(thread_handle, &attributes, ThreadFunc, delegate);

  pthread_attr_destroy(&attributes);
  return success;
}

}  // anonymous namespace

// static
bool PlatformThread::Create(size_t stack_size, Delegate* delegate,
                            PlatformThreadHandle* thread_handle) {
  return CreateThread(stack_size, true /* joinable thread */, delegate,
                      thread_handle);
}

// static
bool PlatformThread::CreateNonJoinable(size_t stack_size, Delegate* delegate) {
  PlatformThreadHandle unused;

  bool result = CreateThread(stack_size, false /* non-joinable thread */,
                             delegate, &unused);
  return result;
}

// static
void PlatformThread::Join(PlatformThreadHandle thread_handle) {
  pthread_join(thread_handle, nullptr);
}
