/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include <chrono>
#include <thread>

#include "threading/Thread.h"
#include "threading/windows/ThreadPlatformData.h"

namespace js {

inline ThreadId::PlatformData* ThreadId::platformData() {
  static_assert(sizeof platformData_ >= sizeof(PlatformData),
                "platformData_ is too small");
  return reinterpret_cast<PlatformData*>(platformData_);
}

inline const ThreadId::PlatformData* ThreadId::platformData() const {
  static_assert(sizeof platformData_ >= sizeof(PlatformData),
                "platformData_ is too small");
  return reinterpret_cast<const PlatformData*>(platformData_);
}

ThreadId::ThreadId() {
  platformData()->handle = nullptr;
  platformData()->id = 0;
}

ThreadId::operator bool() const { return platformData()->handle; }

bool ThreadId::operator==(const ThreadId& aOther) const {
  return platformData()->id == aOther.platformData()->id;
}

bool Thread::create(unsigned int(__stdcall* aMain)(void*), void* aArg) {
  MOZ_RELEASE_ASSERT(!joinable());

  if (oom::ShouldFailWithOOM()) {
    return false;
  }

  // Use _beginthreadex and not CreateThread, because threads that are
  // created with the latter leak a small amount of memory when they use
  // certain msvcrt functions and then exit.
  uintptr_t handle = _beginthreadex(nullptr, options_.stackSize(), aMain, aArg,
                                    STACK_SIZE_PARAM_IS_A_RESERVATION,
                                    &id_.platformData()->id);
  if (!handle) {
    // On either Windows or POSIX we can't be sure if id_ was initalisad. So
    // reset it manually.
    id_ = ThreadId();
    return false;
  }
  id_.platformData()->handle = reinterpret_cast<HANDLE>(handle);
  return true;
}

void Thread::join() {
  MOZ_RELEASE_ASSERT(joinable());
  DWORD r = WaitForSingleObject(id_.platformData()->handle, INFINITE);
  MOZ_RELEASE_ASSERT(r == WAIT_OBJECT_0);
  BOOL success = CloseHandle(id_.platformData()->handle);
  MOZ_RELEASE_ASSERT(success);
  id_ = ThreadId();
}

void Thread::detach() {
  MOZ_RELEASE_ASSERT(joinable());
  BOOL success = CloseHandle(id_.platformData()->handle);
  MOZ_RELEASE_ASSERT(success);
  id_ = ThreadId();
}

ThreadId ThreadId::ThisThreadId() {
  ThreadId id;
  id.platformData()->handle = GetCurrentThread();
  id.platformData()->id = GetCurrentThreadId();
  MOZ_RELEASE_ASSERT(id != ThreadId());
  return id;
}

void ThisThread::SetName(const char* name) {
  MOZ_RELEASE_ASSERT(name);

#ifdef _MSC_VER
  // Setting the thread name requires compiler support for structured
  // exceptions, so this only works when compiled with MSVC.
  static const DWORD THREAD_NAME_EXCEPTION = 0x406D1388;
  static const DWORD THREAD_NAME_INFO_TYPE = 0x1000;

#  pragma pack(push, 8)
  struct THREADNAME_INFO {
    DWORD dwType;
    LPCSTR szName;
    DWORD dwThreadID;
    DWORD dwFlags;
  };
#  pragma pack(pop)

  THREADNAME_INFO info;
  info.dwType = THREAD_NAME_INFO_TYPE;
  info.szName = name;
  info.dwThreadID = GetCurrentThreadId();
  info.dwFlags = 0;

  __try {
    RaiseException(THREAD_NAME_EXCEPTION, 0, sizeof(info) / sizeof(ULONG_PTR),
                   (ULONG_PTR*)&info);
  } __except (EXCEPTION_EXECUTE_HANDLER) {
    // Do nothing.
  }
#endif  // _MSC_VER
}

void ThisThread::GetName(char* nameBuffer, size_t len) {
  MOZ_RELEASE_ASSERT(len > 0);
  *nameBuffer = '\0';
}

void ThisThread::SleepMilliseconds(size_t ms) {
  std::this_thread::sleep_for(std::chrono::milliseconds(ms));
}

}  // namespace js