// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

#include "platform/globals.h"
#if defined(DART_HOST_OS_MACOS) && !defined(DART_USE_ABSL)

#include "bin/thread.h"
#include "bin/thread_macos.h"

#include <mach/mach_host.h>    // NOLINT
#include <mach/mach_init.h>    // NOLINT
#include <mach/mach_port.h>    // NOLINT
#include <mach/mach_traps.h>   // NOLINT
#include <mach/task_info.h>    // NOLINT
#include <mach/thread_act.h>   // NOLINT
#include <mach/thread_info.h>  // NOLINT
#include <sys/errno.h>         // NOLINT
#include <sys/sysctl.h>        // NOLINT
#include <sys/types.h>         // NOLINT

#include "platform/assert.h"
#include "platform/utils.h"

namespace dart {
namespace bin {

#define VALIDATE_PTHREAD_RESULT(result)                                        \
  if (result != 0) {                                                           \
    const int kBufferSize = 1024;                                              \
    char error_message[kBufferSize];                                           \
    Utils::StrError(result, error_message, kBufferSize);                       \
    FATAL("pthread error: %d (%s)", result, error_message);                    \
  }

#ifdef DEBUG
#define RETURN_ON_PTHREAD_FAILURE(result)                                      \
  if (result != 0) {                                                           \
    const int kBufferSize = 1024;                                              \
    char error_message[kBufferSize];                                           \
    Utils::StrError(result, error_message, kBufferSize);                       \
    fprintf(stderr, "%s:%d: pthread error: %d (%s)\n", __FILE__, __LINE__,     \
            result, error_message);                                            \
    return result;                                                             \
  }
#else
#define RETURN_ON_PTHREAD_FAILURE(result)                                      \
  if (result != 0) {                                                           \
    return result;                                                             \
  }
#endif

class ThreadStartData {
 public:
  ThreadStartData(const char* name,
                  Thread::ThreadStartFunction function,
                  uword parameter)
      : name_(name), function_(function), parameter_(parameter) {}

  const char* name() const { return name_; }
  Thread::ThreadStartFunction function() const { return function_; }
  uword parameter() const { return parameter_; }

 private:
  const char* name_;
  Thread::ThreadStartFunction function_;
  uword parameter_;

  DISALLOW_COPY_AND_ASSIGN(ThreadStartData);
};

// Dispatch to the thread start function provided by the caller. This trampoline
// is used to ensure that the thread is properly destroyed if the thread just
// exits.
static void* ThreadStart(void* data_ptr) {
  ThreadStartData* data = reinterpret_cast<ThreadStartData*>(data_ptr);

  const char* name = data->name();
  Thread::ThreadStartFunction function = data->function();
  uword parameter = data->parameter();
  delete data;

  // Set the thread name. We need to impose a limit on the name length so that
  // we can know how large of a buffer to use when retrieving the name. We
  // truncate the name at 16 bytes to be consistent with Android and Linux.
  char truncated_name[16];
  snprintf(truncated_name, sizeof(truncated_name), "%s", name);
  pthread_setname_np(name);

  // Call the supplied thread start function handing it its parameters.
  function(parameter);

  return nullptr;
}

int Thread::Start(const char* name,
                  ThreadStartFunction function,
                  uword parameter) {
  pthread_attr_t attr;
  int result = pthread_attr_init(&attr);
  RETURN_ON_PTHREAD_FAILURE(result);

  result = pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
  RETURN_ON_PTHREAD_FAILURE(result);

  result = pthread_attr_setstacksize(&attr, Thread::GetMaxStackSize());
  RETURN_ON_PTHREAD_FAILURE(result);

  ThreadStartData* data = new ThreadStartData(name, function, parameter);

  pthread_t tid;
  result = pthread_create(&tid, &attr, ThreadStart, data);
  RETURN_ON_PTHREAD_FAILURE(result);

  result = pthread_attr_destroy(&attr);
  RETURN_ON_PTHREAD_FAILURE(result);

  return 0;
}

const ThreadId Thread::kInvalidThreadId = static_cast<ThreadId>(nullptr);

intptr_t Thread::GetMaxStackSize() {
  const int kStackSize = (128 * kWordSize * KB);
  return kStackSize;
}

ThreadId Thread::GetCurrentThreadId() {
  return pthread_self();
}

bool Thread::Compare(ThreadId a, ThreadId b) {
  return (pthread_equal(a, b) != 0);
}

Mutex::Mutex() {
  pthread_mutexattr_t attr;
  int result = pthread_mutexattr_init(&attr);
  VALIDATE_PTHREAD_RESULT(result);

#if defined(DEBUG)
  result = pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_ERRORCHECK);
  VALIDATE_PTHREAD_RESULT(result);
#endif  // defined(DEBUG)

  result = pthread_mutex_init(data_.mutex(), &attr);
  // Verify that creating a pthread_mutex succeeded.
  VALIDATE_PTHREAD_RESULT(result);

  result = pthread_mutexattr_destroy(&attr);
  VALIDATE_PTHREAD_RESULT(result);
}

Mutex::~Mutex() {
  int result = pthread_mutex_destroy(data_.mutex());
  // Verify that the pthread_mutex was destroyed.
  VALIDATE_PTHREAD_RESULT(result);
}

void Mutex::Lock() {
  int result = pthread_mutex_lock(data_.mutex());
  // Specifically check for dead lock to help debugging.
  ASSERT(result != EDEADLK);
  ASSERT(result == 0);  // Verify no other errors.
  // TODO(iposva): Do we need to track lock owners?
}

bool Mutex::TryLock() {
  int result = pthread_mutex_trylock(data_.mutex());
  // Return false if the lock is busy and locking failed.
  if ((result == EBUSY) || (result == EDEADLK)) {
    return false;
  }
  ASSERT(result == 0);  // Verify no other errors.
  // TODO(iposva): Do we need to track lock owners?
  return true;
}

void Mutex::Unlock() {
  // TODO(iposva): Do we need to track lock owners?
  int result = pthread_mutex_unlock(data_.mutex());
  // Specifically check for wrong thread unlocking to aid debugging.
  ASSERT(result != EPERM);
  ASSERT(result == 0);  // Verify no other errors.
}

Monitor::Monitor() {
  pthread_mutexattr_t attr;
  int result = pthread_mutexattr_init(&attr);
  VALIDATE_PTHREAD_RESULT(result);

#if defined(DEBUG)
  result = pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_ERRORCHECK);
  VALIDATE_PTHREAD_RESULT(result);
#endif  // defined(DEBUG)

  result = pthread_mutex_init(data_.mutex(), &attr);
  VALIDATE_PTHREAD_RESULT(result);

  result = pthread_mutexattr_destroy(&attr);
  VALIDATE_PTHREAD_RESULT(result);

  result = pthread_cond_init(data_.cond(), nullptr);
  VALIDATE_PTHREAD_RESULT(result);
}

Monitor::~Monitor() {
  int result = pthread_mutex_destroy(data_.mutex());
  VALIDATE_PTHREAD_RESULT(result);

  result = pthread_cond_destroy(data_.cond());
  VALIDATE_PTHREAD_RESULT(result);
}

void Monitor::Enter() {
  int result = pthread_mutex_lock(data_.mutex());
  VALIDATE_PTHREAD_RESULT(result);
  // TODO(iposva): Do we need to track lock owners?
}

void Monitor::Exit() {
  // TODO(iposva): Do we need to track lock owners?
  int result = pthread_mutex_unlock(data_.mutex());
  VALIDATE_PTHREAD_RESULT(result);
}

Monitor::WaitResult Monitor::Wait(int64_t millis) {
  return WaitMicros(millis * kMicrosecondsPerMillisecond);
}

Monitor::WaitResult Monitor::WaitMicros(int64_t micros) {
  // TODO(iposva): Do we need to track lock owners?
  Monitor::WaitResult retval = kNotified;
  if (micros == kNoTimeout) {
    // Wait forever.
    int result = pthread_cond_wait(data_.cond(), data_.mutex());
    VALIDATE_PTHREAD_RESULT(result);
  } else {
    struct timespec ts;
    int64_t secs = micros / kMicrosecondsPerSecond;
    if (secs > kMaxInt32) {
      // Avoid truncation of overly large timeout values.
      secs = kMaxInt32;
    }
    int64_t nanos =
        (micros - (secs * kMicrosecondsPerSecond)) * kNanosecondsPerMicrosecond;
    ts.tv_sec = static_cast<int32_t>(secs);
    ts.tv_nsec = static_cast<long>(nanos);  // NOLINT (long used in timespec).
    int result =
        pthread_cond_timedwait_relative_np(data_.cond(), data_.mutex(), &ts);
    ASSERT((result == 0) || (result == ETIMEDOUT));
    if (result == ETIMEDOUT) {
      retval = kTimedOut;
    }
  }
  return retval;
}

void Monitor::Notify() {
  // TODO(iposva): Do we need to track lock owners?
  int result = pthread_cond_signal(data_.cond());
  VALIDATE_PTHREAD_RESULT(result);
}

void Monitor::NotifyAll() {
  // TODO(iposva): Do we need to track lock owners?
  int result = pthread_cond_broadcast(data_.cond());
  VALIDATE_PTHREAD_RESULT(result);
}

}  // namespace bin
}  // namespace dart

#endif  // defined(DART_HOST_OS_MACOS) && !defined(DART_USE_ABSL)