/**

 * WinPR: Windows Portable Runtime

 * Synchronization Functions

 *

 * Copyright 2012 Marc-Andre Moreau <marcandre.moreau@gmail.com>

 * Copyright 2014 Hardening <contact@hardening-consulting.com>

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

#include <winpr/config.h>

#ifdef WINPR_HAVE_UNISTD_H

#include <unistd.h>

#endif

#include <winpr/assert.h>

#include <errno.h>

#include <winpr/crt.h>

#include <winpr/synch.h>

#include <winpr/platform.h>

#include <winpr/sysinfo.h>

#include "synch.h"

#include "pollset.h"

#include "../thread/thread.h"

#include <winpr/thread.h>

#include <winpr/debug.h>

#include "../log.h"

#define TAG WINPR_TAG("sync.wait")

/**

 * WaitForSingleObject

 * WaitForSingleObjectEx

 * WaitForMultipleObjectsEx

 * SignalObjectAndWait

 */

#ifndef _WIN32

#include <stdlib.h>

#include <time.h>

#include <sys/time.h>

#include <sys/wait.h>

#include "../handle/handle.h"

#include "../pipe/pipe.h"

/* clock_gettime is not implemented on OSX prior to 10.12 */

#if defined(__MACH__) && defined(__APPLE__)

#include <mach/mach_time.h>

#ifndef CLOCK_REALTIME

#define CLOCK_REALTIME 0

#endif

#ifndef CLOCK_MONOTONIC

#define CLOCK_MONOTONIC 0

#endif

/* clock_gettime is not implemented on OSX prior to 10.12 */

int _mach_clock_gettime(int clk_id, struct timespec* t);

int _mach_clock_gettime(int clk_id, struct timespec* t)

{

  UINT64 time = 0;

  double seconds = 0.0;

  double nseconds = 0.0;

  mach_timebase_info_data_t timebase = { 0 };

  mach_timebase_info(&timebase);

  time = mach_absolute_time();

  nseconds = ((double)time * (double)timebase.numer) / ((double)timebase.denom);

  seconds = ((double)time * (double)timebase.numer) / ((double)timebase.denom * 1e9);

  t->tv_sec = seconds;

  t->tv_nsec = nseconds;

  return 0;

}

/* if clock_gettime is declared, then __CLOCK_AVAILABILITY will be defined */

#ifdef __CLOCK_AVAILABILITY

/* If we compiled with Mac OSX 10.12 or later, then clock_gettime will be declared

 * * but it may be NULL at runtime. So we need to check before using it. */

int _mach_safe_clock_gettime(int clk_id, struct timespec* t);

int _mach_safe_clock_gettime(int clk_id, struct timespec* t)

{

  if (clock_gettime)

  {

    return clock_gettime(clk_id, t);

  }

  return _mach_clock_gettime(clk_id, t);

}

#define clock_gettime _mach_safe_clock_gettime

#else

#define clock_gettime _mach_clock_gettime

#endif

#endif

/**

 * Drop in replacement for pthread_mutex_timedlock

 * http://code.google.com/p/android/issues/detail?id=7807

 * http://aleksmaus.blogspot.ca/2011/12/missing-pthreadmutextimedlock-on.html

 */

#if !defined(WINPR_HAVE_PTHREAD_MUTEX_TIMEDLOCK)

#include <pthread.h>

static long long ts_difftime(const struct timespec* o, const struct timespec* n)

{

  long long oldValue = o->tv_sec * 1000000000LL + o->tv_nsec;

  long long newValue = n->tv_sec * 1000000000LL + n->tv_nsec;

  return newValue - oldValue;

}

#ifdef ANDROID

#if (__ANDROID_API__ >= 21)

#define CONST_NEEDED const

#else

#define CONST_NEEDED

#endif

#define STATIC_NEEDED

#else /* ANDROID */

#define CONST_NEEDED const

#define STATIC_NEEDED static

#endif

STATIC_NEEDED int pthread_mutex_timedlock(pthread_mutex_t* mutex,

                                          CONST_NEEDED struct timespec* timeout)

{

  struct timespec timenow = { 0 };

  struct timespec sleepytime = { 0 };

  unsigned long long diff = 0;

  int retcode = -1;

  /* This is just to avoid a completely busy wait */

  clock_gettime(CLOCK_MONOTONIC, &timenow);

  diff = ts_difftime(&timenow, timeout);

  sleepytime.tv_sec = diff / 1000000000LL;

  sleepytime.tv_nsec = diff % 1000000000LL;

  while ((retcode = pthread_mutex_trylock(mutex)) == EBUSY)

  {

    clock_gettime(CLOCK_MONOTONIC, &timenow);

    if (ts_difftime(timeout, &timenow) >= 0)

    {

      return ETIMEDOUT;

    }

    nanosleep(&sleepytime, NULL);

  }

  return retcode;

}

#endif

static void ts_add_ms(struct timespec* ts, DWORD dwMilliseconds)

{

  ts->tv_sec += dwMilliseconds / 1000L;

  ts->tv_nsec += (dwMilliseconds % 1000L) * 1000000L;

  ts->tv_sec += ts->tv_nsec / 1000000000L;

  ts->tv_nsec = ts->tv_nsec % 1000000000L;

}

DWORD WaitForSingleObjectEx(HANDLE hHandle, DWORD dwMilliseconds, BOOL bAlertable)

{

  ULONG Type = 0;

  WINPR_HANDLE* Object = NULL;

  WINPR_POLL_SET pollset = { 0 };

  if (!winpr_Handle_GetInfo(hHandle, &Type, &Object))

  {

    WLog_ERR(TAG, "invalid hHandle.");

    SetLastError(ERROR_INVALID_HANDLE);

    return WAIT_FAILED;

  }

  if (Type == HANDLE_TYPE_PROCESS && winpr_Handle_getFd(hHandle) == -1)

  {

    /* note: if we have pidfd support (under linux and we have managed to associate a

     *    pidfd with our process), we use the regular method with pollset below.

     *    If not (on other platforms) we do a waitpid */

    WINPR_PROCESS* process = (WINPR_PROCESS*)Object;

    do

    {

      DWORD status = 0;

      DWORD waitDelay = 0;

      int ret = waitpid(process->pid, &(process->status), WNOHANG);

      if (ret == process->pid)

      {

        process->dwExitCode = (DWORD)process->status;

        return WAIT_OBJECT_0;

      }

      else if (ret < 0)

      {

        WLog_ERR(TAG, "waitpid failure [%d] %s", errno, strerror(errno));

        SetLastError(ERROR_INTERNAL_ERROR);

        return WAIT_FAILED;

      }

      /* sleep by slices of 50ms */

      waitDelay = (dwMilliseconds < 50) ? dwMilliseconds : 50;

      status = SleepEx(waitDelay, bAlertable);

      if (status != 0)

        return status;

      dwMilliseconds -= waitDelay;

    } while (dwMilliseconds > 50);

    return WAIT_TIMEOUT;

  }

  if (Type == HANDLE_TYPE_MUTEX)

  {

    WINPR_MUTEX* mutex = (WINPR_MUTEX*)Object;

    if (dwMilliseconds != INFINITE)

    {

      int status = 0;

      struct timespec timeout = { 0 };

      clock_gettime(CLOCK_MONOTONIC, &timeout);

      ts_add_ms(&timeout, dwMilliseconds);

      status = pthread_mutex_timedlock(&mutex->mutex, &timeout);

      if (ETIMEDOUT == status)

        return WAIT_TIMEOUT;

    }

    else

    {

      pthread_mutex_lock(&mutex->mutex);

    }

    return WAIT_OBJECT_0;

  }

  else

  {

    int status = -1;

    WINPR_THREAD* thread = NULL;

    BOOL isSet = FALSE;

    size_t extraFds = 0;

    DWORD ret = 0;

    BOOL autoSignaled = FALSE;

    if (bAlertable)

    {

      thread = (WINPR_THREAD*)_GetCurrentThread();

      if (thread)

      {

        /* treat reentrancy, we can't switch to alertable state when we're already

           treating completions */

        if (thread->apc.treatingCompletions)

          bAlertable = FALSE;

        else

          extraFds = thread->apc.length;

      }

      else

      {

        /* called from a non WinPR thread */

        bAlertable = FALSE;

      }

    }

    int fd = winpr_Handle_getFd(Object);

    if (fd < 0)

    {

      WLog_ERR(TAG, "winpr_Handle_getFd did not return a fd!");

      SetLastError(ERROR_INVALID_HANDLE);

      return WAIT_FAILED;

    }

    if (!pollset_init(&pollset, 1 + extraFds))

    {

      WLog_ERR(TAG, "unable to initialize pollset");

      SetLastError(ERROR_INTERNAL_ERROR);

      return WAIT_FAILED;

    }

    if (!pollset_add(&pollset, fd, Object->Mode))

    {

      WLog_ERR(TAG, "unable to add fd in pollset");

      goto out;

    }

    if (bAlertable && !apc_collectFds(thread, &pollset, &autoSignaled))

    {

      WLog_ERR(TAG, "unable to collect APC fds");

      goto out;

    }

    if (!autoSignaled)

    {

      status = pollset_poll(&pollset, dwMilliseconds);

      if (status < 0)

      {

        WLog_ERR(TAG, "pollset_poll() failure [%d] %s", errno, strerror(errno));

        goto out;

      }

    }

    ret = WAIT_TIMEOUT;

    if (bAlertable && apc_executeCompletions(thread, &pollset, 1))

      ret = WAIT_IO_COMPLETION;

    isSet = pollset_isSignaled(&pollset, 0);

    pollset_uninit(&pollset);

    if (!isSet)

      return ret;

    return winpr_Handle_cleanup(Object);

  }

out:

  pollset_uninit(&pollset);

  SetLastError(ERROR_INTERNAL_ERROR);

  return WAIT_FAILED;

}

DWORD WaitForSingleObject(HANDLE hHandle, DWORD dwMilliseconds)

{

  return WaitForSingleObjectEx(hHandle, dwMilliseconds, FALSE);

}

DWORD WaitForMultipleObjectsEx(DWORD nCount, const HANDLE* lpHandles, BOOL bWaitAll,

                               DWORD dwMilliseconds, BOOL bAlertable)

{

  DWORD signalled = 0;

  DWORD polled = 0;

  DWORD poll_map[MAXIMUM_WAIT_OBJECTS] = { 0 };

  BOOL signalled_handles[MAXIMUM_WAIT_OBJECTS] = { FALSE };

  int fd = -1;

  DWORD index = 0;

  int status = -1;

  ULONG Type = 0;

  WINPR_HANDLE* Object = NULL;

  WINPR_THREAD* thread = NULL;

  WINPR_POLL_SET pollset = { 0 };

  DWORD ret = WAIT_FAILED;

  size_t extraFds = 0;

  UINT64 now = 0, dueTime = 0;

  if (!nCount || (nCount > MAXIMUM_WAIT_OBJECTS))

  {

    WLog_ERR(TAG, "invalid handles count(%" PRIu32 ")", nCount);

    return WAIT_FAILED;

  }

  if (bAlertable)

  {

    thread = winpr_GetCurrentThread();

    if (thread)

    {

      /* treat reentrancy, we can't switch to alertable state when we're already

         treating completions */

      if (thread->apc.treatingCompletions)

        bAlertable = FALSE;

      else

        extraFds = thread->apc.length;

    }

    else

    {

      /* most probably we're not called from WinPR thread, so we can't have any APC */

      bAlertable = FALSE;

    }

  }

  if (!pollset_init(&pollset, nCount + extraFds))

  {

    WLog_ERR(TAG, "unable to initialize pollset for nCount=%" PRIu32 " extraCount=%" PRIu32 "",

             nCount, extraFds);

    return WAIT_FAILED;

  }

  signalled = 0;

  now = GetTickCount64();

  if (dwMilliseconds != INFINITE)

    dueTime = now + dwMilliseconds;

  else

    dueTime = 0xFFFFFFFFFFFFFFFF;

  do

  {

    BOOL autoSignaled = FALSE;

    polled = 0;

    /* first collect file descriptors to poll */

    for (index = 0; index < nCount; index++)

    {

      if (bWaitAll)

      {

        if (signalled_handles[index])

          continue;

        poll_map[polled] = index;

      }

      if (!winpr_Handle_GetInfo(lpHandles[index], &Type, &Object))

      {

        WLog_ERR(TAG, "invalid event file descriptor at %" PRIu32, index);

        winpr_log_backtrace(TAG, WLOG_ERROR, 20);

        SetLastError(ERROR_INVALID_HANDLE);

        goto out;

      }

      fd = winpr_Handle_getFd(Object);

      if (fd == -1)

      {

        WLog_ERR(TAG, "invalid file descriptor at %" PRIu32, index);

        winpr_log_backtrace(TAG, WLOG_ERROR, 20);

        SetLastError(ERROR_INVALID_HANDLE);

        goto out;

      }

      if (!pollset_add(&pollset, fd, Object->Mode))

      {

        WLog_ERR(TAG, "unable to register fd in pollset at %" PRIu32, index);

        winpr_log_backtrace(TAG, WLOG_ERROR, 20);

        SetLastError(ERROR_INVALID_HANDLE);

        goto out;

      }

      polled++;

    }

    /* treat file descriptors of the APC if needed */

    if (bAlertable && !apc_collectFds(thread, &pollset, &autoSignaled))

    {

      WLog_ERR(TAG, "unable to register APC fds");

      winpr_log_backtrace(TAG, WLOG_ERROR, 20);

      SetLastError(ERROR_INTERNAL_ERROR);

      goto out;

    }

    /* poll file descriptors */

    status = 0;

    if (!autoSignaled)

    {

      DWORD waitTime;

      if (dwMilliseconds == INFINITE)

        waitTime = INFINITE;

      else

        waitTime = (DWORD)(dueTime - now);

      status = pollset_poll(&pollset, waitTime);

      if (status < 0)

      {

#ifdef WINPR_HAVE_POLL_H

        WLog_ERR(TAG, "poll() handle %" PRIu32 " (%" PRIu32 ") failure [%d] %s", index,

                 nCount, errno, strerror(errno));

#else

        WLog_ERR(TAG, "select() handle %" PRIu32 " (%" PRIu32 ") failure [%d] %s", index,

                 nCount, errno, strerror(errno));

#endif

        winpr_log_backtrace(TAG, WLOG_ERROR, 20);

        SetLastError(ERROR_INTERNAL_ERROR);

        goto out;

      }

    }

    /* give priority to the APC queue, to return WAIT_IO_COMPLETION */

    if (bAlertable && apc_executeCompletions(thread, &pollset, polled))

    {

      ret = WAIT_IO_COMPLETION;

      goto out;

    }

    /* then treat pollset */

    if (status)

    {

      for (index = 0; index < polled; index++)

      {

        DWORD handlesIndex = 0;

        BOOL signal_set = FALSE;

        if (bWaitAll)

          handlesIndex = poll_map[index];

        else

          handlesIndex = index;

        signal_set = pollset_isSignaled(&pollset, index);

        if (signal_set)

        {

          DWORD rc = winpr_Handle_cleanup(lpHandles[handlesIndex]);

          if (rc != WAIT_OBJECT_0)

          {

            WLog_ERR(TAG, "error in cleanup function for handle at index=%" PRIu32,

                     handlesIndex);

            ret = rc;

            goto out;

          }

          if (bWaitAll)

          {

            signalled_handles[handlesIndex] = TRUE;

            /* Continue checks from last position. */

            for (; signalled < nCount; signalled++)

            {

              if (!signalled_handles[signalled])

                break;

            }

          }

          else

          {

            ret = (WAIT_OBJECT_0 + handlesIndex);

            goto out;

          }

          if (signalled >= nCount)

          {

            ret = WAIT_OBJECT_0;

            goto out;

          }

        }

      }

    }

    if (bAlertable && thread->apc.length > extraFds)

    {

      pollset_uninit(&pollset);

      extraFds = thread->apc.length;

      if (!pollset_init(&pollset, nCount + extraFds))

      {

        WLog_ERR(TAG, "unable reallocate pollset");

        SetLastError(ERROR_INTERNAL_ERROR);

        return WAIT_FAILED;

      }

    }

    else

      pollset_reset(&pollset);

    now = GetTickCount64();

  } while (now < dueTime);

  ret = WAIT_TIMEOUT;

out:

  pollset_uninit(&pollset);

  return ret;

}

DWORD WaitForMultipleObjects(DWORD nCount, const HANDLE* lpHandles, BOOL bWaitAll,

                             DWORD dwMilliseconds)

{

  return WaitForMultipleObjectsEx(nCount, lpHandles, bWaitAll, dwMilliseconds, FALSE);

}

DWORD SignalObjectAndWait(HANDLE hObjectToSignal, HANDLE hObjectToWaitOn, DWORD dwMilliseconds,

                          BOOL bAlertable)

{

  if (!SetEvent(hObjectToSignal))

    return WAIT_FAILED;

  return WaitForSingleObjectEx(hObjectToWaitOn, dwMilliseconds, bAlertable);

}

#endif