text: /**************************************************************************
   *
   * Copyright 2020 Lag Free Games, LLC
   * All Rights Reserved.
   *
   * Permission is hereby granted, free of charge, to any person obtaining a
   * copy of this software and associated documentation files (the
   * "Software"), to deal in the Software without restriction, including
   * without limitation the rights to use, copy, modify, merge, publish,
   * distribute, sub license, and/or sell copies of the Software, and to
   * permit persons to whom the Software is furnished to do so, subject to
   * the following conditions:
   *
   * The above copyright notice and this permission notice (including the
   * next paragraph) shall be included in all copies or substantial portions
   * of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
   * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
   * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
   * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
   * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
   * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
   *
   **************************************************************************/
  
  #ifndef CND_MONOTONIC_H
  #define CND_MONOTONIC_H
  
  #include "c11/threads.h"
  #include "util/os_time.h"
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  struct u_cnd_monotonic
  {
  #ifdef _WIN32
     CONDITION_VARIABLE condvar;
  #else
     pthread_cond_t cond;
  #endif
  };
  
  static inline int
  u_cnd_monotonic_init(struct u_cnd_monotonic *cond)
  {
     assert(cond != NULL);
  
  #ifdef _WIN32
     InitializeConditionVariable(&cond->condvar);
     return thrd_success;
  #else
     int ret = thrd_error;
     pthread_condattr_t condattr;
     if (pthread_condattr_init(&condattr) == 0) {
        if ((pthread_condattr_setclock(&condattr, CLOCK_MONOTONIC) == 0) &&
           (pthread_cond_init(&cond->cond, &condattr) == 0)) {
           ret = thrd_success;
        }
  
        pthread_condattr_destroy(&condattr);
     }
  
     return ret;
  #endif
  }
  
  static inline void
  u_cnd_monotonic_destroy(struct u_cnd_monotonic *cond)
  {
     assert(cond != NULL);
  
  #ifdef _WIN32
     // Do nothing
  #else
     pthread_cond_destroy(&cond->cond);
  #endif
  }
  
  static inline int
  u_cnd_monotonic_broadcast(struct u_cnd_monotonic *cond)
  {
     assert(cond != NULL);
  
  #ifdef _WIN32
     WakeAllConditionVariable(&cond->condvar);
     return thrd_success;
  #else
     return (pthread_cond_broadcast(&cond->cond) == 0) ? thrd_success : thrd_error;
  #endif
  }
  
  static inline int
  u_cnd_monotonic_signal(struct u_cnd_monotonic *cond)
  {
     assert(cond != NULL);
  
  #ifdef _WIN32
     WakeConditionVariable(&cond->condvar);
     return thrd_success;
  #else
     return (pthread_cond_signal(&cond->cond) == 0) ? thrd_success : thrd_error;
  #endif
  }
  
  static inline int
  u_cnd_monotonic_timedwait(struct u_cnd_monotonic *cond, mtx_t *mtx, const struct timespec *abs_time)
  {
     assert(cond != NULL);
     assert(mtx != NULL);
     assert(abs_time != NULL);
  
  #ifdef _WIN32
     const uint64_t future = (abs_time->tv_sec * 1000) + (abs_time->tv_nsec / 1000000);
     const uint64_t now = os_time_get_nano() / 1000000;
     const DWORD timeout = (future > now) ? (DWORD)(future - now) : 0;
     if (SleepConditionVariableCS(&cond->condvar, mtx, timeout))
        return thrd_success;
     return (GetLastError() == ERROR_TIMEOUT) ? thrd_timedout : thrd_error;
  #else
     int rt = pthread_cond_timedwait(&cond->cond, mtx, abs_time);
     if (rt == ETIMEDOUT)
        return thrd_timedout;
     return (rt == 0) ? thrd_success : thrd_error;
  #endif
  }
  
  static inline int
  u_cnd_monotonic_wait(struct u_cnd_monotonic *cond, mtx_t *mtx)
  {
     assert(cond != NULL);
     assert(mtx != NULL);
  
  #ifdef _WIN32
     SleepConditionVariableCS(&cond->condvar, mtx, INFINITE);
     return thrd_success;
  #else
     return (pthread_cond_wait(&cond->cond, mtx) == 0) ? thrd_success : thrd_error;
  #endif
  }
  
  #ifdef __cplusplus
  }
  #endif
  
  #endif
  