thr_cond.cc

/* Copyright (c) 2014, 2024, Oracle and/or its affiliates.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2.0,
   as published by the Free Software Foundation.

   This program is designed to work with certain software (including
   but not limited to OpenSSL) that is licensed under separate terms,
   as designated in a particular file or component or in included license
   documentation.  The authors of MySQL hereby grant you an additional
   permission to link the program and your derivative works with the
   separately licensed software that they have either included with
   the program or referenced in the documentation.

   Without limiting anything contained in the foregoing, this file,
   which is part of C Driver for MySQL (Connector/C), is also subject to the
   Universal FOSS Exception, version 1.0, a copy of which can be found at
   http://oss.oracle.com/licenses/universal-foss-exception.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License, version 2.0, for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */

/**
  @file mysys/thr_cond.cc
*/

#ifdef SAFE_MUTEX

#include "thr_cond.h"

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>

#include "my_thread_local.h"

int safe_cond_wait(native_cond_t *cond, safe_mutex_t *mp, const char *file,
                   uint line) {
  int error;
  native_mutex_lock(&mp->global);
  if (mp->count == 0) {
    fprintf(
        stderr,
        "safe_mutex: Trying to cond_wait on a unlocked mutex at %s, line %d\n",
        file, line);
    fflush(stderr);
    abort();
  }
  if (!my_thread_equal(my_thread_self(), mp->thread)) {
    fprintf(stderr,
            "safe_mutex: Trying to cond_wait on a mutex at %s, line %d  that "
            "was locked by another thread at: %s, line: %d\n",
            file, line, mp->file, mp->line);
    fflush(stderr);
    abort();
  }

  if (mp->count-- != 1) {
    fprintf(stderr,
            "safe_mutex:  Count was %d on locked mutex at %s, line %d\n",
            mp->count + 1, file, line);
    fflush(stderr);
    abort();
  }
  native_mutex_unlock(&mp->global);
  error = native_cond_wait(cond, &mp->mutex);
  native_mutex_lock(&mp->global);
  if (error) {
    fprintf(stderr,
            "safe_mutex: Got error: %d (%d) when doing a safe_mutex_wait at "
            "%s, line %d\n",
            error, errno, file, line);
    fflush(stderr);
    abort();
  }
  mp->thread = my_thread_self();
  if (mp->count++) {
#ifndef NDEBUG
    fprintf(stderr,
            "safe_mutex:  Count was %d in thread 0x%x when locking mutex at "
            "%s, line %d\n",
            mp->count - 1, my_thread_var_id(), file, line);
    fflush(stderr);
#endif
    abort();
  }
  mp->file = file;
  mp->line = line;
  native_mutex_unlock(&mp->global);
  return error;
}

int safe_cond_timedwait(native_cond_t *cond, safe_mutex_t *mp,
                        const struct timespec *abstime, const char *file,
                        uint line) {
  int error;
  native_mutex_lock(&mp->global);
  if (mp->count != 1 || !my_thread_equal(my_thread_self(), mp->thread)) {
    fprintf(
        stderr,
        "safe_mutex: Trying to cond_wait at %s, line %d on a not hold mutex\n",
        file, line);
    fflush(stderr);
    abort();
  }
  mp->count--; /* Mutex will be released */
  native_mutex_unlock(&mp->global);
  error = native_cond_timedwait(cond, &mp->mutex, abstime);
#ifdef EXTRA_DEBUG
  if (error != 0 && error != EINTR && !is_timeout(error)) {
    fprintf(stderr,
            "safe_mutex: Got error: %d (%d) when doing a safe_cond_timedwait "
            "at %s, line %d\n",
            error, errno, file, line);
  }
#endif
  native_mutex_lock(&mp->global);
  mp->thread = my_thread_self();
  if (mp->count++) {
#ifndef NDEBUG
    fprintf(stderr,
            "safe_mutex:  Count was %d in thread 0x%x when locking mutex at "
            "%s, line %d (error: %d (%d))\n",
            mp->count - 1, my_thread_var_id(), file, line, error, error);
    fflush(stderr);
#endif
    abort();
  }
  mp->file = file;
  mp->line = line;
  native_mutex_unlock(&mp->global);
  return error;
}

#endif