1 /*
   2  * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "semaphore_windows.hpp"
  27 #include "utilities/debug.hpp"
  28 
  29 #include <windows.h>
  30 #include <errno.h>
  31 
  32 WindowsSemaphore::WindowsSemaphore(uint value) {
  33   _semaphore = ::CreateSemaphore(NULL, value, LONG_MAX, NULL);
  34 
  35   guarantee(_semaphore != NULL, err_msg("CreateSemaphore failed with error code: %lu", GetLastError()));
  36 }
  37 
  38 WindowsSemaphore::~WindowsSemaphore() {
  39   ::CloseHandle(_semaphore);
  40 }
  41 
  42 void WindowsSemaphore::signal(uint count) {
  43   if (count > 0) {
  44     BOOL ret = ::ReleaseSemaphore(_semaphore, count, NULL);
  45 
  46     assert(ret != 0, err_msg("ReleaseSemaphore failed with error code: %lu", GetLastError()));
  47   }
  48 }
  49 
  50 void WindowsSemaphore::wait() {
  51   DWORD ret = ::WaitForSingleObject(_semaphore, INFINITE);
  52   assert(ret != WAIT_FAILED,   err_msg("WaitForSingleObject failed with error code: %lu", GetLastError()));
  53   assert(ret == WAIT_OBJECT_0, err_msg("WaitForSingleObject failed with return value: %lu", ret));
  54 }
  55 
  56 bool WindowsSemaphore::trywait() {
  57   DWORD ret = ::WaitForSingleObject(_semaphore, 0);
  58   assert(ret != WAIT_FAILED,   err_msg("WaitForSingleObject failed with error code: %lu", GetLastError()));
  59   return ret == WAIT_OBJECT_0;
  60 }