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- /**
- * Tencent is pleased to support the open source community by making Tars available.
- *
- * Copyright (C) 2016THL A29 Limited, a Tencent company. All rights reserved.
- *
- * Licensed under the BSD 3-Clause License (the "License"); you may not use this file except
- * in compliance with the License. You may obtain a copy of the License at
- *
- * https://opensource.org/licenses/BSD-3-Clause
- *
- * 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 "util/tc_shm.h"
- #include "util/tc_common.h"
- #include <cassert>
- #include <errno.h>
- namespace tars
- {
- TC_Shm::TC_Shm(size_t iShmSize, key_t iKey, bool bOwner) : _pshm(NULL)
- {
- init(iShmSize, iKey, bOwner);
- }
- TC_Shm::~TC_Shm()
- {
- if (_bOwner)
- {
- detach();
- }
- }
- void TC_Shm::init(size_t iShmSize, key_t iKey, bool bOwner)
- {
- assert(_pshm == NULL);
- #if TARGET_PLATFORM_WINDOWS
- _bOwner = bOwner;
- // 首先试图打开一个命名的内存映射文件对象
- HANDLE hMap = ::OpenFileMapping(FILE_MAP_ALL_ACCESS, 0, TC_Common::tostr(iKey).c_str());
- if (NULL == hMap)
- {
- // 打开失败,创建之
- hMap = ::CreateFileMapping(INVALID_HANDLE_VALUE, NULL,PAGE_READWRITE,0, (DWORD)iShmSize, TC_Common::tostr(iKey).c_str());
- // 映射对象的一个视图,得到指向共享内存的指针,设置里面的数据
- _pshm = ::MapViewOfFile(hMap, FILE_MAP_ALL_ACCESS, 0, 0, 0);
- }
- else
- { // 打开成功,映射对象的一个视图,得到指向共享内存的指针,显示出里面的数据
- _pshm = ::MapViewOfFile(hMap, FILE_MAP_ALL_ACCESS, 0, 0, 0);
- }
- _shemID = hMap;
- _shmKey = iKey;
- #else
- _bOwner = bOwner;
- //注意_bCreate的赋值位置:保证多线程用一个对象的时候也不会有问题
- //试图创建
- if ((_shemID = shmget(iKey, iShmSize, IPC_CREAT | IPC_EXCL | 0666)) < 0)
- {
- _bCreate = false;
- //有可能是已经存在同样的key_shm,则试图连接
- if ((_shemID = shmget(iKey, iShmSize, 0666)) < 0)
- {
- THROW_EXCEPTION_SYSCODE(TC_Shm_Exception, "[TC_Shm::init()] shmget error");
- // throw TC_Shm_Exception("[TC_Shm::init()] shmget error", TC_Exception::getSystemCode());
- }
- }
- else
- {
- _bCreate = true;
- }
- //try to access shm
- if ((_pshm = shmat(_shemID, NULL, 0)) == (char *) - 1)
- {
- THROW_EXCEPTION_SYSCODE(TC_Shm_Exception, "[TC_Shm::init()] shmat error");
- // throw TC_Shm_Exception("[TC_Shm::init()] shmat error", TC_Exception::getSystemCode());
- }
- _shmSize = iShmSize;
- _shmKey = iKey;
- #endif
- }
- int TC_Shm::detach()
- {
- #if TARGET_PLATFORM_WINDOWS
- if (_pshm != NULL)
- {
- UnmapViewOfFile(_pshm);
- CloseHandle(_shemID);
- _pshm = NULL;
- }
- return 0;
- #else
- int iRetCode = 0;
- if (_pshm != NULL)
- {
- iRetCode = shmdt(_pshm);
- _pshm = NULL;
- }
- return iRetCode;
- #endif
- }
- int TC_Shm::del()
- {
- #if TARGET_PLATFORM_WINDOWS
- return 0;
- #else
- int iRetCode = 0;
- if (_pshm != NULL)
- {
- iRetCode = shmctl(_shemID, IPC_RMID, 0);
- _pshm = NULL;
- }
- return iRetCode;
- #endif
- }
- }
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