homework-jianmu/source/os/src/osShm.c

72 lines
1.6 KiB
C

/*
* Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
*
* This program is free software: you can use, redistribute, and/or modify
* it under the terms of the GNU Affero General Public License, version 3
* or later ("AGPL"), as published by the Free Software Foundation.
*
* 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.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#define ALLOW_FORBID_FUNC
#define _DEFAULT_SOURCE
#include "os.h"
int32_t taosCreateShm(SShm* pShm, int32_t shmsize) {
int32_t shmid = shmget(IPC_PRIVATE, shmsize, IPC_CREAT | 0600);
if (shmid < 0) {
return -1;
}
void* shmptr = shmat(shmid, NULL, 0);
if (shmptr == NULL) {
return -1;
}
pShm->id = shmid;
pShm->size = shmsize;
pShm->ptr = shmptr;
return 0;
}
void taosDropShm(SShm* pShm) {
if (pShm->id > 0) {
if (pShm->ptr != NULL) {
shmdt(pShm->ptr);
}
shmctl(pShm->id, IPC_RMID, NULL);
}
pShm->id = 0;
pShm->size = 0;
pShm->ptr = NULL;
}
int32_t taosAttachShm(SShm* pShm) {
if (pShm->id > 0 && pShm->size > 0) {
pShm->ptr = shmat(pShm->id, NULL, 0);
if (pShm->ptr != NULL) {
return 0;
}
}
return -1;
}
void taosDetachShm(SShm* pShm) {
if (pShm->id > 0) {
if (pShm->ptr != NULL) {
shmdt(pShm->ptr);
pShm->ptr = NULL;
}
}
pShm->id = 0;
pShm->size = 0;
pShm->ptr = NULL;
}