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

91 lines
2.0 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"
#define MAX_SHMIDS 6
static int32_t shmids[MAX_SHMIDS] = {0};
static void taosDeleteCreatedShms() {
for (int32_t i = 0; i < MAX_SHMIDS; ++i) {
int32_t shmid = shmids[i] - 1;
if (shmid >= 0) {
shmctl(shmid, IPC_RMID, NULL);
}
}
}
int32_t taosCreateShm(SShm* pShm, int32_t key, int32_t shmsize) {
pShm->id = -1;
#if 1
key_t __shkey = IPC_PRIVATE;
int32_t __shmflag = IPC_CREAT | IPC_EXCL | 0600;
#else
key_t __shkey = 0X95270000 + key;
int32_t __shmflag = IPC_CREAT | 0600;
#endif
int32_t shmid = shmget(__shkey, shmsize, __shmflag);
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;
#if 0
if (key >= 0 && key < MAX_SHMIDS) {
shmids[key] = pShm->id + 1;
}
atexit(taosDeleteCreatedShms);
#else
shmctl(pShm->id, IPC_RMID, NULL);
#endif
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 = -1;
pShm->size = 0;
pShm->ptr = NULL;
}
int32_t taosAttachShm(SShm* pShm) {
errno = 0;
void* ptr = shmat(pShm->id, NULL, 0);
if (errno == 0) {
pShm->ptr = ptr;
}
return errno;
}