98 lines
2.6 KiB
C
98 lines
2.6 KiB
C
#include <unistd.h>
|
|
#include <stdio.h>
|
|
#include <sys/mman.h>
|
|
#include <string.h>
|
|
#include <sys/types.h>
|
|
#include <sys/stat.h>
|
|
#include <fcntl.h>
|
|
#include <errno.h>
|
|
#include <sys/wait.h>
|
|
#include <sys/ipc.h>
|
|
#include <sys/shm.h>
|
|
|
|
#define DEBUG
|
|
|
|
#ifdef DEBUG
|
|
#define dprintf(...) \
|
|
do { \
|
|
char msg[1024]; \
|
|
sprintf(msg, __VA_ARGS__); \
|
|
fprintf(stderr, "%s,%s", __FUNCTION__, msg); \
|
|
} while (0);
|
|
#define eprintf(...) \
|
|
do { \
|
|
char msg[1024]; \
|
|
sprintf(msg, __VA_ARGS__); \
|
|
fprintf(stderr, "%s,%s", __FUNCTION__, msg); \
|
|
} while (0);
|
|
#else
|
|
#define dprintf(...) do { } while (0)
|
|
#define eprintf(...) do { } while (0)
|
|
#endif
|
|
|
|
#define CHKANDJUMP(cond, err, ...) \
|
|
do { \
|
|
if(cond) { \
|
|
eprintf(__VA_ARGS__); \
|
|
ret = err; \
|
|
goto fn_fail; \
|
|
} \
|
|
} while(0)
|
|
|
|
int sz_mem[] = {
|
|
4 * (1ULL<<10),
|
|
2 * (1ULL<<20),
|
|
1 * (1ULL<<30),
|
|
134217728};
|
|
|
|
#define SZ_INDEX 0
|
|
|
|
int main(int argc, char** argv) {
|
|
void* mem;
|
|
int ret = 0;
|
|
pid_t pid;
|
|
int status;
|
|
key_t key = ftok(argv[0], 0);
|
|
int shmid;
|
|
|
|
shmid = shmget(key, sz_mem[SZ_INDEX], IPC_CREAT | 0660);
|
|
CHKANDJUMP(shmid == -1, 255, "shmget failed: %s\n", strerror(errno));
|
|
|
|
pid = fork();
|
|
CHKANDJUMP(pid == -1, 255, "fork failed\n");
|
|
if(pid == 0) {
|
|
mem = shmat(shmid, NULL, 0);
|
|
CHKANDJUMP(mem == (void*)-1, 255, "shmat failed: %s\n", strerror(errno));
|
|
|
|
*((unsigned long*)mem) = 0x1234;
|
|
|
|
ret = shmdt(mem);
|
|
CHKANDJUMP(ret == -1, 255, "shmdt failed\n");
|
|
|
|
_exit(123);
|
|
} else {
|
|
mem = shmat(shmid, NULL, 0);
|
|
CHKANDJUMP(mem == (void*)-1, 255, "shmat failed: %s\n", strerror(errno));
|
|
|
|
|
|
ret = waitpid(pid, &status, 0);
|
|
CHKANDJUMP(ret == -1, 255, "waitpid failed\n");
|
|
|
|
printf("%lx\n", *((unsigned long*)mem));
|
|
|
|
#if 0
|
|
struct shmid_ds buf;
|
|
ret = shmctl(shmid, IPC_RMID, &buf);
|
|
CHKANDJUMP(ret == -1, 255, "shmctl failed\n");
|
|
#endif
|
|
|
|
ret = shmdt(mem);
|
|
CHKANDJUMP(ret == -1, 255, "shmdt failed\n");
|
|
}
|
|
|
|
fn_exit:
|
|
return ret;
|
|
fn_fail:
|
|
goto fn_exit;
|
|
}
|