Bernt
110 lines
2.3 KiB
C
110 lines
2.3 KiB
C
#include "shm.h"
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#include <sys/mman.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <unistd.h>
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#include <stdlib.h>
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#include <string.h>
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#include <errno.h>
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struct crt_shm {
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int fd;
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void* ptr;
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size_t size;
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char name[256];
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};
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crt_shm_t* crt_shm_create(const char* name, size_t size) {
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crt_shm_t* shm = calloc(1, sizeof(crt_shm_t));
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if (!shm) return NULL;
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strncpy(shm->name, name, sizeof(shm->name) - 1);
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shm->size = size;
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shm->fd = shm_open(name, O_CREAT | O_RDWR, 0666);
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if (shm->fd < 0) {
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free(shm);
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return NULL;
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}
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if (ftruncate(shm->fd, size) < 0) {
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close(shm->fd);
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shm_unlink(name);
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free(shm);
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return NULL;
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}
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shm->ptr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, shm->fd, 0);
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if (shm->ptr == MAP_FAILED) {
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close(shm->fd);
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shm_unlink(name);
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free(shm);
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return NULL;
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}
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memset(shm->ptr, 0, size);
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return shm;
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}
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crt_shm_t* crt_shm_open(const char* name) {
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crt_shm_t* shm = calloc(1, sizeof(crt_shm_t));
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if (!shm) return NULL;
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strncpy(shm->name, name, sizeof(shm->name) - 1);
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shm->fd = shm_open(name, O_RDWR, 0666);
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if (shm->fd < 0) {
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free(shm);
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return NULL;
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}
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struct stat st;
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if (fstat(shm->fd, &st) < 0) {
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close(shm->fd);
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free(shm);
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return NULL;
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}
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shm->size = st.st_size;
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shm->ptr = mmap(NULL, shm->size, PROT_READ | PROT_WRITE, MAP_SHARED, shm->fd, 0);
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if (shm->ptr == MAP_FAILED) {
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close(shm->fd);
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free(shm);
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return NULL;
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}
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return shm;
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}
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void crt_shm_close(crt_shm_t* shm) {
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if (!shm) return;
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if (shm->ptr && shm->ptr != MAP_FAILED) {
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munmap(shm->ptr, shm->size);
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}
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if (shm->fd >= 0) {
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close(shm->fd);
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}
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free(shm);
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}
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void* crt_shm_ptr(crt_shm_t* shm) {
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return shm ? shm->ptr : NULL;
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}
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size_t crt_shm_size(crt_shm_t* shm) {
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return shm ? shm->size : 0;
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}
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int crt_shm_resize(crt_shm_t* shm, size_t new_size) {
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if (!shm || !shm->ptr) return -1;
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if (munmap(shm->ptr, shm->size) < 0) return -1;
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if (ftruncate(shm->fd, new_size) < 0) return -1;
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shm->ptr = mmap(NULL, new_size, PROT_READ | PROT_WRITE, MAP_SHARED, shm->fd, 0);
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if (shm->ptr == MAP_FAILED) return -1;
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shm->size = new_size;
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return 0;
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}
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