44 lines
677 B
C
44 lines
677 B
C
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void randname(char *buf) {
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struct timespec ts;
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clock_gettime(CLOCK_REALTIME, &ts);
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long r = ts.tv_nsec;
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for (int i = 0; i < 6; ++i) {
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buf[i] = 'A'+(r&15)+(r&16)*2;
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r >>= 5;
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}
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}
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int anonymous_shm_open(void) {
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char name[] = "/shm-XXXXXX";
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int retries = 100;
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do {
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randname(name + strlen(name) - 6);
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--retries;
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int fd = shm_open(name, O_RDWR | O_CREAT | O_EXCL, 0600);
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if (fd >= 0) {
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shm_unlink(name);
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return fd;
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}
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} while (retries > 0 && errno == EEXIST);
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return -1;
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}
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int create_shm_file(off_t size) {
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int fd = anonymous_shm_open();
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if (fd < 0) {
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return fd;
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}
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if (ftruncate(fd, size) < 0) {
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close(fd);
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return -1;
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}
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return fd;
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}
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