1 /* Licensed under Apache License v2.0 - see LICENSE file for details */
5 #define _XOPEN_SOURCE 700
15 #define pgup(x, pgsz) (((x) + (pgsz) - 1) & ~((pgsz) - 1))
17 void *rszshm_mk(struct rszshm *r, size_t flen, const char *fname, struct rszshm_scan scan)
19 long pgsz = sysconf(_SC_PAGE_SIZE);
21 char *m, *tgt, *p = NULL;
23 if (!r || flen == 0 || scan.len < flen + sizeof(*r->hdr) ||
24 !scan.start || scan.len == 0 || scan.hop == 0 || scan.iter == 0 ||
25 (fname && strnlen(fname, RSZSHM_PATH_MAX) == RSZSHM_PATH_MAX)) {
30 *r = (typeof(*r)) { -1, 0, "", NULL, NULL };
31 strcpy(r->fname, fname ? fname : RSZSHM_DFLT_FNAME);
33 flen = pgup(flen + sizeof(*r->hdr), pgsz);
34 scan.len = pgup(scan.len, pgsz);
36 for (i = 1, tgt = scan.start; i <= scan.iter; i++) {
37 m = mmap(tgt, scan.len, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANON|MAP_NORESERVE, -1, 0);
44 tgt += (i % 2 == 0 ? 1 : -1) * i * scan.hop;
51 if ((p = strstr(r->fname, "XXXXXX/")) != NULL) {
54 if (!mkdtemp(r->fname))
59 if ((r->fd = open(r->fname, O_CREAT|O_EXCL|O_RDWR, p ? 0600 : 0666)) == -1)
62 if (ftruncate(r->fd, flen) == -1)
65 if (mmap(m, flen, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, r->fd, 0) == MAP_FAILED)
68 *(r->hdr = (typeof(r->hdr)) m) = (typeof(*r->hdr)) { flen, scan.len, m };
70 if (msync(m, sizeof(*r->hdr), MS_SYNC) == -1)
74 r->cap = flen - sizeof(*r->hdr);
75 r->dat = m + sizeof(*r->hdr);
81 if (m && m != MAP_FAILED)
96 void *rszshm_at(struct rszshm *r, const char *fname)
99 int fd = -1, ret, errno_;
102 if (!r || !fname || !fname[0] ||
103 strnlen(fname, RSZSHM_PATH_MAX) == RSZSHM_PATH_MAX) {
108 if ((fd = open(fname, O_RDWR)) == -1)
111 if ((ret = read(fd, &h, sizeof(h))) == -1)
114 if (ret != sizeof(h) || !h.addr || h.flen == 0 || h.max == 0) {
119 m = mmap(h.addr, h.max, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANON|MAP_NORESERVE, -1, 0);
127 if (mmap(m, h.flen, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, fd, 0) == MAP_FAILED)
130 *r = (typeof(*r)) { .fd = fd, .flen = h.flen, .hdr = (typeof(r->hdr)) m,
131 .dat = m + sizeof(h), .cap = h.flen - sizeof(h) };
132 strcpy(r->fname, fname);
138 if (m && m != MAP_FAILED)
146 int rszshm_up(struct rszshm *r)
155 if (mmap(r->hdr, flen, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, r->fd, 0) == MAP_FAILED)
159 r->cap = flen - sizeof(*r->hdr);
163 int rszshm_grow(struct rszshm *r)
168 if ((ret = rszshm_up(r)) != 0)
171 if (r->flen == r->hdr->max) {
176 if (flock(r->fd, LOCK_EX) == -1)
179 if ((ret = rszshm_up(r)) == 0) {
180 int flen = r->hdr->flen * 2 < r->hdr->max ? r->hdr->flen * 2 : r->hdr->max;
182 if (ftruncate(r->fd, flen) != -1 &&
183 mmap(r->hdr, flen, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, r->fd, 0) != MAP_FAILED) {
184 r->flen = r->hdr->flen = flen;
185 r->cap = flen - sizeof(*r->hdr);
192 flock(r->fd, LOCK_UN);
196 int rszshm_dt(struct rszshm *r)
201 /* ok to call twice, since free macro calls this */
205 ret[0] = msync(r->hdr, r->flen, MS_SYNC);
206 ret[1] = munmap(r->hdr, r->hdr->max);
207 ret[2] = close(r->fd);
215 return ret[0] == 0 && ret[1] == 0 && ret[2] == 0 ? 0 : -1;
218 int rszshm_unlink(struct rszshm *r)
221 return unlink(r->fname);
224 int rszshm_rmdir(struct rszshm *r)
231 if ((p = strrchr(r->fname, '/')) == NULL) {
237 ret = rmdir(r->fname);