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xserver: Clean up lockfile creation a bit

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This commit is contained in:
Kristian Høgsberg 2011-08-11 17:48:38 -04:00
parent 534222b4d9
commit f6ee695805
1 changed files with 79 additions and 60 deletions
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139
compositor/xserver-launcher.c
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@ -648,14 +648,69 @@ bind_to_unix_socket(int display)
return fd;
}
static int
create_lockfile(int display, char *lockfile, size_t lsize)
{
char pid[16], *end;
int fd, size;
pid_t other;
snprintf(lockfile, lsize, "/tmp/.X%d-lock", display);
fd = open(lockfile, O_WRONLY | O_CLOEXEC | O_CREAT | O_EXCL, 0444);
if (fd < 0 && errno == EEXIST) {
fd = open(lockfile, O_CLOEXEC, O_RDONLY);
if (fd < 0 || read(fd, pid, 11) != 11) {
fprintf(stderr, "can't read lock file %s: %s\n",
lockfile, strerror(errno));
errno = EEXIST;
return -1;
}
other = strtol(pid, &end, 0);
if (end != pid + 10) {
fprintf(stderr, "can't parse lock file %s\n",
lockfile);
errno = EEXIST;
return -1;
}
if (kill(other, 0) < 0 && errno == ESRCH) {
/* stale lock file; unlink and try again */
fprintf(stderr,
"unlinking stale lock file %s\n", lockfile);
unlink(lockfile);
errno = EAGAIN;
return -1;
}
errno = EEXIST;
return -1;
} else if (fd < 0) {
fprintf(stderr, "failed to create lock file %s: %s\n",
lockfile, strerror(errno));
return -1;
}
/* Subtle detail: we use the pid of the wayland
* compositor, not the xserver in the lock file. */
size = snprintf(pid, sizeof pid, "%10d\n", getpid());
if (write(fd, pid, size) != size) {
unlink(lockfile);
close(fd);
return -1;
}
close(fd);
return 0;
}
int
wlsc_xserver_init(struct wlsc_compositor *compositor)
{
struct wl_display *display = compositor->wl_display;
struct wlsc_xserver *mxs;
char lockfile[256], pid[16], *end;
pid_t other;
int fd, size;
char lockfile[256];
mxs = malloc(sizeof *mxs);
memset(mxs, 0, sizeof *mxs);
@ -664,70 +719,34 @@ wlsc_xserver_init(struct wlsc_compositor *compositor)
mxs->wl_display = display;
mxs->display = 0;
do {
snprintf(lockfile, sizeof lockfile,
"/tmp/.X%d-lock", mxs->display);
fd = open(lockfile,
O_WRONLY | O_CLOEXEC | O_CREAT | O_EXCL, 0444);
if (fd < 0 && errno == EEXIST) {
fd = open(lockfile, O_CLOEXEC, O_RDONLY);
if (fd < 0 || read(fd, pid, 11) != 11) {
fprintf(stderr,
"can't read lock file %s: %s\n",
lockfile, strerror(errno));
mxs->display++;
continue;
}
other = strtol(pid, &end, 0);
if (end != pid + 10) {
fprintf(stderr, "can't parse lock file %s\n",
lockfile);
mxs->display++;
continue;
}
if (kill(other, 0) < 0 && errno == ESRCH) {
/* stale lock file; unlink and try again */
fprintf(stderr,
"unlinking stale lock file %s\n",
lockfile);
unlink(lockfile);
continue;
}
retry:
if (create_lockfile(mxs->display, lockfile, sizeof lockfile) < 0) {
if (errno == EAGAIN) {
goto retry;
} else if (errno == EEXIST) {
mxs->display++;
continue;
} else if (fd < 0) {
fprintf(stderr, "failed to create lock file %s: %s\n",
lockfile, strerror(errno));
goto retry;
} else {
free(mxs);
return -1;
}
}
/* Subtle detail: we use the pid of the wayland
* compositor, not the xserver in the lock file. */
size = snprintf(pid, sizeof pid, "%10d\n", getpid());
write(fd, pid, size);
close(fd);
mxs->abstract_fd = bind_to_abstract_socket(mxs->display);
if (mxs->abstract_fd < 0 && errno == EADDRINUSE) {
mxs->display++;
unlink(lockfile);
goto retry;
}
mxs->abstract_fd = bind_to_abstract_socket(mxs->display);
if (mxs->abstract_fd < 0 && errno == EADDRINUSE) {
mxs->display++;
unlink(lockfile);
continue;
}
mxs->unix_fd = bind_to_unix_socket(mxs->display);
if (mxs->unix_fd < 0) {
unlink(lockfile);
close(mxs->abstract_fd);
free(mxs);
return -1;
}
break;
} while (errno != 0);
mxs->unix_fd = bind_to_unix_socket(mxs->display);
if (mxs->unix_fd < 0) {
unlink(lockfile);
close(mxs->abstract_fd);
free(mxs);
return -1;
}
fprintf(stderr, "xserver listening on display :%d\n", mxs->display);