comparison contrib/chg/chg.c @ 28455:412ee35a8005

chg: do not write pidfile

Current pidfile logic will only keep the pid of the newest server, which is
not very useful if we want to kill all servers, and will become outdated if
the server auto exits after being idle for too long.

Besides, the server-side pidfile writing logic runs before chgserver gets
confighash so it's not trivial to append confighash to pidfile basename like
we did for socket file.

This patch removes --pidfile from the command starting chgserver and switches
to an alternative way (unlink socket file) to stop the server.

28454:8062869860b8

struct cmdserveropts {
	char sockname[UNIX_PATH_MAX];
	char redirectsockname[UNIX_PATH_MAX];
	char lockfile[UNIX_PATH_MAX];
	char pidfile[UNIX_PATH_MAX];
	size_t argsize;
	const char **args;
	int lockfd;
};

	}

	const char *basename = (envsockname) ? envsockname : sockdir;
	const char *sockfmt = (envsockname) ? "%s" : "%s/server";
	const char *lockfmt = (envsockname) ? "%s.lock" : "%s/lock";
	const char *pidfmt = (envsockname) ? "%s.pid" : "%s/pid";
	r = snprintf(opts->sockname, sizeof(opts->sockname), sockfmt, basename);
	if (r < 0 || (size_t)r >= sizeof(opts->sockname))
		abortmsg("too long TMPDIR or CHGSOCKNAME (r = %d)", r);
	r = snprintf(opts->lockfile, sizeof(opts->lockfile), lockfmt, basename);
	if (r < 0 || (size_t)r >= sizeof(opts->lockfile))
		abortmsg("too long TMPDIR or CHGSOCKNAME (r = %d)", r);
	r = snprintf(opts->pidfile, sizeof(opts->pidfile), pidfmt, basename);
	if (r < 0 || (size_t)r >= sizeof(opts->pidfile))
		abortmsg("too long TMPDIR or CHGSOCKNAME (r = %d)", r);
}

/*
 * Acquire a file lock that indicates a client is trying to start and connect

		hgcmd,
		"serve",
		"--cmdserver", "chgunix",
		"--address", opts->sockname,
		"--daemon-postexec", "chdir:/",
		"--pid-file", opts->pidfile,
		"--config", "extensions.chgserver=",
	};
	size_t baseargvsize = sizeof(baseargv) / sizeof(baseargv[0]);
	size_t argsize = baseargvsize + opts->argsize + 1;

	unlockcmdserver(opts);
	return hgc;
}

static void killcmdserver(const struct cmdserveropts *opts, int sig)
{
	FILE *fp = fopen(opts->pidfile, "r");
	if (!fp)
		abortmsg("cannot open %s (errno = %d)", opts->pidfile, errno);
	int pid = 0;
	int n = fscanf(fp, "%d", &pid);
	fclose(fp);
	if (n != 1 || pid <= 0)
		abortmsg("cannot read pid from %s", opts->pidfile);

	if (kill((pid_t)pid, sig) < 0) {
		if (errno == ESRCH)
			return;
		abortmsg("cannot kill %d (errno = %d)", pid, errno);
	}
}

static pid_t peerpid = 0;

	initcmdserveropts(&opts);
	setcmdserveropts(&opts);
	setcmdserverargs(&opts, argc, argv);

	if (argc == 2) {
		int sig = 0;
		if (strcmp(argv[1], "--kill-chg-daemon") == 0)
			sig = SIGTERM;
		if (sig > 0) {
			killcmdserver(&opts, sig);
			return 0;
		}
	}

	hgclient_t *hgc;

28455:412ee35a8005

struct cmdserveropts {
	char sockname[UNIX_PATH_MAX];
	char redirectsockname[UNIX_PATH_MAX];
	char lockfile[UNIX_PATH_MAX];
	size_t argsize;
	const char **args;
	int lockfd;
};

	}

	const char *basename = (envsockname) ? envsockname : sockdir;
	const char *sockfmt = (envsockname) ? "%s" : "%s/server";
	const char *lockfmt = (envsockname) ? "%s.lock" : "%s/lock";
	r = snprintf(opts->sockname, sizeof(opts->sockname), sockfmt, basename);
	if (r < 0 || (size_t)r >= sizeof(opts->sockname))
		abortmsg("too long TMPDIR or CHGSOCKNAME (r = %d)", r);
	r = snprintf(opts->lockfile, sizeof(opts->lockfile), lockfmt, basename);
	if (r < 0 || (size_t)r >= sizeof(opts->lockfile))
		abortmsg("too long TMPDIR or CHGSOCKNAME (r = %d)", r);
}

/*
 * Acquire a file lock that indicates a client is trying to start and connect

		hgcmd,
		"serve",
		"--cmdserver", "chgunix",
		"--address", opts->sockname,
		"--daemon-postexec", "chdir:/",
		"--config", "extensions.chgserver=",
	};
	size_t baseargvsize = sizeof(baseargv) / sizeof(baseargv[0]);
	size_t argsize = baseargvsize + opts->argsize + 1;

	unlockcmdserver(opts);
	return hgc;
}

static void killcmdserver(const struct cmdserveropts *opts)
{
	/* resolve config hash */
	char *resolvedpath = realpath(opts->sockname, NULL);
	if (resolvedpath) {
		unlink(resolvedpath);
		free(resolvedpath);
	}
}

static pid_t peerpid = 0;

	initcmdserveropts(&opts);
	setcmdserveropts(&opts);
	setcmdserverargs(&opts, argc, argv);

	if (argc == 2) {
		if (strcmp(argv[1], "--kill-chg-daemon") == 0) {
			killcmdserver(&opts);
			return 0;
		}
	}

	hgclient_t *hgc;