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Allow kfcgi(8) to handle SIGHUP to shut down its children and restart them.

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kristapsdz committed 2016-03-15 03:48:03 +00:00
1 parent 0629b5fda8
commit de85ff2c83
2 files changed
+179 -73
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kfcgi.c
+176 -73
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@@ -49,8 +49,6 @@ struct worker {
int ctrl; /* control socket */
pid_t pid; /* process */
time_t last; /* last deschedule or 0 if never */
unsigned flags; /* flags on this worker */
#define WORK_EXITING 0x01
};
/*
@@ -58,12 +56,20 @@ struct worker {
*/
static volatile sig_atomic_t stop = 0;
static volatile sig_atomic_t chld = 0;
static volatile sig_atomic_t hup = 0;
static int verbose = 0;
static void dbg(const char *fmt, ...)
__attribute__((format(printf, 1, 2)));
static void
sighandlehup(int sig)
{
hup = 1;
}
static void
sighandlestop(int sig)
{
@@ -254,13 +260,13 @@ varpool_start(struct worker *w, const struct worker *ws,
if ( ! xsocketpair(pair))
return(0);
w->ctrl = pair[0];
if (-1 == (w->pid = fork())) {
syslog(LOG_ERR, "fork: worker: %m");
close(pair[0]);
close(pair[1]);
w->ctrl = -1;
return(0);
} else if (0 == w->pid) {
/*
@@ -284,10 +290,11 @@ varpool_start(struct worker *w, const struct worker *ws,
/* Close the child descriptor. */
if (-1 == close(pair[1])) {
syslog(LOG_ERR, "close: worker pipe: %m");
syslog(LOG_ERR, "close: worker-%u pipe: %m", w->pid);
return(0);
}
dbg("worker-%u: started", w->pid);
return(1);
}
@@ -298,8 +305,8 @@ varpool_start(struct worker *w, const struct worker *ws,
* This is an EXPERIMENTAL extension.
*/
static int
varpool(size_t wsz, size_t maxwsz, int fd,
const char *sockpath, char *argv[])
varpool(size_t wsz, size_t maxwsz, time_t waittime,
int fd, const char *sockpath, char *argv[])
{
struct worker *ws;
struct worker *slough;
@@ -313,23 +320,32 @@ varpool(size_t wsz, size_t maxwsz, int fd,
time_t t;
sigset_t set;
minwsz = wsz;
dbg("YOU ARE RUNNING VARIABLE MODE AT YOUR OWN RISK.");
signal(SIGCHLD, sighandlechld);
signal(SIGTERM, sighandlestop);
signal(SIGHUP, sighandlehup);
sigemptyset(&set);
sigaddset(&set, SIGCHLD);
sigaddset(&set, SIGTERM);
sigaddset(&set, SIGHUP);
sigprocmask(SIG_BLOCK, &set, NULL);
again:
stop = chld = hup = 0;
/*
* Allocate worker array, polling descriptor array, and slough
* array (exiting workers).
* Set our initial exit code and our acceptance status.
*/
accepting = 1;
minwsz = wsz;
ws = calloc(wsz, sizeof(struct worker));
sloughmaxsz = (maxwsz - minwsz) * 2;
slough = calloc(sloughmaxsz, sizeof(struct worker));
pfdmaxsz = wsz + 1;
pfd = calloc(pfdmaxsz, sizeof(struct pollfd));
exitcode = 0;
sloughsz = 0;
if (NULL == ws || NULL == pfd || NULL == slough) {
/* Serious problems. */
@@ -342,30 +358,20 @@ varpool(size_t wsz, size_t maxwsz, int fd,
return(0);
}
/* Zeroth pfd is always the domain socket. */
pfd[0].fd = fd;
pfd[0].events = POLLIN;
/* Guard against bad de-allocation. */
for (i = 0; i < wsz; i++) {
ws[i].ctrl = ws[i].fd = -1;
ws[i].pid = -1;
}
/* Zeroth pfd is always the domain socket. */
pfd[0].fd = fd;
pfd[0].events = POLLIN;
sloughsz = 0;
accepting = 1;
pfdsz = 1;
/*
* Dying children should notify us that something is horribly
* wrong and we should exit.
* Also handle SIGTERM in the same way.
* Start with these signals BLOCKED.
*/
signal(SIGCHLD, sighandlechld);
signal(SIGTERM, sighandlestop);
sigemptyset(&set);
sigaddset(&set, SIGCHLD);
sigaddset(&set, SIGTERM);
sigprocmask(SIG_BLOCK, &set, NULL);
/*
* Start up the [initial] worker processes.
* We'll later spin up workers when we need them.
@@ -423,12 +429,23 @@ pollagain:
assert(-1 != ws[i].pid);
rc = waitpid(ws[i].pid, NULL, WNOHANG);
if (rc < 0) {
syslog(LOG_ERR, "waitpid: "
"worker check: %m");
syslog(LOG_ERR, "wait: worker-%u "
"check: %m", ws[i].pid);
goto out;
} else if (0 == rc)
continue;
syslog(LOG_ERR, "worker unexpectedly exited");
/*
* We found a process that has already exited.
* Close its fd as well so that we know that the
* pid of -1 means it's completely finished.
*/
syslog(LOG_ERR, "worker-%u "
"unexpectedly exited", ws[i].pid);
if (-1 == close(ws[i].ctrl))
syslog(LOG_ERR, "close: worker-%u "
"control socket: %m",
ws[wsz - 1].pid);
ws[i].pid = -1;
goto out;
}
@@ -440,15 +457,20 @@ pollagain:
i++;
continue;
} else if (rc < 0) {
syslog(LOG_ERR, "waitpid: "
"exited worker check: %m");
syslog(LOG_ERR, "wait: sloughed "
"worker-%u check: %m",
slough[i].pid);
goto out;
}
dbg("slough: releasing %u\n", slough[i].pid);
dbg("slough: releasing worker-%u\n",
slough[i].pid);
if (i < sloughsz - 1)
slough[i] = slough[sloughsz - 1];
sloughsz--;
}
} else if (hup) {
dbg("servicing restart request");
goto out;
}
/*
@@ -465,7 +487,7 @@ pollagain:
assert(wsz > 1);
if (-1 == ws[wsz - 1].fd &&
t - ws[wsz - 1].last > 10) {
t - ws[wsz - 1].last > waittime) {
assert(-1 != ws[wsz - 1].ctrl);
assert(-1 != ws[wsz - 1].pid);
assert(-1 == ws[wsz - 1].fd);
@@ -479,12 +501,14 @@ pollagain:
/* Close down the worker in the usual way. */
if (-1 == close(ws[wsz - 1].ctrl)) {
syslog(LOG_ERR, "close: worker "
"control socket: %m");
syslog(LOG_ERR, "close: worker-%u "
"control socket: %m",
ws[wsz - 1].pid);
goto out;
}
if (-1 == kill(ws[wsz - 1].pid, SIGTERM)) {
syslog(LOG_ERR, "kill: worker: %m");
syslog(LOG_ERR, "kill: worker-%u: %m",
ws[wsz - 1].pid);
goto out;
}
@@ -492,7 +516,8 @@ pollagain:
* Append the dying client to the slough array,
* since workers may take time to die.
*/
dbg("slough <- acquiring %u\n", ws[wsz - 1].pid);
dbg("slough: acquiring worker-%u\n",
ws[wsz - 1].pid);
slough[sloughsz++] = ws[wsz - 1];
/* Reallocations. */
@@ -557,7 +582,7 @@ pollagain:
goto out;
}
dbg("child-%u -> release %d", ws[j].pid, afd);
dbg("worker-%u: release %d", ws[j].pid, afd);
/*
* Close the descriptor (that we still hold) and mark
@@ -656,19 +681,27 @@ pollagain:
assert(i < wsz);
ws[i].fd = afd;
dbg("child-%u <- acquire %d "
dbg("worker-%u: acquire %d "
"(pollers %zu/%zu: workers %zu/%zu)",
ws[i].pid, afd, pfdsz, pfdmaxsz, wsz, maxwsz);
pfd[pfdsz].events = POLLIN;
pfd[pfdsz].fd = ws[i].ctrl;
pfdsz++;
if ( ! fullwritefd(ws[i].ctrl, ws[i].fd, &ws[i].fd, sizeof(int)))
goto out;
goto pollagain;
if (fullwritefd(ws[i].ctrl, ws[i].fd, &ws[i].fd, sizeof(int)))
goto pollagain;
out:
if (close(fd) < 0)
syslog(LOG_ERR, "close: control: %m");
if ( ! hup) {
/*
* If we're not going to restart, then close the FastCGI
* file descriptor as soon as possible.
*/
dbg("closing control socket");
if (-1 == close(fd))
syslog(LOG_ERR, "close: control: %m");
fd = -1;
}
/*
* Close the application's control socket; then, if that doesn't
@@ -676,27 +709,52 @@ out:
* we also deliver a SIGTERM.
*/
for (i = 0; i < wsz; i++) {
if (-1 != ws[i].ctrl && -1 == close(ws[i].ctrl))
syslog(LOG_ERR, "close: worker control: %m");
if (-1 != ws[i].pid && -1 == kill(ws[i].pid, SIGTERM))
syslog(LOG_ERR, "kill: worker: %m");
if (-1 == ws[i].pid)
continue;
dbg("worker-%u: terminating", ws[i].pid);
if (-1 == close(ws[i].ctrl))
syslog(LOG_ERR, "close: "
"worker-%u control: %m", ws[i].pid);
if (-1 == kill(ws[i].pid, SIGTERM))
syslog(LOG_ERR, "kill: "
"worker-%u: %m", ws[i].pid);
}
/*
* Now wait for the children and pending children.
*/
for (i = 0; i < wsz; i++)
if (-1 != ws[i].pid &&
-1 == waitpid(ws[i].pid, NULL, 0))
syslog(LOG_ERR, "waitpid: worker: %m");
for (i = 0; i < wsz; i++) {
if (-1 == ws[i].pid)
continue;
dbg("worker-%u: reaping", ws[i].pid);
if (-1 == waitpid(ws[i].pid, NULL, 0))
syslog(LOG_ERR, "wait: "
"worker-%u: %m", ws[i].pid);
}
for (i = 0; i < sloughsz; i++)
for (i = 0; i < sloughsz; i++) {
dbg("sloughed worker-%u: reaping", slough[i].pid);
if (-1 == waitpid(slough[i].pid, NULL, 0))
syslog(LOG_ERR, "waitpid: slough: %m");
syslog(LOG_ERR, "wait: sloughed "
"worker-%u: %m", slough[i].pid);
}
free(ws);
free(slough);
free(pfd);
if (hup)
goto again;
/*
* Now we're really exiting.
* Do our final cleanup if we didn't already...
*/
if (-1 != fd) {
dbg("closing control socket");
if (-1 == close(fd))
syslog(LOG_ERR, "close: control: %m");
}
return(exitcode);
}
@@ -707,6 +765,23 @@ fixedpool(size_t wsz, int fd, const char *sockpath, char *argv[])
size_t i;
sigset_t set, oset;
/*
* Dying children should notify us that something is horribly
* wrong and we should exit.
* Also handle SIGTERM in the same way.
*/
signal(SIGTERM, sighandlestop);
signal(SIGCHLD, sighandlestop);
signal(SIGHUP, sighandlehup);
sigemptyset(&set);
sigaddset(&set, SIGCHLD);
sigaddset(&set, SIGTERM);
sigaddset(&set, SIGHUP);
sigprocmask(SIG_BLOCK, &set, &oset);
again:
hup = stop = chld = 0;
/* Allocate worker array. */
if (NULL == (ws = calloc(wsz, sizeof(pid_t)))) {
syslog(LOG_ERR, "calloc: initialisation: %m");
@@ -715,21 +790,13 @@ fixedpool(size_t wsz, int fd, const char *sockpath, char *argv[])
return(0);
}
/*
* "Zero" the workers.
* This is in case the initialisation fails.
*/
for (i = 0; i < wsz; i++)
ws[i] = -1;
/*
* Dying children should notify us that something is horribly
* wrong and we should exit.
* Also handle SIGTERM in the same way.
*/
signal(SIGTERM, sighandlestop);
signal(SIGCHLD, sighandlestop);
sigemptyset(&set);
sigaddset(&set, SIGCHLD);
sigaddset(&set, SIGTERM);
sigprocmask(SIG_BLOCK, &set, &oset);
for (i = 0; i < wsz; i++) {
if (-1 == (ws[i] = fork())) {
syslog(LOG_ERR, "fork: worker: %m");
@@ -752,22 +819,49 @@ fixedpool(size_t wsz, int fd, const char *sockpath, char *argv[])
}
}
/* Close local reference to server. */
close(fd);
sigsuspend(&oset);
dbg("servicing exit request");
if (stop)
dbg("servicing exit request");
else if (chld)
syslog(LOG_ERR, "worker unexpectedly exited");
else
dbg("servicing restart request");
out:
if ( ! hup) {
/*
* If we're not going to restart, then close the FastCGI
* file descriptor as soon as possible.
*/
if (-1 == close(fd))
syslog(LOG_ERR, "close: control: %m");
fd = -1;
}
/*
* Now wait on the children.
* This can take forever, but properly-written children will
* exit when receiving SIGTERM.
*/
for (i = 0; i < wsz; i++)
if (-1 != ws[i] && -1 == kill(ws[i], SIGTERM))
syslog(LOG_ERR, "kill: worker: %m");
syslog(LOG_ERR, "kill: worker-%u: %m", ws[i]);
for (i = 0; i < wsz; i++)
if (-1 != ws[i] && -1 == waitpid(ws[i], NULL, 0))
syslog(LOG_ERR, "kill: waitpid: %m");
syslog(LOG_ERR, "wait: worker-%u: %m", ws[i]);
free(ws);
if (hup)
goto again;
/*
* Now we're really exiting.
* Do our final cleanup if we didn't already...
*/
if (-1 != fd && -1 == close(fd))
syslog(LOG_ERR, "close: control: %m");
return(1);
}
@@ -778,6 +872,7 @@ main(int argc, char *argv[])
pid_t *ws;
struct passwd *pw;
size_t i, wsz, sz, lsz, maxwsz;
time_t waittime;
const char *pname, *sockpath, *chpath,
*sockuser, *procuser, *errstr;
struct sockaddr_un sun;
@@ -806,8 +901,9 @@ main(int argc, char *argv[])
varp = 0;
nod = 0;
maxwsz = lsz = 0;
waittime = 60 * 5;
while (-1 != (c = getopt(argc, argv, "l:p:n:N:s:u:U:rvd")))
while (-1 != (c = getopt(argc, argv, "l:p:n:N:s:u:U:rvdw:")))
switch (c) {
case ('l'):
useq = 1;
@@ -853,6 +949,13 @@ main(int argc, char *argv[])
case ('d'):
nod = 1;
break;
case ('w'):
waittime = strtonum(optarg, 0, INT_MAX, &errstr);
if (NULL == errstr)
break;
fprintf(stderr, "-w must be "
"between 0 and %d\n", INT_MAX);
return(EXIT_FAILURE);
default:
goto usage;
}
@@ -1002,7 +1105,7 @@ main(int argc, char *argv[])
openlog(getprogname(), LOG_PID, LOG_DAEMON);
c = varp ?
varpool(wsz, maxwsz, fd, sockpath, nargv) :
varpool(wsz, maxwsz, waittime, fd, sockpath, nargv) :
fixedpool(wsz, fd, sockpath, nargv);
free(nargv);
man/kfcgi.8
+3
View File
@@ -68,6 +68,9 @@ To properly stop a
.Nm
server, send it a
.Dv SIGTERM .
If you send a
.Dv SIGHUP
to the process, it will restart all workers.
.\" .Sh CONTEXT
.\" For section 9 functions only.
.\" .Sh IMPLEMENTATION NOTES