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authorLaurent Bercot <ska-skaware@skarnet.org>2015-06-15 18:27:25 +0000
committerLaurent Bercot <ska-skaware@skarnet.org>2015-06-15 18:27:25 +0000
commit0a39023fd7229371dd3e505208a1c0e073414ac2 (patch)
tree9689d12f7b1ae6c0144bbcb446ab1f0ee5dedfff /src
parent9cc5f3b25284ddca50ad1a19a83b1d1153dc9f5d (diff)
downloads6-0a39023fd7229371dd3e505208a1c0e073414ac2.tar.xz
- Readiness notification support in s6-supervise
- s6-notifywhenup deprecated - Change abundantly documented - rc for 2.1.4.0
Diffstat (limited to 'src')
-rw-r--r--src/supervision/s6-notifywhenup.c1
-rw-r--r--src/supervision/s6-supervise.c127
2 files changed, 102 insertions, 26 deletions
diff --git a/src/supervision/s6-notifywhenup.c b/src/supervision/s6-notifywhenup.c
index 6d66fe1..8c45926 100644
--- a/src/supervision/s6-notifywhenup.c
+++ b/src/supervision/s6-notifywhenup.c
@@ -72,6 +72,7 @@ int main (int argc, char const *const *argv, char const *const *envp)
argc -= l.ind ; argv += l.ind ;
}
if (!argc) dieusage() ;
+ strerr_warnw1x("this program is deprecated. Use a notification-fd file instead.") ;
{
int p[2] ;
diff --git a/src/supervision/s6-supervise.c b/src/supervision/s6-supervise.c
index 4aaf371..13c751e 100644
--- a/src/supervision/s6-supervise.c
+++ b/src/supervision/s6-supervise.c
@@ -1,7 +1,6 @@
/* ISC license. */
#include <sys/types.h>
-#include <sys/stat.h>
#include <sys/wait.h>
#include <unistd.h>
#include <errno.h>
@@ -47,8 +46,8 @@ typedef action_t *action_t_ref ;
static tain_t deadline ;
static s6_svstatus_t status = { .stamp = TAIN_ZERO, .pid = 0, .flagwant = 1, .flagwantup = 1, .flagpaused = 0, .flagfinishing = 0, .wstat = 0 } ;
static state_t state = DOWN ;
-static int flagsetsid = 1 ;
static int cont = 1 ;
+static int notifyfd = -1 ;
static inline void settimeout (int secs)
{
@@ -137,21 +136,64 @@ static void killc (void)
announce() ;
}
+static void failcoe (int fd)
+{
+ register int e = errno ;
+ fd_write(fd, "", 1) ;
+ errno = e ;
+}
+
+static int maybesetsid (void)
+{
+ if (access("nosetsid", F_OK) < 0)
+ {
+ if (errno != ENOENT) return 0 ;
+ setsid() ;
+ }
+ return 1 ;
+}
+
static void trystart (void)
{
int p[2] ;
+ int notifyp[2] = { -1, -1 } ;
+ unsigned int fd ;
pid_t pid ;
if (pipecoe(p) < 0)
{
settimeout(60) ;
- strerr_warnwu1sys("pipecoe (waiting 60 seconds)") ;
+ strerr_warnwu1sys("pipe (waiting 60 seconds)") ;
return ;
}
+ {
+ char buf[UINT_FMT + 1] ;
+ register int r = openreadnclose("notification-fd", buf, UINT_FMT) ;
+ if (r < 0)
+ {
+ if (errno != ENOENT)
+ strerr_warnwu1sys("open notification-fd") ;
+ }
+ else
+ {
+ buf[byte_chr(buf, r, '\n')] = 0 ;
+ if (!uint0_scan(buf, &fd))
+ strerr_warnw1x("invalid notification-fd") ;
+ else if (pipe(notifyp) < 0)
+ {
+ settimeout(60) ;
+ strerr_warnwu1sys("pipe (waiting 60 seconds)") ;
+ fd_close(p[1]) ; fd_close(p[0]) ;
+ return ;
+ }
+ }
+ }
pid = fork() ;
if (pid < 0)
{
settimeout(60) ;
strerr_warnwu1sys("fork (waiting 60 seconds)") ;
+ if (notifyp[1] >= 0) fd_close(notifyp[1]) ;
+ if (notifyp[0] >= 0) fd_close(notifyp[0]) ;
fd_close(p[1]) ; fd_close(p[0]) ;
return ;
}
@@ -160,14 +202,25 @@ static void trystart (void)
char const *cargv[2] = { "run", 0 } ;
PROG = "s6-supervise (child)" ;
selfpipe_finish() ;
- fd_close(p[0]) ;
+ if (notifyp[0] >= 0) close(notifyp[0]) ;
+ close(p[0]) ;
if (unlink(S6_SUPERVISE_READY_FILENAME) < 0 && errno != ENOENT)
strerr_warnwu1sys("unlink " S6_SUPERVISE_READY_FILENAME) ;
- if (flagsetsid) setsid() ;
+ if (notifyp[1] >= 0 && fd_move((int)fd, notifyp[1]) < 0)
+ {
+ failcoe(p[1]) ;
+ strerr_diefu1sys(127, "move notification descriptor") ;
+ }
+ if (!maybesetsid())
+ {
+ failcoe(p[1]) ;
+ strerr_diefu1sys(127, "access ./nosetsid") ;
+ }
execve("./run", (char *const *)cargv, (char *const *)environ) ;
- fd_write(p[1], "", 1) ;
+ failcoe(p[1]) ;
strerr_dieexec(127, "run") ;
}
+ if (notifyp[1] >= 0) fd_close(notifyp[1]) ;
fd_close(p[1]) ;
{
char c ;
@@ -189,6 +242,7 @@ static void trystart (void)
}
}
fd_close(p[0]) ;
+ notifyfd = notifyp[0] ;
settimeout_infinite() ;
state = UP ;
status.pid = pid ;
@@ -249,7 +303,7 @@ static inline void tryfinish (int islast)
selfpipe_finish() ;
fmt0[uint_fmt(fmt0, WIFSIGNALED(status.wstat) ? 256 : WEXITSTATUS(status.wstat))] = 0 ;
fmt1[uint_fmt(fmt1, WTERMSIG(status.wstat))] = 0 ;
- if (flagsetsid) setsid() ;
+ maybesetsid() ;
execve("./finish", cargv, (char *const *)environ) ;
_exit(127) ;
}
@@ -269,6 +323,11 @@ static void uplastup_z (int islast)
status.wstat = status.pid ;
status.pid = 0 ;
tain_copynow(&status.stamp) ;
+ if (notifyfd >= 0)
+ {
+ fd_close(notifyfd) ;
+ notifyfd = -1 ;
+ }
tryfinish(islast) ;
announce() ;
ftrigw_notifyb_nosig(S6_SUPERVISE_EVENTDIR, "d", 1) ;
@@ -368,11 +427,36 @@ static action_t_ref const actions[5][23] =
} ;
+
/* The main loop.
It just loops around the iopause(), calling snippets of code in "actions" when needed. */
-static void handle_signals (void)
+static inline void handle_notifyfd (void)
+{
+ char buf[4096] ;
+ register int r = 1 ;
+ while (r > 0)
+ {
+ r = sanitize_read(fd_read(notifyfd, buf, 4096)) ;
+ if (r > 0 && byte_chr(buf, r, '\n') < r)
+ {
+ char pack[TAIN_PACK] ;
+ tain_pack(pack, &STAMP) ;
+ if (!openwritenclose_suffix(S6_SUPERVISE_READY_FILENAME, pack, TAIN_PACK, ".new"))
+ strerr_warnwu3sys("open ", S6_SUPERVISE_READY_FILENAME, " for writing") ;
+ ftrigw_notifyb_nosig(S6_SUPERVISE_EVENTDIR, "U", 1) ;
+ r = -1 ;
+ }
+ if (r < 0)
+ {
+ fd_close(notifyfd) ;
+ notifyfd = -1 ;
+ }
+ }
+}
+
+static inline void handle_signals (void)
{
for (;;)
{
@@ -410,7 +494,7 @@ static void handle_signals (void)
}
}
-static void handle_control (int fd)
+static inline void handle_control (int fd)
{
for (;;)
{
@@ -428,7 +512,7 @@ static void handle_control (int fd)
int main (int argc, char const *const *argv)
{
- iopause_fd x[2] = { { -1, IOPAUSE_READ, 0 }, { -1, IOPAUSE_READ, 0 } } ;
+ iopause_fd x[3] = { { -1, IOPAUSE_READ, 0 }, { -1, IOPAUSE_READ, 0 }, { -1, IOPAUSE_READ, 0 } } ;
PROG = "s6-supervise" ;
if (argc < 2) strerr_dieusage(100, USAGE) ;
if (chdir(argv[1]) < 0) strerr_diefu2sys(111, "chdir to ", argv[1]) ;
@@ -460,21 +544,9 @@ int main (int argc, char const *const *argv)
if (!ftrigw_clean(S6_SUPERVISE_EVENTDIR))
strerr_warnwu2sys("ftrigw_clean ", S6_SUPERVISE_EVENTDIR) ;
- {
- struct stat st ;
- if (stat("down", &st) == -1)
- {
- if (errno != ENOENT)
- strerr_diefu1sys(111, "stat down") ;
- }
- else status.flagwantup = 0 ;
- if (stat("nosetsid", &st) == -1)
- {
- if (errno != ENOENT)
- strerr_diefu1sys(111, "stat nosetsid") ;
- }
- else flagsetsid = 0 ;
- }
+ if (access("down", F_OK) == 0) status.flagwantup = 0 ;
+ else if (errno != ENOENT)
+ strerr_diefu1sys(111, "access ./down") ;
tain_now_g() ;
settimeout(0) ;
@@ -484,13 +556,16 @@ int main (int argc, char const *const *argv)
while (cont)
{
- register int r = iopause_g(x, 2, &deadline) ;
+ register int r ;
+ x[2].fd = notifyfd ;
+ r = iopause_g(x, 2 + (notifyfd >= 0), &deadline) ;
if (r < 0) strerr_diefu1sys(111, "iopause") ;
else if (!r) (*actions[state][V_TIMEOUT])() ;
else
{
if ((x[0].revents | x[1].revents) & IOPAUSE_EXCEPT)
strerr_diefu1x(111, "iopause: trouble with pipes") ;
+ if (notifyfd >= 0 && x[2].revents & IOPAUSE_READ) handle_notifyfd() ;
if (x[0].revents & IOPAUSE_READ) handle_signals() ;
else if (x[1].revents & IOPAUSE_READ) handle_control(x[1].fd) ;
}