From 0a39023fd7229371dd3e505208a1c0e073414ac2 Mon Sep 17 00:00:00 2001 From: Laurent Bercot Date: Mon, 15 Jun 2015 18:27:25 +0000 Subject: - Readiness notification support in s6-supervise - s6-notifywhenup deprecated - Change abundantly documented - rc for 2.1.4.0 --- src/supervision/s6-notifywhenup.c | 1 + src/supervision/s6-supervise.c | 127 ++++++++++++++++++++++++++++++-------- 2 files changed, 102 insertions(+), 26 deletions(-) (limited to 'src/supervision') 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 -#include #include #include #include @@ -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) ; } -- cgit v1.2.3