Add process group support to s6-supervise

Signed-off-by: Laurent Bercot <ska@appnovation.com>

1 files changed, 52 insertions, 17 deletions

diff --git a/src/supervision/s6-supervise.c b/src/supervision/s6-supervise.c
index 2f3b9a7..3201127 100644
--- a/src/supervision/s6-supervise.c
+++ b/src/supervision/s6-supervise.c
@@ -43,7 +43,7 @@ typedef enum trans_e trans_t, *trans_t_ref ;
 enum trans_e
 {
   V_TIMEOUT, V_CHLD, V_TERM, V_HUP, V_QUIT, V_INT,
-  V_a, V_b, V_q, V_h, V_k, V_t, V_i, V_1, V_2, V_p, V_c, V_y, V_r,
+  V_a, V_b, V_q, V_h, V_k, V_t, V_i, V_1, V_2, V_p, V_c, V_y, V_r, V_P, V_C, V_K,
   V_o, V_d, V_u, V_D, V_U, V_x, V_O, V_Q
 } ;
 
@@ -73,6 +73,7 @@ typedef action_t *action_t_ref ;
 static tain deadline ;
 static tain nextstart = TAIN_ZERO ;
 static s6_svstatus_t status = S6_SVSTATUS_ZERO ;
+static int finish_wstat ;
 static state_t state = DOWN ;
 static int notifyfd = -1 ;
 static char const *servicename = 0 ;
@@ -130,6 +131,7 @@ static inline int read_downsig (void)
 static void set_down_and_ready (char const *s, unsigned int n)
 {
   status.pid = 0 ;
+  status.pgid = 0 ;
   status.flagfinishing = 0 ;
   status.flagready = 1 ;
   state = DOWN ;
@@ -152,11 +154,14 @@ static void bail (void)
   gflags.cont = 0 ;
 }
 
+static void killI (void)
+{
+  if (status.pgid > 0) killpg(status.pgid, SIGINT) ;
+}
+
 static void sigint (void)
 {
-  pid_t pgid = getpgid(status.pid) ;
-  if (pgid == -1) strerr_warnwu1sys("getpgid") ;
-  else killpg(pgid, SIGINT) ;
+  killI() ;
   bail() ;
 }
 
@@ -253,6 +258,31 @@ static void killr (void)
   kill(status.pid, read_downsig()) ;
 }
 
+static void killP (void)
+{
+  if (status.pgid > 0)
+  {
+    killpg(status.pgid, SIGSTOP) ;
+    status.flagpaused = 1 ;
+    announce() ;
+  }
+}
+
+static void killC (void)
+{
+  if (status.pgid > 0)
+  {
+    killpg(status.pgid, SIGCONT) ;
+    status.flagpaused = 0 ;
+    announce() ;
+  }
+}
+
+static void killK (void)
+{
+  if (status.pgid > 0) killpg(status.pgid, SIGKILL) ;
+}
+
 static void trystart (void)
 {
   cspawn_fileaction fa[2] =
@@ -341,6 +371,9 @@ static void trystart (void)
     fd_close(notifyp[1]) ;
     notifyfd = notifyp[0] ;
   }
+  status.pgid = getpgid(status.pid) ;
+  if (status.pgid == -1)
+    strerr_warnwu1sys("getpgid() (process group control commands will have no effect)") ;
   settimeout_infinite() ;
   nextstart = tain_zero ;
   state = UP ;
@@ -411,9 +444,9 @@ static int uplastup_z (void)
   unsigned int n ;
   char fmt0[UINT_FMT] ;
   char fmt1[UINT_FMT] ;
-  char const *cargv[5] = { "finish", fmt0, fmt1, servicename, 0 } ;
+  char fmt2[PID_FMT] ;
+  char const *cargv[6] = { "finish", fmt0, fmt1, servicename, status.pgid > 0 ? fmt2 : "-1", 0 } ;
 
-  status.wstat = (int)status.pid ;
   status.flagpaused = 0 ;
   status.flagready = 0 ;
   gflags.dying = 0 ;
@@ -425,6 +458,7 @@ static int uplastup_z (void)
   }
   fmt0[uint_fmt(fmt0, WIFSIGNALED(status.wstat) ? 256 : WEXITSTATUS(status.wstat))] = 0 ;
   fmt1[uint_fmt(fmt1, WTERMSIG(status.wstat))] = 0 ;
+  if (status.pgid > 0) fmt2[pid_fmt(fmt2, status.pgid)] = 0 ;
 
   if (!read_uint("max-death-tally", &n)) n = 100 ;
   if (n > S6_MAX_DEATH_TALLY) n = S6_MAX_DEATH_TALLY ;
@@ -458,6 +492,7 @@ static int uplastup_z (void)
       tain_add_g(&deadline, &tto) ;
     else settimeout_infinite() ;
   }
+  status.pgid = getpgid(status.pid) ;
   status.flagfinishing = 1 ;
   announce() ;
   ftrigw_notifyb_nosig(S6_SUPERVISE_EVENTDIR, "d", 1) ;
@@ -532,8 +567,7 @@ static void finishtimeout (void)
 
 static void finish_z (void)
 {
-  int wstat = (int)status.pid ;
-  if (WIFEXITED(wstat) && WEXITSTATUS(wstat) == 125)
+  if (WIFEXITED(finish_wstat) && WEXITSTATUS(finish_wstat) == 125)
   {
     status.flagwantup = 0 ;
     set_down_and_ready("OD", 2) ;
@@ -553,22 +587,22 @@ static void lastfinish_z (void)
   bail() ;
 }
 
-static action_t_ref const actions[5][27] =
+static action_t_ref const actions[5][30] =
 {
   { &downtimeout, &nop, &bail, &bail, &bail, &bail,
-    &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop,
+    &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop,
     &down_o, &wantdown, &down_u, &wantDOWN, &down_U, &bail, &wantdown, &wantDOWN },
   { &uptimeout, &up_z, &up_term, &up_x, &bail, &sigint,
-    &killa, &killb, &killq, &killh, &killk, &killt, &killi, &kill1, &kill2, &killp, &killc, &killy, &killr,
+    &killa, &killb, &killq, &killh, &killk, &killt, &killi, &kill1, &kill2, &killp, &killc, &killy, &killr, &killP, &killC, &killK,
     &wantdown, &up_d, &wantup, &up_D, &wantUP, &up_x, &wantdown, &wantDOWN },
   { &finishtimeout, &finish_z, &finish_x, &finish_x, &bail, &sigint,
-    &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop,
+    &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop,
     &wantdown, &wantdown, &wantup, &wantDOWN, &wantUP, &finish_x, &wantdown, &wantDOWN },
   { &uptimeout, &lastup_z, &up_d, &closethem, &bail, &sigint,
-    &killa, &killb, &killq, &killh, &killk, &killt, &killi, &kill1, &kill2, &killp, &killc, &killy, &killr,
+    &killa, &killb, &killq, &killh, &killk, &killt, &killi, &kill1, &kill2, &killp, &killc, &killy, &killr, &killP, &killC, &killK,
     &wantdown, &up_d, &wantup, &up_D, &wantUP, &closethem, &wantdown, &wantDOWN },
   { &finishtimeout, &lastfinish_z, &nop, &closethem, &bail, &sigint,
-    &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop,
+    &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop,
     &wantdown, &wantdown, &wantup, &wantDOWN, &wantUP, &closethem, &wantdown, &wantDOWN }
 } ;
 
@@ -620,7 +654,8 @@ static inline void handle_signals (void)
             if (errno != ECHILD) strerr_diefu1sys(111, "wait_pid_nohang") ;
             else break ;
           else if (!r) break ;
-          status.pid = (pid_t)wstat ; /* don't overwrite status.wstat if it's ./finish */
+          if (status.flagfinishing) finish_wstat = wstat ;
+          else status.wstat = wstat ;
           (*actions[state][V_CHLD])() ;
         }
         break ;
@@ -652,8 +687,8 @@ static inline void handle_control (int fd)
     else if (!r) break ;
     else
     {
-      size_t pos = byte_chr("abqhkti12pcyroduDUxOQ", 21, c) ;
-      if (pos < 21) (*actions[state][V_a + pos])() ;
+      size_t pos = byte_chr("abqhkti12pcyrPCKoduDUxOQ", 24, c) ;
+      if (pos < 24) (*actions[state][V_a + pos])() ;
     }
   }
 }