Add s6-svc -Q

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

3 files changed, 29 insertions, 25 deletions

diff --git a/doc/s6-svc.html b/doc/s6-svc.html
index 24b139d..7c2e30a 100644
--- a/doc/s6-svc.html
+++ b/doc/s6-svc.html
@@ -79,6 +79,9 @@ and stdout redirected to <tt>/dev/null</tt>. </li>
  <li> <tt>-O</tt>&nbsp;: mark the service to run once at most. iow: do not
 restart the supervised process when it dies. If it is down when the command
 is received, do not even start it. </li>
+ <li> <tt>-Q</tt>&nbsp;: once at most, and create a <tt>./down</tt> file.
+Like <tt>-D</tt>, but do not terminate the service if it is currently
+running. </li>
  <li> <tt>-r</tt>&nbsp;: If the service is up, restart it, by sending it a
 signal to kill it and letting <a href="s6-supervise.html">s6-supervise</a>
 start it again. By default, the signal is a SIGTERM; this can be configured
diff --git a/src/supervision/s6-supervise.c b/src/supervision/s6-supervise.c
index fa96a02..5611b98 100644
--- a/src/supervision/s6-supervise.c
+++ b/src/supervision/s6-supervise.c
@@ -40,7 +40,7 @@ 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_o, V_d, V_u, V_D, V_U, V_x, V_O
+  V_o, V_d, V_u, V_D, V_U, V_x, V_O, V_Q
 } ;
 
 typedef enum state_e state_t, *state_t_ref ;
@@ -416,6 +416,18 @@ static void wantup (void)
   announce() ;
 }
 
+static void wantDOWN (void)
+{
+  adddown() ;
+  wantdown() ;
+}
+
+static void wantUP (void)
+{
+  deldown() ;
+  wantup() ;
+}
+
 static void downtimeout (void)
 {
   if (status.flagwantup) trystart() ;
@@ -434,16 +446,10 @@ static void down_u (void)
   trystart() ;
 }
 
-static void down_D (void)
-{
-  adddown() ;
-  wantdown() ;
-}
-
 static void down_U (void)
 {
-  deldown() ;
-  down_u() ;
+  wantUP() ;
+  trystart() ;
 }
 
 static int uplastup_z (void)
@@ -559,12 +565,6 @@ static void up_D (void)
   up_d() ;
 }
 
-static void up_U (void)
-{
-  deldown() ;
-  wantup() ;
-}
-
 static void up_x (void)
 {
   state = LASTUP ;
@@ -607,23 +607,23 @@ static void lastfinish_z (void)
   bail() ;
 }
 
-static action_t_ref const actions[5][26] =
+static action_t_ref const actions[5][27] =
 {
   { &downtimeout, &nop, &bail, &bail, &bail, &bail,
     &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop,
-    &down_o, &wantdown, &down_u, &down_D, &down_U, &bail, &wantdown },
+    &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,
-    &wantdown, &up_d, &wantup, &up_D, &up_U, &up_x, &wantdown },
+    &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,
-    &wantdown, &wantdown, &wantup, &down_D, &up_U, &finish_x, &wantdown },
+    &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,
-    &wantdown, &up_d, &wantup, &up_D, &up_U, &closethem, &wantdown },
+    &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,
-    &wantdown, &wantdown, &wantup, &down_D, &up_U, &closethem, &wantdown }
+    &wantdown, &wantdown, &wantup, &wantDOWN, &wantUP, &closethem, &wantdown, &wantDOWN }
 } ;
 
 
@@ -706,8 +706,8 @@ static inline void handle_control (int fd)
     else if (!r) break ;
     else
     {
-      size_t pos = byte_chr("abqhkti12pcyroduDUxO", 20, c) ;
-      if (pos < 20) (*actions[state][V_a + pos])() ;
+      size_t pos = byte_chr("abqhkti12pcyroduDUxOQ", 21, c) ;
+      if (pos < 21) (*actions[state][V_a + pos])() ;
     }
   }
 }
diff --git a/src/supervision/s6-svc.c b/src/supervision/s6-svc.c
index 4485248..1586056 100644
--- a/src/supervision/s6-svc.c
+++ b/src/supervision/s6-svc.c
@@ -13,7 +13,7 @@
 #include <s6/config.h>
 #include <s6/supervise.h>
 
-#define USAGE "s6-svc [ -wu | -wU | -wd | -wD | -wr | -wR ] [ -T timeout ] [ -abqhkti12pcyroduDUxO ] servicedir"
+#define USAGE "s6-svc [ -wu | -wU | -wd | -wD | -wr | -wR ] [ -T timeout ] [ -abqhkti12pcyroduDUxOQ ] servicedir"
 #define dieusage() strerr_dieusage(100, USAGE)
 
 #define DATASIZE 63
@@ -30,7 +30,7 @@ int main (int argc, char const *const *argv)
     subgetopt l = SUBGETOPT_ZERO ;
     for (;;)
     {
-      int opt = subgetopt_r(argc, argv, "abqhkti12pcyroduDUxOT:w:", &l) ;
+      int opt = subgetopt_r(argc, argv, "abqhkti12pcyroduDUxOQT:w:", &l) ;
       if (opt == -1) break ;
       switch (opt)
       {
@@ -54,6 +54,7 @@ int main (int argc, char const *const *argv)
         case 'U' :
         case 'x' :
         case 'O' :
+        case 'Q' :
         {
           if (datalen >= DATASIZE) strerr_dief1x(100, "too many commands") ;
           data[datalen++] = opt ;