prefork-interp: watcher plan

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

diff --git a/cprogs/prefork-interp.c b/cprogs/prefork-interp.c
index 6c9a1ff5343451d1600ffedc034fcd034acaf10c..429790ae3cb0fd238c5cd9e83532b857f7088909 100644 (file)
--- a/cprogs/prefork-interp.c
+++ b/cprogs/prefork-interp.c
@@ -21,15 +21,25 @@
  *                            === acquire lock ===
  *                               makes new listening socket
  *                               makes first-instance socketpair
+ *                               makes watcher pipes
+ *                            forks watcher and awaits
  *                            forks setup (script, sock fds indicated in env)
  *                            fd0, fd1, fd2: from-outer
  *                            other fd: call(client-end)(fake)
  *                            reaps setup (and reports error)
  *                            (implicitly releases lock)
  *
+ *     watcher                fd[012]: watcher pipes
+ *                            starts watch on socket path
+ *                            sets stderr to line buffered
+ *                            sets stdin to nonblocking
+ *                            daemonises
+ *                            when socket stat changes, quit
+ *
  *     setup (pre-exec)       fd0: null,
  *                            fd[12]: fd2-from-outer
- *                            env fds: listener, call(server-end)(fake)
+ *                            env fds: listener, call(server-end)(fake),
+ *                                      watcher read, watcher write
  *                            close fd: lockfile
  *                            possibly clean env, argv
  *