From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Thu, 18 Aug 2022 18:46:13 +0000 (+0100)
Subject: prefork-interp: watcher plan
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?a=commitdiff_plain;h=423fdb18ee1fe242157c0fc866e376629e9493e4;p=chiark-utils.git

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 6c9a1ff..429790a 100644
--- 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
  *