From cc0e2956ae662b2e2c9b60e525ecf8df6196b4c1 Mon Sep 17 00:00:00 2001
From: Moe Jette <jette1@llnl.gov>
Date: Mon, 14 Feb 2011 15:59:41 +0000
Subject: [PATCH] comment why we require salloc to run in the foreground
---
src/salloc/salloc.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/src/salloc/salloc.c b/src/salloc/salloc.c
index 19224b497d1..a0c1ffb3bf9 100644
--- a/src/salloc/salloc.c
+++ b/src/salloc/salloc.c
@@ -165,7 +165,11 @@ int main(int argc, char *argv[])
is_interactive = isatty(STDIN_FILENO);
if (is_interactive) {
bool sent_msg = false;
- /* Wait as long as we are running in the background */
+ /*
+ * Job control: interactive sub-processes run in the foreground
+ * process group of the controlling terminal. In order to grant
+ * this (tcsetpgrp), salloc needs to be in the foreground first.
+ */
while (tcgetpgrp(STDIN_FILENO) != (pid = getpgrp())) {
if (!sent_msg) {
error("Waiting for program to be placed in "
--
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