[PATCHv3 01/10] git p4 test: wait longer for p4d to start and test its pid

From: Pete Wyckoff <pw@padd.com>
Date: Jun 28, 2012, 02:48 UTC
Message-ID: <20120628024807.GA16349@padd.com>
In-Reply-To: <7vfw9g78w5.fsf@alter.siamese.dyndns.org>

Running tests at high parallelism on a slow machine, 5 sec is not enough to wait for p4d to start. Change it to 5 minutes, adding an environment variable P4D_START_PATIENCE to shrink that if needed in automated test environments.

Also check if the pid of the p4d that we started is still around. If not, quit waiting for it immediately.

Remove all the confusing && chaining and simplify the code.

Thanks-to: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Pete Wyckoff <pw@padd.com>
---
 t/lib-git-p4.sh | 38 ++++++++++++++++++++++++++++++++------
 1 file changed, 32 insertions(+), 6 deletions(-)

gitster@pobox.com wrote on Wed, 27 Jun 2012 14:16 -0700:

> In other words, I think it would make it much more clear to write
> this part like this:

[..]

Much nicer. I think I got hung up on always &&-chaining instead of writing the code so it works. This version steals your suggestions almost verbatim. Tested under scenarios where p4d was slow, hung or died, as well as when it works as usual.

Just this patch changed; if it's easy to replace one in the series? Else I could resend all 10.

		-- Pete

diff --git a/t/lib-git-p4.sh b/t/lib-git-p4.sh
index 121e380..eea46a4 100644
--- a/t/lib-git-p4.sh
+++ b/t/lib-git-p4.sh
@@ -33,17 +33,42 @@ pidfile="$TRASH_DIRECTORY/p4d.pid"
 
 start_p4d() {
 	mkdir -p "$db" "$cli" "$git" &&
+	rm -f "$pidfile" &&
 	(
 		p4d -q -r "$db" -p $P4DPORT &
 		echo $! >"$pidfile"
 	) &&
-	for i in 1 2 3 4 5 ; do
-		p4 info >/dev/null 2>&1 && break || true &&
-		echo waiting for p4d to start &&
+
+	# This gives p4d a long time to start up, as it can be
+	# quite slow depending on the machine.  Set this environment
+	# variable to something smaller to fail faster in, say,
+	# an automated test setup.  If the p4d process dies, that
+	# will be caught with the "kill -0" check below.
+	i=${P4D_START_PATIENCE:-300}
+	pid=$(cat "$pidfile")
+	ready=
+	while test $i -gt 0
+	do
+		# succeed when p4 client commands start to work
+		if p4 info >/dev/null 2>&1
+		then
+			ready=true
+			break
+		fi
+		# fail if p4d died
+		kill -0 $pid 2>/dev/null || break
+		echo waiting for p4d to start
 		sleep 1
-	done &&
-	# complain if it never started
-	p4 info >/dev/null &&
+		i=$(( $i - 1 ))
+	done
+
+	if test -z "$ready"
+	then
+		# p4d failed to start
+		return 1
+	fi
+
+	# build a client
 	(
 		cd "$cli" &&
 		p4 client -i <<-EOF
@@ -53,6 +78,7 @@ start_p4d() {
 		View: //depot/... //client/...
 		EOF
 	)
+	return 0
 }
 
 kill_p4d() {

-- 
1.7.11.1.69.g485c1e0