From: William Lallemand <wlallemand@haproxy.com>
Date: Fri, 16 Nov 2018 15:57:20 +0000 (+0100)
Subject: MEDIUM: jobs: support unstoppable jobs for soft stop
X-Git-Tag: v1.9-dev7~114
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a719926cf894c352c26419bc39bd37e21f615c0c;p=thirdparty%2Fhaproxy.git

MEDIUM: jobs: support unstoppable jobs for soft stop

This patch allows a process to properly quit when some jobs are still
active, this feature is handled by the unstoppable_jobs variable, which
must be atomically incremented.

During each new iteration of run_poll_loop() the break condition of the
loop is now (jobs - unstoppable_jobs) == 0.

The unique usage of this at the moment is to handle the socketpair CLI
of a the worker during the stopping of the process.  During the soft
stop, we could mark the CLI listener as an unstoppable job and still
handle new connections till every other jobs are stopped.
---

diff --git a/include/types/global.h b/include/types/global.h
index 344003a915..5210323048 100644
--- a/include/types/global.h
+++ b/include/types/global.h
@@ -224,6 +224,7 @@ extern unsigned long pid_bit;   /* bit corresponding to the process id */
 extern int  actconn;            /* # of active sessions */
 extern int  listeners;
 extern int  jobs;               /* # of active jobs (listeners, sessions, open devices) */
+extern int  unstoppable_jobs;   /* # of active jobs that can't be stopped during a soft stop */
 extern int  active_peers;       /* # of active peers (connection attempts and successes) */
 extern int  connected_peers;    /* # of really connected peers */
 extern THREAD_LOCAL struct buffer trash;
diff --git a/include/types/stats.h b/include/types/stats.h
index 75250447ec..85cc906da1 100644
--- a/include/types/stats.h
+++ b/include/types/stats.h
@@ -290,6 +290,7 @@ enum info_field {
 	INF_DESCRIPTION,
 	INF_STOPPING,
 	INF_JOBS,
+	INF_UNSTOPPABLE_JOBS,
 	INF_LISTENERS,
 	INF_ACTIVE_PEERS,
 	INF_CONNECTED_PEERS,
diff --git a/src/haproxy.c b/src/haproxy.c
index 494160ad8e..f066ec9784 100644
--- a/src/haproxy.c
+++ b/src/haproxy.c
@@ -177,6 +177,7 @@ struct activity activity[MAX_THREADS] __attribute__((aligned(64))) = { };
 int stopping;	/* non zero means stopping in progress */
 int killed;	/* non zero means a hard-stop is triggered */
 int jobs = 0;   /* number of active jobs (conns, listeners, active tasks, ...) */
+int unstoppable_jobs = 0;  /* number of active jobs that can't be stopped during a soft stop */
 int active_peers = 0; /* number of active peers (connection attempts and connected) */
 int connected_peers = 0; /* number of connected peers (verified ones) */
 
@@ -2617,7 +2618,7 @@ static void run_poll_loop()
 		next = wake_expired_tasks();
 
 		/* stop when there's nothing left to do */
-		if (jobs == 0)
+		if ((jobs - unstoppable_jobs) == 0)
 			break;
 
 		/* expire immediately if events are pending */
diff --git a/src/stats.c b/src/stats.c
index 07a5ef74ea..0574260d99 100644
--- a/src/stats.c
+++ b/src/stats.c
@@ -132,6 +132,7 @@ const char *info_field_names[INF_TOTAL_FIELDS] = {
 	[INF_DESCRIPTION]                    = "description",
 	[INF_STOPPING]                       = "Stopping",
 	[INF_JOBS]                           = "Jobs",
+	[INF_UNSTOPPABLE_JOBS]               = "Unstoppable Jobs",
 	[INF_LISTENERS]                      = "Listeners",
 	[INF_ACTIVE_PEERS]                   = "ActivePeers",
 	[INF_CONNECTED_PEERS]                = "ConnectedPeers",
@@ -3300,6 +3301,7 @@ int stats_fill_info(struct field *info, int len)
 		info[INF_DESCRIPTION]            = mkf_str(FO_CONFIG|FN_OUTPUT|FS_SERVICE, global.desc);
 	info[INF_STOPPING]                       = mkf_u32(0, stopping);
 	info[INF_JOBS]                           = mkf_u32(0, jobs);
+	info[INF_UNSTOPPABLE_JOBS]               = mkf_u32(0, unstoppable_jobs);
 	info[INF_LISTENERS]                      = mkf_u32(0, listeners);
 	info[INF_ACTIVE_PEERS]                   = mkf_u32(0, active_peers);
 	info[INF_CONNECTED_PEERS]                = mkf_u32(0, connected_peers);