From 738a6d76f6afc92e53776f6aa9f8d8493598dc8a Mon Sep 17 00:00:00 2001
From: Thierry FOURNIER <thierry.fournier@ozon.io>
Date: Mon, 17 Jul 2017 00:14:07 +0200
Subject: [PATCH] MEDIUM: threads/tasks: Add lock around notifications

This patch add lock around some notification calls
---
 include/common/hathreads.h |  4 +++-
 include/proto/task.h       | 21 +++++++++++++++++----
 include/types/task.h       |  3 +++
 3 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/include/common/hathreads.h b/include/common/hathreads.h
index a5a25b47e..774fe7b67 100644
--- a/include/common/hathreads.h
+++ b/include/common/hathreads.h
@@ -166,6 +166,7 @@ enum lock_label {
 	VARS_LOCK,
 	COMP_POOL_LOCK,
 	LUA_LOCK,
+	NOTIF_LOCK,
 	LOCK_LABELS
 };
 struct lock_stat {
@@ -253,7 +254,8 @@ static inline void show_lock_stats()
 					   "LISTENER", "LISTENER_QUEUE", "PROXY", "SERVER",
 					   "UPDATED_SERVERS", "LBPRM", "SIGNALS", "STK_TABLE", "STK_SESS",
 					   "APPLETS", "PEER", "BUF_WQ", "STREAMS", "SSL", "SSL_GEN_CERTS",
-					   "PATREF", "PATEXP", "PATLRU", "VARS", "COMP_POOL", "LUA" };
+					   "PATREF", "PATEXP", "PATLRU", "VARS", "COMP_POOL", "LUA",
+					   "NOTIF" };
 	int lbl;
 
 	for (lbl = 0; lbl < LOCK_LABELS; lbl++) {
diff --git a/include/proto/task.h b/include/proto/task.h
index bc3a17316..cb98fefc7 100644
--- a/include/proto/task.h
+++ b/include/proto/task.h
@@ -294,6 +294,7 @@ static inline struct notification *notification_new(struct list *purge, struct l
 		return NULL;
 	LIST_ADDQ(purge, &com->purge_me);
 	LIST_ADDQ(event, &com->wake_me);
+	SPIN_INIT(&com->lock);
 	com->task = wakeup;
 	return com;
 }
@@ -308,9 +309,15 @@ static inline void notification_purge(struct list *purge)
 
 	/* Delete all pending communication signals. */
 	list_for_each_entry_safe(com, back, purge, purge_me) {
+		SPIN_LOCK(NOTIF_LOCK, &com->lock);
 		LIST_DEL(&com->purge_me);
-		LIST_DEL(&com->wake_me);
-		pool_free2(pool2_notification, com);
+		if (!com->task) {
+			SPIN_UNLOCK(NOTIF_LOCK, &com->lock);
+			pool_free2(pool2_notification, com);
+			continue;
+		}
+		com->task = NULL;
+		SPIN_UNLOCK(NOTIF_LOCK, &com->lock);
 	}
 }
 
@@ -324,10 +331,16 @@ static inline void notification_wake(struct list *wake)
 
 	/* Wake task and delete all pending communication signals. */
 	list_for_each_entry_safe(com, back, wake, wake_me) {
-		LIST_DEL(&com->purge_me);
+		SPIN_LOCK(NOTIF_LOCK, &com->lock);
 		LIST_DEL(&com->wake_me);
+		if (!com->task) {
+			SPIN_UNLOCK(NOTIF_LOCK, &com->lock);
+			pool_free2(pool2_notification, com);
+			continue;
+		}
 		task_wakeup(com->task, TASK_WOKEN_MSG);
-		pool_free2(pool2_notification, com);
+		com->task = NULL;
+		SPIN_UNLOCK(NOTIF_LOCK, &com->lock);
 	}
 }
 
diff --git a/include/types/task.h b/include/types/task.h
index da7c929bc..799e6c5ed 100644
--- a/include/types/task.h
+++ b/include/types/task.h
@@ -56,6 +56,9 @@ struct notification {
 	struct list wake_me; /* Part of list of signals to be targeted if an
 	                        event occurs. */
 	struct task *task; /* The task to be wake if an event occurs. */
+#ifdef USE_THREAD
+	HA_SPINLOCK_T lock;
+#endif
 };
 
 /* The base for all tasks */