From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Fri, 10 Feb 2023 17:24:44 +0000 (-0500)
Subject: Document grace period polling in rcu-api.md
X-Git-Tag: v0.14.0~6
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=a88a3a8607e2aa7bbd5848f5d1f80c8cb0d55715;p=userspace-rcu.git

Document grace period polling in rcu-api.md

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I74631072d19cbe1212be6d1ab4f08778d59f67dd
---

diff --git a/doc/rcu-api.md b/doc/rcu-api.md
index e8ec022..4163eef 100644
--- a/doc/rcu-api.md
+++ b/doc/rcu-api.md
@@ -60,6 +60,26 @@ started: this is not a reader-writer lock. The duration
 actually waited is called an RCU grace period.
 
 
+```c
+struct urcu_gp_poll_state start_poll_synchronize_rcu(void);
+```
+
+Start polling on grace period. The returned poll state should be
+queried using `poll_state_synchronize_rcu` to check whether the
+grace period has completed.
+
+`start_poll_synchronize_rcu` should be called from registered RCU
+read-side threads.  For the QSBR flavor, the caller should be online.
+
+
+```c
+bool poll_state_synchronize_rcu(struct urcu_gp_poll_state state);
+```
+
+Poll the grace period state. Return true if quiescence was reached since
+the grace period was started, return false otherwise.
+
+
 ```c
 void call_rcu(struct rcu_head *head,
               void (*func)(struct rcu_head *head));