From: Andres Freund <andres@anarazel.de>
Date: Thu, 31 Dec 2020 04:42:08 +0000 (-0800)
Subject: condition variable: add ConditionVariableCancelSleepEx().
X-Git-Url: http://git.postgresql.org/gitweb/static/gitweb.js?a=commitdiff_plain;h=87003acd0bc7664dc74c1aebe7c0e5d4ec8a06a4;p=users%2Fandresfreund%2Fpostgres.git

condition variable: add ConditionVariableCancelSleepEx().

Author:
Reviewed-By:
Discussion: https://postgr.es/m/
Backpatch:
---

diff --git a/src/backend/storage/lmgr/condition_variable.c b/src/backend/storage/lmgr/condition_variable.c
index 0a61ff0031..77f8d4b907 100644
--- a/src/backend/storage/lmgr/condition_variable.c
+++ b/src/backend/storage/lmgr/condition_variable.c
@@ -218,7 +218,7 @@ ConditionVariableTimedSleep(ConditionVariable *cv, long timeout,
  * during transaction abort to clean up any unfinished CV sleep.
  */
 void
-ConditionVariableCancelSleep(void)
+ConditionVariableCancelSleepEx(bool only_broadcasts)
 {
 	ConditionVariable *cv = cv_sleep_target;
 	bool		signaled = false;
@@ -238,12 +238,18 @@ ConditionVariableCancelSleep(void)
 	 * there is one.  Otherwise a call to ConditionVariableSignal() might get
 	 * lost, despite there being another process ready to handle it.
 	 */
-	if (signaled)
+	if (signaled && !only_broadcasts)
 		ConditionVariableSignal(cv);
 
 	cv_sleep_target = NULL;
 }
 
+void
+ConditionVariableCancelSleep(void)
+{
+	ConditionVariableCancelSleepEx(false);
+}
+
 /*
  * Wake up the oldest process sleeping on the CV, if there is any.
  *
diff --git a/src/include/storage/condition_variable.h b/src/include/storage/condition_variable.h
index 4cba0eccff..dbfe68238b 100644
--- a/src/include/storage/condition_variable.h
+++ b/src/include/storage/condition_variable.h
@@ -57,6 +57,7 @@ extern void ConditionVariableSleep(ConditionVariable *cv, uint32 wait_event_info
 extern bool ConditionVariableTimedSleep(ConditionVariable *cv, long timeout,
 										uint32 wait_event_info);
 extern void ConditionVariableCancelSleep(void);
+extern void ConditionVariableCancelSleepEx(bool only_broadcasts);
 
 /*
  * Optionally, ConditionVariablePrepareToSleep can be called before entering