The state of a wait node must be accessed atomically. Also, the action
of busy loading until the teardown state is seen must follow a
CMM_ACQUIRE semantic while storing the teardown must follow a
CMM_RELEASE semantic.
Change-Id: I9cd9cf4cd9ab2081551d7f33c0b1c23c3cf3942f
Co-authored-by: Mathieu Desnoyers <mathieu.desnoy...@efficios.com>
Signed-off-by: Olivier Dion <od...@efficios.com>
---
src/urcu-wait.h | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/src/urcu-wait.h b/src/urcu-wait.h
index ef5f7ed..4667a13 100644
--- a/src/urcu-wait.h
+++ b/src/urcu-wait.h
@@ -135,7 +135,7 @@ void urcu_adaptative_wake_up(struct urcu_wait_node *wait)
urcu_die(errno);
}
/* Allow teardown of struct urcu_wait memory. */
- uatomic_or(&wait->state, URCU_WAIT_TEARDOWN);
+ uatomic_or_mo(&wait->state, URCU_WAIT_TEARDOWN, CMM_RELEASE);
}
/*
@@ -193,7 +193,7 @@ skip_futex_wait:
break;
caa_cpu_relax();
}
- while (!(uatomic_read(&wait->state) & URCU_WAIT_TEARDOWN))
+ while (!(uatomic_load(&wait->state, CMM_ACQUIRE) & URCU_WAIT_TEARDOWN))
poll(NULL, 0, 10);
urcu_posix_assert(uatomic_read(&wait->state) & URCU_WAIT_TEARDOWN);
}
@@ -209,7 +209,7 @@ void urcu_wake_all_waiters(struct urcu_waiters *waiters)
caa_container_of(iter, struct urcu_wait_node, node);
/* Don't wake already running threads */
- if (wait_node->state & URCU_WAIT_RUNNING)
+ if (uatomic_load(&wait_node->state, CMM_RELAXED) &
URCU_WAIT_RUNNING)
continue;
urcu_adaptative_wake_up(wait_node);
}
--
2.39.2
_______________________________________________
lttng-dev mailing list
lttng-dev@lists.lttng.org
https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
