* Global grace period counter.
* Contains the current RCU_GP_CTR_BIT.
* Also has a RCU_GP_CTR_BIT of 1, to accelerate the reader fast path.
+ * Written to only by writer with mutex taken. Read by both writer and readers.
*/
long urcu_gp_ctr = RCU_GP_COUNT;
+/*
+ * Written to only by each individual reader. Read by both the reader and the
+ * writers.
+ */
long __thread urcu_active_readers;
/* Thread IDs of registered readers */
*/
static void switch_next_urcu_qparity(void)
{
- urcu_gp_ctr ^= RCU_GP_CTR_BIT;
+ STORE_SHARED(urcu_gp_ctr, urcu_gp_ctr ^ RCU_GP_CTR_BIT);
}
#ifdef DEBUG_FULL_MB
* 0 quiescent state. Failure to do so could result in the writer
* waiting forever while new readers are always accessing data (no
* progress).
+ * Ensured by STORE_SHARED and LOAD_SHARED.
*/
- smp_mc();
/*
* Wait for previous parity to be empty of readers.
* committing qparity update to memory. Failure to do so could result in
* the writer waiting forever while new readers are always accessing
* data (no progress).
+ * Ensured by STORE_SHARED and LOAD_SHARED.
*/
- smp_mc();
switch_next_urcu_qparity(); /* 1 -> 0 */
* 1 quiescent state. Failure to do so could result in the writer
* waiting forever while new readers are always accessing data (no
* progress).
+ * Ensured by STORE_SHARED and LOAD_SHARED.
*/
- smp_mc();
/*
* Wait for previous parity to be empty of readers.