#include <poll.h>
#include "urcu/wfcqueue.h"
+#include "urcu/wfstack.h"
#include "urcu/map/urcu-qsbr.h"
#define BUILD_QSBR_LIB
#include "urcu/static/urcu-qsbr.h"
#include "urcu/tls-compat.h"
#include "urcu-die.h"
+#include "urcu-wait.h"
/* Do not #define _LGPL_SOURCE to ensure we can emit the wrapper symbols */
#undef _LGPL_SOURCE
static CDS_LIST_HEAD(registry);
+struct gp_waiters_thread {
+ struct cds_wfs_node node;
+ struct urcu_wait wait;
+};
+
+/*
+ * Stack keeping threads awaiting to wait for a grace period. Contains
+ * struct gp_waiters_thread objects.
+ */
+static struct cds_wfs_stack gp_waiters = {
+ .head = CDS_WFS_END,
+ .lock = PTHREAD_MUTEX_INITIALIZER,
+};
+
static void mutex_lock(pthread_mutex_t *mutex)
{
int ret;
CDS_LIST_HEAD(cur_snap_readers);
CDS_LIST_HEAD(qsreaders);
unsigned long was_online;
+ struct gp_waiters_thread gp_waiters_thread;
+ struct cds_wfs_head *gp_waiters_head;
+ struct cds_wfs_node *waiters_iter, *waiters_iter_n;
was_online = URCU_TLS(rcu_reader).ctr;
else
cmm_smp_mb();
+ /*
+ * Add ourself to gp_waiters stack of threads awaiting to wait
+ * for a grace period. Proceed to perform the grace period only
+ * if we are the first thread added into the stack.
+ */
+ cds_wfs_node_init(&gp_waiters_thread.node);
+ urcu_wait_init(&gp_waiters_thread.wait);
+ if (cds_wfs_push(&gp_waiters, &gp_waiters_node) != 0) {
+ /* Not first in stack: will be awakened by another thread. */
+ urcu_adaptative_busy_wait(&gp_waiters_thread.wait);
+ goto gp_end;
+ }
+
mutex_lock(&rcu_gp_lock);
+ /*
+ * Pop all waiters into our local stack head.
+ */
+ gp_waiters_head = __cds_wfs_pop_all(&gp_waiters);
+
if (cds_list_empty(®istry))
goto out;
out:
mutex_unlock(&rcu_gp_lock);
+ /* Wake all waiters in our stack head, excluding ourself. */
+ cds_wfs_for_each_blocking_safe(gp_waiters_head, waiters_iter,
+ waiters_iter_n) {
+ struct gp_waiters_thread *wt;
+
+ wt = caa_container_of(waiters_iter,
+ struct gp_waiters_thread, node);
+ if (wt == &gp_waiters_thread)
+ continue;
+ urcu_adaptative_wake_up(&wt->wait);
+ }
+
+gp_end:
/*
* Finish waiting for reader threads before letting the old ptr being
* freed.
{
CDS_LIST_HEAD(qsreaders);
unsigned long was_online;
+ struct gp_waiters_thread gp_waiters_thread;
+ struct cds_wfs_head *gp_waiters_head;
+ struct cds_wfs_node *waiters_iter, *waiters_iter_n;
was_online = URCU_TLS(rcu_reader).ctr;
else
cmm_smp_mb();
+ /*
+ * Add ourself to gp_waiters stack of threads awaiting to wait
+ * for a grace period. Proceed to perform the grace period only
+ * if we are the first thread added into the stack.
+ */
+ cds_wfs_node_init(&gp_waiters_thread.node);
+ urcu_wait_init(&gp_waiters_thread.wait);
+ if (cds_wfs_push(&gp_waiters, &gp_waiters_thread.node) != 0) {
+ /* Not first in stack: will be awakened by another thread. */
+ urcu_adaptative_busy_wait(&gp_waiters_thread.wait);
+ goto gp_end;
+ }
+
mutex_lock(&rcu_gp_lock);
+
+ /*
+ * Pop all waiters into our local stack head.
+ */
+ gp_waiters_head = __cds_wfs_pop_all(&gp_waiters);
+
if (cds_list_empty(®istry))
goto out;
out:
mutex_unlock(&rcu_gp_lock);
+ /* Wake all waiters in our stack head, excluding ourself. */
+ cds_wfs_for_each_blocking_safe(gp_waiters_head, waiters_iter,
+ waiters_iter_n) {
+ struct gp_waiters_thread *wt;
+
+ wt = caa_container_of(waiters_iter,
+ struct gp_waiters_thread, node);
+ if (wt == &gp_waiters_thread)
+ continue;
+ urcu_adaptative_wake_up(&wt->wait);
+ }
+
+gp_end:
if (was_online)
rcu_thread_online();
else