Add compile time assertion that array and sequence have integer elements

[lttng-ust.git] / liblttng-ust / tracepoint.c

diff --git a/liblttng-ust/tracepoint.c b/liblttng-ust/tracepoint.c
index 2c25d46250b603c6ed3e5c987f24aae905ef482a..b109fe30152b2968f7aba03736bab0cae53dbd89 100644 (file)
--- a/liblttng-ust/tracepoint.c
+++ b/liblttng-ust/tracepoint.c
@@ -26,7 +26,7 @@
 #include <stdio.h>
 
 #include <urcu/arch.h>
-#include <urcu-bp.h>
+#include <urcu/urcu-bp.h>
 #include <urcu/hlist.h>
 #include <urcu/uatomic.h>
 #include <urcu/compiler.h>
@@ -53,6 +53,22 @@ struct {
 /* Set to 1 to enable tracepoint debug output */
 static const int tracepoint_debug;
 static int initialized;
+
+/*
+ * If tracepoint_destructors_state = 1, tracepoint destructors are
+ * enabled. They are disabled otherwise.
+ */
+static int tracepoint_destructors_state = 1;
+
+/*
+ * Expose the now deprecated symbol __tracepoints__disable_destructors for
+ * backward compatibility of applications built against old versions of
+ * lttng-ust. We need to keep __tracepoints__disable_destructors up to date
+ * within the new destructor disabling API because old applications read this
+ * symbol directly.
+ */
+int __tracepoints__disable_destructors __attribute__((weak));
+
 static void (*new_tracepoint_cb)(struct lttng_ust_tracepoint *);
 
 /*
@@ -150,7 +166,7 @@ static void release_probes(void *old)
        if (old) {
                struct tp_probes *tp_probes = caa_container_of(old,
                        struct tp_probes, probes[0]);
-               synchronize_rcu();
+               urcu_bp_synchronize_rcu();
                free(tp_probes);
        }
 }
@@ -734,7 +750,7 @@ void __tracepoint_probe_prune_release_queue(void)
        release_queue_need_update = 0;
 
        /* Wait for grace period between all sync_callsites and free. */
-       synchronize_rcu();
+       urcu_bp_synchronize_rcu();
 
        cds_list_for_each_entry_safe(pos, next, &release_probes, u.list) {
                cds_list_del(&pos->u.list);
@@ -825,7 +841,7 @@ void tracepoint_probe_update_all(void)
 
        tracepoint_update_probes();
        /* Wait for grace period between update_probes and free. */
-       synchronize_rcu();
+       urcu_bp_synchronize_rcu();
        cds_list_for_each_entry_safe(pos, next, &release_probes, u.list) {
                cds_list_del(&pos->u.list);
                free(pos);
@@ -971,15 +987,40 @@ void exit_tracepoint(void)
 
 void tp_rcu_read_lock_bp(void)
 {
-       rcu_read_lock_bp();
+       urcu_bp_read_lock();
 }
 
 void tp_rcu_read_unlock_bp(void)
 {
-       rcu_read_unlock_bp();
+       urcu_bp_read_unlock();
 }
 
 void *tp_rcu_dereference_sym_bp(void *p)
 {
-       return rcu_dereference_bp(p);
+       return urcu_bp_dereference(p);
+}
+
+/*
+ * Programs that have threads that survive after they exit, and therefore call
+ * library destructors, should disable the tracepoint destructors by calling
+ * tp_disable_destructors(). This will leak the tracepoint
+ * instrumentation library shared object, leaving its teardown to the operating
+ * system process teardown.
+ *
+ * To access and/or modify this value, users need to use a combination of
+ * dlopen(3) and dlsym(3) to get an handle on the
+ * tp_disable_destructors and tp_get_destructors_state symbols below.
+ */
+void tp_disable_destructors(void)
+{
+       uatomic_set(&tracepoint_destructors_state, 0);
+}
+
+/*
+ * Returns 1 if the destructors are enabled and should be executed.
+ * Returns 0 if the destructors are disabled.
+ */
+int tp_get_destructors_state(void)
+{
+       return uatomic_read(&tracepoint_destructors_state);
 }