X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=liblttng-ust%2Flttng-context-vtid.c;h=7d83b87c90bcf804f796e497d5ecd35162668cb0;hb=af21f7816739b0f9db8b4006ef4378ddc2de0157;hp=dd443774d4c9ef35386cda1d1c4f3e067682a381;hpb=7dd08bec735b428479201f9f84d59c78deabdf57;p=lttng-ust.git

diff --git a/liblttng-ust/lttng-context-vtid.c b/liblttng-ust/lttng-context-vtid.c
index dd443774..7d83b87c 100644
--- a/liblttng-ust/lttng-context-vtid.c
+++ b/liblttng-ust/lttng-context-vtid.c
@@ -26,13 +26,14 @@
 #include <lttng/ust-tracer.h>
 #include <lttng/ringbuffer-config.h>
 #include <lttng/ust-tid.h>
+#include <urcu/tls-compat.h>
 #include "lttng-tracer-core.h"
 
 /*
  * We cache the result to ensure we don't trigger a system call for
  * each event.
  */
-static __thread pid_t cached_vtid;
+static DEFINE_URCU_TLS(pid_t, cached_vtid);
 
 /*
  * Upon fork or clone, the TID assigned to our thread is not the same as
@@ -41,7 +42,7 @@ static __thread pid_t cached_vtid;
  */
 void lttng_context_vtid_reset(void)
 {
-	cached_vtid = 0;
+	URCU_TLS(cached_vtid) = 0;
 }
 
 static
@@ -59,10 +60,20 @@ void vtid_record(struct lttng_ctx_field *field,
 		 struct lttng_ust_lib_ring_buffer_ctx *ctx,
 		 struct lttng_channel *chan)
 {
-	if (caa_unlikely(!cached_vtid))
-		cached_vtid = gettid();
-	lib_ring_buffer_align_ctx(ctx, lttng_alignof(cached_vtid));
-	chan->ops->event_write(ctx, &cached_vtid, sizeof(cached_vtid));
+	if (caa_unlikely(!URCU_TLS(cached_vtid)))
+		URCU_TLS(cached_vtid) = gettid();
+	lib_ring_buffer_align_ctx(ctx, lttng_alignof(URCU_TLS(cached_vtid)));
+	chan->ops->event_write(ctx, &URCU_TLS(cached_vtid),
+		sizeof(URCU_TLS(cached_vtid)));
+}
+
+static
+void vtid_get_value(struct lttng_ctx_field *field,
+		union lttng_ctx_value *value)
+{
+	if (caa_unlikely(!URCU_TLS(cached_vtid)))
+		URCU_TLS(cached_vtid) = gettid();
+	value->s64 = URCU_TLS(cached_vtid);
 }
 
 int lttng_add_vtid_to_ctx(struct lttng_ctx **ctx)
@@ -86,6 +97,7 @@ int lttng_add_vtid_to_ctx(struct lttng_ctx **ctx)
 	field->event_field.type.u.basic.integer.encoding = lttng_encode_none;
 	field->get_size = vtid_get_size;
 	field->record = vtid_record;
+	field->get_value = vtid_get_value;
 	return 0;
 }
 
@@ -94,5 +106,5 @@ int lttng_add_vtid_to_ctx(struct lttng_ctx **ctx)
  */
 void lttng_fixup_vtid_tls(void)
 {
-	asm volatile ("" : : "m" (cached_vtid));
+	asm volatile ("" : : "m" (URCU_TLS(cached_vtid)));
 }