X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=liblttng-ust%2Flttng-context-vpid.c;h=11978e6e33d8e0f93ac4fb0bd34e12495790d7e4;hb=98357ffd0125c23387d42d4b706c56077392326d;hp=949529c606c253d6fdf272360658370ad818b2d7;hpb=77aa5901fd3f09001fb7e78f3533cf58c6d345e5;p=lttng-ust.git

diff --git a/liblttng-ust/lttng-context-vpid.c b/liblttng-ust/lttng-context-vpid.c
index 949529c6..11978e6e 100644
--- a/liblttng-ust/lttng-context-vpid.c
+++ b/liblttng-ust/lttng-context-vpid.c
@@ -20,23 +20,13 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#define _LGPL_SOURCE
 #include <sys/types.h>
 #include <unistd.h>
 #include <lttng/ust-events.h>
 #include <lttng/ust-tracer.h>
 #include <lttng/ringbuffer-config.h>
 
-#ifdef __linux__
-static inline
-pid_t wrapper_getpid(void)
-{
-	return getpid();
-}
-
-void lttng_context_vpid_reset(void)
-{
-}
-#else
 /*
  * We cache the result to ensure we don't trigger a system call for
  * each event.
@@ -44,11 +34,16 @@ void lttng_context_vpid_reset(void)
 static pid_t cached_vpid;
 
 static inline
-pid_t wrapper_getpid(void)
+pid_t wrapper_getvpid(void)
 {
-	if (caa_unlikely(!cached_vpid))
-		cached_vpid = getpid();
-	return cached_vpid;
+	pid_t vpid;
+
+	vpid = CMM_LOAD_SHARED(cached_vpid);
+	if (caa_unlikely(!vpid)) {
+		vpid = getpid();
+		CMM_STORE_SHARED(cached_vpid, vpid);
+	}
+	return vpid;
 }
 
 /*
@@ -57,12 +52,11 @@ pid_t wrapper_getpid(void)
  */
 void lttng_context_vpid_reset(void)
 {
-	cached_vpid = 0;
+	CMM_STORE_SHARED(cached_vpid, 0);
 }
-#endif
 
 static
-size_t vpid_get_size(size_t offset)
+size_t vpid_get_size(struct lttng_ctx_field *field, size_t offset)
 {
 	size_t size = 0;
 
@@ -76,21 +70,17 @@ void vpid_record(struct lttng_ctx_field *field,
 		 struct lttng_ust_lib_ring_buffer_ctx *ctx,
 		 struct lttng_channel *chan)
 {
-	pid_t pid;
+	pid_t vpid = wrapper_getvpid();
 
-	pid = wrapper_getpid();
-	lib_ring_buffer_align_ctx(ctx, lttng_alignof(pid));
-	chan->ops->event_write(ctx, &pid, sizeof(pid));
+	lib_ring_buffer_align_ctx(ctx, lttng_alignof(vpid));
+	chan->ops->event_write(ctx, &vpid, sizeof(vpid));
 }
 
 static
 void vpid_get_value(struct lttng_ctx_field *field,
-		union lttng_ctx_value *value)
+		struct lttng_ctx_value *value)
 {
-	pid_t pid;
-
-	pid = wrapper_getpid();
-	value->s64 = pid;
+	value->u.s64 = wrapper_getvpid();
 }
 
 int lttng_add_vpid_to_ctx(struct lttng_ctx **ctx)
@@ -115,5 +105,6 @@ int lttng_add_vpid_to_ctx(struct lttng_ctx **ctx)
 	field->get_size = vpid_get_size;
 	field->record = vpid_record;
 	field->get_value = vpid_get_value;
+	lttng_context_update(*ctx);
 	return 0;
 }