X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=liblttng-ust%2Flttng-context-vpid.c;h=11978e6e33d8e0f93ac4fb0bd34e12495790d7e4;hb=6c737d0594cac0d969e1948ea1ed55c15be9cec8;hp=5e5ed145d944adf08be61755eaa32faefe3e52b4;hpb=3fbec7dc3645facd9e809cf161ba3435a377ce56;p=lttng-ust.git

diff --git a/liblttng-ust/lttng-context-vpid.c b/liblttng-ust/lttng-context-vpid.c
index 5e5ed145..11978e6e 100644
--- a/liblttng-ust/lttng-context-vpid.c
+++ b/liblttng-ust/lttng-context-vpid.c
@@ -27,17 +27,6 @@
 #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.
@@ -45,11 +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;
 }
 
 /*
@@ -58,9 +52,8 @@ 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(struct lttng_ctx_field *field, size_t offset)
@@ -77,21 +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,
 		struct lttng_ctx_value *value)
 {
-	pid_t pid;
-
-	pid = wrapper_getpid();
-	value->u.s64 = pid;
+	value->u.s64 = wrapper_getvpid();
 }
 
 int lttng_add_vpid_to_ctx(struct lttng_ctx **ctx)