tracepoint: Refactor representation of nested types

[lttng-ust.git] / liblttng-ust / lttng-context-vpid.c

diff --git a/liblttng-ust/lttng-context-vpid.c b/liblttng-ust/lttng-context-vpid.c
index 7d8091be0351052e3db95602dd839bd7a5d95406..54aa8d2a811a5d7768d65ab6ce0c5baa823edfe0 100644 (file)
--- a/liblttng-ust/lttng-context-vpid.c
+++ b/liblttng-ust/lttng-context-vpid.c
@@ -20,23 +20,14 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#define _LGPL_SOURCE
+#include <stddef.h>
 #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 +35,16 @@ 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;
 }
 
 /*
@@ -57,9 +53,8 @@ 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)
@@ -76,21 +71,17 @@ 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)
@@ -106,12 +97,12 @@ int lttng_add_vpid_to_ctx(struct lttng_ctx **ctx)
        }
        field->event_field.name = "vpid";
        field->event_field.type.atype = atype_integer;
-       field->event_field.type.u.basic.integer.size = sizeof(pid_t) * CHAR_BIT;
-       field->event_field.type.u.basic.integer.alignment = lttng_alignof(pid_t) * CHAR_BIT;
-       field->event_field.type.u.basic.integer.signedness = lttng_is_signed_type(pid_t);
-       field->event_field.type.u.basic.integer.reverse_byte_order = 0;
-       field->event_field.type.u.basic.integer.base = 10;
-       field->event_field.type.u.basic.integer.encoding = lttng_encode_none;
+       field->event_field.type.u.integer.size = sizeof(pid_t) * CHAR_BIT;
+       field->event_field.type.u.integer.alignment = lttng_alignof(pid_t) * CHAR_BIT;
+       field->event_field.type.u.integer.signedness = lttng_is_signed_type(pid_t);
+       field->event_field.type.u.integer.reverse_byte_order = 0;
+       field->event_field.type.u.integer.base = 10;
+       field->event_field.type.u.integer.encoding = lttng_encode_none;
        field->get_size = vpid_get_size;
        field->record = vpid_record;
        field->get_value = vpid_get_value;