*/
#define _LGPL_SOURCE
+#include <stddef.h>
#include <sys/types.h>
#include <unistd.h>
#include <lttng/ust-events.h>
* We cache the result to ensure we don't trigger a system call for
* each event.
*/
-static DEFINE_URCU_TLS_IE(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
*/
void lttng_context_vtid_reset(void)
{
- URCU_TLS(cached_vtid) = 0;
+ CMM_STORE_SHARED(URCU_TLS(cached_vtid), 0);
}
static
return size;
}
+static inline
+pid_t wrapper_getvtid(void)
+{
+ pid_t vtid;
+
+ vtid = CMM_LOAD_SHARED(URCU_TLS(cached_vtid));
+ if (caa_unlikely(!vtid)) {
+ vtid = lttng_gettid();
+ CMM_STORE_SHARED(URCU_TLS(cached_vtid), vtid);
+ }
+ return vtid;
+}
+
static
void vtid_record(struct lttng_ctx_field *field,
struct lttng_ust_lib_ring_buffer_ctx *ctx,
struct lttng_channel *chan)
{
- 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)));
+ pid_t vtid = wrapper_getvtid();
+
+ lib_ring_buffer_align_ctx(ctx, lttng_alignof(vtid));
+ chan->ops->event_write(ctx, &vtid, sizeof(vtid));
}
static
void vtid_get_value(struct lttng_ctx_field *field,
struct lttng_ctx_value *value)
{
- if (caa_unlikely(!URCU_TLS(cached_vtid)))
- URCU_TLS(cached_vtid) = gettid();
- value->u.s64 = URCU_TLS(cached_vtid);
+ value->u.s64 = wrapper_getvtid();
}
int lttng_add_vtid_to_ctx(struct lttng_ctx **ctx)
}
field->event_field.name = "vtid";
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 = vtid_get_size;
field->record = vtid_record;
field->get_value = vtid_get_value;