+++ /dev/null
-/*
- * SPDX-License-Identifier: LGPL-2.1-only
- *
- * Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * LTTng UST vpid context.
- */
-
-#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>
-
-#include "context-internal.h"
-
-/*
- * We cache the result to ensure we don't trigger a system call for
- * each event.
- */
-static pid_t cached_vpid;
-
-static inline
-pid_t wrapper_getvpid(void)
-{
- pid_t vpid;
-
- vpid = CMM_LOAD_SHARED(cached_vpid);
- if (caa_unlikely(!vpid)) {
- vpid = getpid();
- CMM_STORE_SHARED(cached_vpid, vpid);
- }
- return vpid;
-}
-
-/*
- * Upon fork or clone, the PID assigned to our thread is not the same as
- * we kept in cache.
- */
-void lttng_context_vpid_reset(void)
-{
- CMM_STORE_SHARED(cached_vpid, 0);
-}
-
-static
-size_t vpid_get_size(struct lttng_ust_ctx_field *field, size_t offset)
-{
- size_t size = 0;
-
- size += lib_ring_buffer_align(offset, lttng_alignof(pid_t));
- size += sizeof(pid_t);
- return size;
-}
-
-static
-void vpid_record(struct lttng_ust_ctx_field *field,
- struct lttng_ust_lib_ring_buffer_ctx *ctx,
- struct lttng_channel *chan)
-{
- pid_t vpid = wrapper_getvpid();
-
- lib_ring_buffer_align_ctx(ctx, lttng_alignof(vpid));
- chan->ops->event_write(ctx, &vpid, sizeof(vpid));
-}
-
-static
-void vpid_get_value(struct lttng_ust_ctx_field *field,
- struct lttng_ust_ctx_value *value)
-{
- value->u.s64 = wrapper_getvpid();
-}
-
-int lttng_add_vpid_to_ctx(struct lttng_ust_ctx **ctx)
-{
- struct lttng_ust_ctx_field *field;
-
- field = lttng_append_context(ctx);
- if (!field)
- return -ENOMEM;
- if (lttng_find_context(*ctx, "vpid")) {
- lttng_remove_context_field(ctx, field);
- return -EEXIST;
- }
- field->event_field->name = "vpid";
- field->event_field->type.atype = atype_integer;
- 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;
- lttng_context_update(*ctx);
- return 0;
-}