+++ /dev/null
-/*
- * (C) Copyright 2009-2011 -
- * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * LTTng UST vtid context.
- *
- * Dual LGPL v2.1/GPL v2 license.
- */
-
-#include <sys/types.h>
-#include <unistd.h>
-#include <lttng/ust-events.h>
-#include <lttng/ust-tracer.h>
-#include <lttng/ringbuffer-config.h>
-
-#ifdef __linux__
-#include <syscall.h>
-#endif
-
-#if defined(_syscall0)
-_syscall0(pid_t, gettid)
-#elif defined(__NR_gettid)
-static inline pid_t gettid(void)
-{
- return syscall(__NR_gettid);
-}
-#else
-#warning "use pid as tid"
-static inline pid_t gettid(void)
-{
- return getpid();
-}
-#endif
-
-/*
- * We cache the result to ensure we don't trigger a system call for
- * each event.
- */
-static __thread pid_t cached_vtid;
-
-/*
- * Upon fork or clone, the TID assigned to our thread is not the same as
- * we kept in cache. Luckily, we are the only thread surviving in the
- * child process, so we can simply clear our cached version.
- */
-void lttng_context_vtid_reset(void)
-{
- cached_vtid = 0;
-}
-
-static
-size_t vtid_get_size(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 vtid_record(struct lttng_ctx_field *field,
- struct lttng_ust_lib_ring_buffer_ctx *ctx,
- struct ltt_channel *chan)
-{
- if (caa_unlikely(!cached_vtid))
- cached_vtid = gettid();
- lib_ring_buffer_align_ctx(ctx, lttng_alignof(cached_vtid));
- chan->ops->event_write(ctx, &cached_vtid, sizeof(cached_vtid));
-}
-
-int lttng_add_vtid_to_ctx(struct lttng_ctx **ctx)
-{
- struct lttng_ctx_field *field;
-
- field = lttng_append_context(ctx);
- if (!field)
- return -ENOMEM;
- if (lttng_find_context(*ctx, "vtid")) {
- lttng_remove_context_field(ctx, field);
- return -EEXIST;
- }
- 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->get_size = vtid_get_size;
- field->record = vtid_record;
- return 0;
-}