src/lib/lttng-ust/lttng-context-pthread-id.c

   1 /*
   2  * SPDX-License-Identifier: LGPL-2.1-only
   3  *
   4  * Copyright (C) 2009-2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   5  *
   6  * LTTng UST pthread_id context.
   7  */
   8
   9 #define _LGPL_SOURCE
  10 #include <limits.h>
  11 #include <stddef.h>
  12 #include <pthread.h>
  13 #include <lttng/ust-events.h>
  14 #include <lttng/ust-tracer.h>
  15 #include <lttng/ust-ringbuffer-context.h>
  16
  17 #include "context-internal.h"
  18
  19 static
  20 size_t pthread_id_get_size(void *priv __attribute__((unused)),
  21                 size_t offset)
  22 {
  23         size_t size = 0;
  24
  25         size += lttng_ust_ring_buffer_align(offset, lttng_ust_rb_alignof(unsigned long));
  26         size += sizeof(unsigned long);
  27         return size;
  28 }
  29
  30 static
  31 void pthread_id_record(void *priv __attribute__((unused)),
  32                  struct lttng_ust_ring_buffer_ctx *ctx,
  33                  struct lttng_ust_channel_buffer *chan)
  34 {
  35         unsigned long pthread_id;
  36
  37         pthread_id = (unsigned long) pthread_self();
  38         chan->ops->event_write(ctx, &pthread_id, sizeof(pthread_id), lttng_ust_rb_alignof(pthread_id));
  39 }
  40
  41 static
  42 void pthread_id_get_value(void *priv __attribute__((unused)),
  43                 struct lttng_ust_ctx_value *value)
  44 {
  45         value->u.s64 = (unsigned long) pthread_self();
  46 }
  47
  48 static const struct lttng_ust_ctx_field *ctx_field = lttng_ust_static_ctx_field(
  49         lttng_ust_static_event_field("pthread_id",
  50                 lttng_ust_static_type_integer(sizeof(unsigned long) * CHAR_BIT,
  51                                 lttng_ust_rb_alignof(unsigned long) * CHAR_BIT,
  52                                 lttng_ust_is_signed_type(unsigned long),
  53                                 LTTNG_UST_BYTE_ORDER, 10),
  54                 false, false),
  55         pthread_id_get_size,
  56         pthread_id_record,
  57         pthread_id_get_value,
  58         NULL, NULL);
  59
  60 int lttng_add_pthread_id_to_ctx(struct lttng_ust_ctx **ctx)
  61 {
  62         int ret;
  63
  64         if (lttng_find_context(*ctx, ctx_field->event_field->name)) {
  65                 ret = -EEXIST;
  66                 goto error_find_context;
  67         }
  68         ret = lttng_ust_context_append(ctx, ctx_field);
  69         if (ret)
  70                 return ret;
  71         return 0;
  72
  73 error_find_context:
  74         return ret;
  75 }