liblttng-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/ringbuffer-context.h>
  16
  17 #include "context-internal.h"
  18
  19 static
  20 size_t pthread_id_get_size(struct lttng_ust_ctx_field *field, size_t offset)
  21 {
  22         size_t size = 0;
  23
  24         size += lttng_ust_lib_ring_buffer_align(offset, lttng_alignof(unsigned long));
  25         size += sizeof(unsigned long);
  26         return size;
  27 }
  28
  29 static
  30 void pthread_id_record(struct lttng_ust_ctx_field *field,
  31                  struct lttng_ust_lib_ring_buffer_ctx *ctx,
  32                  struct lttng_ust_channel_buffer *chan)
  33 {
  34         unsigned long pthread_id;
  35
  36         pthread_id = (unsigned long) pthread_self();
  37         lttng_ust_lib_ring_buffer_align_ctx(ctx, lttng_alignof(pthread_id));
  38         chan->ops->event_write(ctx, &pthread_id, sizeof(pthread_id));
  39 }
  40
  41 static
  42 void pthread_id_get_value(struct lttng_ust_ctx_field *field,
  43                 struct lttng_ust_ctx_value *value)
  44 {
  45         value->u.s64 = (unsigned long) pthread_self();
  46 }
  47
  48 int lttng_add_pthread_id_to_ctx(struct lttng_ust_ctx **ctx)
  49 {
  50         struct lttng_ust_ctx_field *field;
  51         struct lttng_ust_type_common *type;
  52         int ret;
  53
  54         type = lttng_ust_create_type_integer(sizeof(unsigned long) * CHAR_BIT,
  55                         lttng_alignof(unsigned long) * CHAR_BIT,
  56                         lttng_ust_is_signed_type(unsigned long),
  57                         BYTE_ORDER, 10);
  58         if (!type)
  59                 return -ENOMEM;
  60         field = lttng_append_context(ctx);
  61         if (!field) {
  62                 ret = -ENOMEM;
  63                 goto error_context;
  64         }
  65         if (lttng_find_context(*ctx, "pthread_id")) {
  66                 ret = -EEXIST;
  67                 goto error_find_context;
  68         }
  69         field->event_field->name = strdup("pthread_id");
  70         if (!field->event_field->name) {
  71                 ret = -ENOMEM;
  72                 goto error_name;
  73         }
  74         field->event_field->type = type;
  75         field->get_size = pthread_id_get_size;
  76         field->record = pthread_id_record;
  77         field->get_value = pthread_id_get_value;
  78         lttng_context_update(*ctx);
  79         return 0;
  80
  81 error_name:
  82 error_find_context:
  83         lttng_remove_context_field(ctx, field);
  84 error_context:
  85         lttng_ust_destroy_type(type);
  86         return ret;
  87 }