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 <stddef.h>
  11 #include <pthread.h>
  12 #include <lttng/ust-events.h>
  13 #include <lttng/ust-tracer.h>
  14 #include <lttng/ringbuffer-context.h>
  15
  16 #include "context-internal.h"
  17
  18 static
  19 size_t pthread_id_get_size(struct lttng_ust_ctx_field *field, size_t offset)
  20 {
  21         size_t size = 0;
  22
  23         size += lib_ring_buffer_align(offset, lttng_alignof(unsigned long));
  24         size += sizeof(unsigned long);
  25         return size;
  26 }
  27
  28 static
  29 void pthread_id_record(struct lttng_ust_ctx_field *field,
  30                  struct lttng_ust_lib_ring_buffer_ctx *ctx,
  31                  struct lttng_channel *chan)
  32 {
  33         unsigned long pthread_id;
  34
  35         pthread_id = (unsigned long) pthread_self();
  36         lib_ring_buffer_align_ctx(ctx, lttng_alignof(pthread_id));
  37         chan->ops->event_write(ctx, &pthread_id, sizeof(pthread_id));
  38 }
  39
  40 static
  41 void pthread_id_get_value(struct lttng_ust_ctx_field *field,
  42                 struct lttng_ust_ctx_value *value)
  43 {
  44         value->u.s64 = (unsigned long) pthread_self();
  45 }
  46
  47 int lttng_add_pthread_id_to_ctx(struct lttng_ust_ctx **ctx)
  48 {
  49         struct lttng_ust_ctx_field *field;
  50         struct lttng_ust_type_common *type;
  51         int ret;
  52
  53         type = lttng_ust_create_type_integer(sizeof(unsigned long) * CHAR_BIT,
  54                         lttng_alignof(unsigned long) * CHAR_BIT,
  55                         lttng_is_signed_type(unsigned long),
  56                         BYTE_ORDER, 10);
  57         if (!type)
  58                 return -ENOMEM;
  59         field = lttng_append_context(ctx);
  60         if (!field) {
  61                 ret = -ENOMEM;
  62                 goto error_context;
  63         }
  64         if (lttng_find_context(*ctx, "pthread_id")) {
  65                 ret = -EEXIST;
  66                 goto error_find_context;
  67         }
  68         field->event_field->name = strdup("pthread_id");
  69         if (!field->event_field->name) {
  70                 ret = -ENOMEM;
  71                 goto error_name;
  72         }
  73         field->event_field->type = type;
  74         field->get_size = pthread_id_get_size;
  75         field->record = pthread_id_record;
  76         field->get_value = pthread_id_get_value;
  77         lttng_context_update(*ctx);
  78         return 0;
  79
  80 error_name:
  81 error_find_context:
  82         lttng_remove_context_field(ctx, field);
  83 error_context:
  84         lttng_ust_destroy_type(type);
  85         return ret;
  86 }