liblttng-ust/lttng-context-pthread-id.c

   1 /*
   2  * lttng-context-pthread-id.c
   3  *
   4  * LTTng UST pthread_id context.
   5  *
   6  * Copyright (C) 2009-2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; only
  11  * version 2.1 of the License.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #define _LGPL_SOURCE
  24 #include <stddef.h>
  25 #include <pthread.h>
  26 #include <lttng/ust-events.h>
  27 #include <lttng/ust-tracer.h>
  28 #include <lttng/ringbuffer-config.h>
  29
  30 static
  31 size_t pthread_id_get_size(struct lttng_ctx_field *field, size_t offset)
  32 {
  33         size_t size = 0;
  34
  35         size += lib_ring_buffer_align(offset, lttng_alignof(unsigned long));
  36         size += sizeof(unsigned long);
  37         return size;
  38 }
  39
  40 static
  41 void pthread_id_record(struct lttng_ctx_field *field,
  42                  struct lttng_ust_lib_ring_buffer_ctx *ctx,
  43                  struct lttng_channel *chan)
  44 {
  45         unsigned long pthread_id;
  46
  47         pthread_id = (unsigned long) pthread_self();
  48         lib_ring_buffer_align_ctx(ctx, lttng_alignof(pthread_id));
  49         chan->ops->event_write(ctx, &pthread_id, sizeof(pthread_id));
  50 }
  51
  52 static
  53 void pthread_id_get_value(struct lttng_ctx_field *field,
  54                 struct lttng_ctx_value *value)
  55 {
  56         value->u.s64 = (unsigned long) pthread_self();
  57 }
  58
  59 int lttng_add_pthread_id_to_ctx(struct lttng_ctx **ctx)
  60 {
  61         struct lttng_ctx_field *field;
  62
  63         field = lttng_append_context(ctx);
  64         if (!field)
  65                 return -ENOMEM;
  66         if (lttng_find_context(*ctx, "pthread_id")) {
  67                 lttng_remove_context_field(ctx, field);
  68                 return -EEXIST;
  69         }
  70         field->event_field.name = "pthread_id";
  71         field->event_field.type.atype = atype_integer;
  72         field->event_field.type.u.integer.size = sizeof(unsigned long) * CHAR_BIT;
  73         field->event_field.type.u.integer.alignment = lttng_alignof(unsigned long) * CHAR_BIT;
  74         field->event_field.type.u.integer.signedness = lttng_is_signed_type(unsigned long);
  75         field->event_field.type.u.integer.reverse_byte_order = 0;
  76         field->event_field.type.u.integer.base = 10;
  77         field->event_field.type.u.integer.encoding = lttng_encode_none;
  78         field->get_size = pthread_id_get_size;
  79         field->record = pthread_id_record;
  80         field->get_value = pthread_id_get_value;
  81         lttng_context_update(*ctx);
  82         return 0;
  83 }