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-config.h>
  15
  16 #include "context-internal.h"
  17
  18 static
  19 size_t pthread_id_get_size(struct lttng_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_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_ctx_field *field,
  42                 struct lttng_ctx_value *value)
  43 {
  44         value->u.s64 = (unsigned long) pthread_self();
  45 }
  46
  47 int lttng_add_pthread_id_to_ctx(struct lttng_ctx **ctx)
  48 {
  49         struct lttng_ctx_field *field;
  50
  51         field = lttng_append_context(ctx);
  52         if (!field)
  53                 return -ENOMEM;
  54         if (lttng_find_context(*ctx, "pthread_id")) {
  55                 lttng_remove_context_field(ctx, field);
  56                 return -EEXIST;
  57         }
  58         field->event_field.name = "pthread_id";
  59         field->event_field.type.atype = atype_integer;
  60         field->event_field.type.u.integer.size = sizeof(unsigned long) * CHAR_BIT;
  61         field->event_field.type.u.integer.alignment = lttng_alignof(unsigned long) * CHAR_BIT;
  62         field->event_field.type.u.integer.signedness = lttng_is_signed_type(unsigned long);
  63         field->event_field.type.u.integer.reverse_byte_order = 0;
  64         field->event_field.type.u.integer.base = 10;
  65         field->event_field.type.u.integer.encoding = lttng_encode_none;
  66         field->get_size = pthread_id_get_size;
  67         field->record = pthread_id_record;
  68         field->get_value = pthread_id_get_value;
  69         lttng_context_update(*ctx);
  70         return 0;
  71 }