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 static
  17 size_t pthread_id_get_size(struct lttng_ctx_field *field, size_t offset)
  18 {
  19         size_t size = 0;
  20
  21         size += lib_ring_buffer_align(offset, lttng_alignof(unsigned long));
  22         size += sizeof(unsigned long);
  23         return size;
  24 }
  25
  26 static
  27 void pthread_id_record(struct lttng_ctx_field *field,
  28                  struct lttng_ust_lib_ring_buffer_ctx *ctx,
  29                  struct lttng_channel *chan)
  30 {
  31         unsigned long pthread_id;
  32
  33         pthread_id = (unsigned long) pthread_self();
  34         lib_ring_buffer_align_ctx(ctx, lttng_alignof(pthread_id));
  35         chan->ops->event_write(ctx, &pthread_id, sizeof(pthread_id));
  36 }
  37
  38 static
  39 void pthread_id_get_value(struct lttng_ctx_field *field,
  40                 struct lttng_ctx_value *value)
  41 {
  42         value->u.s64 = (unsigned long) pthread_self();
  43 }
  44
  45 int lttng_add_pthread_id_to_ctx(struct lttng_ctx **ctx)
  46 {
  47         struct lttng_ctx_field *field;
  48
  49         field = lttng_append_context(ctx);
  50         if (!field)
  51                 return -ENOMEM;
  52         if (lttng_find_context(*ctx, "pthread_id")) {
  53                 lttng_remove_context_field(ctx, field);
  54                 return -EEXIST;
  55         }
  56         field->event_field.name = "pthread_id";
  57         field->event_field.type.atype = atype_integer;
  58         field->event_field.type.u.integer.size = sizeof(unsigned long) * CHAR_BIT;
  59         field->event_field.type.u.integer.alignment = lttng_alignof(unsigned long) * CHAR_BIT;
  60         field->event_field.type.u.integer.signedness = lttng_is_signed_type(unsigned long);
  61         field->event_field.type.u.integer.reverse_byte_order = 0;
  62         field->event_field.type.u.integer.base = 10;
  63         field->event_field.type.u.integer.encoding = lttng_encode_none;
  64         field->get_size = pthread_id_get_size;
  65         field->record = pthread_id_record;
  66         field->get_value = pthread_id_get_value;
  67         lttng_context_update(*ctx);
  68         return 0;
  69 }