src/lib/lttng-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/ust-ringbuffer-context.h>
  16
  17 #include "context-internal.h"
  18
  19 static
  20 size_t pthread_id_get_size(void *priv __attribute__((unused)),
  21                 struct lttng_ust_probe_ctx *probe_ctx __attribute__((unused)),
  22                 size_t offset)
  23 {
  24         size_t size = 0;
  25
  26         size += lttng_ust_ring_buffer_align(offset, lttng_ust_rb_alignof(unsigned long));
  27         size += sizeof(unsigned long);
  28         return size;
  29 }
  30
  31 static
  32 void pthread_id_record(void *priv __attribute__((unused)),
  33                 struct lttng_ust_probe_ctx *probe_ctx __attribute__((unused)),
  34                 struct lttng_ust_ring_buffer_ctx *ctx,
  35                 struct lttng_ust_channel_buffer *chan)
  36 {
  37         unsigned long pthread_id;
  38
  39         pthread_id = (unsigned long) pthread_self();
  40         chan->ops->event_write(ctx, &pthread_id, sizeof(pthread_id), lttng_ust_rb_alignof(pthread_id));
  41 }
  42
  43 static
  44 void pthread_id_get_value(void *priv __attribute__((unused)),
  45                 struct lttng_ust_probe_ctx *probe_ctx __attribute__((unused)),
  46                 struct lttng_ust_ctx_value *value)
  47 {
  48         value->u.u64 = (unsigned long) pthread_self();
  49 }
  50
  51 static const struct lttng_ust_ctx_field *ctx_field = lttng_ust_static_ctx_field(
  52         lttng_ust_static_event_field("pthread_id",
  53                 lttng_ust_static_type_integer(sizeof(unsigned long) * CHAR_BIT,
  54                                 lttng_ust_rb_alignof(unsigned long) * CHAR_BIT,
  55                                 lttng_ust_is_signed_type(unsigned long),
  56                                 LTTNG_UST_BYTE_ORDER, 10),
  57                 false, false),
  58         pthread_id_get_size,
  59         pthread_id_record,
  60         pthread_id_get_value,
  61         NULL, NULL);
  62
  63 int lttng_add_pthread_id_to_ctx(struct lttng_ust_ctx **ctx)
  64 {
  65         int ret;
  66
  67         if (lttng_find_context(*ctx, ctx_field->event_field->name)) {
  68                 ret = -EEXIST;
  69                 goto error_find_context;
  70         }
  71         ret = lttng_ust_context_append(ctx, ctx_field);
  72         if (ret)
  73                 return ret;
  74         return 0;
  75
  76 error_find_context:
  77         return ret;
  78 }