doc/examples/easy-ust/sample_component_provider.h

   1 /*
   2  * SPDX-License-Identifier: MIT
   3  *
   4  * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   5  * Copyright (C) 2011-2012 Matthew Khouzam <matthew.khouzam@ericsson.com>
   6  */
   7
   8 /*
   9  * Sample lttng-ust tracepoint provider.
  10  */
  11
  12 /*
  13  * First part: defines
  14  * We undef a macro before defining it as it can be used in several files.
  15  */
  16
  17 /*
  18  * Must be included before include tracepoint provider
  19  * ex.: project_event
  20  * ex.: project_component_event
  21  *
  22  * Optional company name goes here
  23  * ex.: com_efficios_project_component_event
  24  *
  25  * In this example, "sample" is the project, and "component" is the
  26  * component.
  27  */
  28 #undef TRACEPOINT_PROVIDER
  29 #define TRACEPOINT_PROVIDER sample_component
  30
  31 /*
  32  * include file (this files's name)
  33  */
  34 #undef TRACEPOINT_INCLUDE
  35 #define TRACEPOINT_INCLUDE "./sample_component_provider.h"
  36
  37 /*
  38  * Add this precompiler conditionals to ensure the tracepoint event generation
  39  * can include this file more than once.
  40  */
  41 #if !defined(_SAMPLE_COMPONENT_PROVIDER_H) || defined(TRACEPOINT_HEADER_MULTI_READ)
  42 #define _SAMPLE_COMPONENT_PROVIDER_H
  43 /*
  44  * Add this to allow programs to call "tracepoint(...):
  45  */
  46 #include <lttng/tracepoint.h>
  47
  48 /*
  49  * The following tracepoint event writes a message (c string) into the
  50  * field message of the trace event message in the provider
  51  * sample_component in other words:
  52  *
  53  *    sample_component:message:message = text.
  54  */
  55 TRACEPOINT_EVENT(
  56         /*
  57          * provider name, not a variable but a string starting with a letter
  58          * and containing either letters, numbers or underscores.
  59          * Needs to be the same as TRACEPOINT_PROVIDER
  60          */
  61         sample_component,
  62         /*
  63          * tracepoint name, same format as sample provider. Does not need to be
  64          * declared before. in this case the name is "message"
  65          */
  66         message,
  67         /*
  68          * TP_ARGS macro contains the arguments passed for the tracepoint
  69          * it is in the following format
  70          *              TP_ARGS( type1, name1, type2, name2, ... type10, name10)
  71          * where there can be from zero to ten elements.
  72          * typeN is the datatype, such as int, struct or double **.
  73          * name is the variable name (in "int myInt" the name would be myint)
  74          *              TP_ARGS() is valid to mean no arguments
  75          *              TP_ARGS( void ) is valid too
  76          */
  77         TP_ARGS(char *, text),
  78         /*
  79          * TP_FIELDS describes how to write the fields of the trace event.
  80          * You can use the args here
  81          */
  82         TP_FIELDS(
  83         /*
  84          * The ctf_string macro takes a c string and writes it into a field
  85          * named "message"
  86          */
  87                 ctf_string(message, text)
  88         )
  89 )
  90 /*
  91  * Trace loglevel, shows the level of the trace event. It can be TRACE_EMERG,
  92  * TRACE_ALERT, TRACE_CRIT, TRACE_ERR, TRACE_WARNING, TRACE_INFO or others.
  93  * If this is not set, TRACE_DEFAULT is assumed.
  94  * The first two arguments identify the tracepoint
  95  * See details in <lttng/tracepoint.h> line 347
  96  */
  97 TRACEPOINT_LOGLEVEL(
  98        /*
  99         * The provider name, must be the same as the provider name in the
 100         * TRACEPOINT_EVENT and as TRACEPOINT_PROVIDER above.
 101         */
 102         sample_component,
 103        /*
 104         * The tracepoint name, must be the same as the tracepoint name in the
 105         * TRACEPOINT_EVENT
 106         */
 107         message,
 108        /*
 109         * The tracepoint loglevel. Warning, some levels are abbreviated and
 110         * others are not, please see <lttng/tracepoint.h>
 111         */
 112         TRACE_WARNING)
 113
 114 #endif /* _SAMPLE_COMPONENT_PROVIDER_H */
 115
 116 /*
 117  * Add this after defining the tracepoint events to expand the macros.
 118  */
 119 #include <lttng/tracepoint-event.h>