doc/examples/easy-ust/sample_component_provider.h

   1 /*
   2  * Copyright (C) 2011-2012  Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   3  * Copyright (C) 2011-2012  Matthew Khouzam <matthew.khouzam@ericsson.com>
   4  *
   5  * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
   6  * OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
   7  *
   8  * Permission is hereby granted to use or copy this program for any
   9  * purpose,  provided the above notices are retained on all copies.
  10  * Permission to modify the code and to distribute modified code is
  11  * granted, provided the above notices are retained, and a notice that
  12  * the code was modified is included with the above copyright notice.
  13  */
  14
  15 /*
  16  * Sample lttng-ust tracepoint provider.
  17  */
  18
  19 /*
  20  * First part: defines
  21  * We undef a macro before defining it as it can be used in several files.
  22  */
  23
  24 /*
  25  * Must be included before include tracepoint provider
  26  * ex.: project_event
  27  * ex.: project_component_event
  28  *
  29  * Optional company name goes here
  30  * ex.: com_efficios_project_component_event
  31  *
  32  * In this example, "sample" is the project, and "component" is the
  33  * component.
  34  */
  35 #undef TRACEPOINT_PROVIDER
  36 #define TRACEPOINT_PROVIDER sample_component
  37
  38 /*
  39  * include file (this files's name)
  40  */
  41 #undef TRACEPOINT_INCLUDE_FILE
  42 #define TRACEPOINT_INCLUDE_FILE ./sample_component_provider.h
  43
  44 /*
  45  * Add this macro and its matching element to make sure the program
  46  * works in c++.
  47  */
  48 #ifdef __cplusplus
  49 #extern "C"{
  50 #endif /*__cplusplus */
  51
  52 /*
  53  * Add this precompiler conditionals to ensure the tracepoint event generation
  54  * can include this file more than once.
  55  */
  56 #if !defined(_SAMPLE_COMPONENT_PROVIDER_H) || defined(TRACEPOINT_HEADER_MULTI_READ)
  57 #define _SAMPLE_COMPONENT_PROVIDER_H
  58 /*
  59  * Add this to allow programs to call "tracepoint(...):
  60  */
  61 #include <lttng/tracepoint.h>
  62
  63 /*
  64  * The following tracepoint event writes a message (c string) into the
  65  * field message of the trace event message in the provider
  66  * sample_component in other words:
  67  *
  68  *    sample_component:message:message = text.
  69  */
  70 TRACEPOINT_EVENT(
  71         /*
  72          * provider name, not a variable but a string starting with a letter
  73          * and containing either letters, numbers or underscores.
  74          * Needs to be the same as TRACEPOINT_PROVIDER
  75          */
  76         sample_component,
  77         /*
  78          * tracepoint name, same format as sample provider. Does not need to be
  79          * declared before. in this case the name is "message"
  80          */
  81         message,
  82         /*
  83          * TP_ARGS macro contains the arguments passed for the tracepoint
  84          * it is in the following format
  85          *              TP_ARGS( type1, name1, type2, name2, ... type10, name10)
  86          * where there can be from zero to ten elements.
  87          * typeN is the datatype, such as int, struct or double **.
  88          * name is the variable name (in "int myInt" the name would be myint)
  89          *              TP_ARGS() is valid to mean no arguments
  90          *              TP_ARGS( void ) is valid too
  91          */
  92         TP_ARGS(char *, text),
  93         /*
  94          * TP_FIELDS describes how to write the fields of the trace event.
  95          * You can use the args here
  96          */
  97         TP_FIELDS(
  98         /*
  99          * The ctf_string macro takes a c string and writes it into a field
 100          * named "message"
 101          */
 102                 ctf_string(message, text)
 103         )
 104 )
 105 /*
 106  * Trace loglevel, shows the level of the trace event. It can be TRACE_EMERG,
 107  * TRACE_ALERT, TRACE_CRIT, TRACE_ERR, TRACE_WARNING, TRACE_INFO or others.
 108  * If this is not set, TRACE_DEFAULT is assumed.
 109  * The first two arguments identify the tracepoint
 110  * See details in <lttng/tracepoint.h> line 347
 111  */
 112 TRACEPOINT_LOGLEVEL(
 113        /*
 114         * The provider name, must be the same as the provider name in the
 115         * TRACEPOINT_EVENT and as TRACEPOINT_PROVIDER above.
 116         */
 117         sample_component,
 118        /*
 119         * The tracepoint name, must be the same as the tracepoint name in the
 120         * TRACEPOINT_EVENT
 121         */
 122         message,
 123        /*
 124         * The tracepoint loglevel. Warning, some levels are abbreviated and
 125         * others are not, please see <lttng/tracepoint.h>
 126         */
 127         TRACE_WARNING)
 128
 129 #endif /* _SAMPLE_COMPONENT_PROVIDER_H */
 130
 131 /*
 132  * Add this after defining the tracepoint events to expand the macros.
 133  */
 134 #include <lttng/tracepoint-event.h>
 135
 136 /*
 137  * Add this macro and its matching element to make sure the program
 138  * works in c++.
 139  */
 140 #ifdef __cplusplus
 141 }
 142 #endif /*__cplusplus */