Fix lttng-ust(3) manpage

[lttng-ust.git] / doc / man / lttng-ust.3

diff --git a/doc/man/lttng-ust.3 b/doc/man/lttng-ust.3
index 27b32e9ff6bac1ee77f2ab221d1c80ff9f8e501c..7624e88f1d86ff4a31db0d85dc0ede48c9d35019 100644 (file)
--- a/doc/man/lttng-ust.3
+++ b/doc/man/lttng-ust.3
@@ -12,7 +12,7 @@ Link liblttng-ust.so with applications, following this manpage.
 .SH "DESCRIPTION"
 
 .PP
 .SH "DESCRIPTION"
 
 .PP

-LTTng-UST, the Linux Trace Toolkit Next Generation Userspace Tracer, is
+LTTng-UST, the Linux Trace Toolkit Next Generation Userspace Tracer, is a

 port of the low-overhead tracing capabilities of the LTTng kernel tracer
 to user-space. The library "liblttng-ust" enables tracing of
 applications and libraries.
 port of the low-overhead tracing capabilities of the LTTng kernel tracer
 to user-space. The library "liblttng-ust" enables tracing of
 applications and libraries.


@@ -33,18 +33,22 @@ script, through an example:
 .nf
 
 To create a tracepoint provider, within a build tree similar to
 .nf
 
 To create a tracepoint provider, within a build tree similar to

-examples/easy-ust installed with lttng-ust documentation, a
-sample_component_provider.h for the general layout. This manpage will
-focus on the various types that can be recorded into a trace event:
+examples/easy-ust installed with lttng-ust documentation, see
+sample_component_provider.h for the general layout. You will need to
+define TRACEPOINT_CREATE_PROBES before including your tracepoint
+provider probe in one source file of your application. See tp.c from
+easy-ust for an example of a tracepoint probe source file. This manpage
+will focus on the various types that can be recorded into a trace
+event:

 
 TRACEPOINT_EVENT(
        /*
         * provider name, not a variable but a string starting with a
 
 TRACEPOINT_EVENT(
        /*
         * provider name, not a variable but a string starting with a

-        * letter and containing either letters, numbers or underscores. 
+        * letter and containing either letters, numbers or underscores.

         * Needs to be the same as TRACEPOINT_PROVIDER. Needs to
         * follow the namespacing guide-lines in lttng/tracepoint.h:
         * Needs to be the same as TRACEPOINT_PROVIDER. Needs to
         * follow the namespacing guide-lines in lttng/tracepoint.h:

-        * 
-        * Must be included before include tracepoint provider 
+        *
+        * Must be included before include tracepoint provider

         * ex.: project_event
         * ex.: project_component_event
         *
         * ex.: project_event
         * ex.: project_component_event
         *


@@ -59,19 +63,19 @@ TRACEPOINT_EVENT(
        /*
         * tracepoint name, same format as sample provider. Does not
         * need to be declared before. in this case the name is
        /*
         * tracepoint name, same format as sample provider. Does not
         * need to be declared before. in this case the name is

-        * "message" 
+        * "message"

         */
        message,
 
        /*
         */
        message,
 
        /*

-        * TP_ARGS macro contains the arguments passed for the tracepoint 
+        * TP_ARGS macro contains the arguments passed for the tracepoint

         * it is in the following format
         *            TP_ARGS(type1, name1, type2, name2, ... type10,
                                 name10)
         * it is in the following format
         *            TP_ARGS(type1, name1, type2, name2, ... type10,
                                 name10)

-        * where there can be from zero to ten elements. 
-        * typeN is the datatype, such as int, struct or double **. 
+        * where there can be from zero to ten elements.
+        * typeN is the datatype, such as int, struct or double **.

         * name is the variable name (in "int myInt" the name would be
         * name is the variable name (in "int myInt" the name would be

-        * myint) 
+        * myint)

         *            TP_ARGS() is valid to mean no arguments
         *            TP_ARGS(void) is valid too
         */
         *            TP_ARGS() is valid to mean no arguments
         *            TP_ARGS(void) is valid too
         */


@@ -80,7 +84,7 @@ TRACEPOINT_EVENT(
                 double, doublearg, float, floatarg),
 
        /*
                 double, doublearg, float, floatarg),
 
        /*

-        * TP_FIELDS describes how to write the fields of the trace event. 
+        * TP_FIELDS describes how to write the fields of the trace event.

         * You can put expressions in the "argument expression" area,
         * typically using the input arguments from TP_ARGS.
         */
         * You can put expressions in the "argument expression" area,
         * typically using the input arguments from TP_ARGS.
         */


@@ -109,7 +113,7 @@ TRACEPOINT_EVENT(
                /*
                 * ctf_array: a statically-sized array.
                 * args: (type, field name, argument expression, value)
                /*
                 * ctf_array: a statically-sized array.
                 * args: (type, field name, argument expression, value)

-                */ 
+                */

                ctf_array(long, arrfield1, values, 3)
 
                /*
                ctf_array(long, arrfield1, values, 3)
 
                /*


@@ -117,7 +121,7 @@ TRACEPOINT_EVENT(
                 * a string. No need to be terminated by a null
                 * character.
                 * Behavior is undefined if "text" argument is NULL.
                 * a string. No need to be terminated by a null
                 * character.
                 * Behavior is undefined if "text" argument is NULL.

-                */ 
+                */

                ctf_array_text(char, arrfield2, text, 10)
 
                /*
                ctf_array_text(char, arrfield2, text, 10)
 
                /*


@@ -129,7 +133,7 @@ TRACEPOINT_EVENT(
                 * be preferred to "char", since the signedness of
                 * "char" is implementation-defined.
                 * Behavior is undefined if "text" argument is NULL.
                 * be preferred to "char", since the signedness of
                 * "char" is implementation-defined.
                 * Behavior is undefined if "text" argument is NULL.

-                */ 
+                */

                ctf_sequence(char, seqfield1, text,
                             size_t, textlen)
 
                ctf_sequence(char, seqfield1, text,
                             size_t, textlen)
 


@@ -156,6 +160,11 @@ TRACEPOINT_EVENT(
                ctf_float(double, doublefield, doublearg)
        )
 )
                ctf_float(double, doublefield, doublearg)
        )
 )

+
+There can be an arbitrary number of tracepoint providers within an
+application, but they must each have their own provider name. Duplicate
+provider names are not allowed.
+

 .fi
 
 .SH "ASSIGNING LOGLEVEL TO EVENTS"
 .fi
 
 .SH "ASSIGNING LOGLEVEL TO EVENTS"


@@ -168,7 +177,7 @@ following construct:
        TRACEPOINT_LOGLEVEL(< [com_company_]project[_component] >,
                < event >, < loglevel_name >)
 
        TRACEPOINT_LOGLEVEL(< [com_company_]project[_component] >,
                < event >, < loglevel_name >)
 

- The first field is the provider name, the second field is the name of
+The first field is the provider name, the second field is the name of

 the tracepoint, and the third field is the loglevel name.  A
 TRACEPOINT_EVENT should be declared prior to the the TRACEPOINT_LOGLEVEL
 for a given tracepoint name. The TRACEPOINT_PROVIDER must be already
 the tracepoint, and the third field is the loglevel name.  A
 TRACEPOINT_EVENT should be declared prior to the the TRACEPOINT_LOGLEVEL
 for a given tracepoint name. The TRACEPOINT_PROVIDER must be already


@@ -176,54 +185,54 @@ declared before declaring a TRACEPOINT_LOGLEVEL.
 
 The loglevels go from 0 to 14. Higher numbers imply the most verbosity
 (higher event throughput expected.
 
 The loglevels go from 0 to 14. Higher numbers imply the most verbosity
 (higher event throughput expected.

-  
+

 Loglevels 0 through 6, and loglevel 14, match syslog(3) loglevels
 semantic. Loglevels 7 through 13 offer more fine-grained selection of
 debug information.
 Loglevels 0 through 6, and loglevel 14, match syslog(3) loglevels
 semantic. Loglevels 7 through 13 offer more fine-grained selection of
 debug information.

-  
+

    TRACE_EMERG           0
    system is unusable
    TRACE_EMERG           0
    system is unusable

-  
+

    TRACE_ALERT           1
    action must be taken immediately
    TRACE_ALERT           1
    action must be taken immediately

-  
+

    TRACE_CRIT            2
    critical conditions
    TRACE_CRIT            2
    critical conditions

-  
+

    TRACE_ERR             3
    error conditions
    TRACE_ERR             3
    error conditions

-  
+

    TRACE_WARNING         4
    warning conditions
    TRACE_WARNING         4
    warning conditions

-  
+

    TRACE_NOTICE          5
    normal, but significant, condition
    TRACE_NOTICE          5
    normal, but significant, condition

-  
+

    TRACE_INFO            6
    informational message
    TRACE_INFO            6
    informational message

-  
+

    TRACE_DEBUG_SYSTEM    7
    debug information with system-level scope (set of programs)
    TRACE_DEBUG_SYSTEM    7
    debug information with system-level scope (set of programs)

-  
+

    TRACE_DEBUG_PROGRAM   8
    debug information with program-level scope (set of processes)
    TRACE_DEBUG_PROGRAM   8
    debug information with program-level scope (set of processes)

-  
+

    TRACE_DEBUG_PROCESS   9
    debug information with process-level scope (set of modules)
    TRACE_DEBUG_PROCESS   9
    debug information with process-level scope (set of modules)

-  
+

    TRACE_DEBUG_MODULE    10
    debug information with module (executable/library) scope (set of
    units)
    TRACE_DEBUG_MODULE    10
    debug information with module (executable/library) scope (set of
    units)

-  
+

    TRACE_DEBUG_UNIT      11
    debug information with compilation unit scope (set of functions)
    TRACE_DEBUG_UNIT      11
    debug information with compilation unit scope (set of functions)

-  
+

    TRACE_DEBUG_FUNCTION  12
    debug information with function-level scope
    TRACE_DEBUG_FUNCTION  12
    debug information with function-level scope

-  
+

    TRACE_DEBUG_LINE      13
    debug information with line-level scope (TRACEPOINT_EVENT default)
    TRACE_DEBUG_LINE      13
    debug information with line-level scope (TRACEPOINT_EVENT default)

-  
+

    TRACE_DEBUG           14
    debug-level message (trace_printf default)
 
    TRACE_DEBUG           14
    debug-level message (trace_printf default)
 


@@ -249,7 +258,7 @@ lttng(1) through lttng-sessiond(8).
 Even though LTTng-UST supports tracepoint() call site duplicates having
 the same provider and event name, it is recommended to use a
 provider event name pair only once within the source code to help
 Even though LTTng-UST supports tracepoint() call site duplicates having
 the same provider and event name, it is recommended to use a
 provider event name pair only once within the source code to help

-mapping events back to their call sites when analyzing the trace.
+map events back to their call sites when analyzing the trace.

 .fi
 
 .SH "BUILDING/LINKING THE TRACEPOINT PROVIDER"
 .fi
 
 .SH "BUILDING/LINKING THE TRACEPOINT PROVIDER"


@@ -272,8 +281,10 @@ carefully:
       library with "\-llttng-ust".
     - Include the tracepoint provider header into all C files using
       the provider.
       library with "\-llttng-ust".
     - Include the tracepoint provider header into all C files using
       the provider.

-    - Example:
-      - tests/hello/  hello.c tp.c ust_tests_hello.h Makefile.example
+    - Examples:
+      - doc/examples/easy-ust/   sample.c sample_component_provider.h tp.c
+        Makefile
+      - doc/examples/hello-static-lib/   hello.c tp.c ust_test_hello.h Makefile

 
   2) Compile the Tracepoint Provider separately from the application,
      using dynamic linking:
 
   2) Compile the Tracepoint Provider separately from the application,
      using dynamic linking:


@@ -291,7 +302,7 @@ carefully:
       needed. Another way is to dlopen the tracepoint probe when needed
       by the application.
     - Example:
       needed. Another way is to dlopen the tracepoint probe when needed
       by the application.
     - Example:

-      - doc/examples/demo   demo.c  tp*.c ust_tests_demo*.h demo-trace
+      - doc/examples/demo   demo.c  tp*.c ust_tests_demo*.h demo-trace Makefile

 
   - Note about dlclose() usage: it is not safe to use dlclose on a
     provider shared object that is being actively used for tracing due
 
   - Note about dlclose() usage: it is not safe to use dlclose on a
     provider shared object that is being actively used for tracing due


@@ -376,7 +387,7 @@ lttng-sessiond(8)
 
 .PP
 Older lttng-ust libraries reject more recent, and incompatible, probe
 
 .PP
 Older lttng-ust libraries reject more recent, and incompatible, probe

-providers. Newer lttng-ust librairies accept older probe providers, even
+providers. Newer lttng-ust libraries accept older probe providers, even

 though some newer features might not be available with those providers.
 .PP
 
 though some newer features might not be available with those providers.
 .PP