[lttng-dev] [Patch LTTng-ust 7/7] Update the LTTng documentation with CTF named enumerations
gbastien+lttng at versatic.net
Fri Jan 24 15:04:45 EST 2014
Signed-off-by: Geneviève Bastien <gbastien+lttng at versatic.net>
doc/man/lttng-ust.3 | 54 +++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 54 insertions(+)
diff --git a/doc/man/lttng-ust.3 b/doc/man/lttng-ust.3
index 7624e88..d474225 100644
@@ -158,6 +158,14 @@ TRACEPOINT_EVENT(
ctf_float(float, floatfield, floatarg)
ctf_float(double, doublefield, doublearg)
+ * ctf_enum: a field using a previously defined named enumeration
+ * args: (provider, enum name, field name, argument expression)
+ * The enumeration itself and its values must have been defined
+ * previously with the TRACEPOINT_ENUM macro, described below.
+ ctf_enum(sample_component, enumeration_name, enumfield, enumarg)
@@ -165,6 +173,52 @@ 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.
+The CTF specification also supports some named basic and compound types that
+can be defined inside a tracepoint provider and used as fields in the
+tracepoint. This shows how to specify them and what they can be used for:
+The enumeration is a mapping between an integer and a string. It can be used
+to have a more compact trace in cases where the possible values for a field are
+ * The provider name, as described in the TRACEPOINT_EVENT macro
+ * The name of this enumeration, that will be used when using this
+ * metadata type in tracepoint fields
+ * Integer type by which this enumeration will be represented.
+ * It can be: char, int, long or any variant on those
+ * TP_ENUM_VALUES describe the values of this enumeration and what they
+ * map to.
+ * Maps an integer with this string value. By default, enumerations
+ * start at 0 and increment 1 for each entry.
+ * Maps the string value to integers in the range 'start' to 'end'
+ * inclusively. If 'start' == 'end', then the string is mapped to
+ * a specific value.
+ ctf_enum_range(start, end, string_value)
.SH "ASSIGNING LOGLEVEL TO EVENTS"
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