3. Event stream
An event stream is divided in contiguous event packets of variable size. These
-subdivisions have a variable size. An event packet can contain a certain amount
-of padding at the end. The rationale for the event stream design choices is
-explained in Appendix B. Stream Header Rationale.
-
-An event stream is divided in contiguous event packets of variable size. These
-subdivisions have a variable size. An event packet can contain a certain amount
-of padding at the end. The stream header is repeated at the beginning of each
-event packet.
+subdivisions have a variable size. An event packet can contain a certain
+amount of padding at the end. The stream header is repeated at the
+beginning of each event packet. The rationale for the event stream
+design choices is explained in Appendix B. Stream Header Rationale.
The event stream header will therefore be referred to as the "event packet
header" throughout the rest of this document.
the newly defined type name (for typedef), or the field name (for
declarations located within structure and variants). Array and sequence,
declared with square brackets ("[" "]"), are part of the declarator,
-similarly to C99.
+similarly to C99. The enumeration type specifier and variant tag name
+(both specified with "<" ">") are part of the type specifier.
A definition associates a type to a location in the event structure
-hierarchy (see Section 6).
+hierarchy (see Section 6). This association is denoted by ":=", as shown
+in Section 7.3.
7.2 Metadata Scopes
scope must be specified when a variant refers to a tag field located in
a different dynamic scope.
+The information available in the dynamic scopes can be thought of as the
+current tracing context. At trace production, information about the
+current context is saved into the specified scope field levels. At trace
+consumption, for each event, the current trace context is therefore
+readable by accessing the upper dynamic scopes.
+
-7.2 Metadata Examples
+7.3 Metadata Examples
The grammar representing the CTF metadata is presented in
Appendix C. CTF Metadata Grammar. This section presents a rather ligher
assignment-operator:
=
+type-assignment-operator:
+ :=
+
constant-expression:
unary-expression
2.2) Declarations:
declaration:
- declaration-specifiers ;
- declaration-specifiers storage-class-specifier declaration-specifiers declarator-list ;
+ declaration-specifiers declarator-list-opt ;
ctf-specifier ;
declaration-specifiers:
+ storage-class-specifier declaration-specifiers-opt
type-specifier declaration-specifiers-opt
type-qualifier declaration-specifiers-opt
unsigned
_Bool
_Complex
+ _Imaginary
struct-specifier
variant-specifier
enum-specifier