-Common Trace Format (CTF) Specification (v1.8.1)
+Common Trace Format (CTF) Specification (v1.8.2)
Mathieu Desnoyers, EfficiOS Inc.
specified between "< >" after the "variant" keyword for unnamed
variants, and after "variant name" for named variants.
-The alignment of the variant is the alignment of the type as selected by the tag
-value for the specific instance of the variant. The alignment of the type
-containing the variant is independent of the variant alignment. The size of the
-variant is the size as selected by the tag value for the specific instance of
-the variant.
+The alignment of the variant is the alignment of the type as selected by
+the tag value for the specific instance of the variant. The size of the
+variant is the size as selected by the tag value for the specific
+instance of the variant.
+
+The alignment of the type containing the variant is independent of the
+variant alignment. For instance, if a structure contains two fields, a
+32-bit integer, aligned on 32 bits, and a variant, which contains two
+choices: either a 32-bit field, aligned on 32 bits, or a 64-bit field,
+aligned on 64 bits, the alignment of the outmost structure will be
+32-bit (the alignment of its largest field, disregarding the alignment
+of the variant). The alignment of the variant will depend on the
+selector: if the variant's 32-bit field is selected, its alignment will
+be 32-bit, or 64-bit otherwise. It is important to note that variants
+are specifically tailored for compactness in a stream. Therefore, the
+relative offsets of compound type fields can vary depending on
+the offset at which the compound type starts if it contains a variant
+that itself contains a type with alignment larger than the largest field
+contained within the compound type. This is caused by the fact that the
+compound type may contain the enumeration that select the variant's
+choice, and therefore the alignment to be applied to the compound type
+cannot be determined before encountering the enumeration.
Each variant type selector possess a field name, which is a unique
identifier within the variant. The identifier is not allowed to use any
uint32_t stream_packet_count;
uint32_t events_discarded;
uint32_t cpu_id;
- uint32_t/uint16_t content_size;
- uint32_t/uint16_t packet_size;
+ uint64_t/uint32_t/uint16_t content_size;
+ uint64_t/uint32_t/uint16_t packet_size;
uint8_t compression_scheme;
uint8_t encryption_scheme;
uint8_t checksum_scheme;
id = value; /* Numeric identifier within the stream */
stream_id = stream_id;
loglevel = value;
+ model.emf.uri = "string";
context := struct {
...
};
};
};
+callsite {
+ name = "event_name";
+ func = "func_name";
+ file = "myfile.c";
+ line = 39;
+ ip = 0x40096c;
+};
+
/* More detail on types in section 4. Types */
/*
keyword: is one of
align
+callsite
const
char
clock
stream { ctf-assignment-expression-list-opt }
env { ctf-assignment-expression-list-opt }
trace { ctf-assignment-expression-list-opt }
+ callsite { ctf-assignment-expression-list-opt }
typealias declaration-specifiers abstract-declarator-list type-assignment-operator declaration-specifiers abstract-declarator-list
typealias declaration-specifiers abstract-declarator-list type-assignment-operator declarator-list