-# Common Trace Format (CTF) Specification (v1.8.2)
+# Common Trace Format (CTF) Specification (v1.8.3)
**Author**: Mathieu Desnoyers, [EfficiOS Inc.](http://www.efficios.com/)
}
~~~
+An enumeration field can have an integral value for which the associated
+enumeration type does not map to a string.
+
### 4.2 Compound types
Compound are aggregation of type declarations. Compound types include
while (or after) writing the last event in the packet. The inclusive
range between these timestamps should include all event timestamps
assigned to events contained within the packet. The timestamp at the
- beginning of an event packet is guaranteed to be below or equal the
- timestamp at the end of that event packet. The timestamp at the end
- of an event packet is guaranteed to be below or equal the
- timestamps at the end of any following packet within the same stream.
- See [Clocks](#spec8) for more detail.
+ beginning of an event packet is guaranteed to be less than or equal
+ to the timestamp at the end of that event packet. The timestamp at
+ the beginning of an event packet is guaranteed to be greater than or
+ equal to timestamps at the beginning of any prior packet within the
+ same stream. The timestamp at the end of an event packet is
+ guaranteed to be less than or equal to the timestamps at the end of
+ any following packet within the same stream. See [Clocks](#spec8)
+ for more detail.
* **Events discarded count**. Snapshot of a per-stream
free-running counter, counting the number of events discarded that
were supposed to be written in the stream after the last event in
};
~~~
-If the magic number is not present, tools such as `file` will have no
-mean to discover the file type.
+If the magic number (`magic` field) is not present,
+tools such as `file` will have no mean to discover the file type.
-If the uuid is not present, no validation that the metadata actually
-corresponds to the stream is performed.
+If the `uuid` field is not present, no validation that the metadata
+actually corresponds to the stream is performed.
-If the stream_id packet header field is missing, the trace can only
+If the `stream_id` packet header field is missing, the trace can only
contain a single stream. Its `id` field can be left out, and its events
don't need to declare a `stream_id` field.
POSIX.1 Epoch, 1970-01-01 00:00:00 +0000 (UTC), to the zero of value
of the clock. The `offset_s` field is in seconds. The `offset` field is
in (1/freq) units. If any of the `offset_s` or `offset` field is not
-present, it is assigned the 0 value. The field `absolute` is `TRUE` if
-the clock is a global reference across different clock UUID
-(e.g. NTP time). Otherwise, `absolute` is `FALSE`, and the clock can
-be considered as synchronized only with other clocks that have the same
-UUID.
+present, it is assigned the 0 value. Both `offset_s` and `offset`
+fields are signed integers. The field `absolute` is `TRUE` if the clock
+is a global reference across different clock UUID (e.g. NTP time).
+Otherwise, `absolute` is `FALSE`, and the clock can be considered as
+synchronized only with other clocks that have the same UUID.
Secondly, a reference to this clock should be added within an integer
type:
};
~~~
-For a N-bit integer type referring to a clock, if the integer overflows
+Within the stream event context, event context, and event payload,
+fields of N-bit integer type referring to a clock, if the integer overflows
compared to the N low order bits of the clock prior value found in the
same stream, then it is assumed that one, and only one, overflow
occurred. It is therefore important that events encoding time on a small
In a packet context, clock field names ending with `_begin` and `_end`
have a special meaning: this refers to the timestamps at, respectively,
-the beginning and the end of each packet.
-
+the beginning and the end of each packet. Those are required to be
+complete representations of the clock value.
## A. Helper macros
projects / ctf.git / blobdiff