6.1 Event Header
6.1.1 Type 1 - Few event IDs
6.1.2 Type 2 - Many event IDs
- 6.2 Event Context
+ 6.2 Stream Event Context and Event Context
6.3 Event Payload
6.3.1 Padding
6.3.2 Alignment
explicitly. Alignment values must be power of two. Compound types are
aligned as specified in their individual specification.
+The base offset used for field alignment is the start of the packet
+containing the field. For instance, a field aligned on 32-bit needs to
+be at an offset multiple of 32-bit from the start of the packet that
+contains it.
+
TSDL meta-data attribute representation of a specific alignment:
align = value; /* value in bits */
size = value; /* value in bits, no default */
align = value; /* value in bits */
/* based used for pretty-printing output, default: decimal. */
- base = decimal OR dec OR OR d OR i OR u OR 10 OR hexadecimal OR hex OR x OR X OR p OR 16
+ base = decimal OR dec OR d OR i OR u OR 10 OR hexadecimal OR hex OR x OR X OR p OR 16
OR octal OR oct OR o OR 8 OR binary OR b OR 2;
/* character encoding, default: none */
encoding = none or UTF8 or ASCII;
type (for compatibility with C99). The "int" type must be previously
declared. E.g.:
-typealias integer { size = 32; align = 32; signed = true } := int;
+typealias integer { size = 32; align = 32; signed = true; } := int;
enum {
...
The event packet header consists of two parts: the "event packet header"
is the same for all streams of a trace. The second part, the "event
packet context", is described on a per-stream basis. Both are described
-in the TSDL meta-data. The packets are aligned on architecture-page-sized
-addresses.
+in the TSDL meta-data.
Event packet header (all fields are optional, specified by TSDL meta-data):
while (or before) writing the first event and 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 Section 8. Clocks 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 overall structure of an event is:
-1 - Stream Packet Context (as specified by the stream meta-data)
- 2 - Event Header (as specified by the stream meta-data)
- 3 - Stream Event Context (as specified by the stream meta-data)
- 4 - Event Context (as specified by the event meta-data)
- 5 - Event Payload (as specified by the event meta-data)
+1 - Event Header (as specified by the stream meta-data)
+ 2 - Stream Event Context (as specified by the stream meta-data)
+ 3 - Event Context (as specified by the event meta-data)
+ 4 - Event Payload (as specified by the event meta-data)
This structure defines an implicit dynamic scoping, where variants
located in inner structures (those with a higher number in the listing
Types uintX_t represent an X-bit unsigned integer, as declared with
either:
- typealias integer { size = X; align = X; signed = false } := uintX_t;
+ typealias integer { size = X; align = X; signed = false; } := uintX_t;
or
- typealias integer { size = X; align = 1; signed = false } := uintX_t;
+ typealias integer { size = X; align = 1; signed = false; } := uintX_t;
+
+For more information about timestamp fields, see Section 8. Clocks.
6.1.1 Type 1 - Few event IDs
} align(16); /* or align(8) */
-6.2 Event Context
+6.2 Stream Event Context and Event Context
The event context contains information relative to the current event.
The choice and meaning of this information is specified by the TSDL
};
For a N-bit integer type referring to a clock, if the integer overflows
-compared to the N low order bits of the clock prior value, then it is
-assumed that one, and only one, overflow occurred. It is therefore
-important that events encoding time on a small number of bits happen
-frequently enough to detect when more than one N-bit overflow occurs.
+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
+number of bits happen frequently enough to detect when more than one
+N-bit overflow occurs.
In a packet context, clock field names ending with "_begin" and "_end"
have a special meaning: this refers to the time-stamps at, respectively,