Add offset_s to deal with offset overflow

[ctf.git] / common-trace-format-specification.txt

diff --git a/common-trace-format-specification.txt b/common-trace-format-specification.txt
index 90a669b849a4fb45f7b47e66723f64e1c3217f12..545fbc7ebaa98ffeb602e481fcf038935c476ade 100644 (file)
--- a/common-trace-format-specification.txt
+++ b/common-trace-format-specification.txt
@@ -1256,40 +1256,42 @@ Describing a clock and how it is used by streams is threefold: first,
 the clock and clock topology should be described in a "clock"
 description block, e.g.:
 
 the clock and clock topology should be described in a "clock"
 description block, e.g.:
 

-typealias integer { size = 32; align = 32; signed = true } := uint32_t;
-
-enum clocks : uint32_t {
-       cycle_counter,
-};
-
-clock[cycle_counter] {
+clock {
+       name = cycle_counter_sync;

        uuid = "62189bee-96dc-11e0-91a8-cfa3d89f3923";
        uuid = "62189bee-96dc-11e0-91a8-cfa3d89f3923";

-       description = "Local CPU cycle counter";
+       description = "Cycle counter synchronized across CPUs";

        freq = 1000000000;             /* frequency, in Hz */
        /* precision in seconds is: 1000 * (1/freq) */
        precision = 1000;
        freq = 1000000000;             /* frequency, in Hz */
        /* precision in seconds is: 1000 * (1/freq) */
        precision = 1000;

-       /* clock value offset from Epoch is: offset * (1/freq) */
-       offset = 1326476837897235420;
+       /*
+        * clock value offset from Epoch is:
+        * offset_s + (offset * (1/freq))
+        */
+       offset_s = 1326476837;
+       offset = 897235420;

 };
 
 };
 

-The optional field "uuid" is the unique identifier of the clock. It can
-be used to correlate different traces that use the same clock. An
-optional textual description string can be added with the "description"
-field. The "freq" field is the initial frequency of the clock, in Hz. If
-the "freq" field is not present, the frequency is assumed to be
-1000000000 (providing clock increment of 1 ns). The optional "precision"
-field details the uncertainty on the clock measurements, in (1/freq)
-units. The "offset" field indicates the offset from POSIX.1 Epoch,
-1970-01-01 00:00:00 +0000 (UTC), to the zero of value of the clock, in
-(1/freq) units. If the "offset" field is not present, it is assigned the
-0 value.
+The mandatory "name" field specifies the name of the clock identifier,
+which can later be used as a reference. The optional field "uuid" is the
+unique identifier of the clock. It can be used to correlate different
+traces that use the same clock. An optional textual description string
+can be added with the "description" field. The "freq" field is the
+initial frequency of the clock, in Hz. If the "freq" field is not
+present, the frequency is assumed to be 1000000000 (providing clock
+increment of 1 ns). The optional "precision" field details the
+uncertainty on the clock measurements, in (1/freq) units. The "offset_s"
+and "offset" fields indicate the offset from 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.

 
 Secondly, a reference to this clock should be added within an integer
 type:
 
 typealias integer {
        size = 64; align = 1; signed = false;
 
 Secondly, a reference to this clock should be added within an integer
 type:
 
 typealias integer {
        size = 64; align = 1; signed = false;

-       map = clock[cycle_counter].value;
+       map = clock.cycle_counter_sync.value;

 } := uint64_ccnt_t;
 
 Thirdly, stream declarations can reference the clock they use as a
 } := uint64_ccnt_t;
 
 Thirdly, stream declarations can reference the clock they use as a