Changeset db84bb2 for lib/format_linux_int.c

Timestamp:

02/28/17 13:49:40 (4 years ago)

Author:

Shane Alcock <salcock@…>

Branches:

4.0.1-hotfixes, cachetimestamps, develop, dpdk-ndag, etsilive, master, ndag_format, rc-4.0.1, rc-4.0.2, rc-4.0.3, rc-4.0.4, ringdecrementfix, ringperformance, ringtimestampfixes

Children:

6fb691b, 9d29d1e

Parents:

dea08f1

Message:

Ensure packet->order is always strictly incrementing

We cannot equate timestamp with packet->order, as some timestamp
methods are not strictly monotonic (ring: and int:).

Each format is now responsible for determining packet->order
during pread, so that the format can detect and correct such
inaccuracies.

More specifically, ring: and int: will cache the last reported
timestamp per thread and if time goes backwards, the order will
be set to last+1, otherwise the timestamp will be used.

DAG and DPDK still use the timestamp for ordering, since there
have been no issues with the timestamp ordering for these formats
(thus far!).

File:

• lib/format_linux_int.c (modified) (2 diffs)

lib/format_linux_int.c

@@ -286 +286 @@
         }
 
+
         /* Buffer contains all of our packet (including our custom header) so
          * we just need to get prepare_packet to set all our packet pointers
@@ -294 +295 @@
                 return -1;
         
+        if (hdr->timestamptype == TS_TIMEVAL) {
+                packet->order = (((uint64_t)hdr->tv.tv_sec) << 32)
+                            + ((((uint64_t)hdr->tv.tv_usec) << 32) /1000000);
+        } else if (hdr->timestamptype == TS_TIMESPEC) {
+                packet->order = (((uint64_t)hdr->ts.tv_sec) << 32)
+                            + ((((uint64_t)hdr->ts.tv_nsec) << 32) /1000000000);
+        } else {
+                packet->order = 0;
+        }
+
+        if (packet->order <= stream->last_timestamp) {
+                packet->order = stream->last_timestamp + 1;
+        }
+
+        stream->last_timestamp = packet->order;
+
         return hdr->wirelen+sizeof(*hdr);
 }