Map realtime to clock_monotonic.
This maps a monotonic timestamp to the
corresponding real-time timestamp, which
can be used to match up the traces with
other logs that use real-time.
Also write clock_sync records first instead of at
the end, to avoid not being to write it due to the
buffer being full.
Bug: 23668823
Change-Id: I644aeea496197e194ec30f808f754e3e043d905f
diff --git a/cmds/atrace/atrace.cpp b/cmds/atrace/atrace.cpp
index 9def406..26c5b4a 100644
--- a/cmds/atrace/atrace.cpp
+++ b/cmds/atrace/atrace.cpp
@@ -264,9 +264,27 @@
static void writeClockSyncMarker()
{
char buffer[128];
+ int len = 0;
+ int fd = open(k_traceMarkerPath, O_WRONLY);
+ if (fd == -1) {
+ fprintf(stderr, "error opening %s: %s (%d)\n", k_traceMarkerPath,
+ strerror(errno), errno);
+ return;
+ }
float now_in_seconds = systemTime(CLOCK_MONOTONIC) / 1000000000.0f;
- snprintf(buffer, 128, "trace_event_clock_sync: parent_ts=%f\n", now_in_seconds);
- writeStr(k_traceMarkerPath, buffer);
+
+ len = snprintf(buffer, 128, "trace_event_clock_sync: parent_ts=%f\n", now_in_seconds);
+ if (write(fd, buffer, len) != len) {
+ fprintf(stderr, "error writing clock sync marker %s (%d)\n", strerror(errno), errno);
+ }
+
+ int64_t realtime_in_ms = systemTime(CLOCK_REALTIME) / 1000000;
+ len = snprintf(buffer, 128, "trace_event_clock_sync: realtime_ts=%" PRId64 "\n", realtime_in_ms);
+ if (write(fd, buffer, len) != len) {
+ fprintf(stderr, "error writing clock sync marker %s (%d)\n", strerror(errno), errno);
+ }
+
+ close(fd);
}
// Enable or disable a kernel option by writing a "1" or a "0" into a /sys
@@ -646,7 +664,6 @@
// Disable tracing in the kernel.
static void stopTrace()
{
- writeClockSyncMarker();
setTracingEnabled(false);
}
@@ -940,6 +957,7 @@
// another.
ok = clearTrace();
+ writeClockSyncMarker();
if (ok && !async) {
// Sleep to allow the trace to be captured.
struct timespec timeLeft;