// RUNS IN SIGHANDLER CONTEXT
void TableTicker::UnwinderTick(TickSample* sample)
{
if (!sample->threadProfile) {
// Platform doesn't support multithread, so use the main thread profile we created
sample->threadProfile = GetPrimaryThreadProfile();
}
ThreadProfile& currThreadProfile = *sample->threadProfile;
/* Get hold of an empty inter-thread buffer into which to park
the ProfileEntries for this sample. */
UnwinderThreadBuffer* utb = uwt__acquire_empty_buffer();
/* This could fail, if no buffers are currently available, in which
case we must give up right away. We cannot wait for a buffer to
become available, as that risks deadlock. */
if (!utb)
return;
/* Manufacture the ProfileEntries that we will give to the unwinder
thread, and park them in |utb|. */
// Marker(s) come before the sample
PseudoStack* stack = currThreadProfile.GetPseudoStack();
for (int i = 0; stack->getMarker(i) != NULL; i++) {
utb__addEntry( utb, ProfileEntry('m', stack->getMarker(i)) );
}
stack->mQueueClearMarker = true;
bool recordSample = true;
if (mJankOnly) {
// if we are on a different event we can discard any temporary samples
// we've kept around
if (sLastSampledEventGeneration != sCurrentEventGeneration) {
// XXX: we also probably want to add an entry to the profile to help
// distinguish which samples are part of the same event. That, or record
// the event generation in each sample
currThreadProfile.erase();
}
sLastSampledEventGeneration = sCurrentEventGeneration;
recordSample = false;
// only record the events when we have a we haven't seen a tracer
// event for 100ms
if (!sLastTracerEvent.IsNull()) {
TimeDuration delta = sample->timestamp - sLastTracerEvent;
if (delta.ToMilliseconds() > 100.0) {
recordSample = true;
}
}
}
// JRS 2012-Sept-27: this logic used to involve mUseStackWalk.
// That should be reinstated, but for the moment, use the
// settings in sUnwindMode and sUnwindInterval.
// Add a native-backtrace request, or add pseudo backtrace entries,
// or both.
switch (sUnwindMode) {
case UnwNATIVE: /* Native only */
// add a "do native stack trace now" hint. This will be actioned
// by the unwinder thread as it processes the entries in this
// sample.
utb__addEntry( utb, ProfileEntry('h'/*hint*/, 'N'/*native-trace*/) );
break;
case UnwPSEUDO: /* Pseudo only */
/* Add into |utb|, the pseudo backtrace entries */
genPseudoBacktraceEntries(utb, stack, sample);
break;
case UnwCOMBINED: /* Both Native and Pseudo */
utb__addEntry( utb, ProfileEntry('h'/*hint*/, 'N'/*native-trace*/) );
genPseudoBacktraceEntries(utb, stack, sample);
break;
case UnwINVALID:
default:
MOZ_CRASH();
}
if (recordSample) {
// add a "flush now" hint
utb__addEntry( utb, ProfileEntry('h'/*hint*/, 'F'/*flush*/) );
}
// Add any extras
if (!sLastTracerEvent.IsNull() && sample) {
TimeDuration delta = sample->timestamp - sLastTracerEvent;
utb__addEntry( utb, ProfileEntry('r', delta.ToMilliseconds()) );
}
if (sample) {
TimeDuration delta = sample->timestamp - sStartTime;
utb__addEntry( utb, ProfileEntry('t', delta.ToMilliseconds()) );
}
if (sLastFrameNumber != sFrameNumber) {
utb__addEntry( utb, ProfileEntry('f', sFrameNumber) );
sLastFrameNumber = sFrameNumber;
}
/* So now we have, in |utb|, the complete set of entries we want to
push into the circular buffer. This may also include a 'h' 'F'
entry, which is "flush now" hint, and/or a 'h' 'N' entry, which
is a "generate a native backtrace and add it to the buffer right
now" hint. Hand them off to the helper thread, together with
stack and register context needed to do a native unwind, if that
is currently enabled. */
/* If a native unwind has been requested, we'll start it off using
the context obtained from the signal handler, to avoid the
problem of having to unwind through the signal frame itself. */
/* On Linux and Android, the initial register state is in the
supplied sample->context. But on MacOS it's not, so we have to
fake it up here (sigh). */
if (sUnwindMode == UnwNATIVE || sUnwindMode == UnwCOMBINED) {
# if defined(SPS_PLAT_amd64_linux) || defined(SPS_PLAT_arm_android) \
|| defined(SPS_PLAT_x86_linux) || defined(SPS_PLAT_x86_android)
void* ucV = (void*)sample->context;
# elif defined(SPS_PLAT_amd64_darwin)
struct __darwin_mcontext64 mc;
memset(&mc, 0, sizeof(mc));
ucontext_t uc;
memset(&uc, 0, sizeof(uc));
uc.uc_mcontext = &mc;
mc.__ss.__rip = (uint64_t)sample->pc;
mc.__ss.__rsp = (uint64_t)sample->sp;
mc.__ss.__rbp = (uint64_t)sample->fp;
void* ucV = (void*)&uc;
# elif defined(SPS_PLAT_x86_darwin)
struct __darwin_mcontext32 mc;
memset(&mc, 0, sizeof(mc));
ucontext_t uc;
memset(&uc, 0, sizeof(uc));
uc.uc_mcontext = &mc;
mc.__ss.__eip = (uint32_t)sample->pc;
mc.__ss.__esp = (uint32_t)sample->sp;
mc.__ss.__ebp = (uint32_t)sample->fp;
void* ucV = (void*)&uc;
# elif defined(SPS_OS_windows)
/* Totally fake this up so it at least builds. No idea if we can
even ever get here on Windows. */
void* ucV = NULL;
# else
# error "Unsupported platform"
# endif
uwt__release_full_buffer(&currThreadProfile, utb, ucV);
} else {
uwt__release_full_buffer(&currThreadProfile, utb, NULL);
}
}
void TableTicker::InplaceTick(TickSample* sample)
{
ThreadProfile& currThreadProfile = *sample->threadProfile;
// Marker(s) come before the sample
PseudoStack* stack = currThreadProfile.GetPseudoStack();
for (int i = 0; stack->getMarker(i) != NULL; i++) {
addDynamicTag(currThreadProfile, 'm', stack->getMarker(i));
}
stack->mQueueClearMarker = true;
bool recordSample = true;
if (mJankOnly) {
// if we are on a different event we can discard any temporary samples
// we've kept around
if (sLastSampledEventGeneration != sCurrentEventGeneration) {
// XXX: we also probably want to add an entry to the profile to help
// distinguish which samples are part of the same event. That, or record
// the event generation in each sample
currThreadProfile.erase();
}
sLastSampledEventGeneration = sCurrentEventGeneration;
recordSample = false;
// only record the events when we have a we haven't seen a tracer event for 100ms
if (!sLastTracerEvent.IsNull()) {
TimeDuration delta = sample->timestamp - sLastTracerEvent;
if (delta.ToMilliseconds() > 100.0) {
recordSample = true;
}
}
}
#if defined(USE_BACKTRACE) || defined(USE_NS_STACKWALK)
if (mUseStackWalk) {
doNativeBacktrace(currThreadProfile, sample);
} else {
doSampleStackTrace(stack, currThreadProfile, mAddLeafAddresses ? sample : nullptr);
}
#else
doSampleStackTrace(stack, currThreadProfile, mAddLeafAddresses ? sample : nullptr);
#endif
if (recordSample)
currThreadProfile.flush();
if (!sLastTracerEvent.IsNull() && sample && currThreadProfile.IsMainThread()) {
TimeDuration delta = sample->timestamp - sLastTracerEvent;
currThreadProfile.addTag(ProfileEntry('r', delta.ToMilliseconds()));
}
if (sample) {
TimeDuration delta = sample->timestamp - sStartTime;
currThreadProfile.addTag(ProfileEntry('t', delta.ToMilliseconds()));
}
if (sLastFrameNumber != sFrameNumber) {
currThreadProfile.addTag(ProfileEntry('f', sFrameNumber));
sLastFrameNumber = sFrameNumber;
}
}
