Bug 1357829 added a third kind of sample, in addition to the existing
"periodic" and "synchronous" samples. This patch cleans things up around that
change. In particular, it cleans up TickSample, which is a mess of semi-related
things.
The patch does the following.
- It removes everything from TickSample except the register values and renames
TickSample as Registers. Almost all the removed stuff is available in
ThreadInfo anyway, and the patch adds a ThreadInfo argument to various
functions. (Doing it this way wasn't possible until recently because a
ThreadInfo wasn't available in profiler_get_backtrace() until recently.)
One non-obvious consequence: in synchronous samples we used to use a value of
0 for the stackTop. Because synchronous samples now use ThreadInfo directly,
they are able to use the proper stack top value from ThreadInfo::mStackTop.
This will presumably only improve the quality of the stack traces.
- It splits Tick() in two and renames the halves DoPeriodicSample() and
DoSyncSample().
- It reorders arguments in some functions so that ProfileBuffer (the output) is
always last, and inputs are passed in roughly the order they are obtained.
- It adds a comment at the top of platform.cpp explaining the three kinds of
sample.
- It renames a couple of other things.
--HG--
extra : rebase_source : 61f4bf75ff5a2c331e8e39dcbb2bf3563606ebb0
Occasionally marionette tries to get the accessibility element while the
elements are still being built. This causes getAccessibleFor to return
null when there actually should be an accessibility element available.
Instead, if the document is busy, wait until it finishes to get the
accessibility element.
This was causing a crash on nightly. The browser would try to collect only a
native stack, and then attempt to dereference the null pointer for the
pseudostack. I think this didn't happen on infra as it only occurs when the user
has hung a sufficient number of times.
MozReview-Commit-ID: 6RSW2llKBjT
These are no longer needed as we have the data we were looking for.
MozReview-Commit-ID: 3WlPng3mAwt
--HG--
extra : rebase_source : 73a390f85f5c0894d53a5e8ee10b19278af58282
extra : amend_source : 6a2b9ff4191715d0ac6e43f92af1e64c59123ac6
The InvalidCookieDomainError type is missing a status lookup key in
testing/marionette/error.js. This adds "invalid cookie domain" as a
reverse lookup for the type.
MozReview-Commit-ID: 69hkk28axtt
--HG--
extra : rebase_source : 19628df79d89f7fbaf821cc1847e1be241ff56af
This patch uses the profiler_suspend_sample_thread method which was added in
part 1.
With this patch, we no longer manually run code to pause the target thread,
instead using the profiler's provided code to do so. In addition, we no longer
manually walk the stack to collect native stack frames, instead relying on the
profiler's cross-platform stack walking logic.
This helps remove some of the code from ThreadStackHelper which was redundant
with the profiler. Much of the pseudostack code in ThreadStackHelper is also
redundant, and should hopefully be eliminated in a follow-up.
MozReview-Commit-ID: 4RjLHt6inH9
This patch performs a refactoring to the internals of the profiler in order to
expose a function, profiler_suspend_and_sample_thread, which can be called from a
background thread to suspend, sample the native stack, and then resume the
target passed-in thread.
The interface was designed to expose as few internals of the profiler as
possible, exposing only a single callback which accepts the list of program
counters and stack pointers collected during the backtrace.
A method `profiler_current_thread_id` was also added to get the thread_id of the
current thread, which can then be passed by another thread into
profiler_suspend_sample_thread to sample the stack of that thread.
This is implemented in two parts:
1) Splitting SamplerThread into two classes: Sampler, and SamplerThread.
Sampler was created to extract the core logic from SamplerThread which manages
unix signals on android and linux, as well as suspends the target thread on all
platforms. SamplerThread was then modified to subclass this type, adding the
extra methods and fields required for the creation and management of the actual
Sampler Thread.
Some work was done to ensure that the methods on Sampler would not require
ActivePS to be present, as we intend to sample threads when the profiler is not
active for the Background Hang Reporter.
2) Moving the Tick() logic into the TickController interface.
A TickController interface was added to platform which has 2 methods: Tick and
Backtrace. The Tick method replaces the previous Tick() static method, allowing
it to be overridden by a different consumer of SuspendAndSampleAndResumeThread,
while the Backtrace() method replaces the previous MergeStacksIntoProfile
method, allowing it to be overridden by different consumers of
DoNativeBacktrace.
This interface object is then used to wrap implementation specific data, such as
the ProfilerBuffer, and is threaded through the SuspendAndSampleAndResumeThread
and DoNativeBacktrace methods.
This change added 2 virtual calls to the SamplerThread's critical section, which
I believe should be a small enough overhead that it will not affect profiling
performance. These virtual calls could be avoided using templating, but I
decided that doing so would be unnecessary.
MozReview-Commit-ID: AT48xb2asgV