IndexedDB database operations are written such that they must execute
synchronously. For this reason, the add/put operation reads/writes its
Blobs to disk in a synchronous fashion. However, with the introduction
of SendStream-backed Blobs for large (>1 MiB) blobs whose contents are
streamed to the parent replacing nsStringInputStream-backed Blobs
(whose contents were sent up in a single IPC message that might exceed
the size limit and cause a crash), this has no longer been a safe
assumption. However, the problems weren't immediately obvious because
most pre-WASM Blobs are smaller than the 1MiB threshold and even when
they exceeded the size, their memory-backed contents could rapidly be
sent to the parent via IPC, making NS_BASE_STREAM_WOULD_BLOCK errors
rare/hard to reproduce. (rr and its enforced single-threading is a
good way to reproduce, however. Also, see the testing patch on the
bug that introduces artificial delays into SendStream.)
Included SpecialPowersObserver.jsm minor changes to "CreateFiles":
- appendRelativePath is used instead of appendPath because appendPath
only allows a single path component to be appended. In other words,
file creation is limited to files at the root of the profile
directory using appendPath, which is needlessly limiting.
- outStream is now closed even if no data is provided. This is
essential on windows where file deletion only occurs when all handles
are closed. Without this fix, "RemoveFiles" side-effect of deleting
the created files might not take effect until garbage collection runs
and collects the outStream.
The patch also moves some Sampler methods from platform.cpp to Sampler.cpp. Now
all Sampler methods are in Sampler.cpp except for a small number of
platform-specific ones, which are in platform-*.cpp.
--HG--
rename : tools/profiler/core/GeckoSampler.cpp => tools/profiler/core/Sampler.cpp
extra : rebase_source : a13862dccfcb1c78567cc9eb22e92b8410d2e544
There's no point having them as separate classes. This removes the need for
some virtual functions, too.
--HG--
extra : rebase_source : b2607ba2431ae043b6e015f4f435b0d660b02d71
They're defined separately for each platform, but the definitions are almost
identical and can be commoned up.
--HG--
extra : rebase_source : 67b7f88410db1951a20f03f6c156aa6b35a3ee20
It's a clumsy cross-platform abstraction. GetCurrentId() and tid_t are the only
genuinely cross-platform things in it, and the patch keeps those in place.
The remaining methods are not implemented on all platforms (none are
implemented on Linux) and the fields are all used on either Mac or Windows, but
not both. So the patch moves the relevant Thread method implementations and
fields into the existing SamplerThread classes. There is sufficiently little
overlap between the two SamplerThread classes that there is no point sharing a
base class between them. This avoids the need for virtual functions, and
simplifies thread naming on Mac.
The patch also changes some of the existing code to use Gecko style, e.g.
|mFoo| instead of |foo_| for class fields.
This variable is set in GeckoSampler's destructor and cleared in GeckoSampler's
destructor, which means it's just another handle to the GeckoSampler singleton,
which means it duplicates gSampler.
This patch replaces its uses with gSampler uses. This exposes various places
where GeckoSampler is being accessed off the main thread, which I have marked
with XXX comments.
--HG--
extra : rebase_source : 3c2d012b4d38d353022f384c31a528096a462711
There is a single GeckoSampler and it is currently only accessed on the main
thread, so it's silly to use TLS for it; a normal global variable is better.
This patch also adds main thread assertions to a number of the profiler_*()
functions. Even though bug 1330184 may get rid of some of them, right now they
are a useful as both a sanity check and documentation.
--HG--
extra : rebase_source : 7613eb3cc8089b31180365f6463c81f4556c7b66
This is a function which is called in Servo_StyleSet_FillKeyframesForName to
append a Gecko's Keyframe into nsTArray<Keyframe>.
Without this function we need to end up exposing ComputedTimingFunction class
and Maybe<> as FFI.
MozReview-Commit-ID: 2EpltR4rMVh
