Since we are running python3 from an embeddable zip installation, a
C runtime environment is required, on Windows. We manipulate the PATH
to pick it up from the firefox installation.
Currently Mozharness creates a Python 2.7 virtualenvironment with all
the packages needed for Mozharness to run plus any applications that
need to execute within it.
For Talos, we now need a second Python virtual environment for
mitmproxy, however, this package is for Python 3 and not
for Python 2 (perhaps it could have worked).
In any case, having the ability to support create Python 3
virtual environments will be handy. Specially since the approach
of creating virtual environments is not by using 'virtualenv /path/to/venv'
but by calling the venv module like 'python3 -m venv /path/to/venv'.
The initial implementation only supports a list of modules.
The following iteration will support requirement files and other
parameters needed for pip and internal pypi hosts.
Originally authored by armenzg.
The movmskps SSE instruction only transfers 4 bits from the xmm
register. This work for Bool32x4 and Bool64x2 vectors, but it misses
lanes of the Bool16x8 and Bool8x16 types.
Use a pmovmskb SSE2 instruction instead which transfers 16 byte sign
bits from the xmm register. This lets us resolve even Bool8x16 lanes
correctly.
We know that the input vector is a boolean type, so each lane is known
to be either 0 or -1. There is no harm in checking too many bits of the
types with lanes wider than 8 bits. It won't affect the result.
This patch matches Chrome's behavior almost exactly, except it uses a slightly
different formula for the deltaY value that results in the same movement speed
as Chrome but doesn't drift over time.
Tested by confirming that trackpad pinch zoom now works on maps.google.com,
wego.here.com, and figma.com.
`beginGestureWithEvent` and `endGestureWithEvent` are not called for
applications that link against the macOS 10.11 or later SDK when we're running
on macOS 10.11 or later.
For compatibility with all supported macOS versions, we have to call
{begin,end}GestureWithEvent ourselves based on the event phase when we're using
the 10.11+ SDK.
See: https://developer.apple.com/reference/appkit/nsresponder/1526368-begingesturewithevent
NO_TLS used to be hardcoded on mac because up to 10.6, __thread was not
supported. Until recently, we still supported for 10.6, and it's not the
case anymore, so we could make mac builds use __thread.
Unfortunately, on OSX, __thread circles back calling malloc to allocate
storage on first access, so we have an infinite loop problem here.
Fortunately, pthread_keys don't have this property, so we can use that
instead. It doesn't appear to have significantly more overhead (and TLS
overhead is small anyways compared to the amount of work involved in
allocating memory with mozjemalloc).
At the same time, we uniformize the initialization sequence between
mozjemalloc and mozjemalloc+replace-malloc, such that we have less
occasions for surprises when riding the trains (replace-malloc being
nightly only), ensuring the zone registration happens at the end of
mozjemalloc's initialization.
The function, when passed `true`, creates a new arena with no attachment
in the global list of arenas, and assigns it to the current thread.
When passed `false`, it restores the default arena.
Some details are left out because they don't matter yet, as the sole
initial use of the API is going to invoke the function when stylo rayon
threads start up, which happens exactly once per thread, and at thread
exit time, which happens at shutdown, if ever.
This simplifies things, and leaves those details to followup(s):
- Arenas can't simply be killed when the function is called with `false`
again (or when the thread dies) because they may still contain valid
allocations that could have been passed to other threads. Those arenas
should be kept until they are empty.
- jemalloc_stats doesn't know about them and will under-report memory
usage.
- pre/post fork hooks don't know about them and will not force-unlock
their locks. In practice, until those arenas are used for something
else than the style system, this can't lead to the dead-locks that
these hooks help prevent because nothing should be touching pointers
allocated through them after fork.
