Allocate the stack with uncommited guard pages on either side, if
any faulting accesses to these occur then the call-ret SP value is
reset to the default and execution resumed.
Prevents invalidations being missed under the following circumstances:
Thread A JITs block A into the global codebuffer, adding the guest to host
mapping to its CodePages, thread A is then killed.
Thread B then performs SMC on block A. An exception will be triggered but
as CodePages was stored per-thread, and thread A is now killed when all
threads are iterated over by the frontend to perform invalidations it
will be missed.
The accumulator is introduced to handle the case where multiple threads
have the same code entry in their local caches but share the same codebuffer.
Consider a thread C in the above example that also has block A in its cache,
without an accumulator, when invalidating thread B the entrypoint of A is erased
from the shared guest to host map. So when C is invalidated, the local cache entry
for A is not removed since it was removed from CodePages when invalidating B.
Consider a page with two blocks in it, A and B. Block A performs SMC on B then A.
With the previous logic, the SMC write of B would unprotect the page and then
the inline SMC touching A would not be detected and a single-step would not be forced.
Rather than relying on wine-specific alphabetical behaviour, that
has since been changed. Rely on their addresses being sorted which
is more stable behaviour also present in Windows.
Avoid hardcoding the file name. Upstream Clang currently expects the aarch64 variant of
compiler-rt. Changing this to use arm64ec in the file name could be problematic in the future,
if the MinGW toolchain gains support for ARM64X. Querying Clang for the correct file name is
the most forward-compatible approach.
Instead of keeping the vlaue as a string array in the MetaLayer, convert
the value to its final type once.
Improves performance in some hotpaths that were doing config based
string conversion in a relatively high frequency.
This differs from the existing GPUVis backend in a number of ways:
* Tracy is optimized for minimal overhead and nanosecond-resolution profiling
* Tracy supports live tracing (in addition to capture-based operation)
* Tracy has a richer feature set and a more polished UI (notably, statistics and histograms are generated out-of-the-box)
* GPUVis supports tracing multiple processes, whereas Tracy is single-process only
To use this backend, one of the environment variables FEX_PROFILE_TARGET_NAME
or FEX_PROFILE_TARGET_PATH must be defined to select the application under
profile by name or by path suffix.
Additionally, FEX_PROFILE_WAIT_FOR_FORK=1 may be needed for games that fork on startup.
Ryan Houdek