Since commit 940f32c1a8 building the Tracy
library on Linux using a GCC version < 11 would result in compile errors
due to symbol redefinitions of __get_cpuid_max, __get_cpuid and
__get_cpuid_count.
This is because prior to GCC 11 the cpuid.h header file did not have any
include guards and thus including this header more than once would
produce the abovementioned errors.
To work around this issue, including cpuid.h has been wrapped into a
custom header file that itself uses include guards and thus shields
cpuid.h from being included multiple times.
Fixes#452
Previously a bitmap of buffers was repeatedly scanned to see which buffers
still contain data. This process was needlessly wasting cycles (seen as a
hotspot when profiled) and worse yet, the workload increased with the number
of CPU cores (=> buffers used) to handle.
The new implementation instead maintains a list of buffer indices that have to
be handled. This list does not contain empty buffers, so each loop iteration
performs some work, instead of just spinning in search for buffers to handle.
Initializing structures for callstack processing (building memory map of the
process, gathering kernel symbols, etc) takes some time, which in some cases
may be significant.
Callstack queries are now handled on a separate thread. In such setup it no
longer makes sense to block main thread execution with this lengthy init
process.
All the heavy initialization phase has been now moved to this separate
processing thread. Some initial callstack queries may now not produce
responses as promptly as before, but this is only because the main thread is
able to start working earlier.
Some parts of the initialization process may be critical to do in the main
thread, for example because the function responsible for gathering callstacks
must be loaded first. This is done still on the main thread, in a new function
InitCallstackCritical().
