pool:
- the winpr implementation fallback was not used on older windows editions
- drop useless and conflicting TP_CALLBACK_ENVIRON_V3
- fix race conditions by using use proper one-time initialization
- on win32 WinPR tried to load several pool/callback_environment functions
from kernel32.dll but since these are defined as inline functions in the
windows headers, no windows edition has ever exported them in any dll.
- removed callback_environment.c and added corresponding static inline
function to pool.h
- fix segfault in TestPoolWork: CloseThreadpoolWork() must not be called
if there is a cleanup group associated with the work object since calling
CloseThreadpoolCleanupGroupMember() already releases the work object
sync:
- The windows headers incorrectly define InitializeCriticalEx support if
_WIN32_WINNT >= 0x0403 instead of >= 0x0600 (Vista)
- created a compatible define to deal with this issue
- Complete implementation including recursion support
- Added an intensive ctest (TestSynchCritical)
- Struct members are used exactly as Windows does it internally:
LockCount starts at -1, RecursionCount at 0
- Same performance optimizations as internally on Windows:
- Fast lock acquisition path using CAS -> SpinCount -> wait
- SpinCount automatically disabled on uniprocessor systems
- On Linux SpinCount is disabled because it provided no advantage over NPTL/futex in all tests
Support for CRITICAL_SECTION's DebugInfo is not yet included (but trivial to add).
- Improved/completed(almost) winpr's critical section implementation
- Replaced WaitForSingleObject locking with critical sections
Note:
WaitForSingleObject should _never_ be used for granular low-contention
locks as it _always_ enters the kernel.
Just replacing WaitForSingleObject locking in Bufferpool with
EnterCriticalSection boosts the multithreaded rfx decoder
performance by almost 400% on win32.
