wait() is redesigned with two pathes:
fast path: Use spinlock to wait for notify signal. If the
signal hasn't been received for some loops, go to slow path.
slow path: Use condition_variable's wait().
Improve monitor wrapper for better performance.
Fix some bugs left from name removing patch.
Change-Id: I893a8353121a25d11e37c8e631caf31cc1fc1f24
[ROCm/clr commit: f2ff56af9c]
Implement std::mutex based monitor that has much
simpler logics than legacy monitor.
Create DEBUG_CLR_USE_STDMUTEX_IN_AMD_MONITOR to
toggle them.
If DEBUG_CLR_USE_STDMUTEX_IN_AMD_MONITOR = false
(by default), use legacy monitor;
If DEBUG_CLR_USE_STDMUTEX_IN_AMD_MONITOR = true,
use std::mutex based monitor.
If no perf drop of stl::mutex based monitor,
legacy one will be removed later.
Change-Id: I1d21368ff462477d3238d71e4e2a1a7d6b9167ad
[ROCm/clr commit: 73c02041e1]
Use strncpy instead of strcpy to ensure the arrays will not be
overflowered. Only copy one less than size of char array to leave a
NUL character at the end even if the copy is truncated provided the
original object is zeroed memory.
Change-Id: I00f7679630cf28dcb9a51cb0aba2810a4f4c72b9
[ROCm/clr commit: e0448535a3]
Replace amd::Atomic with std::atomic. Remove make_atomic uses by
converting the variable to std::atomic and making sure the memory
order is relaxed when synchronizes-with is not needed.
Delete utils/atomic.hpp.
Change-Id: I0b36db8d604a8510ac6e36b32885fd16a1b8ccfa
[ROCm/clr commit: 5d4b6f74d3]
There is a small window where a thread can go to sleep in
Monitor::wait after releasing the lock but before another thread
notifies the monitor and updates the on-deck thread.
A simple approach to fix this problem is to wake-up the Monitor::wait
every 10 milliseconds and check if it is on-deck.
Change-Id: I4b9abda89d1fc653cdae2b4c84cdda01efde1cf2
[ROCm/clr commit: 5079410c94]
There is no synchronize with relationship between the monitor micro-
lock and the onDeck microlock, so it is possible for an onDeck.load to
move above a contendersList.store, or a contendersList.load to move
above an ondeck.store.
To fix this issue a full memory fence (mm_mfence on x86) is needed
after the last store in the contendersList and onDeck critical regions.
Change-Id: I5beb7dfe0d21010c5bf00cd65d59b9c7af58e919
[ROCm/clr commit: f10435a1ef]
Tao Sang
kjayapra-amd
agunashe
Tony Tye
Laurent Morichetti