fix: possible preemption under FiberAtomicGuard #4692
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romange
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1. Fix FreeMemWithEvictionStep that could preempt under FiberAtomicGuard. This could happen during the return from the inner loop. Now, we break from the guard first and then preempt in a safe place. 2. Rename LocalBlockingCounter to LocalLatch because it's a variation of latch (see std::latch for example). 3. Rename PreUpdate to PreUpdateBlocking to emphasize it can block. 4. Fix mutations counting: consider either insertions or changing the existing entry. Before that we incremented this counter for misses as well. Signed-off-by: Roman Gershman <roman@dragonflydb.io>
kostasrim
approved these changes
Mar 4, 2025
| @@ -481,15 +481,15 @@ BorrowedInterpreter::~BorrowedInterpreter() { | |||
| ServerState::tlocal()->ReturnInterpreter(interpreter_); | |||
| } | |||
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| void LocalBlockingCounter::unlock() { | |||
| DCHECK(mutating_ > 0); | |||
| void LocalLatch::unlock() { | |||
adiholden
approved these changes
Mar 4, 2025
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This could happen during the return from the inner loop. Now, we break
from the guard first and then preempt in a safe place.
because it's a variation of latch (see std::latch for example).
Before that we incremented this counter for misses as well.