Don't fail on "try" fns if failed to get spinLock

In SharedSpinLock: Only fail on "try" fns after spinLock was acquired
and condition is not met.
This commit is contained in:
Stephen Seo 2023-10-19 21:07:08 +09:00
parent 5c96151a23
commit 5665d4481a

View file

@ -40,7 +40,9 @@ UDPC::LockObj<false> UDPC::SharedSpinLock::spin_read_lock() {
} }
UDPC::LockObj<false> UDPC::SharedSpinLock::try_spin_read_lock() { UDPC::LockObj<false> UDPC::SharedSpinLock::try_spin_read_lock() {
bool expected = false; bool expected;
while (true) {
expected = false;
if (spinLock.compare_exchange_weak(expected, true, std::memory_order_acquire, std::memory_order_relaxed)) { if (spinLock.compare_exchange_weak(expected, true, std::memory_order_acquire, std::memory_order_relaxed)) {
if (!write) { if (!write) {
++read; ++read;
@ -48,6 +50,8 @@ UDPC::LockObj<false> UDPC::SharedSpinLock::try_spin_read_lock() {
return LockObj<false>(selfWeakPtr, Badge{}); return LockObj<false>(selfWeakPtr, Badge{});
} else { } else {
spinLock.store(false, std::memory_order_release); spinLock.store(false, std::memory_order_release);
break;
}
} }
} }
return LockObj<false>{}; return LockObj<false>{};
@ -87,7 +91,9 @@ UDPC::LockObj<true> UDPC::SharedSpinLock::spin_write_lock() {
} }
UDPC::LockObj<true> UDPC::SharedSpinLock::try_spin_write_lock() { UDPC::LockObj<true> UDPC::SharedSpinLock::try_spin_write_lock() {
bool expected = false; bool expected;
while (true) {
expected = false;
if (spinLock.compare_exchange_weak(expected, true, std::memory_order_acquire, std::memory_order_relaxed)) { if (spinLock.compare_exchange_weak(expected, true, std::memory_order_acquire, std::memory_order_relaxed)) {
if (!write && read == 0) { if (!write && read == 0) {
write = true; write = true;
@ -95,6 +101,8 @@ UDPC::LockObj<true> UDPC::SharedSpinLock::try_spin_write_lock() {
return LockObj<true>(selfWeakPtr, Badge{}); return LockObj<true>(selfWeakPtr, Badge{});
} else { } else {
spinLock.store(false, std::memory_order_release); spinLock.store(false, std::memory_order_release);
break;
}
} }
} }
return LockObj<true>{}; return LockObj<true>{};
@ -142,7 +150,9 @@ UDPC::LockObj<false> UDPC::SharedSpinLock::trade_write_for_read_lock(UDPC::LockO
UDPC::LockObj<false> UDPC::SharedSpinLock::try_trade_write_for_read_lock(UDPC::LockObj<true> &lockObj) { UDPC::LockObj<false> UDPC::SharedSpinLock::try_trade_write_for_read_lock(UDPC::LockObj<true> &lockObj) {
if (lockObj.isValid() && lockObj.badge.isValid) { if (lockObj.isValid() && lockObj.badge.isValid) {
bool expected = false; bool expected;
while (true) {
expected = false;
if (spinLock.compare_exchange_weak(expected, true, std::memory_order_acquire, std::memory_order_relaxed)) { if (spinLock.compare_exchange_weak(expected, true, std::memory_order_acquire, std::memory_order_relaxed)) {
if (write && read == 0) { if (write && read == 0) {
read = 1; read = 1;
@ -153,6 +163,8 @@ UDPC::LockObj<false> UDPC::SharedSpinLock::try_trade_write_for_read_lock(UDPC::L
return LockObj<false>(selfWeakPtr, Badge{}); return LockObj<false>(selfWeakPtr, Badge{});
} else { } else {
spinLock.store(false, std::memory_order_release); spinLock.store(false, std::memory_order_release);
break;
}
} }
} }
} }
@ -184,7 +196,9 @@ UDPC::LockObj<true> UDPC::SharedSpinLock::trade_read_for_write_lock(UDPC::LockOb
UDPC::LockObj<true> UDPC::SharedSpinLock::try_trade_read_for_write_lock(UDPC::LockObj<false> &lockObj) { UDPC::LockObj<true> UDPC::SharedSpinLock::try_trade_read_for_write_lock(UDPC::LockObj<false> &lockObj) {
if (lockObj.isValid() && lockObj.badge.isValid) { if (lockObj.isValid() && lockObj.badge.isValid) {
bool expected = false; bool expected;
while (true) {
expected = false;
if (spinLock.compare_exchange_weak(expected, true, std::memory_order_acquire, std::memory_order_relaxed)) { if (spinLock.compare_exchange_weak(expected, true, std::memory_order_acquire, std::memory_order_relaxed)) {
if (!write && read == 1) { if (!write && read == 1) {
read = 0; read = 0;
@ -195,6 +209,8 @@ UDPC::LockObj<true> UDPC::SharedSpinLock::try_trade_read_for_write_lock(UDPC::Lo
return LockObj<true>(selfWeakPtr, Badge{}); return LockObj<true>(selfWeakPtr, Badge{});
} else { } else {
spinLock.store(false, std::memory_order_release); spinLock.store(false, std::memory_order_release);
break;
}
} }
} }
} }