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[PATCH 33/35] qemu_co_rwlock_upgrade
From: |
Paolo Bonzini |
Subject: |
[PATCH 33/35] qemu_co_rwlock_upgrade |
Date: |
Thu, 10 Mar 2022 13:44:11 +0100 |
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
util/qemu-coroutine-lock.c | 30 +++++++++++++++++++++++-------
1 file changed, 23 insertions(+), 7 deletions(-)
diff --git a/util/qemu-coroutine-lock.c b/util/qemu-coroutine-lock.c
index c0541171d4..9674e8e3e3 100644
--- a/util/qemu-coroutine-lock.c
+++ b/util/qemu-coroutine-lock.c
@@ -552,23 +552,39 @@ CoroutineAction qemu_co_rwlock_wrlock(CoRwlock *lock)
return CO_INIT_FRAME(qemu_co_rwlock_wrlock, lock);
}
-#if 0
-void qemu_co_rwlock_upgrade(CoRwlock *lock)
+CO_DECLARE_FRAME(qemu_co_rwlock_upgrade, CoRwlock *lock, CoRwTicket my_ticket);
+static CoroutineAction co__qemu_co_rwlock_upgrade(void *_frame)
{
- qemu_co_mutex_lock(&lock->mutex);
+ struct FRAME__qemu_co_rwlock_upgrade *_f = _frame;
+ CO_ARG(lock);
+
+switch(_f->_step) {
+case 0:
+_f->_step = 1;
+ return qemu_co_mutex_lock(&lock->mutex);
+case 1:
assert(lock->owners > 0);
/* For fairness, wait if a writer is in line. */
if (lock->owners == 1 && QSIMPLEQ_EMPTY(&lock->tickets)) {
lock->owners = -1;
qemu_co_mutex_unlock(&lock->mutex);
} else {
- CoRwTicket my_ticket = { false, qemu_coroutine_self() };
+ _f->my_ticket = (CoRwTicket){ false, qemu_coroutine_self() };
lock->owners--;
- QSIMPLEQ_INSERT_TAIL(&lock->tickets, &my_ticket, next);
+ QSIMPLEQ_INSERT_TAIL(&lock->tickets, &_f->my_ticket, next);
qemu_co_rwlock_maybe_wake_one(lock);
- qemu_coroutine_yield();
+_f->_step = 2;
+ return qemu_coroutine_yield();
+case 2:
assert(lock->owners == -1);
}
+ break;
+}
+return stack_free(&_f->common);
+}
+
+CoroutineAction qemu_co_rwlock_upgrade(CoRwlock *lock)
+{
+ return CO_INIT_FRAME(qemu_co_rwlock_upgrade, lock);
}
-#endif
--
2.35.1
- [PATCH 29/35] qemu_co_rwlock_rdlock, (continued)
- [PATCH 29/35] qemu_co_rwlock_rdlock, Paolo Bonzini, 2022/03/10
- [PATCH 17/35] /basic/in_coroutine, Paolo Bonzini, 2022/03/10
- [PATCH 11/35] convert CoMutex to stackless coroutines, Paolo Bonzini, 2022/03/10
- [PATCH 22/35] /perf/function-call, Paolo Bonzini, 2022/03/10
- [PATCH 23/35] /perf/cost, Paolo Bonzini, 2022/03/10
- [PATCH 24/35] /basic/no-dangling-access, Paolo Bonzini, 2022/03/10
- [PATCH 28/35] qemu_co_rwlock_maybe_wake_one, Paolo Bonzini, 2022/03/10
- [PATCH 31/35] qemu_co_rwlock_downgrade, Paolo Bonzini, 2022/03/10
- [PATCH 34/35] /locking/co-rwlock/upgrade, Paolo Bonzini, 2022/03/10
- [PATCH 35/35] /locking/co-rwlock/downgrade, Paolo Bonzini, 2022/03/10
- [PATCH 33/35] qemu_co_rwlock_upgrade,
Paolo Bonzini <=
- Re: [PATCH experiment 00/35] stackless coroutine backend, Stefan Hajnoczi, 2022/03/10
- Re: [PATCH experiment 00/35] stackless coroutine backend, Paolo Bonzini, 2022/03/10
- Re: [PATCH experiment 00/35] stackless coroutine backend, Stefan Hajnoczi, 2022/03/11
- Re: [PATCH experiment 00/35] stackless coroutine backend, Paolo Bonzini, 2022/03/11
- Re: [PATCH experiment 00/35] stackless coroutine backend, Daniel P . Berrangé, 2022/03/11
- Re: [PATCH experiment 00/35] stackless coroutine backend, Paolo Bonzini, 2022/03/13
- Re: [PATCH experiment 00/35] stackless coroutine backend, Stefan Hajnoczi, 2022/03/14