diff options
author | Peter Maydell <peter.maydell@linaro.org> | 2021-03-31 16:38:49 +0100 |
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committer | Peter Maydell <peter.maydell@linaro.org> | 2021-03-31 16:38:49 +0100 |
commit | 1bd16067b652cce41a9214d0c62c73d5b45ab4b1 (patch) | |
tree | 594b7ebcd1e1e348f5a25f7670af6e7d8d8072ac /include | |
parent | 6ee55e1d10c25c2f6bf5ce2084ad2327e17affa5 (diff) | |
parent | b6489ac06695e257ea0a9841364577e247fdee30 (diff) |
Merge remote-tracking branch 'remotes/stefanha-gitlab/tags/block-pull-request' into staging
Pull request
A fix for VDI image files and more generally for CoRwlock.
# gpg: Signature made Wed 31 Mar 2021 10:50:39 BST
# gpg: using RSA key 8695A8BFD3F97CDAAC35775A9CA4ABB381AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>" [full]
# gpg: aka "Stefan Hajnoczi <stefanha@gmail.com>" [full]
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35 775A 9CA4 ABB3 81AB 73C8
* remotes/stefanha-gitlab/tags/block-pull-request:
test-coroutine: Add rwlock downgrade test
test-coroutine: Add rwlock upgrade test
coroutine-lock: Reimplement CoRwlock to fix downgrade bug
coroutine-lock: Store the coroutine in the CoWaitRecord only once
block/vdi: Don't assume that blocks are larger than VdiHeader
block/vdi: When writing new bmap entry fails, don't leak the buffer
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'include')
-rw-r--r-- | include/qemu/coroutine.h | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/include/qemu/coroutine.h b/include/qemu/coroutine.h index 84eab6e3bf..ce5b9c6851 100644 --- a/include/qemu/coroutine.h +++ b/include/qemu/coroutine.h @@ -237,11 +237,15 @@ bool qemu_co_enter_next_impl(CoQueue *queue, QemuLockable *lock); bool qemu_co_queue_empty(CoQueue *queue); +typedef struct CoRwTicket CoRwTicket; typedef struct CoRwlock { - int pending_writer; - int reader; CoMutex mutex; - CoQueue queue; + + /* Number of readers, or -1 if owned for writing. */ + int owners; + + /* Waiting coroutines. */ + QSIMPLEQ_HEAD(, CoRwTicket) tickets; } CoRwlock; /** @@ -260,10 +264,9 @@ void qemu_co_rwlock_rdlock(CoRwlock *lock); /** * Write Locks the CoRwlock from a reader. This is a bit more efficient than * @qemu_co_rwlock_unlock followed by a separate @qemu_co_rwlock_wrlock. - * However, if the lock cannot be upgraded immediately, control is transferred - * to the caller of the current coroutine. Also, @qemu_co_rwlock_upgrade - * only overrides CoRwlock fairness if there are no concurrent readers, so - * another writer might run while @qemu_co_rwlock_upgrade blocks. + * Note that if the lock cannot be upgraded immediately, control is transferred + * to the caller of the current coroutine; another writer might run while + * @qemu_co_rwlock_upgrade blocks. */ void qemu_co_rwlock_upgrade(CoRwlock *lock); |