diff options
author | Stefan Hajnoczi <stefanha@redhat.com> | 2014-03-03 11:30:03 +0100 |
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committer | Stefan Hajnoczi <stefanha@redhat.com> | 2014-03-13 14:42:21 +0100 |
commit | 2da61b671eb89fcaa306738f44eed472977d6587 (patch) | |
tree | 61673e48ab889a6ea113ff4d2be2d48d7108d1a1 /async.c | |
parent | 11f590b1a242492a0108da42f40f0e2b20f0a778 (diff) |
rfifolock: add recursive FIFO lock
QemuMutex does not guarantee fairness and cannot be acquired
recursively:
Fairness means each locker gets a turn and the scheduler cannot cause
starvation.
Recursive locking is useful for composition, it allows a sequence of
locking operations to be invoked atomically by acquiring the lock around
them.
This patch adds RFifoLock, a recursive lock that guarantees FIFO order.
Its first user is added in the next patch.
RFifoLock has one additional feature: it can be initialized with an
optional contention callback. The callback is invoked whenever a thread
must wait for the lock. For example, it can be used to poke the current
owner so that they release the lock soon.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'async.c')
0 files changed, 0 insertions, 0 deletions