Merge remote-tracking branch 'remotes/ericb/tags/pull-nbd-2019-10-22' into staging

nbd patches for 2019-10-22

- add ability for NBD client reconnect

# gpg: Signature made Wed 23 Oct 2019 02:53:08 BST
# gpg:                using RSA key 71C2CC22B1C4602927D2F3AAA7A16B4A2527436A
# gpg: Good signature from "Eric Blake <eblake@redhat.com>" [full]
# gpg:                 aka "Eric Blake (Free Software Programmer) <ebb9@byu.net>" [full]
# gpg:                 aka "[jpeg image of size 6874]" [full]
# Primary key fingerprint: 71C2 CC22 B1C4 6029 27D2  F3AA A7A1 6B4A 2527 436A

* remotes/ericb/tags/pull-nbd-2019-10-22:
  iotests: test nbd reconnect
  block/nbd: nbd reconnect
  qemu-coroutine-sleep: introduce qemu_co_sleep_wake

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 21 insertions, 2 deletions

diff --git a/include/qemu/coroutine.h b/include/qemu/coroutine.h
index 9801e7f5a4..8d55663062 100644
--- a/include/qemu/coroutine.h
+++ b/include/qemu/coroutine.h
@@ -273,10 +273,29 @@ void qemu_co_rwlock_wrlock(CoRwlock *lock);
  */
 void qemu_co_rwlock_unlock(CoRwlock *lock);
 
+typedef struct QemuCoSleepState QemuCoSleepState;
+
+/**
+ * Yield the coroutine for a given duration. During this yield, @sleep_state
+ * (if not NULL) is set to an opaque pointer, which may be used for
+ * qemu_co_sleep_wake(). Be careful, the pointer is set back to zero when the
+ * timer fires. Don't save the obtained value to other variables and don't call
+ * qemu_co_sleep_wake from another aio context.
+ */
+void coroutine_fn qemu_co_sleep_ns_wakeable(QEMUClockType type, int64_t ns,
+                                            QemuCoSleepState **sleep_state);
+static inline void coroutine_fn qemu_co_sleep_ns(QEMUClockType type, int64_t ns)
+{
+    qemu_co_sleep_ns_wakeable(type, ns, NULL);
+}
+
 /**
- * Yield the coroutine for a given duration
+ * Wake a coroutine if it is sleeping in qemu_co_sleep_ns. The timer will be
+ * deleted. @sleep_state must be the variable whose address was given to
+ * qemu_co_sleep_ns() and should be checked to be non-NULL before calling
+ * qemu_co_sleep_wake().
  */
-void coroutine_fn qemu_co_sleep_ns(QEMUClockType type, int64_t ns);
+void qemu_co_sleep_wake(QemuCoSleepState *sleep_state);
 
 /**
  * Yield until a file descriptor becomes readable