From c1c69c1b13d64f7d892c8b661714fe388b1a6047 Mon Sep 17 00:00:00 2001
From: Eric Blake <eblake@redhat.com>
Date: Wed, 20 Aug 2014 16:40:09 +0200
Subject: [PATCH 2/7] blockjob: Add block_job_yield()

Message-id: <1408552814-23031-3-git-send-email-eblake@redhat.com>
Patchwork-id: 60644
O-Subject: [qemu-kvm-rhev 7.0.z PATCH 2/7] blockjob: Add block_job_yield()
Bugzilla: 1132806
RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>
RH-Acked-by: Fam Zheng <famz@redhat.com>
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

From: Fam Zheng <famz@redhat.com>

This will unset busy flag and put coroutine to sleep, can be used to
wait for QMP complete/cancel.

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
(cherry picked from commit dc71ce45ded4e872e25c2de32d5e7a71842b0985)
Signed-off-by: Eric Blake <eblake@redhat.com>

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 blockjob.c               |   14 ++++++++++++++
 include/block/blockjob.h |    8 ++++++++
 2 files changed, 22 insertions(+), 0 deletions(-)

diff --git a/blockjob.c b/blockjob.c
index a4430a0..1117ee7 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -206,6 +206,20 @@ void block_job_sleep_ns(BlockJob *job, QEMUClock *clock, int64_t ns)
     job->busy = true;
 }
 
+void block_job_yield(BlockJob *job)
+{
+    assert(job->busy);
+
+    /* Check cancellation *before* setting busy = false, too!  */
+    if (block_job_is_cancelled(job)) {
+        return;
+    }
+
+    job->busy = false;
+    qemu_coroutine_yield();
+    job->busy = true;
+}
+
 BlockJobInfo *block_job_query(BlockJob *job)
 {
     BlockJobInfo *info = g_new0(BlockJobInfo, 1);
diff --git a/include/block/blockjob.h b/include/block/blockjob.h
index 5a7d859..11f7c7e 100644
--- a/include/block/blockjob.h
+++ b/include/block/blockjob.h
@@ -144,6 +144,14 @@ void *block_job_create(const BlockJobDriver *driver, BlockDriverState *bs,
 void block_job_sleep_ns(BlockJob *job, QEMUClock *clock, int64_t ns);
 
 /**
+ * block_job_yield:
+ * @job: The job that calls the function.
+ *
+ * Yield the block job coroutine.
+ */
+void block_job_yield(BlockJob *job);
+
+/**
  * block_job_completed:
  * @job: The job being completed.
  * @ret: The status code.
-- 
1.7.1