[Qemu-devel] [PATCH v2 1/4] blockjob: Add block_job_yield()

[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>
---
 blockjob.c               | 14 ++++++++++++++
 include/block/blockjob.h |  8 ++++++++
 2 files changed, 22 insertions(+)

diff --git a/blockjob.c b/blockjob.c
index 7d84ca1..a85146a 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -210,6 +210,20 @@ void block_job_sleep_ns(BlockJob *job, QEMUClockType type, 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 c0a7875..ac313ea 100644
--- a/include/block/blockjob.h
+++ b/include/block/blockjob.h
@@ -147,6 +147,14 @@ void *block_job_create(const BlockJobDriver *driver, BlockDriverState *bs,
 void block_job_sleep_ns(BlockJob *job, QEMUClockType type, 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.
-- 
2.0.0