Patchwork [v12,2/5] CoQueue: introduce qemu_co_queue_wait_insert_head

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Submitter Zhi Yong Wu
Date Nov. 3, 2011, 8:57 a.m.
Message ID <1320310649-7639-3-git-send-email-wuzhy@linux.vnet.ibm.com>
Download mbox | patch
Permalink /patch/123416/
State New
Headers show

Comments

Zhi Yong Wu - Nov. 3, 2011, 8:57 a.m.
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
---
 qemu-coroutine-lock.c |    8 ++++++++
 qemu-coroutine.h      |    6 ++++++
 2 files changed, 14 insertions(+), 0 deletions(-)

Patch

diff --git a/qemu-coroutine-lock.c b/qemu-coroutine-lock.c
index 6b58160..9549c07 100644
--- a/qemu-coroutine-lock.c
+++ b/qemu-coroutine-lock.c
@@ -61,6 +61,14 @@  void coroutine_fn qemu_co_queue_wait(CoQueue *queue)
     assert(qemu_in_coroutine());
 }
 
+void coroutine_fn qemu_co_queue_wait_insert_head(CoQueue *queue)
+{
+    Coroutine *self = qemu_coroutine_self();
+    QTAILQ_INSERT_HEAD(&queue->entries, self, co_queue_next);
+    qemu_coroutine_yield();
+    assert(qemu_in_coroutine());
+}
+
 bool qemu_co_queue_next(CoQueue *queue)
 {
     Coroutine *next;
diff --git a/qemu-coroutine.h b/qemu-coroutine.h
index b8fc4f4..8a2e5d2 100644
--- a/qemu-coroutine.h
+++ b/qemu-coroutine.h
@@ -118,6 +118,12 @@  void qemu_co_queue_init(CoQueue *queue);
 void coroutine_fn qemu_co_queue_wait(CoQueue *queue);
 
 /**
+ * Adds the current coroutine to the head of the CoQueue and transfers control to the
+ * caller of the coroutine.
+ */
+void coroutine_fn qemu_co_queue_wait_insert_head(CoQueue *queue);
+
+/**
  * Restarts the next coroutine in the CoQueue and removes it from the queue.
  *
  * Returns true if a coroutine was restarted, false if the queue is empty.