diff mbox

[PULL,46/53] blockdev: add note that block_job_cb() must be thread-safe

Message ID 1415015456-25086-47-git-send-email-stefanha@redhat.com
State New
Headers show

Commit Message

Stefan Hajnoczi Nov. 3, 2014, 11:50 a.m. UTC 
This function is correct but we should document the constraint that
everything must be thread-safe.

Emitting QMP events and scheduling BHs are both thread-safe so nothing
needs to be done here.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 1413889440-32577-5-git-send-email-stefanha@redhat.com
---
 blockdev.c | 5 +++++
 1 file changed, 5 insertions(+)
diff mbox

Patch

diff --git a/blockdev.c b/blockdev.c
index 741df98..774051b 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1929,6 +1929,11 @@  out:
 
 static void block_job_cb(void *opaque, int ret)
 {
+    /* Note that this function may be executed from another AioContext besides
+     * the QEMU main loop.  If you need to access anything that assumes the
+     * QEMU global mutex, use a BH or introduce a mutex.
+     */
+
     BlockDriverState *bs = opaque;
     const char *msg = NULL;