aio: add a ThreadPool instance to AioContext
This patch adds a ThreadPool to AioContext. It's possible that some
AioContext instances will never use the ThreadPool, so defer creation
until aio_get_thread_pool().
The reason why AioContext should have the ThreadPool is because the
ThreadPool is bound to a AioContext instance where the work item's
callback function is invoked. It doesn't make sense to keep the
ThreadPool pointer anywhere other than AioContext. For example,
block/raw-posix.c can get its AioContext's ThreadPool and submit work.
Special note about headers: I used struct ThreadPool in aio.h because
there is a circular dependency if aio.h includes thread-pool.h.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/async.c b/async.c
index f2d47ba..90fe906 100644
--- a/async.c
+++ b/async.c
@@ -24,6 +24,7 @@
#include "qemu-common.h"
#include "block/aio.h"
+#include "block/thread-pool.h"
#include "qemu/main-loop.h"
/***********************************************************/
@@ -172,6 +173,7 @@
{
AioContext *ctx = (AioContext *) source;
+ thread_pool_free(ctx->thread_pool);
aio_set_event_notifier(ctx, &ctx->notifier, NULL, NULL);
event_notifier_cleanup(&ctx->notifier);
g_array_free(ctx->pollfds, TRUE);
@@ -190,6 +192,14 @@
return &ctx->source;
}
+ThreadPool *aio_get_thread_pool(AioContext *ctx)
+{
+ if (!ctx->thread_pool) {
+ ctx->thread_pool = thread_pool_new(ctx);
+ }
+ return ctx->thread_pool;
+}
+
void aio_notify(AioContext *ctx)
{
event_notifier_set(&ctx->notifier);
@@ -200,6 +210,7 @@
AioContext *ctx;
ctx = (AioContext *) g_source_new(&aio_source_funcs, sizeof(AioContext));
ctx->pollfds = g_array_new(FALSE, FALSE, sizeof(GPollFD));
+ ctx->thread_pool = NULL;
event_notifier_init(&ctx->notifier, false);
aio_set_event_notifier(ctx, &ctx->notifier,
(EventNotifierHandler *)
