[Qemu-devel] [PULL 01/18] io: store reference to thread information in the QIOTask struct

["Marc-André Lureau" <marcandre.lureau@redhat.com>]

From: Daniel P. Berrangé <berrange@redhat.com>

Currently the struct QIOTaskThreadData is only needed by the worker
thread, but a subsequent patch will need to access it from another
context.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20190123172740.32452-2-berrange@redhat.com>
[ Marc-André - applied Daniel fixup ]
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
---
 io/task.c | 64 +++++++++++++++++++++++++++++--------------------------
 1 file changed, 34 insertions(+), 30 deletions(-)

diff --git a/io/task.c b/io/task.c
index 2886a2c1bc..396866b10f 100644
--- a/io/task.c
+++ b/io/task.c
@@ -24,6 +24,14 @@
 #include "qemu/thread.h"
 #include "trace.h"
 
+struct QIOTaskThreadData {
+    QIOTaskWorker worker;
+    gpointer opaque;
+    GDestroyNotify destroy;
+    GMainContext *context;
+};
+
+
 struct QIOTask {
     Object *source;
     QIOTaskFunc func;
@@ -32,6 +40,7 @@ struct QIOTask {
     Error *err;
     gpointer result;
     GDestroyNotify destroyResult;
+    struct QIOTaskThreadData *thread;
 };
 
 
@@ -57,6 +66,18 @@ QIOTask *qio_task_new(Object *source,
 
 static void qio_task_free(QIOTask *task)
 {
+    if (task->thread) {
+        if (task->thread->destroy) {
+            task->thread->destroy(task->thread->opaque);
+        }
+
+        if (task->thread->context) {
+            g_main_context_unref(task->thread->context);
+        }
+
+        g_free(task->thread);
+    }
+
     if (task->destroy) {
         task->destroy(task->opaque);
     }
@@ -72,31 +93,12 @@ static void qio_task_free(QIOTask *task)
 }
 
 
-struct QIOTaskThreadData {
-    QIOTask *task;
-    QIOTaskWorker worker;
-    gpointer opaque;
-    GDestroyNotify destroy;
-    GMainContext *context;
-};
-
-
 static gboolean qio_task_thread_result(gpointer opaque)
 {
-    struct QIOTaskThreadData *data = opaque;
+    QIOTask *task = opaque;
 
-    trace_qio_task_thread_result(data->task);
-    qio_task_complete(data->task);
-
-    if (data->destroy) {
-        data->destroy(data->opaque);
-    }
-
-    if (data->context) {
-        g_main_context_unref(data->context);
-    }
-
-    g_free(data);
+    trace_qio_task_thread_result(task);
+    qio_task_complete(task);
 
     return FALSE;
 }
@@ -104,22 +106,23 @@ static gboolean qio_task_thread_result(gpointer opaque)
 
 static gpointer qio_task_thread_worker(gpointer opaque)
 {
-    struct QIOTaskThreadData *data = opaque;
+    QIOTask *task = opaque;
     GSource *idle;
 
-    trace_qio_task_thread_run(data->task);
-    data->worker(data->task, data->opaque);
+    trace_qio_task_thread_run(task);
+
+    task->thread->worker(task, task->thread->opaque);
 
     /* We're running in the background thread, and must only
      * ever report the task results in the main event loop
      * thread. So we schedule an idle callback to report
      * the worker results
      */
-    trace_qio_task_thread_exit(data->task);
+    trace_qio_task_thread_exit(task);
 
     idle = g_idle_source_new();
-    g_source_set_callback(idle, qio_task_thread_result, data, NULL);
-    g_source_attach(idle, data->context);
+    g_source_set_callback(idle, qio_task_thread_result, task, NULL);
+    g_source_attach(idle, task->thread->context);
 
     return NULL;
 }
@@ -138,17 +141,18 @@ void qio_task_run_in_thread(QIOTask *task,
         g_main_context_ref(context);
     }
 
-    data->task = task;
     data->worker = worker;
     data->opaque = opaque;
     data->destroy = destroy;
     data->context = context;
 
+    task->thread = data;
+
     trace_qio_task_thread_start(task, worker, opaque);
     qemu_thread_create(&thread,
                        "io-task-worker",
                        qio_task_thread_worker,
-                       data,
+                       task,
                        QEMU_THREAD_DETACHED);
 }
 
-- 
2.20.1.519.g8feddda32c