[Qemu-devel] [PATCH 03/12] Add callback function to ThreadletWork structure.

[Arun R Bharadwaj <arun@linux.vnet.ibm.com>]

This patch adds the callback function to the ThreadletWork
structure and moves aio handler as a callback function.

Signed-off-by: Arun R Bharadwaj <arun@linux.vnet.ibm.com>
---
 posix-aio-compat.c |   89 +++++++++++++++++++++++++++++-----------------------
 1 files changed, 50 insertions(+), 39 deletions(-)

diff --git a/posix-aio-compat.c b/posix-aio-compat.c
index ddf42f5..4fa2c47 100644
--- a/posix-aio-compat.c
+++ b/posix-aio-compat.c
@@ -36,6 +36,7 @@ static QemuCond aiocb_completion;
 typedef struct ThreadletWork
 {
     QTAILQ_ENTRY(ThreadletWork) node;
+    void (*func)(struct ThreadletWork *work);
 } ThreadletWork;
 
 struct qemu_paiocb {
@@ -308,18 +309,14 @@ static ssize_t handle_aiocb_rw(struct qemu_paiocb *aiocb)
     return nbytes;
 }
 
-static void *aio_thread(void *unused)
+static void *threadlet_worker(void *data)
 {
-    pid_t pid;
-    ThreadletWork *work;
-
-    pid = getpid();
 
     while (1) {
-        struct qemu_paiocb *aiocb;
         ssize_t ret = 0;
         qemu_timeval tv;
         struct timespec ts;
+        ThreadletWork *work;
 
         qemu_gettimeofday(&tv);
         ts.tv_sec = tv.tv_sec + 10;
@@ -332,52 +329,64 @@ static void *aio_thread(void *unused)
             ret = cond_timedwait(&cond, &lock, &ts);
         }
 
-        if (QTAILQ_EMPTY(&request_list))
+        if (QTAILQ_EMPTY(&request_list)) {
+            idle_threads--;
+            cur_threads--;
+            mutex_unlock(&lock);
             break;
-
+        }
         work = QTAILQ_FIRST(&request_list);
         QTAILQ_REMOVE(&request_list, work, node);
-
-        aiocb = container_of(work, struct qemu_paiocb, work);
-
-        aiocb->active = 1;
         idle_threads--;
         mutex_unlock(&lock);
 
-        switch (aiocb->aio_type & QEMU_AIO_TYPE_MASK) {
-        case QEMU_AIO_READ:
-        case QEMU_AIO_WRITE:
-            ret = handle_aiocb_rw(aiocb);
-            break;
-        case QEMU_AIO_FLUSH:
-            ret = handle_aiocb_flush(aiocb);
-            break;
-        case QEMU_AIO_IOCTL:
-            ret = handle_aiocb_ioctl(aiocb);
-            break;
-        default:
-            fprintf(stderr, "invalid aio request (0x%x)\n", aiocb->aio_type);
-            ret = -EINVAL;
-            break;
-        }
-
+        work->func(work);
         mutex_lock(&lock);
         idle_threads++;
         mutex_unlock(&lock);
 
-        qemu_mutex_lock(&aiocb_mutex);
-        aiocb->ret = ret;
-        qemu_cond_broadcast(&aiocb_completion);
-        qemu_mutex_unlock(&aiocb_mutex);
+    }
+
+    return NULL;
+}
+
+static void handle_work(ThreadletWork *work)
+{
+    pid_t pid;
+    ssize_t ret = 0;
+    struct qemu_paiocb *aiocb;
 
-        if (kill(pid, aiocb->ev_signo)) die("kill failed");
+    pid = getpid();
+    qemu_mutex_lock(&aiocb_mutex);
+    aiocb = container_of(work, struct qemu_paiocb, work);
+    aiocb->active = 1;
+    qemu_mutex_unlock(&aiocb_mutex);
+
+    switch (aiocb->aio_type & QEMU_AIO_TYPE_MASK) {
+    case QEMU_AIO_READ:
+    case QEMU_AIO_WRITE:
+        ret = handle_aiocb_rw(aiocb);
+        break;
+    case QEMU_AIO_FLUSH:
+        ret = handle_aiocb_flush(aiocb);
+        break;
+    case QEMU_AIO_IOCTL:
+        ret = handle_aiocb_ioctl(aiocb);
+        break;
+    default:
+        fprintf(stderr, "invalid aio request (0x%x)\n", aiocb->aio_type);
+        ret = -EINVAL;
+        break;
     }
 
-    idle_threads--;
-    cur_threads--;
-    mutex_unlock(&lock);
+    qemu_mutex_lock(&aiocb_mutex);
+    aiocb->ret = ret;
+    qemu_cond_broadcast(&aiocb_completion);
+    qemu_mutex_unlock(&aiocb_mutex);
 
-    return NULL;
+    if (kill(pid, aiocb->ev_signo)) {
+        die("kill failed");
+    }
 }
 
 static void spawn_thread(void)
@@ -391,7 +400,7 @@ static void spawn_thread(void)
     if (sigfillset(&set)) die("sigfillset");
     if (sigprocmask(SIG_SETMASK, &set, &oldset)) die("sigprocmask");
 
-    thread_create(&thread_id, &attr, aio_thread, NULL);
+    thread_create(&thread_id, &attr, threadlet_worker, NULL);
 
     if (sigprocmask(SIG_SETMASK, &oldset, NULL)) die("sigprocmask restore");
 }
@@ -406,6 +415,8 @@ static void qemu_paio_submit(struct qemu_paiocb *aiocb)
     mutex_lock(&lock);
     if (idle_threads == 0 && cur_threads < max_threads)
         spawn_thread();
+
+    aiocb->work.func = handle_work;
     QTAILQ_INSERT_TAIL(&request_list, &aiocb->work, node);
     mutex_unlock(&lock);
     cond_signal(&cond);