--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/symbian-qemu-0.9.1-12/qemu-symbian-svp/aio.c	Fri Jul 31 15:01:17 2009 +0100
@@ -0,0 +1,195 @@
+/*
+ * QEMU aio implementation
+ *
+ * Copyright IBM, Corp. 2008
+ *
+ * Authors:
+ *  Anthony Liguori   <aliguori@us.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu-common.h"
+#include "block.h"
+#include "sys-queue.h"
+#include "qemu_socket.h"
+
+typedef struct AioHandler AioHandler;
+
+/* The list of registered AIO handlers */
+static LIST_HEAD(, AioHandler) aio_handlers;
+
+/* This is a simple lock used to protect the aio_handlers list.  Specifically,
+ * it's used to ensure that no callbacks are removed while we're walking and
+ * dispatching callbacks.
+ */
+static int walking_handlers;
+
+struct AioHandler
+{
+    int fd;
+    IOHandler *io_read;
+    IOHandler *io_write;
+    AioFlushHandler *io_flush;
+    int deleted;
+    void *opaque;
+    LIST_ENTRY(AioHandler) node;
+};
+
+static AioHandler *find_aio_handler(int fd)
+{
+    AioHandler *node;
+
+    LIST_FOREACH(node, &aio_handlers, node) {
+        if (node->fd == fd)
+            return node;
+    }
+
+    return NULL;
+}
+
+int qemu_aio_set_fd_handler(int fd,
+                            IOHandler *io_read,
+                            IOHandler *io_write,
+                            AioFlushHandler *io_flush,
+                            void *opaque)
+{
+    AioHandler *node;
+
+    node = find_aio_handler(fd);
+
+    /* Are we deleting the fd handler? */
+    if (!io_read && !io_write) {
+        if (node) {
+            /* If the lock is held, just mark the node as deleted */
+            if (walking_handlers)
+                node->deleted = 1;
+            else {
+                /* Otherwise, delete it for real.  We can't just mark it as
+                 * deleted because deleted nodes are only cleaned up after
+                 * releasing the walking_handlers lock.
+                 */
+                LIST_REMOVE(node, node);
+                qemu_free(node);
+            }
+        }
+    } else {
+        if (node == NULL) {
+            /* Alloc and insert if it's not already there */
+            node = qemu_mallocz(sizeof(AioHandler));
+            if (node == NULL)
+                return -ENOMEM;
+            node->fd = fd;
+            LIST_INSERT_HEAD(&aio_handlers, node, node);
+        }
+        /* Update handler with latest information */
+        node->io_read = io_read;
+        node->io_write = io_write;
+        node->io_flush = io_flush;
+        node->opaque = opaque;
+    }
+
+    qemu_set_fd_handler2(fd, NULL, io_read, io_write, opaque);
+
+    return 0;
+}
+
+void qemu_aio_flush(void)
+{
+    AioHandler *node;
+    int ret;
+
+    do {
+        ret = 0;
+
+        LIST_FOREACH(node, &aio_handlers, node) {
+            ret |= node->io_flush(node->opaque);
+        }
+
+        qemu_aio_wait();
+    } while (ret > 0);
+}
+
+void qemu_aio_wait(void)
+{
+    int ret;
+
+    if (qemu_bh_poll())
+        return;
+
+    do {
+        AioHandler *node;
+        fd_set rdfds, wrfds;
+        int max_fd = -1;
+
+        walking_handlers = 1;
+
+        FD_ZERO(&rdfds);
+        FD_ZERO(&wrfds);
+
+        /* fill fd sets */
+        LIST_FOREACH(node, &aio_handlers, node) {
+            /* If there aren't pending AIO operations, don't invoke callbacks.
+             * Otherwise, if there are no AIO requests, qemu_aio_wait() would
+             * wait indefinitely.
+             */
+            if (node->io_flush && node->io_flush(node->opaque) == 0)
+                continue;
+
+            if (!node->deleted && node->io_read) {
+                FD_SET(node->fd, &rdfds);
+                max_fd = MAX(max_fd, node->fd + 1);
+            }
+            if (!node->deleted && node->io_write) {
+                FD_SET(node->fd, &wrfds);
+                max_fd = MAX(max_fd, node->fd + 1);
+            }
+        }
+
+        walking_handlers = 0;
+
+        /* No AIO operations?  Get us out of here */
+        if (max_fd == -1)
+            break;
+
+        /* wait until next event */
+        ret = select(max_fd, &rdfds, &wrfds, NULL, NULL);
+        if (ret == -1 && errno == EINTR)
+            continue;
+
+        /* if we have any readable fds, dispatch event */
+        if (ret > 0) {
+            walking_handlers = 1;
+
+            /* we have to walk very carefully in case
+             * qemu_aio_set_fd_handler is called while we're walking */
+            node = LIST_FIRST(&aio_handlers);
+            while (node) {
+                AioHandler *tmp;
+
+                if (!node->deleted &&
+                    FD_ISSET(node->fd, &rdfds) &&
+                    node->io_read) {
+                    node->io_read(node->opaque);
+                }
+                if (!node->deleted &&
+                    FD_ISSET(node->fd, &wrfds) &&
+                    node->io_write) {
+                    node->io_write(node->opaque);
+                }
+
+                tmp = node;
+                node = LIST_NEXT(node, node);
+
+                if (tmp->deleted) {
+                    LIST_REMOVE(tmp, node);
+                    qemu_free(tmp);
+                }
+            }
+
+            walking_handlers = 0;
+        }
+    } while (ret == 0);
+}