[virtio-9p] Add infrastructure to support glib threads and coroutines.

This patch is originally made by Arun Bharadwaj for glib support.
Later Harsh Prateek Bora added coroutines support.
This version implemented with suggestions from
Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>.

Signed-off-by: Arun R Bharadwaj <arun@linux.vnet.ibm.com>
Signed-off-by: Harsh Prateek Bora <harsh@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri "<jvrao@linux.vnet.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

1 files changed, 102 insertions, 0 deletions

diff --git a/hw/9pfs/virtio-9p-coth.c b/hw/9pfs/virtio-9p-coth.c
new file mode 100644
index 0000000000..ae05658632
--- /dev/null
+++ b/hw/9pfs/virtio-9p-coth.c
@@ -0,0 +1,102 @@
+/*
+ * Virtio 9p backend
+ *
+ * Copyright IBM, Corp. 2010
+ *
+ * Authors:
+ *  Harsh Prateek Bora <harsh@linux.vnet.ibm.com>
+ *  Venkateswararao Jujjuri(JV) <jvrao@linux.vnet.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-char.h"
+#include "fsdev/qemu-fsdev.h"
+#include "qemu-thread.h"
+#include "qemu-coroutine.h"
+#include "virtio-9p-coth.h"
+
+/* v9fs glib thread pool */
+static V9fsThPool v9fs_pool;
+
+void co_run_in_worker_bh(void *opaque)
+{
+    Coroutine *co = opaque;
+    g_thread_pool_push(v9fs_pool.pool, co, NULL);
+}
+
+static void v9fs_qemu_process_req_done(void *arg)
+{
+    char byte;
+    ssize_t len;
+    Coroutine *co;
+
+    do {
+        len = read(v9fs_pool.rfd, &byte, sizeof(byte));
+    } while (len == -1 &&  errno == EINTR);
+
+    while ((co = g_async_queue_try_pop(v9fs_pool.completed)) != NULL) {
+        qemu_coroutine_enter(co, NULL);
+    }
+}
+
+static void v9fs_thread_routine(gpointer data, gpointer user_data)
+{
+    ssize_t len;
+    char byte = 0;
+    Coroutine *co = data;
+
+    qemu_coroutine_enter(co, NULL);
+
+    g_async_queue_push(v9fs_pool.completed, co);
+    do {
+        len = write(v9fs_pool.wfd, &byte, sizeof(byte));
+    } while (len == -1 && errno == EINTR);
+}
+
+int v9fs_init_worker_threads(void)
+{
+    int ret = 0;
+    int notifier_fds[2];
+    V9fsThPool *p = &v9fs_pool;
+    sigset_t set, oldset;
+
+    sigfillset(&set);
+    /* Leave signal handling to the iothread.  */
+    pthread_sigmask(SIG_SETMASK, &set, &oldset);
+
+    /* init thread system if not already initialized */
+    if (!g_thread_get_initialized()) {
+        g_thread_init(NULL);
+    }
+    if (qemu_pipe(notifier_fds) == -1) {
+        ret = -1;
+        goto err_out;
+    }
+    p->pool = g_thread_pool_new(v9fs_thread_routine, p, -1, FALSE, NULL);
+    if (!p->pool) {
+        ret = -1;
+        goto err_out;
+    }
+    p->completed = g_async_queue_new();
+    if (!p->completed) {
+        /*
+         * We are going to terminate.
+         * So don't worry about cleanup
+         */
+        ret = -1;
+        goto err_out;
+    }
+    p->rfd = notifier_fds[0];
+    p->wfd = notifier_fds[1];
+
+    fcntl(p->rfd, F_SETFL, O_NONBLOCK);
+    fcntl(p->wfd, F_SETFL, O_NONBLOCK);
+
+    qemu_set_fd_handler(p->rfd, v9fs_qemu_process_req_done, NULL, NULL);
+err_out:
+    pthread_sigmask(SIG_SETMASK, &oldset, NULL);
+    return ret;
+}