hw/9pfs/virtio-9p-coth.c

   1 /*
   2  * Virtio 9p backend
   3  *
   4  * Copyright IBM, Corp. 2010
   5  *
   6  * Authors:
   7  *  Harsh Prateek Bora <harsh@linux.vnet.ibm.com>
   8  *  Venkateswararao Jujjuri(JV) <jvrao@linux.vnet.ibm.com>
   9  *
  10  * This work is licensed under the terms of the GNU GPL, version 2.  See
  11  * the COPYING file in the top-level directory.
  12  *
  13  */
  14
  15 #include "qemu-char.h"
  16 #include "fsdev/qemu-fsdev.h"
  17 #include "qemu-thread.h"
  18 #include "qemu-coroutine.h"
  19 #include "virtio-9p-coth.h"
  20
  21 /* v9fs glib thread pool */
  22 static V9fsThPool v9fs_pool;
  23
  24 void co_run_in_worker_bh(void *opaque)
  25 {
  26     Coroutine *co = opaque;
  27     g_thread_pool_push(v9fs_pool.pool, co, NULL);
  28 }
  29
  30 static void v9fs_qemu_process_req_done(void *arg)
  31 {
  32     char byte;
  33     ssize_t len;
  34     Coroutine *co;
  35
  36     do {
  37         len = read(v9fs_pool.rfd, &byte, sizeof(byte));
  38     } while (len == -1 &&  errno == EINTR);
  39
  40     while ((co = g_async_queue_try_pop(v9fs_pool.completed)) != NULL) {
  41         qemu_coroutine_enter(co, NULL);
  42     }
  43 }
  44
  45 static void v9fs_thread_routine(gpointer data, gpointer user_data)
  46 {
  47     ssize_t len;
  48     char byte = 0;
  49     Coroutine *co = data;
  50
  51     qemu_coroutine_enter(co, NULL);
  52
  53     g_async_queue_push(v9fs_pool.completed, co);
  54     do {
  55         len = write(v9fs_pool.wfd, &byte, sizeof(byte));
  56     } while (len == -1 && errno == EINTR);
  57 }
  58
  59 int v9fs_init_worker_threads(void)
  60 {
  61     int ret = 0;
  62     int notifier_fds[2];
  63     V9fsThPool *p = &v9fs_pool;
  64     sigset_t set, oldset;
  65
  66     sigfillset(&set);
  67     /* Leave signal handling to the iothread.  */
  68     pthread_sigmask(SIG_SETMASK, &set, &oldset);
  69
  70     /* init thread system if not already initialized */
  71     if (!g_thread_get_initialized()) {
  72         g_thread_init(NULL);
  73     }
  74     if (qemu_pipe(notifier_fds) == -1) {
  75         ret = -1;
  76         goto err_out;
  77     }
  78     p->pool = g_thread_pool_new(v9fs_thread_routine, p, -1, FALSE, NULL);
  79     if (!p->pool) {
  80         ret = -1;
  81         goto err_out;
  82     }
  83     p->completed = g_async_queue_new();
  84     if (!p->completed) {
  85         /*
  86          * We are going to terminate.
  87          * So don't worry about cleanup
  88          */
  89         ret = -1;
  90         goto err_out;
  91     }
  92     p->rfd = notifier_fds[0];
  93     p->wfd = notifier_fds[1];
  94
  95     fcntl(p->rfd, F_SETFL, O_NONBLOCK);
  96     fcntl(p->wfd, F_SETFL, O_NONBLOCK);
  97
  98     qemu_set_fd_handler(p->rfd, v9fs_qemu_process_req_done, NULL, NULL);
  99 err_out:
 100     pthread_sigmask(SIG_SETMASK, &oldset, NULL);
 101     return ret;
 102 }