exec: Notify cpu_register_map_client caller if the bounce buffer is available

The caller's workflow is like

    if (!address_space_map()) {
        ...
        cpu_register_map_client();
    }

If bounce buffer became available after address_space_map() but before
cpu_register_map_client(), the caller could miss it and has to wait for the
next bounce buffer notify, which may never happen in the worse case.

Just notify the list in cpu_register_map_client().

Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <1426496617-10702-5-git-send-email-famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Fam Zheng 2015-03-16 17:03:36 +08:00 committed by Paolo Bonzini
parent 38e047b50d
commit 33b6c2edf6

23
exec.c
View File

@ -2488,6 +2488,18 @@ QemuMutex map_client_list_lock;
static QLIST_HEAD(map_client_list, MapClient) map_client_list
= QLIST_HEAD_INITIALIZER(map_client_list);
static void cpu_unregister_map_client(void *_client);
static void cpu_notify_map_clients_locked(void)
{
MapClient *client;
while (!QLIST_EMPTY(&map_client_list)) {
client = QLIST_FIRST(&map_client_list);
client->callback(client->opaque);
cpu_unregister_map_client(client);
}
}
void *cpu_register_map_client(void *opaque, void (*callback)(void *opaque))
{
MapClient *client = g_malloc(sizeof(*client));
@ -2496,6 +2508,9 @@ void *cpu_register_map_client(void *opaque, void (*callback)(void *opaque))
client->opaque = opaque;
client->callback = callback;
QLIST_INSERT_HEAD(&map_client_list, client, link);
if (!atomic_read(&bounce.in_use)) {
cpu_notify_map_clients_locked();
}
qemu_mutex_unlock(&map_client_list_lock);
return client;
}
@ -2518,14 +2533,8 @@ static void cpu_unregister_map_client(void *_client)
static void cpu_notify_map_clients(void)
{
MapClient *client;
qemu_mutex_lock(&map_client_list_lock);
while (!QLIST_EMPTY(&map_client_list)) {
client = QLIST_FIRST(&map_client_list);
client->callback(client->opaque);
cpu_unregister_map_client(client);
}
cpu_notify_map_clients_locked();
qemu_mutex_unlock(&map_client_list_lock);
}