Commit 33b6c2ed authored by Fam Zheng's avatar Fam Zheng Committed by Paolo Bonzini
Browse files

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: default avatarFam Zheng <famz@redhat.com>
Message-Id: <1426496617-10702-5-git-send-email-famz@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 38e047b5

exec.c

+16 −7
Original line number Diff line number Diff line
@@ -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);

}