Re: [Qemu-devel] [PATCH 1/2] extract I/O handler lists to iohandler.c

[Roy Tam <roytam@gmail.com>]

Hi,

2011/3/10 Paolo Bonzini <pbonzini@redhat.com>:
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>        I had this patch queued for a while; only today I noticed the
>        very similar one in virtagent.
>
>  Makefile.objs |    2 +-
>  iohandler.c   |  129 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  qemu-common.h |    3 +
>  vl.c          |  106 ++--------------------------------------------
>  4 files changed, 138 insertions(+), 102 deletions(-)
>  create mode 100644 iohandler.c
>
> diff --git a/Makefile.objs b/Makefile.objs
> index 9e98a66..f282507 100644
> --- a/Makefile.objs
> +++ b/Makefile.objs
> @@ -98,7 +98,7 @@ common-obj-y += buffered_file.o migration.o migration-tcp.o qemu-sockets.o
>  common-obj-y += qemu-char.o savevm.o #aio.o
>  common-obj-y += msmouse.o ps2.o
>  common-obj-y += qdev.o qdev-properties.o
> -common-obj-y += block-migration.o
> +common-obj-y += block-migration.o iohandler.o
>  common-obj-y += pflib.o
>  common-obj-y += bitmap.o bitops.o
>
> diff --git a/iohandler.c b/iohandler.c
> new file mode 100644
> index 0000000..2e30fe3
> --- /dev/null
> +++ b/iohandler.c
> @@ -0,0 +1,129 @@
> +/*
> + * QEMU System Emulator - managing I/O handler
> + *
> + * Copyright (c) 2003-2008 Fabrice Bellard
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a copy
> + * of this software and associated documentation files (the "Software"), to deal
> + * in the Software without restriction, including without limitation the rights
> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
> + * copies of the Software, and to permit persons to whom the Software is
> + * furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
> + * THE SOFTWARE.
> + */
> +
> +#include "config-host.h"
> +#include "qemu-common.h"
> +#include "qemu-char.h"
> +#include "qemu-queue.h"
> +
> +typedef struct IOHandlerRecord {
> +    int fd;
> +    IOCanReadHandler *fd_read_poll;
> +    IOHandler *fd_read;
> +    IOHandler *fd_write;
> +    int deleted;
> +    void *opaque;
> +    QLIST_ENTRY(IOHandlerRecord) next;
> +} IOHandlerRecord;
> +
> +static QLIST_HEAD(, IOHandlerRecord) io_handlers =
> +    QLIST_HEAD_INITIALIZER(io_handlers);
> +
> +
> +/* XXX: fd_read_poll should be suppressed, but an API change is
> +   necessary in the character devices to suppress fd_can_read(). */
> +int qemu_set_fd_handler2(int fd,
> +                         IOCanReadHandler *fd_read_poll,
> +                         IOHandler *fd_read,
> +                         IOHandler *fd_write,
> +                         void *opaque)
> +{
> +    IOHandlerRecord *ioh;
> +
> +    if (!fd_read && !fd_write) {
> +        QLIST_FOREACH(ioh, &io_handlers, next) {
> +            if (ioh->fd == fd) {
> +                ioh->deleted = 1;
> +                break;
> +            }
> +        }
> +    } else {
> +        QLIST_FOREACH(ioh, &io_handlers, next) {
> +            if (ioh->fd == fd)
> +                goto found;
> +        }
> +        ioh = qemu_mallocz(sizeof(IOHandlerRecord));
> +        QLIST_INSERT_HEAD(&io_handlers, ioh, next);
> +    found:
> +        ioh->fd = fd;
> +        ioh->fd_read_poll = fd_read_poll;
> +        ioh->fd_read = fd_read;
> +        ioh->fd_write = fd_write;
> +        ioh->opaque = opaque;
> +        ioh->deleted = 0;
> +    }
> +    return 0;
> +}
> +
> +int qemu_set_fd_handler(int fd,
> +                        IOHandler *fd_read,
> +                        IOHandler *fd_write,
> +                        void *opaque)
> +{
> +    return qemu_set_fd_handler2(fd, NULL, fd_read, fd_write, opaque);
> +}
> +
> +void qemu_iohandler_fill(int *pnfds, fd_set *readfds, fd_set *writefds, fd_set *xfds)
> +{
> +    IOHandlerRecord *ioh;
> +
> +    QLIST_FOREACH(ioh, &io_handlers, next) {
> +        if (ioh->deleted)
> +            continue;
> +        if (ioh->fd_read &&
> +            (!ioh->fd_read_poll ||
> +             ioh->fd_read_poll(ioh->opaque) != 0)) {
> +            FD_SET(ioh->fd, readfds);
> +            if (ioh->fd > *pnfds)
> +                *pnfds = ioh->fd;
> +        }
> +        if (ioh->fd_write) {
> +            FD_SET(ioh->fd, writefds);
> +            if (ioh->fd > *pnfds)
> +                *pnfds = ioh->fd;
> +        }
> +    }
> +}
> +
> +void qemu_iohandler_poll(fd_set *readfds, fd_set *writefds, fd_set *xfds, int ret)
> +{
> +    if (ret > 0) {
> +        IOHandlerRecord *pioh, *ioh;
> +
> +        QLIST_FOREACH_SAFE(ioh, &io_handlers, next, pioh) {
> +            if (!ioh->deleted && ioh->fd_read && FD_ISSET(ioh->fd, readfds)) {
> +                ioh->fd_read(ioh->opaque);
> +            }
> +            if (!ioh->deleted && ioh->fd_write && FD_ISSET(ioh->fd, writefds)) {
> +                ioh->fd_write(ioh->opaque);
> +            }
> +
> +            /* Do this last in case read/write handlers marked it for deletion */
> +            if (ioh->deleted) {
> +                QLIST_REMOVE(ioh, next);
> +                qemu_free(ioh);
> +            }
> +        }
> +    }
> +}
> diff --git a/qemu-common.h b/qemu-common.h
> index 40dad52..27855b0 100644
> --- a/qemu-common.h
> +++ b/qemu-common.h
> @@ -223,6 +223,9 @@ typedef void IOReadHandler(void *opaque, const uint8_t *buf, int size);
>  typedef int IOCanReadHandler(void *opaque);
>  typedef void IOHandler(void *opaque);
>
> +void qemu_iohandler_fill(int *pnfds, fd_set *readfds, fd_set *writefds, fd_set *xfds);
> +void qemu_iohandler_poll(fd_set *readfds, fd_set *writefds, fd_set *xfds, int rc);
> +

This cause compilation error in MinGW:

  CC    qemu-img.o
In file included from qemu-img.c:24:
qemu-common.h:231: error: syntax error before "fd_set"
qemu-common.h:231: warning: function declaration isn't a prototype
qemu-common.h:232: error: syntax error before '*' token
qemu-common.h:232: warning: function declaration isn't a prototype
make: *** [qemu-img.o] Error 1


>  struct ParallelIOArg {
>     void *buffer;
>     int count;
> diff --git a/vl.c b/vl.c
> index b436952..224a564 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -1023,68 +1023,6 @@ void pcmcia_info(Monitor *mon)
>  }
>
>  /***********************************************************/
> -/* I/O handling */
> -
> -typedef struct IOHandlerRecord {
> -    int fd;
> -    IOCanReadHandler *fd_read_poll;
> -    IOHandler *fd_read;
> -    IOHandler *fd_write;
> -    int deleted;
> -    void *opaque;
> -    /* temporary data */
> -    struct pollfd *ufd;
> -    QLIST_ENTRY(IOHandlerRecord) next;
> -} IOHandlerRecord;
> -
> -static QLIST_HEAD(, IOHandlerRecord) io_handlers =
> -    QLIST_HEAD_INITIALIZER(io_handlers);
> -
> -
> -/* XXX: fd_read_poll should be suppressed, but an API change is
> -   necessary in the character devices to suppress fd_can_read(). */
> -int qemu_set_fd_handler2(int fd,
> -                         IOCanReadHandler *fd_read_poll,
> -                         IOHandler *fd_read,
> -                         IOHandler *fd_write,
> -                         void *opaque)
> -{
> -    IOHandlerRecord *ioh;
> -
> -    if (!fd_read && !fd_write) {
> -        QLIST_FOREACH(ioh, &io_handlers, next) {
> -            if (ioh->fd == fd) {
> -                ioh->deleted = 1;
> -                break;
> -            }
> -        }
> -    } else {
> -        QLIST_FOREACH(ioh, &io_handlers, next) {
> -            if (ioh->fd == fd)
> -                goto found;
> -        }
> -        ioh = qemu_mallocz(sizeof(IOHandlerRecord));
> -        QLIST_INSERT_HEAD(&io_handlers, ioh, next);
> -    found:
> -        ioh->fd = fd;
> -        ioh->fd_read_poll = fd_read_poll;
> -        ioh->fd_read = fd_read;
> -        ioh->fd_write = fd_write;
> -        ioh->opaque = opaque;
> -        ioh->deleted = 0;
> -    }
> -    return 0;
> -}
> -
> -int qemu_set_fd_handler(int fd,
> -                        IOHandler *fd_read,
> -                        IOHandler *fd_write,
> -                        void *opaque)
> -{
> -    return qemu_set_fd_handler2(fd, NULL, fd_read, fd_write, opaque);
> -}
> -
> -/***********************************************************/
>  /* machine registration */
>
>  static QEMUMachine *first_machine = NULL;
> @@ -1326,7 +1264,6 @@ void qemu_system_vmstop_request(int reason)
>
>  void main_loop_wait(int nonblocking)
>  {
> -    IOHandlerRecord *ioh;
>     fd_set rfds, wfds, xfds;
>     int ret, nfds;
>     struct timeval tv;
> @@ -1341,56 +1278,23 @@ void main_loop_wait(int nonblocking)
>
>     os_host_main_loop_wait(&timeout);
>
> +    tv.tv_sec = timeout / 1000;
> +    tv.tv_usec = (timeout % 1000) * 1000;
> +
>     /* poll any events */
>     /* XXX: separate device handlers from system ones */
>     nfds = -1;
>     FD_ZERO(&rfds);
>     FD_ZERO(&wfds);
>     FD_ZERO(&xfds);
> -    QLIST_FOREACH(ioh, &io_handlers, next) {
> -        if (ioh->deleted)
> -            continue;
> -        if (ioh->fd_read &&
> -            (!ioh->fd_read_poll ||
> -             ioh->fd_read_poll(ioh->opaque) != 0)) {
> -            FD_SET(ioh->fd, &rfds);
> -            if (ioh->fd > nfds)
> -                nfds = ioh->fd;
> -        }
> -        if (ioh->fd_write) {
> -            FD_SET(ioh->fd, &wfds);
> -            if (ioh->fd > nfds)
> -                nfds = ioh->fd;
> -        }
> -    }
> -
> -    tv.tv_sec = timeout / 1000;
> -    tv.tv_usec = (timeout % 1000) * 1000;
> -
> +    qemu_iohandler_fill(&nfds, &rfds, &wfds, &xfds);
>     slirp_select_fill(&nfds, &rfds, &wfds, &xfds);
>
>     qemu_mutex_unlock_iothread();
>     ret = select(nfds + 1, &rfds, &wfds, &xfds, &tv);
>     qemu_mutex_lock_iothread();
> -    if (ret > 0) {
> -        IOHandlerRecord *pioh;
> -
> -        QLIST_FOREACH_SAFE(ioh, &io_handlers, next, pioh) {
> -            if (!ioh->deleted && ioh->fd_read && FD_ISSET(ioh->fd, &rfds)) {
> -                ioh->fd_read(ioh->opaque);
> -            }
> -            if (!ioh->deleted && ioh->fd_write && FD_ISSET(ioh->fd, &wfds)) {
> -                ioh->fd_write(ioh->opaque);
> -            }
> -
> -            /* Do this last in case read/write handlers marked it for deletion */
> -            if (ioh->deleted) {
> -                QLIST_REMOVE(ioh, next);
> -                qemu_free(ioh);
> -            }
> -        }
> -    }
>
> +    qemu_iohandler_poll(&rfds, &wfds, &xfds, ret);
>     slirp_select_poll(&rfds, &wfds, &xfds, (ret < 0));
>
>     qemu_run_all_timers();
> --
> 1.7.4
>
>
>
>