[Qemu-devel] Re: [PATCH][RFC] Add stdio char device on windows

[Paolo Bonzini <pbonzini@redhat.com>]

On 01/31/2011 06:09 PM, Fabien Chouteau wrote:
> Simple implementation of an stdio char device on Windows.
>
> Signed-off-by: Fabien Chouteau<chouteau@adacore.com>
> ---
>   qemu-char.c |  171 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>   1 files changed, 171 insertions(+), 0 deletions(-)
>
> diff --git a/qemu-char.c b/qemu-char.c
> index edc9ad6..c18e668 100644
> --- a/qemu-char.c
> +++ b/qemu-char.c
> @@ -1436,6 +1436,11 @@ static CharDriverState *qemu_chr_open_pp(QemuOpts *opts)
>
>   #else /* _WIN32 */
>
> +#define STDIO_MAX_CLIENTS 2

Why 2?  If it were 1, you could use a single definition for Unix and Win32.

> +
> +static int stdio_nb_clients;
> +static CharDriverState *stdio_clients[STDIO_MAX_CLIENTS];
> +
>   typedef struct {
>       int max_size;
>       HANDLE hcom, hrecv, hsend;
> @@ -1788,6 +1793,171 @@ static CharDriverState *qemu_chr_open_win_file_out(QemuOpts *opts)
>
>       return qemu_chr_open_win_file(fd_out);
>   }
> +
> +static int win_stdio_write(CharDriverState *chr, const uint8_t *buf, int len)
> +{
> +    HANDLE *Output = GetStdHandle(STD_OUTPUT_HANDLE);

Please use Hungarian notation for Windows objects, i.e. hStdOut.

> +    DWORD   size;
> +    int     len1;
> +
> +    len1 = len;
> +
> +    while (len1>  0) {
> +        if (!WriteFile(Output, buf, len1,&size, NULL)) {
> +            break;
> +        }
> +        buf  += size;
> +        len1 -= size;
> +    }
> +
> +    return len - len1;
> +}
> +
> +static HANDLE *Input;

and hStdIn

> +
> +static void win_stdio_wait_func(void *opaque)
> +{
> +    CharDriverState *chr = opaque;
> +    INPUT_RECORD     buf[4];
> +    int              ret;
> +    DWORD            size;
> +    int              i;
> +
> +    ret = ReadConsoleInput(Input, buf, sizeof(buf)/sizeof(*buf),&size);
> +
> +    if (!ret) {
> +        /* Avoid error storm */
> +        qemu_del_wait_object(Input, NULL, NULL);
> +        return;
> +    }
> +
> +    for (i = 0; i<  size; i++) {
> +        KEY_EVENT_RECORD *kev =&buf[i].Event.KeyEvent;
> +
> +        if (buf[i].EventType == KEY_EVENT&&  kev->bKeyDown) {
> +            int j;
> +            if (kev->uChar.AsciiChar != 0) {
> +                for (j = 0; j<  kev->wRepeatCount; j++)
> +                    if (qemu_chr_can_read(chr)) {
> +                        uint8_t c = kev->uChar.AsciiChar;
> +                        qemu_chr_read(chr,&c, 1);
> +                    }
> +            }
> +        }
> +    }
> +}
> +
> +static HANDLE  InputReadyEvent;
> +static HANDLE  InputDoneEvent;
> +static uint8_t InputBuf;

and hInputReadyEvent, hInputDoneEvent.  Stuff that is not Windows 
objects should use underscores as in win_stdio_buf.

> +
> +static DWORD WINAPI win_stdio_thread(LPVOID param)
> +{
> +    int   ret;
> +    DWORD size;
> +
> +    while (1) {
> +
> +        /* Wait for one byte */
> +        ret = ReadFile(Input,&InputBuf, 1,&size, NULL);
> +
> +        /* Exit in case of error, continue if nothing read */
> +        if (!ret) {
> +            break;
> +        }
> +        if (!size) {
> +            continue;
> +        }
> +
> +        /* Some terminal emulator returns \r\n for Enter, just pass \n */
> +        if (InputBuf == '\r') {
> +            continue;
> +        }
> +
> +        /* Signal the main thread and wait until the byte was eaten */
> +        if (!SetEvent(InputReadyEvent)) {
> +            break;
> +        }
> +        if (WaitForSingleObject(InputDoneEvent, INFINITE) != WAIT_OBJECT_0) {
> +            break;
> +        }
> +    }
> +
> +    qemu_del_wait_object(InputReadyEvent, NULL, NULL);
> +    return 0;
> +}
> +
> +static void win_stdio_thread_wait_func(void *opaque)
> +{
> +    CharDriverState *chr = opaque;
> +
> +    if (qemu_chr_can_read(chr)) {
> +        qemu_chr_read(chr,&InputBuf, 1);
> +    }
> +
> +    SetEvent(InputDoneEvent);
> +}
> +
> +static CharDriverState *qemu_chr_open_win_stdio(QemuOpts *opts)
> +{
> +    CharDriverState *chr;
> +    DWORD            mode;
> +    int              is_console = 0;
> +
> +    Input = GetStdHandle(STD_INPUT_HANDLE);
> +    if (Input == INVALID_HANDLE_VALUE) {
> +        fprintf(stderr, "cannot open stdio: invalid handle\n");
> +        exit(1);
> +    }
> +
> +    is_console = GetConsoleMode(Input,&mode) != 0;
> +
> +    if (stdio_nb_clients>= STDIO_MAX_CLIENTS
> +        || ((display_type != DT_NOGRAPHIC)&&  (stdio_nb_clients != 0))) {
> +        return NULL;
> +    }
> +
> +    chr = qemu_mallocz(sizeof(CharDriverState));
> +    if (!chr) {
> +        return NULL;
> +    }
> +
> +    chr->chr_write = win_stdio_write;
> +
> +    if (stdio_nb_clients == 0) {
> +        if (is_console) {
> +            if (qemu_add_wait_object(InputReadyEvent,
> +                                     win_stdio_thread_wait_func, chr)) {
> +                fprintf(stderr, "qemu_add_wait_object: failed\n");
> +            }
> +        } else {
> +            DWORD   id;
> +            HANDLE *InputThread;
> +
> +            InputReadyEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
> +            InputDoneEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
> +            InputThread = CreateThread(NULL, 0, win_stdio_thread, chr, 0,&id);
> +
> +            if (InputThread == INVALID_HANDLE_VALUE
> +                || InputReadyEvent == INVALID_HANDLE_VALUE
> +                || InputDoneEvent == INVALID_HANDLE_VALUE) {
> +                fprintf(stderr, "cannot create stdio thread or event\n");
> +                exit(1);
> +            }
> +            if (qemu_add_wait_object(Input, win_stdio_thread_wait_func, chr)) {
> +                fprintf(stderr, "qemu_add_wait_object: failed\n");
> +            }
> +        }
> +    }
> +
> +    stdio_clients[stdio_nb_clients++] = chr;
> +    if (stdio_nb_clients == 1 && is_console) {
> +        /* set the terminal in raw mode */
> +        /* ENABLE_QUICK_EDIT_MODE | ENABLE_EXTENDED_FLAGS */
> +        SetConsoleMode(Input, ENABLE_PROCESSED_INPUT);
> +    }
> +    return chr;
> +}
>   #endif /* !_WIN32 */
>
>   /***********************************************************/
> @@ -2477,6 +2647,7 @@ static const struct {
>       { .name = "pipe",      .open = qemu_chr_open_win_pipe },
>       { .name = "console",   .open = qemu_chr_open_win_con },
>       { .name = "serial",    .open = qemu_chr_open_win },
> +    { .name = "stdio",     .open = qemu_chr_open_win_stdio },
>   #else
>       { .name = "file",      .open = qemu_chr_open_file_out },
>       { .name = "pipe",      .open = qemu_chr_open_pipe },

Otherwise looks good, can you wait for 
http://permalink.gmane.org/gmane.comp.emulators.qemu/88490 to be merged 
so that you can add the set_echo implementation too?

Thanks!

Paolo