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

[Fabien Chouteau <chouteau@adacore.com>]

On 01/31/2011 06:43 PM, Paolo Bonzini wrote:
> 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?

OK, I can wait. When do you expect your patches to be ready?

Thanks for your comments,

-- 
Fabien Chouteau