Re: 64-bit support for display device

IMO it must not go to GS_8_1X, because doesn't contribute
a new tested behavior.

Igor.

----- Original Message ----- 
From: "Russell Lang" <[email protected]>
To: <[email protected]>
Sent: Wednesday, February 11, 2004 11:38 AM
Subject: [gs-code-review] 64-bit support for display device


> Ray,
>
> Please review the following patch.  I have not tested it on a 64-
> bit platform (I don't have one).  I would like this added to
> 8.14.  If all goes well it should be harmless.  Worst case is
> probably some compiler warnings when compiled on a 64-bit
> platform.    For HEAD, GS_8_1X and GS_8_0X.
>
> Log message:
>
> Change display device parameter DisplayHandle from an integer
> to a string, to add support for 64-bit platforms.
>
> DETAILS:
>
> The display device passes a (void *) handle to callback
> functions.  The handle is set before the device is opened, and
> attempting to change it afterwards is an error.  The handle may
> be used by the caller to identify an instance of the display
> device, for example it may point to the display instance object
> in the caller. This handle was set using a PostScript integer
> which is 32-bits long, typically with -dDisplayHandle.  The
> existing code will not work correctly on 64-bit architectures.
>
>
> The display device is changed to return a string as the
> DisplayHandle parameter.
> Previously the handle would be set using -dDisplayHandle=1234.
> The changed code allows it to be passed as
>  -dDisplayHandle=1234
>  -dDisplayHandle=(1234)
>  -sDisplayHandle=1234
>  -sDisplayHandle=10#1234
>  -sDisplayHandle=16#04d2
> This should be backward compatible, since users of the
> display device will most likely only set the DisplayHandle,
> not read its value.
>
> The ghostscript example code in dw*.c, dx*.c and dp*.c
> does not use DisplayHandle, so is unaffected by this change.
> GSview does use DisplayHandle and will require this
> change for operation on 64-bit platforms.
>
> It is assumed that size_t is an integer with the same size
> as a pointer.
>
>
> Russell Lang                   [email protected]
> Ghostgum Software Pty Ltd      http://www.ghostgum.com.au/
>
>
>
>


----------------------------------------------------------------------------
----


> diff -u l:src/gdevdsp.c src/gdevdsp.c
> --- l:src/gdevdsp.c Wed Apr 30 09:34:53 2003
> +++ src/gdevdsp.c Wed Feb 11 08:08:53 2004
> @@ -704,9 +704,33 @@
>  {
>      gx_device_display *ddev = (gx_device_display *) dev;
>      int code = gx_default_get_params(dev, plist);
> +    gs_param_string dhandle;
> +    int idx;
> +    int val;
> +    int i = 0;
> +    size_t dptr;
> +    char buf[64];
> +
> +    idx = ((int)sizeof(size_t)) * 8 - 4;
> +    buf[i++] = '1';
> +    buf[i++] = '6';
> +    buf[i++] = '#';
> +    dptr = (size_t)(ddev->pHandle);
> +    while (idx >= 0) {
> + val = (int)(dptr >> idx) & 0xf;
> +        if (val <= 9)
> +     buf[i++] = '0' + val;
> + else
> +     buf[i++] = 'a' - 10 + val;
> + idx -= 4;
> +    }
> +    buf[i] = '\0';
> +
> +    param_string_from_transient_string(dhandle, buf);
> +
>      (void)(code < 0 ||
> - (code = param_write_long(plist,
> -     "DisplayHandle", (long *)(&ddev->pHandle))) < 0 ||
> + (code = param_write_string(plist,
> +     "DisplayHandle", &dhandle)) < 0 ||
>   (code = param_write_int(plist,
>       "DisplayFormat", &ddev->nFormat)) < 0 );
>      return code;
> @@ -731,6 +755,8 @@
>
>      int format;
>      void *handle;
> +    int found_string_handle = 0;
> +    gs_param_string dh = { 0 };
>
>      /* Handle extra parameters */
>
> @@ -757,24 +783,98 @@
>       break;
>      }
>
> -    switch (code = param_read_long(plist, "DisplayHandle", (long
*)(&handle))) {
> +    /* 64-bit systems need to use DisplayHandle as a string */
> +    switch (code = param_read_string(plist, "DisplayHandle", &dh)) {
>   case 0:
> -     if (dev->is_open) {
> - if (ddev->pHandle != handle)
> -     ecode = gs_error_rangecheck;
> - else
> -     break;
> -     }
> -     else
> - ddev->pHandle = handle;
> - break;
> -     goto hdle;
> +        found_string_handle = 1;
> +     break;
>   default:
> +     if ((code == gs_error_typecheck) && (sizeof(size_t) <= 4)) {
> + /* 32-bit systems can use the older long type */
> + switch (code = param_read_long(plist, "DisplayHandle",
> +     (long *)(&handle))) {
> +     case 0:
> + if (dev->is_open) {
> +     if (ddev->pHandle != handle)
> + ecode = gs_error_rangecheck;
> +     else
> + break;
> + }
> + else {
> +     ddev->pHandle = handle;
> +     break;
> + }
> + goto hdle;
> +     default:
> + ecode = code;
> +       hdle:param_signal_error(plist, "DisplayHandle", ecode);
> +     case 1:
> + break;
> + }
> + break;
> +     }
>       ecode = code;
> -   hdle:param_signal_error(plist, "DisplayHandle", ecode);
> +     param_signal_error(plist, "DisplayHandle", ecode);
> +     /* fall through */
>   case 1:
> +     dh.data = 0;
>       break;
>      }
> +    if (found_string_handle) {
> + /*
> + * Convert from a string to a pointer.
> + * It is assumed that size_t has the same size as a pointer.
> + * Allow formats (1234), (10#1234) or (16#04d2).
> + */
> + size_t ptr = 0;
> + int i;
> + int base = 10;
> + int val;
> + code = 0;
> + for (i=0; i<dh.size; i++) {
> +     val = dh.data[i];
> +     if ((val >= '0') && (val <= '9'))
> + val = val - '0';
> +     else if ((val >= 'A') && (val <= 'F'))
> + val = val - 'A' + 10;
> +     else if ((val >= 'a') && (val <= 'f'))
> + val = val - 'a' + 10;
> +     else if (val == '#') {
> + base = (int)ptr;
> + ptr = 0;
> + if ((base != 10) && (base != 16)) {
> +     code = gs_error_rangecheck;
> +     break;
> + }
> + continue;
> +     }
> +     else {
> + code = gs_error_rangecheck;
> + break;
> +     }
> +
> +     if (base == 10)
> + ptr = ptr * 10 + val;
> +     else if (base == 16)
> + ptr = ptr * 16 + val;
> +     else {
> + code = gs_error_rangecheck;
> + break;
> +     }
> + }
> + if (code == 0) {
> +     if (dev->is_open) {
> + if (ddev->pHandle != (void *)ptr)
> +     code = gs_error_rangecheck;
> +     }
> +     else
> + ddev->pHandle = (void *)ptr;
> + }
> + if (code < 0) {
> +     ecode = code;
> +     param_signal_error(plist, "DisplayHandle", ecode);
> + }
> +    }
>
>      if (ecode >= 0) {
>   /* Prevent gx_default_put_params from closing the device. */
> Only in src: gdevdsp.c.orig
> diff -u l:src/gdevdsp.h src/gdevdsp.h
> --- l:src/gdevdsp.h Thu Nov 21 08:36:43 2002
> +++ src/gdevdsp.h Wed Feb 11 08:11:53 2004
> @@ -28,8 +28,10 @@
>   *  gsapi_init_with_args(minst, argc, argv);
>   *
>   * Supported parameters and default values are:
> - * -dDisplayHandle=0                      long
> - *    Caller supplied handle.
> + * -sDisplayHandle=16#04d2 or 1234        string
> + *    Caller supplied handle as a decimal or hexadecimal number
> + *    in a string.  On 32-bit platforms, it may be set
> + *    using -dDisplayHandle=1234 for backward compatibility.
>   *    Included as first parameter of all callback functions.
>   *
>   * -dDisplayFormat=0                      long
>


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