1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
|
/* Copyright (C) 1992, 1994 Aladdin Enterprises. All rights reserved.
This file is part of GNU Ghostscript.
GNU Ghostscript is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY. No author or distributor accepts responsibility to
anyone for the consequences of using it or for whether it serves any
particular purpose or works at all, unless he says so in writing. Refer
to the GNU Ghostscript General Public License for full details.
*/
/* gpcheck.h */
/* Interrupt check interface */
/*
* On some platforms, the interpreter must check periodically for user-
* initiated actions. (Eventually, this may be extended to all platforms,
* to handle multi-tasking through the 'context' facility.) Routines that
* run for a long time must periodically call gp_check_interrupts(), and
* if it returns true, must clean up whatever they are doing and return an
* e_interrupted (or gs_error_interrupted) exceptional condition.
* The return_if_interrupt macro provides a convenient way to do this.
*
* On platforms that require an interrupt check, the makefile defines
* a symbol CHECK_INTERRUPTS. Currently this is only the Microsoft
* Windows platform.
*/
#ifdef CHECK_INTERRUPTS
int gp_check_interrupts(P0());
# define process_interrupts() discard(gp_check_interrupts())
# define return_if_interrupt()\
if ( gp_check_interrupts() )\
return gs_error_interrupt
# define return_check_interrupt(code)\
return (code < 0 ? code :\
gp_check_interrupts() ? gs_error_interrupt :\
code)
#else
# define gp_check_interrupts() 0
# define process_interrupts() DO_NOTHING
# define return_if_interrupt() DO_NOTHING
# define return_check_interrupt(code)\
return (code)
#endif
|
