bruce@servio.UUCP (Bruce Schuchardt) (10/17/89)
I have a queue of programs I would like to port to my DECstation 3100 that require a usleep() function for implementing delays. I can't find a usleep() function under ULTRIX, and am hoping some kind person will share their implementation with me, or point me to the ULTRIX libxx that has one. Please e-mail responses. Thanks! -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Bruce Schuchardt Ph: (503) 629-8383 Servio Logic bruce@servio.SLC.COM Beaverton, OR uunet!servio!bruce
pete@othello (Pete Schmitt) (10/18/89)
Maybe this was discussed before, but why not use napms() in the libcursesX.a library? -pete
muth@buffer.dec.com (Bill Muth) (10/18/89)
Here is a macro for usleep() which appeared in comp.sources.x in the
program xchomp.
#ifdef ULTRIX
#include <sys/time.h>
EXTERN struct timeval st_delay;
#define usleep(x) { st_delay.tv_usec = (x); st_delay.tv_sec = 0; \
select(32, NULL, NULL, NULL, &st_delay); }
#endif
Billmichaud@decvax.dec.com (Jeff Michaud) (10/19/89)
> Here is a macro for usleep() which appeared in comp.sources.x in the > program xchomp. > > #ifdef ULTRIX > #include <sys/time.h> > EXTERN struct timeval st_delay; > #define usleep(x) { st_delay.tv_usec = (x); st_delay.tv_sec = 0; \ > select(32, NULL, NULL, NULL, &st_delay); } > #endif Note however that select will return a invalid argument error if the of u-seconds you give is equiv to a second or more. So something along #ifdef ultrix #define usleep(x) \ { struct timeval delay; \ delay.tv_sec = (int)(x) / 1000000; \ delay.tv_usec = (int)(x) % 1000000; \ select(0, (int *)0, (int *)0, (int *)0, &delay); } #endif Note also that I use 0 as the first argument to select(). Also note that I used a lowercase "ultrix" for the #ifdef as "ultrix" is predefined by ULTRIX's cpp but "ULTRIX" isn't. To make this really generic it should be defined as a function. As a macro things like: if( ... ) usleep(...); else .... because the "usleep(...);" is two statements, ie. a compound statement and the null statement. This can be worked around if you use an explicit compound statement around the "usleep(...);" while keeping your code portable. The question I have is, is the real usleep() function defined to be interruptable? select() is (but that too can be fixed by explicitly blocking signals or by restarting the select() (taking into account time already slept). /--------------------------------------------------------------\ |Jeff Michaud michaud@decwrl.dec.com michaud@decvax.dec.com| |DECnet-ULTRIX #include <standard/disclaimer.h> | \--------------------------------------------------------------/
zvr@natasha.cs.wisc.EDU (Alexios Zavras) (10/19/89)
In article <5508@shlump.nac.dec.com>, michaud@decvax.dec.com (Jeff Michaud) writes: > To make this really generic it should be defined as a function. As a > macro things like: > if( ... ) > usleep(...); > else > .... > because the "usleep(...);" is two statements, ie. a compound statement and > the null statement. This can be worked around if you use an explicit > compound statement around the "usleep(...);" while keeping your code > portable. The way to #define a macro as two or more statements, without having this problem is: #define macro(x) do { stmt1(x); stmt2(x); ... } while (0); So, the definition of usleep() looks like: /*=========================================================================*/ #ifdef ultrix #ifndef _TYPES_ #include <sys/types.h> #endif /* _TYPES_ */ #ifndef __XTIME__ #include <sys/time.h> #endif /* __XTIME__ */ #define usleep(usec) do \ { \ struct timeval usl_delay; \ usl_delay.tv_sec = (int) (usec) / 1000000; \ usl_delay.tv_usec = (int) (usec) % 1000000; \ (void) select(0,(fd_set *)0,(fd_set *)0,(fd_set *)0, &usl_delay);\ } while (0); #endif /* ultrix */ /*=========================================================================*/ > |Jeff Michaud michaud@decwrl.dec.com michaud@decvax.dec.com| -- zvr -- +-----------------------+ Alexios Zavras | Life is once, forever | zvr@cs.wisc.edu +-----------------H C-B-+ zavras@cs.wisc.edu Live from: Wisconsin: land of Orson Welles, Frank Lloyd Wright, Harry Houdini and Spencer Tracy (of Joe McCarthy, too, but we try to forget that)
zvr@natasha.cs.wisc.EDU (Alexios Zavras) (10/20/89)
In article <8896@spool.cs.wisc.edu>, I wrote: > #define macro(x) do { stmt1(x); stmt2(x); ... } while (0); and later... > #define usleep(usec) > do \ > { \ > struct timeval usl_delay; \ > usl_delay.tv_sec = (int) (usec) / 1000000; \ > usl_delay.tv_usec = (int) (usec) % 1000000; \ > (void) select(0,(fd_set *)0,(fd_set *)0,(fd_set *)0, &usl_delay);\ > } while (0); Sorry, I must have been asleep! :-) You naturally have to omit the final `;' in both cases, i.e.: #define macro(x) do { stmt1(x); stmt2(x); ... } while (0) Then you can easily write if (...) macro(...); else ... without any problems... Sorry about that, -- zvr -- +-----------------------+ Alexios Zavras | Life is once, forever | zvr@cs.wisc.edu +-----------------H C-B-+ zavras@cs.wisc.edu Live from: Wisconsin: land of Orson Welles, Frank Lloyd Wright, Harry Houdini and Spencer Tracy (of Joe McCarthy, too, but we try to forget that)