Timing: patch to time extern() and system()

[Jeroen Demeyer <jdemeyer@cage.ugent.be>]

The attached patch changes the PARI timing functions to take into 
account the processor time taken by external programs, with a extern() 
or a system() call in GP.  I think the timing makes a lot more sense 
this way.

Technical note: It works with getrusage() as well as times().  Remark 
that we only count the so called "user time", not the "system time". 
This means we only get the time spent by the actual program, not e.g. 
the loading of the program by the OS.  Also, if the program does 
nothing, that time will not be counted.  Example: system("sleep 1") 
takes 0 ms.

Karim, could you commit this?


Cheers,
Jeroen

Index: src/language/init.c
===================================================================
RCS file: /home/cvs/pari/src/language/init.c,v
retrieving revision 1.241
diff -u -r1.241 init.c
--- src/language/init.c	26 Sep 2004 16:02:18 -0000	1.241
+++ src/language/init.c	4 Oct 2004 19:25:39 -0000
@@ -1907,11 +1907,11 @@
 TIMER(pari_timer *T)
 {
   struct tms t; times(&t);
-  return _get_time(T, t.tms_utime,
+  return _get_time(T, t.tms_utime + t.tms_cutime,
 #ifdef _SC_CLK_TCK
-                      sysconf(_SC_CLK_TCK)
+    sysconf(_SC_CLK_TCK)
 #else
-                      CLK_TCK
+    CLK_TCK
 #endif
   );
 }
@@ -1922,14 +1922,17 @@
 long
 TIMER(pari_timer *T)
 {
-  struct rusage r;
-  struct timeval t;
+  struct rusage r0;
+  struct rusage r1;
   long delay;
 
-  getrusage(0,&r); t = r.ru_utime;
-  delay = 1000 * (t.tv_sec - T->s) + (t.tv_usec - T->us) / 1000;
-  T->us = t.tv_usec;
-  T->s  = t.tv_sec; return delay;
+  getrusage(RUSAGE_SELF, &r0);
+  getrusage(RUSAGE_CHILDREN, &r1);
+  delay = 1000 * (r0.ru_utime.tv_sec + r1.ru_utime.tv_sec - T->s)
+    + (r0.ru_utime.tv_usec + r1.ru_utime.tv_usec - T->us) / 1000;
+  T->us = r0.ru_utime.tv_usec + r1.ru_utime.tv_usec;
+  T->s  = r0.ru_utime.tv_sec + r1.ru_utime.tv_sec;
+  return delay;
 }
 #elif USE_FTIME
 
Index: config/has_getrusage.c
===================================================================
RCS file: /home/cvs/pari/config/has_getrusage.c,v
retrieving revision 1.2
diff -u -r1.2 has_getrusage.c
--- config/has_getrusage.c	7 Jan 2003 20:33:19 -0000	1.2
+++ config/has_getrusage.c	4 Oct 2004 19:25:39 -0000
@@ -4,4 +4,4 @@
 #include <sys/time.h>
 #include <sys/resource.h>
 #include <unistd.h>
-main(){ struct rusage a; printf("%d",getrusage(0,&a));}
+main(){ struct rusage a; printf("%d",getrusage(RUSAGE_SELF,&a));}