allow the user to configure a maximum number of threads.

git-svn-id: https://yap.svn.sf.net/svnroot/yap/trunk@1792 b08c6af1-5177-4d33-ba66-4b1c6b8b522a

C/threads.c

@@ -568,6 +568,12 @@ p_nof_threads(void)
   return Yap_unify(ARG1,MkIntegerTerm(i));
 }
 
+static Int 
+p_max_threads(void)
+{				/* '$max_threads'(+P)	 */
+  return Yap_unify(ARG1,MkIntegerTerm(MAX_WORKERS));
+}
+
 static Int 
 p_nof_threads_created(void)
 {				/* '$nof_threads'(+P)	 */
@@ -583,6 +589,7 @@ p_thread_runtime(void)
 void Yap_InitThreadPreds(void)
 {
   Yap_InitCPred("$no_threads", 0, p_no_threads, HiddenPredFlag);
+  Yap_InitCPred("$max_threads", 1, p_max_threads, HiddenPredFlag);
   Yap_InitCPred("$thread_new_tid", 1, p_thread_new_tid, HiddenPredFlag);
   Yap_InitCPred("$create_thread", 6, p_create_thread, HiddenPredFlag);
   Yap_InitCPred("$thread_self", 1, p_thread_self, SafePredFlag|HiddenPredFlag);
@@ -625,6 +632,12 @@ p_nof_threads(void)
   return Yap_unify(ARG1,MkIntTerm(1));
 }
 
+static Int 
+p_max_threads(void)
+{				/* '$nof_threads'(+P)	 */
+  return Yap_unify(ARG1,MkIntTerm(1));
+}
+
 static Int 
 p_nof_threads_created(void)
 {				/* '$nof_threads'(+P)	 */
@@ -640,6 +653,7 @@ p_thread_runtime(void)
 void Yap_InitThreadPreds(void)
 {
   Yap_InitCPred("$no_threads", 0, p_no_threads, SafePredFlag|HiddenPredFlag);
+  Yap_InitCPred("$max_threads", 1, p_max_threads, SafePredFlag|HiddenPredFlag);
   Yap_InitCPred("$nof_threads", 1, p_nof_threads, SafePredFlag|HiddenPredFlag);
   Yap_InitCPred("$nof_threads_created", 1, p_nof_threads_created, SafePredFlag|HiddenPredFlag);
   Yap_InitCPred("$thread_runtime", 1, p_thread_runtime, SafePredFlag|HiddenPredFlag);

H/Yap.h

@@ -10,7 +10,7 @@
 * File:		Yap.h.m4						 *
 * mods:									 *
 * comments:	main header file for YAP				 *
-* version:      $Id: Yap.h,v 1.18 2006-12-13 16:10:25 vsc Exp $	 *
+* version:      $Id: Yap.h,v 1.19 2007-01-29 10:18:15 vsc Exp $	 *
 *************************************************************************/
 
 #include "config.h"
@@ -141,12 +141,6 @@
 #include <pthread.h>
 #endif
 
-#if defined(YAPOR) || defined(THREADS)
-#define MAX_WORKERS (sizeof(unsigned long) * 8)
-#else
-#define MAX_WORKERS 1
-#endif /* YAPOR */
-
 #if SIZEOF_INT_P==4
 
 #if SIZEOF_INT==4

changes-5.1.html

@@ -16,6 +16,7 @@
 
 <h2>Yap-5.1.2:</h2>
 <ul>
+<li> NEW: --with-max-workers tells us how many threads we can have (request from Paulo Moura).</li>
 <li> FIXED: wchar_t in the WIN32 is unsigned and 16 bits.</li>
 <li> FIXED: stack overflow when growing the delay stack.</li>
 <li> FIXED: overflows with MIN_INT (obs from Marius Filip).</li> 

config.h.in

@@ -297,3 +297,5 @@
 
 #undef GC_NO_TAGS
 
+#undef MAX_WORKERS
+

configure

@@ -698,6 +698,7 @@ INSTALLCLP
 JAVALIBPATH
 JAVAINCPATH
 LAMOBJS
+MAX_WORKERS
 M4GENABSMI
 LIBOBJS
 LTLIBOBJS'
@@ -1319,6 +1320,7 @@ Optional Packages:
  --with-heap-space=space  default heap size in Kbytes
  --with-stack-space=space default stack size in Kbytes
  --with-trail-space=space default trail size in Kbytes
+ --with-max-workers=integer maximum number of threads or parallel processes
 
 Some influential environment variables:
   CC          C compiler command
@@ -3093,6 +3095,22 @@ else
 fi
 
 
+
+# Check whether --with-max-workers was given.
+if test "${with_max_workers+set}" = set; then
+  withval=$with_max_workers; if test "$withval" = yes; then
+	  yap_cv_max_workers="(8*SIZEOF_INT_P)"
+	elif test "$withval" = no; then
+	  yap_cv_max_workers="1"
+	else
+	  yap_cv_max_workers=$withval
+	fi
+else
+  yap_cv_max_workers="(8*SIZEOF_INT_P)"
+fi
+
+
+
 if test "$tabling" = yes -o "$orparallelism" = yes -o "$threads" = yes
 then
   cat >>confdefs.h <<\_ACEOF
@@ -3298,6 +3316,20 @@ cat >>confdefs.h <<_ACEOF
 _ACEOF
 
 
+if test "$or-parallelism" = no -a "$threads" = no
+then
+  cat >>confdefs.h <<\_ACEOF
+#define MAX_WORKERS 1
+_ACEOF
+
+else
+eval "cat >>confdefs.h <<\_ACEOF
+#define MAX_WORKERS ($yap_cv_max_workers)
+_ACEOF
+"
+fi
+
+
 if test "$use_condor" = yes
 then
   use_malloc="yes"
@@ -14862,6 +14894,7 @@ EXEC_SUFFIX=""
 
 
 
+
 
 
 { echo "$as_me:$LINENO: checking for gcc threaded code" >&5
@@ -18590,12 +18623,13 @@ for ac_last_try in false false false false false :; do
 JAVALIBPATH!$JAVALIBPATH$ac_delim
 JAVAINCPATH!$JAVAINCPATH$ac_delim
 LAMOBJS!$LAMOBJS$ac_delim
+MAX_WORKERS!$MAX_WORKERS$ac_delim
 M4GENABSMI!$M4GENABSMI$ac_delim
 LIBOBJS!$LIBOBJS$ac_delim
 LTLIBOBJS!$LTLIBOBJS$ac_delim
 _ACEOF
 
-  if test `sed -n "s/.*$ac_delim\$/X/p" conf$$subs.sed | grep -c X` = 6; then
+  if test `sed -n "s/.*$ac_delim\$/X/p" conf$$subs.sed | grep -c X` = 7; then
     break
   elif $ac_last_try; then
     { { echo "$as_me:$LINENO: error: could not make $CONFIG_STATUS" >&5

configure.in

@@ -223,6 +223,18 @@ AC_ARG_WITH(trail-space,
 	fi,
 	[yap_cv_trail_space=0])
 
+AC_ARG_WITH(max-workers,
+	[ --with-max-workers[=integer] maximum number of threads or parallel processes],
+	if test "$withval" = yes; then
+	  yap_cv_max_workers="(8*SIZEOF_INT_P)"
+	elif test "$withval" = no; then
+	  yap_cv_max_workers="1"
+	else
+	  yap_cv_max_workers=$withval
+	fi,
+	[yap_cv_max_workers="(8*SIZEOF_INT_P)"])
+
+
 if test "$tabling" = yes -o "$orparallelism" = yes -o "$threads" = yes
 then
   AC_DEFINE(MinHeapSpace, (400*SIZEOF_INT_P))
@@ -242,6 +254,14 @@ AC_CANONICAL_SYSTEM
 
 AC_DEFINE_UNQUOTED(HOST_ALIAS,"${target}")
 
+if test "$or-parallelism" = no -a "$threads" = no
+then
+  AC_DEFINE(MAX_WORKERS,1)
+else
+eval "AC_DEFINE(MAX_WORKERS,$yap_cv_max_workers)"
+fi
+
+
 dnl condor does not like dynamic linking on Linux, DEC, and HP-UX platforms.
 if test "$use_condor" = yes 
 then
@@ -1013,6 +1033,7 @@ AC_SUBST(INSTALLCLP)
 AC_SUBST(JAVALIBPATH)
 AC_SUBST(JAVAINCPATH)
 AC_SUBST(LAMOBJS)
+AC_SUBST(MAX_WORKERS)
 
 
 dnl check for threaded code