Replace sched_yield(2) on Linux with select(2) (ITS#3950)

CHANGES

 OpenLDAP 2.3 Change Log
 
 OpenLDAP 2.3.16 Engineering
+	Build environment
+		Replace sched_yield(2) on Linux with select(2) (ITS#3950)
 
 OpenLDAP 2.3.15 Release
 	Fixed slapd strerror logging bug (ITS#4292)

configure

 #! /bin/sh
-# From configure.in OpenLDAP: pkg/ldap/configure.in,v 1.560.2.18 2005/11/26 17:01:54 kurt Exp .
+# From configure.in OpenLDAP: pkg/ldap/configure.in,v 1.560.2.20 2006/01/03 22:16:00 kurt Exp .
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by GNU Autoconf 2.59.
 #
@@ -24740,6 +24740,21 @@ echo "${ECHO_T}$ol_cv_pthread_create_works" >&6
 				{ { echo "$as_me:$LINENO: error: pthread_create is not usable, check environment settings" >&5
 echo "$as_me: error: pthread_create is not usable, check environment settings" >&2;}
    { (exit 1); exit 1; }; }
+			fi
+
+			ol_replace_broken_yield=no
+			case "$target" in
+			*-*-linux*)
+				ol_replace_broken_yield=yes
+			;;
+			esac
+
+			if test $ol_replace_broken_yield = yes ; then
+
+cat >>confdefs.h <<\_ACEOF
+#define REPLACE_BROKEN_YIELD 1
+_ACEOF
+
 			fi
 						if test $ol_with_yielding_select = auto ; then
@@ -42898,7 +42913,6 @@ fi
-
 for ac_func in \
@@ -42950,7 +42964,6 @@ for ac_func in \
 	strtoll			\
 	strspn			\
 	sysconf			\
-	usleep			\
 	waitpid			\
 	wait4			\
 	write			\

configure.in

@@ -1585,6 +1585,18 @@ dnl			[ol_cv_pthread_lpthread_lexc])
 				AC_MSG_ERROR([pthread_create is not usable, check environment settings])
 			fi
 
+			ol_replace_broken_yield=no
+			case "$target" in
+			*-*-linux*) 
+				ol_replace_broken_yield=yes
+			;;
+			esac
+
+			if test $ol_replace_broken_yield = yes ; then
+				AC_DEFINE([REPLACE_BROKEN_YIELD],1,
+					[define if sched_yield yields the entire process])
+			fi
+
 			dnl Check if select causes an yield
 			if test $ol_with_yielding_select = auto ; then
 				AC_CACHE_CHECK([if select yields when using pthreads],
@@ -2564,7 +2576,6 @@ AC_CHECK_FUNCS(		\
 	strtoll			\
 	strspn			\
 	sysconf			\
-	usleep			\
 	waitpid			\
 	wait4			\
 	write			\

include/portable.hin

@@ -777,9 +777,6 @@
 /* Define to 1 if you have the <unistd.h> header file. */
 #undef HAVE_UNISTD_H
 
-/* Define to 1 if you have the `usleep' function. */
-#undef HAVE_USLEEP
-
 /* Define to 1 if you have the <utime.h> header file. */
 #undef HAVE_UTIME_H
 
@@ -903,6 +900,9 @@
 /* Define to the version of this package. */
 #undef PACKAGE_VERSION
 
+/* define if sched_yield yields the entire process */
+#undef REPLACE_BROKEN_YIELD
+
 /* Define as the return type of signal handlers (`int' or `void'). */
 #undef RETSIGTYPE
 

libraries/libldap_r/thr_posix.c

@@ -20,6 +20,13 @@
 
 #include <ac/errno.h>
 
+#ifdef REPLACE_BROKEN_YIELD
+#ifndef HAVE_NANOSLEEP
+#include <ac/socket.h>
+#endif
+#include <ac/time.h>
+#endif
+
 #include "ldap_pvt_thread.h" /* Get the thread interface */
 #define LDAP_THREAD_IMPLEMENTATION
 #define LDAP_THREAD_RDWR_IMPLEMENTATION
@@ -207,7 +214,16 @@ ldap_pvt_thread_kill( ldap_pvt_thread_t thread, int signo )
 int 
 ldap_pvt_thread_yield( void )
 {
-#if HAVE_THR_YIELD
+#ifdef REPLACE_BROKEN_YIELD
+#ifdef HAVE_NANOSLEEP
+	struct timespec t = { 0, 0 };
+	nanosleep(&t, NULL);
+#else
+	struct timeval tv = {0,0};
+	select( 0, NULL, NULL, NULL, &tv );
+#endif
+	return 0;
+#elif HAVE_THR_YIELD
 	return thr_yield();
 
 #elif HAVE_PTHREADS == 10