apr-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "David Jones" <oscare...@gmail.com>
Subject [PATCH] threadproc/unix/thread.c compile failure
Date Wed, 14 Nov 2007 16:02:22 GMT
in trunk Revision 418351 introduced a pthread_yield() call, on zOS, however
pthread_yield has to be passed in a null arg, i.e. pthread_yield(NULL)

I've added further checking to 418351's patch to do a
APR_TRY_COMPILE_NO_WARNING, to see if pthread_yield needs be called with ()
or (NULL) args.  Patch let zOS and linux compile correctly, but
didn't try other platforms.

These  comments in apr_common.m4 got me if its safe though:
dnl APR_TRY_COMPILE_NO_WARNING(INCLUDES, FUNCTION-BODY,
dnl             [ACTIONS-IF-NO-WARNINGS], [ACTIONS-IF-WARNINGS])
dnl
dnl Tries a compile test with warnings activated so that the result
dnl is false if the code doesn't compile cleanly.  For compilers
dnl where it is not known how to activate a "fail-on-error" mode,
dnl it is undefined which of the sets of actions will be run.


so is patch below good enough, or do I need to be safer, ex:
  ac_try_compile of pthread_yield() if works -> has_null_arg =no
 else apr_try_compile_no_warningsof pthread_yield(0) if works ->
has_null_arg =yes
 else has_null_arg = no
(or i could punt and add -DPTHREAD_YIELD_HAS_NULL_ARG to os390 leg in
apr_hints.m4)



Index: configure.in
===================================================================
--- configure.in        (revision 594913)
+++ configure.in        (working copy)
@@ -674,6 +674,14 @@
            dnl ----------------------------- Checking for sched_yield
            AC_CHECK_HEADERS([sched.h])
            AC_CHECK_FUNCS([sched_yield])
+        else
+            AC_CACHE_CHECK([for pthread_yield args],
[apr_cv_pthread_yield_has_null_arg],
+            APR_TRY_COMPILE_NO_WARNING([#include <pthread.h>],
+              [pthread_yield(0);],
+              [apr_cv_pthread_yield_has_null_arg=yes],
[apr_cv_pthread_yield_has_null_arg=no]))
+            if test "$apr_cv_pthread_yield_has_null_arg" = "yes"; then
+               AC_DEFINE(PTHREAD_YIELD_HAS_NULL_ARG, 1, [Define if
pthread_yield has a NULL arg])
+            fi
        fi
    fi
fi
Index: threadproc/unix/thread.c
===================================================================
--- threadproc/unix/thread.c    (revision 594914)
+++ threadproc/unix/thread.c    (working copy)
@@ -251,7 +251,11 @@
APR_DECLARE(void) apr_thread_yield(void)
{
#ifdef HAVE_PTHREAD_YIELD
+#ifdef PTHREAD_YIELD_HAS_NULL_ARG
+    pthread_yield(NULL);
+#else
    pthread_yield();
+#endif /* PTHREAD_YIELD_HAS_NULL_ARG */
#else
#ifdef HAVE_SCHED_YIELD
    sched_yield();

Mime
View raw message