diff options
| -rw-r--r-- | ChangeLog | 2 | ||||
| -rw-r--r-- | configure.ac | 50 | ||||
| -rw-r--r-- | runtime/atomic.h | 18 |
3 files changed, 61 insertions, 9 deletions
@@ -11,6 +11,8 @@ Version 3.21.5 [DEVEL] (rgerhards), 2008-09-?? each input module (else it is blank). - added system property "$myhostname", which contains the name of the local host as it knows itself. +- re-enabled gcc builtin atomic operations and added a proper + ./configure check --------------------------------------------------------------------------- Version 3.21.4 [DEVEL] (rgerhards), 2008-09-04 - removed compile time fixed message size limit (was 2K), limit can now diff --git a/configure.ac b/configure.ac index 8e9f7807..fea7c063 100644 --- a/configure.ac +++ b/configure.ac @@ -107,6 +107,56 @@ AC_TRY_COMPILE([ AC_MSG_RESULT(no; defined as 64) ) +# check for availability of atomic operations +# rgerhards, 2008-09-18, added based on +# http://svn.apache.org/repos/asf/apr/apr/trunk/configure.in + +AC_CACHE_CHECK([whether the compiler provides atomic builtins], [ap_cv_atomic_builtins], +[AC_TRY_RUN([ +int main() +{ + unsigned long val = 1010, tmp, *mem = &val; + + if (__sync_fetch_and_add(&val, 1010) != 1010 || val != 2020) + return 1; + + tmp = val; + + if (__sync_fetch_and_sub(mem, 1010) != tmp || val != 1010) + return 1; + + if (__sync_sub_and_fetch(&val, 1010) != 0 || val != 0) + return 1; + + tmp = 3030; + + if (__sync_val_compare_and_swap(mem, 0, tmp) != 0 || val != tmp) + return 1; + + if (__sync_lock_test_and_set(&val, 4040) != 3030) + return 1; + + mem = &tmp; + + if (__sync_val_compare_and_swap(&mem, &tmp, &val) != &tmp) + return 1; + + __sync_synchronize(); + + if (mem != &val) + return 1; + + return 0; +}], [ap_cv_atomic_builtins=yes], [ap_cv_atomic_builtins=no], [ap_cv_atomic_builtins=no])]) + +if test "$ap_cv_atomic_builtins" = "yes"; then + AC_DEFINE(HAVE_ATOMIC_BUILTINS, 1, [Define if compiler provides atomic builtins]) +fi + + + + + # Large file support AC_ARG_ENABLE(largefile, [AS_HELP_STRING([--enable-largefile],[Enable large file support @<:@default=yes@:>@])], diff --git a/runtime/atomic.h b/runtime/atomic.h index 430ae7f0..d6811628 100644 --- a/runtime/atomic.h +++ b/runtime/atomic.h @@ -1,6 +1,6 @@ /* This header supplies atomic operations. So far, we rely on GCC's - * atomic builtins. I have no idea if we can check them via autotools, - * but I am making the necessary provisioning to live without them if + * atomic builtins. During configure, we check if atomic operatons are + * available. If they are not, I am making the necessary provisioning to live without them if * they are not available. Please note that you should only use the macros * here if you think you can actually live WITHOUT an explicit atomic operation, * because in the non-presence of them, we simply do it without atomicitiy. @@ -36,16 +36,16 @@ #ifndef INCLUDED_ATOMIC_H #define INCLUDED_ATOMIC_H -/* set the following to 1 if we have atomic operations (and #undef it otherwise) */ -/* #define DO_HAVE_ATOMICS 1 */ /* for this release, we disable atomic calls because there seem to be some * portability problems and we can not fix that without destabilizing the build. * They simply came in too late. -- rgerhards, 2008-04-02 */ -/* make sure they are not used! -#define ATOMIC_INC(data) ((void) __sync_fetch_and_add(&data, 1)) -#define ATOMIC_DEC_AND_FETCH(data) __sync_sub_and_fetch(&data, 1) -*/ -#define ATOMIC_INC(data) (++(data)) +#ifdef HAVE_ATOMIC_BUILTINS +# define ATOMIC_INC(data) ((void) __sync_fetch_and_add(&data, 1)) +# define ATOMIC_DEC_AND_FETCH(data) __sync_sub_and_fetch(&data, 1) +#else +# warning "atomic builtins not available, using nul operations" +# define ATOMIC_INC(data) (++(data)) +#endif #endif /* #ifndef INCLUDED_ATOMIC_H */ |