Hi,
Posting to the list before committing since this may be a little bit
controversial.
The patch adds a new argument to the --enable-threads option, which
enables a nptl-only build of apr. This enables the build process to make
better assumptions regarding the behavior (and speed) of a few lock
primitives (ie: apr_posixsem_is_global, much faster on nptl for
inter-process mutexes).
The patch still needs some tweaking here and there, but any comments or
feedback would be greatly appreciated.
--
Davi Arnaut
Index: apr/include/apr.h.in
===================================================================
--- apr.orig/include/apr.h.in
+++ apr/include/apr.h.in
@@ -221,6 +221,7 @@ extern "C" {
#define APR_HAVE_UNION_SEMUN @have_union_semun@
#define APR_HAVE_SCTP @have_sctp@
#define APR_HAVE_IOVEC @have_iovec@
+#define APR_HAVE_NPTL @nptl@
/* APR Feature Macros */
#define APR_HAS_SHARED_MEMORY @sharedmem@
Index: apr/configure.in
===================================================================
--- apr.orig/configure.in
+++ apr/configure.in
@@ -554,6 +554,8 @@ esac
dnl ----------------------------- Checking for Threads
echo "${nl}Checking for Threads..."
+nptl="0"
+
if test -z "$enable_threads"; then
AC_ARG_ENABLE(threads,
[ --enable-threads Enable threading support in APR.],
@@ -584,6 +586,28 @@ else
threads="1"
pthreadh="0"
pthreadser="0"
+ elif test "$enable_threads" = "nptl" &&
+ test "$build_os" = "linux-gnu"; then
+ APR_PTHREADS_CHECK_SAVE
+ APR_PTHREADS_CHECK
+ APR_CHECK_PTHREADS_H([
+ threads="1"
+ pthreadh="1"
+ pthreadser="1" ], [
+ threads="0"
+ pthreadh="0"
+ pthreadser="0"
+ APR_PTHREADS_CHECK_RESTORE ] )
+ AC_MSG_CHECKING(if libpthread is NPTL)
+ case `getconf GNU_LIBPTHREAD_VERSION` in *NPTL*) nptl="1";; esac
+ if test "$nptl" = 1; then
+ AC_MSG_RESULT(yes)
+ APR_SETIFNULL(apr_posixsem_is_global, [yes])
+ else
+ AC_MSG_ERROR([not NPTL])
+ fi
+ elif test "$enable_threads" = "nptl"; then
+ AC_MSG_ERROR(NPTL flag is only valid when building on linux-gnu)
else
# We basically specified that we wanted threads, but not how to implement
# them. In this case, just look for pthreads. In the future, we can check
@@ -683,6 +707,7 @@ case $host in
esac
AC_SUBST(threads)
+AC_SUBST(nptl)
AC_SUBST(have_sigsuspend)
AC_SUBST(have_sigwait)
Index: apr/misc/unix/start.c
===================================================================
--- apr.orig/misc/unix/start.c
+++ apr/misc/unix/start.c
@@ -38,6 +38,22 @@ APR_DECLARE(apr_status_t) apr_app_initia
static int initialized = 0;
+#if APR_HAVE_NPTL
+static int is_runtime_nptl(void)
+{
+ apr_size_t n;
+ char version[512];
+
+ n = confstr(_CS_GNU_LIBPTHREAD_VERSION, version, sizeof(version));
+
+ if (n < 1 || (strstr(version, "NPTL") == NULL)) {
+ return 0;
+ }
+
+ return 1;
+}
+#endif
+
APR_DECLARE(apr_status_t) apr_initialize(void)
{
apr_pool_t *pool;
@@ -47,6 +63,12 @@ APR_DECLARE(apr_status_t) apr_initialize
return APR_SUCCESS;
}
+#if APR_HAVE_NPTL
+ if (!is_runtime_nptl()) {
+ return APR_ENOTIMPL;
+ }
+#endif
+
#if !defined(BEOS) && !defined(OS2)
apr_proc_mutex_unix_setup_lock();
apr_unix_setup_time();
