merge 'lennart' branch back into trunk.

git-svn-id: file:///home/lennart/svn/public/pulseaudio/trunk@1971 fefdeb5f-60dc-0310-8127-8f9354f1896f

src/daemon/ltdl-bind-now.c

@@ -0,0 +1,160 @@
+/* $Id$ */
+
+/***
+  This file is part of PulseAudio.
+
+  Copyright 2004-2006 Lennart Poettering
+  Copyright 2006 Pierre Ossman <ossman@cendio.se> for Cendio AB
+
+  PulseAudio is free software; you can redistribute it and/or modify
+  it under the terms of the GNU Lesser General Public License as published
+  by the Free Software Foundation; either version 2 of the License,
+  or (at your option) any later version.
+
+  PulseAudio is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with PulseAudio; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+  USA.
+***/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#if HAVE_DLFCN_H
+#include <dlfcn.h>
+#endif
+
+#if HAVE_SYS_DL_H
+#include <sys/dl.h>
+#endif
+
+#include <ltdl.h>
+
+#include <pulsecore/macro.h>
+#include <pulsecore/mutex.h>
+#include <pulsecore/thread.h>
+#include <pulsecore/log.h>
+
+#include "ltdl-bind-now.h"
+
+#ifdef RTLD_NOW
+#define PA_BIND_NOW RTLD_NOW
+#elif defined(DL_NOW)
+#define PA_BIND_NOW DL_NOW
+#else
+#undef PA_BIND_NOW
+#endif
+
+static pa_mutex *libtool_mutex = NULL;
+
+PA_STATIC_TLS_DECLARE_NO_FREE(libtool_tls);
+
+static void libtool_lock(void) {
+    pa_mutex_lock(libtool_mutex);
+}
+
+static void libtool_unlock(void) {
+    pa_mutex_unlock(libtool_mutex);
+}
+
+static void libtool_set_error(const char *error) {
+    PA_STATIC_TLS_SET(libtool_tls, (char*) error);
+}
+
+static const char *libtool_get_error(void) {
+    return PA_STATIC_TLS_GET(libtool_tls);
+}
+
+#ifdef PA_BIND_NOW
+
+/*
+  To avoid lazy relocations during runtime in our RT threads we add
+  our own shared object loader with uses RTLD_NOW if it is
+  available. The standard ltdl loader prefers RTLD_LAZY.
+
+  Please note that this loader doesn't have any influence on
+  relocations on any libraries that are already loaded into our
+  process, i.e. because the pulseaudio binary links directly to
+  them. To disable lazy relocations for those libraries it is possible
+  to set $LT_BIND_NOW before starting the pulsaudio binary.
+*/
+
+static lt_module bind_now_open(lt_user_data d, const char *fname) {
+    lt_module m;
+
+    pa_assert(fname);
+
+    if (!(m = dlopen(fname, PA_BIND_NOW))) {
+        libtool_set_error(dlerror());
+        return NULL;
+    }
+
+    return m;
+}
+
+static int bind_now_close(lt_user_data d, lt_module m) {
+
+    pa_assert(m);
+
+    if (dlclose(m) != 0){
+        libtool_set_error(dlerror());
+        return 1;
+    }
+
+    return 0;
+}
+
+static lt_ptr bind_now_find_sym(lt_user_data d, lt_module m, const char *symbol) {
+    lt_ptr ptr;
+
+    pa_assert(m);
+    pa_assert(symbol);
+
+    if (!(ptr = dlsym(m, symbol))) {
+        libtool_set_error(dlerror());
+        return NULL;
+    }
+
+    return ptr;
+}
+
+#endif
+
+void pa_ltdl_init(void) {
+
+#ifdef PA_BIND_NOW
+    lt_dlloader *place;
+    static const struct lt_user_dlloader loader = {
+        .module_open = bind_now_open,
+        .module_close = bind_now_close,
+        .find_sym = bind_now_find_sym
+    };
+#endif
+
+    pa_assert_se(lt_dlinit() == 0);
+    pa_assert_se(libtool_mutex = pa_mutex_new(TRUE, FALSE));
+    pa_assert_se(lt_dlmutex_register(libtool_lock, libtool_unlock, libtool_set_error, libtool_get_error) == 0);
+
+#ifdef PA_BIND_NOW
+
+    if (!(place = lt_dlloader_find("dlopen")))
+        place = lt_dlloader_next(NULL);
+
+    /* Add our BIND_NOW loader as the default module loader. */
+    if (lt_dlloader_add(place, &loader, "bind-now-loader") != 0)
+        pa_log_warn("Failed to add bind-now-loader.");
+#endif
+}
+
+void pa_ltdl_done(void) {
+    pa_assert_se(lt_dlexit() == 0);
+    pa_mutex_free(libtool_mutex);
+    libtool_mutex = NULL;
+}
+