From 3556c233d931ad5ffa46a35cb25cfc057732ebb8 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Fri, 10 May 2013 14:16:40 +0200 Subject: [PATCH] qom: allow turning cast debugging off Cast debugging can have a substantial cost (20% or more). Instead of adding special-cased "fast casts" in the hot paths, we can just disable it in releases. The tracing facilities we just added make it easier to analyze those problems that cast debugging would reveal. Signed-off-by: Paolo Bonzini Message-id: 1368188203-3407-7-git-send-email-pbonzini@redhat.com Signed-off-by: Anthony Liguori --- configure | 9 +++++++++ include/qom/object.h | 11 ++++++----- qom/object.c | 15 +++++++++++---- 3 files changed, 26 insertions(+), 9 deletions(-) diff --git a/configure b/configure index 9439f1c72..cab633299 100755 --- a/configure +++ b/configure @@ -220,6 +220,7 @@ blobs="yes" pkgversion="" pie="" zero_malloc="" +qom_cast_debug="yes" trace_backend="nop" trace_file="trace" spice="" @@ -688,6 +689,10 @@ for opt do ;; --enable-sdl) sdl="yes" ;; + --disable-qom-cast-debug) qom_cast_debug="no" + ;; + --enable-qom-cast-debug) qom_cast_debug="yes" + ;; --disable-virtfs) virtfs="no" ;; --enable-virtfs) virtfs="yes" @@ -3575,6 +3580,7 @@ echo "gcov enabled $gcov" echo "TPM support $tpm" echo "libssh2 support $libssh2" echo "TPM passthrough $tpm_passthrough" +echo "QOM debugging $qom_cast_debug" if test "$sdl_too_old" = "yes"; then echo "-> Your SDL version is too old - please upgrade to have SDL support" @@ -3909,6 +3915,9 @@ echo "CONFIG_UNAME_RELEASE=\"$uname_release\"" >> $config_host_mak if test "$zero_malloc" = "yes" ; then echo "CONFIG_ZERO_MALLOC=y" >> $config_host_mak fi +if test "$qom_cast_debug" = "yes" ; then + echo "CONFIG_QOM_CAST_DEBUG=y" >> $config_host_mak +fi if test "$rbd" = "yes" ; then echo "CONFIG_RBD=y" >> $config_host_mak fi diff --git a/include/qom/object.h b/include/qom/object.h index 38f674f0c..63e2a404d 100644 --- a/include/qom/object.h +++ b/include/qom/object.h @@ -615,8 +615,9 @@ Object *object_dynamic_cast(Object *obj, const char *typename); * * See object_dynamic_cast() for a description of the parameters of this * function. The only difference in behavior is that this function asserts - * instead of returning #NULL on failure. This function is not meant to be - * called directly, but only through the wrapper macro OBJECT_CHECK. + * instead of returning #NULL on failure if QOM cast debugging is enabled. + * This function is not meant to be called directly, but only through + * the wrapper macro OBJECT_CHECK. */ Object *object_dynamic_cast_assert(Object *obj, const char *typename, const char *file, int line, const char *func); @@ -666,9 +667,9 @@ Type type_register(const TypeInfo *info); * * See object_class_dynamic_cast() for a description of the parameters * of this function. The only difference in behavior is that this function - * asserts instead of returning #NULL on failure. This function is not - * meant to be called directly, but only through the wrapper macros - * OBJECT_CLASS_CHECK and INTERFACE_CHECK. + * asserts instead of returning #NULL on failure if QOM cast debugging is + * enabled. This function is not meant to be called directly, but only through + * the wrapper macros OBJECT_CLASS_CHECK and INTERFACE_CHECK. */ ObjectClass *object_class_dynamic_cast_assert(ObjectClass *klass, const char *typename, diff --git a/qom/object.c b/qom/object.c index 1b9c5ce4f..f5f416bc8 100644 --- a/qom/object.c +++ b/qom/object.c @@ -435,12 +435,11 @@ Object *object_dynamic_cast(Object *obj, const char *typename) Object *object_dynamic_cast_assert(Object *obj, const char *typename, const char *file, int line, const char *func) { - Object *inst; - trace_object_dynamic_cast_assert(obj ? obj->class->type->name : "(null)", typename, file, line, func); - inst = object_dynamic_cast(obj, typename); +#ifdef CONFIG_QOM_CAST_DEBUG + Object *inst = object_dynamic_cast(obj, typename); if (!inst && obj) { fprintf(stderr, "%s:%d:%s: Object %p is not an instance of type %s\n", @@ -448,7 +447,9 @@ Object *object_dynamic_cast_assert(Object *obj, const char *typename, abort(); } - return inst; + assert(obj == inst); +#endif + return obj; } ObjectClass *object_class_dynamic_cast(ObjectClass *class, @@ -509,6 +510,12 @@ ObjectClass *object_class_dynamic_cast_assert(ObjectClass *class, trace_object_class_dynamic_cast_assert(class ? class->type->name : "(null)", typename, file, line, func); +#ifndef CONFIG_QOM_CAST_DEBUG + if (!class->interfaces) { + return class; + } +#endif + ret = object_class_dynamic_cast(class, typename); if (!ret && class) { fprintf(stderr, "%s:%d:%s: Object %p is not an instance of type %s\n", -- 2.39.2