Loading a class will finish by trying to execute that class' <clinit>
(static initializer) method. However, this method may require other
classes to load as well. Prior to this patch, it would be possible that
a class would (indirectly) try to load itself, which would deadlock.
This patch introduces a new class state, VM_CLASS_INITIALIZING, which
will prevent the classloader from trying to execute the class'
<clinit> method from within itself.
Signed-off-by: Vegard Nossum <vegard.nos...@gmail.com>
---
include/vm/class.h | 1 +
vm/class.c | 6 ++++--
vm/classloader.c | 4 +++-
vm/jato.c | 5 ++++-
4 files changed, 12 insertions(+), 4 deletions(-)
diff --git a/include/vm/class.h b/include/vm/class.h
index 362853d..a0a2451 100644
--- a/include/vm/class.h
+++ b/include/vm/class.h
@@ -13,6 +13,7 @@ struct vm_object;
enum vm_class_state {
VM_CLASS_LOADED,
VM_CLASS_LINKED,
+ VM_CLASS_INITIALIZING,
VM_CLASS_INITIALIZED,
};
diff --git a/vm/class.c b/vm/class.c
index f2d4fa4..cd19840 100644
--- a/vm/class.c
+++ b/vm/class.c
@@ -201,6 +201,8 @@ int vm_class_init(struct vm_class *vmc, const struct
cafebabe_class *class)
*/
int vm_class_init_object(struct vm_class *vmc)
{
+ assert(vmc->state == VM_CLASS_INITIALIZING);
+
vmc->object = vm_object_alloc(vm_java_lang_Class);
if (!vmc->object) {
NOT_IMPLEMENTED;
@@ -212,7 +214,7 @@ int vm_class_init_object(struct vm_class *vmc)
int vm_class_run_clinit(struct vm_class *vmc)
{
- assert(vmc->state == VM_CLASS_LINKED);
+ assert(vmc->state == VM_CLASS_INITIALIZING);
/* XXX: Make sure there's at most one of these. */
for (uint16_t i = 0; i < vmc->class->methods_count; ++i) {
@@ -254,7 +256,7 @@ struct vm_class *vm_class_resolve_class(struct vm_class
*vmc, uint16_t i)
return NULL;
}
- struct vm_class *class = classloader_load(class_name_str);
+ struct vm_class *class = classloader_load_and_init(class_name_str);
if (!class) {
NOT_IMPLEMENTED;
return NULL;
diff --git a/vm/classloader.c b/vm/classloader.c
index ca83f69..1ce3cf9 100644
--- a/vm/classloader.c
+++ b/vm/classloader.c
@@ -474,7 +474,9 @@ struct vm_class *classloader_load_and_init(const char
*class_name)
if (!vmc)
return NULL;
- if (vmc->state != VM_CLASS_INITIALIZED) {
+ if (vmc->state < VM_CLASS_INITIALIZING) {
+ vmc->state = VM_CLASS_INITIALIZING;
+
if (vm_class_init_object(vmc)) {
NOT_IMPLEMENTED;
return NULL;
diff --git a/vm/jato.c b/vm/jato.c
index 6724477..0819fec 100644
--- a/vm/jato.c
+++ b/vm/jato.c
@@ -179,8 +179,11 @@ static int preload_vm_classes(void)
for (unsigned int i = 0; i < ARRAY_SIZE(preload_entries); ++i) {
const struct preload_entry *pe = &preload_entries[i];
+ struct vm_class *class = *pe->class;
- if (vm_class_init_object(*pe->class)) {
+ class->state = VM_CLASS_INITIALIZING;
+
+ if (vm_class_init_object(class)) {
NOT_IMPLEMENTED;
return 1;
}
--
1.6.0.4
------------------------------------------------------------------------------
_______________________________________________
Jatovm-devel mailing list
Jatovm-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/jatovm-devel
