This commit is contained in:
Daniel D. Daugherty 2013-09-20 12:58:35 -07:00
commit 156b06d897
17 changed files with 407 additions and 338 deletions

View file

@ -1126,21 +1126,11 @@ class BreakpointInfo;
// A collection point for interesting information about the previous
// version(s) of an InstanceKlass. This class uses weak references to
// the information so that the information may be collected as needed
// by the system. If the information is shared, then a regular
// reference must be used because a weak reference would be seen as
// collectible. A GrowableArray of PreviousVersionNodes is attached
// to the InstanceKlass as needed. See PreviousVersionWalker below.
// version(s) of an InstanceKlass. A GrowableArray of PreviousVersionNodes
// is attached to the InstanceKlass as needed. See PreviousVersionWalker below.
class PreviousVersionNode : public CHeapObj<mtClass> {
private:
// A shared ConstantPool is never collected so we'll always have
// a reference to it so we can update items in the cache. We'll
// have a weak reference to a non-shared ConstantPool until all
// of the methods (EMCP or obsolete) have been collected; the
// non-shared ConstantPool becomes collectible at that point.
ConstantPool* _prev_constant_pool; // regular or weak reference
bool _prev_cp_is_weak; // true if not a shared ConstantPool
ConstantPool* _prev_constant_pool;
// If the previous version of the InstanceKlass doesn't have any
// EMCP methods, then _prev_EMCP_methods will be NULL. If all the
@ -1149,8 +1139,8 @@ class PreviousVersionNode : public CHeapObj<mtClass> {
GrowableArray<Method*>* _prev_EMCP_methods;
public:
PreviousVersionNode(ConstantPool* prev_constant_pool, bool prev_cp_is_weak,
GrowableArray<Method*>* prev_EMCP_methods);
PreviousVersionNode(ConstantPool* prev_constant_pool,
GrowableArray<Method*>* prev_EMCP_methods);
~PreviousVersionNode();
ConstantPool* prev_constant_pool() const {
return _prev_constant_pool;
@ -1161,59 +1151,26 @@ public:
};
// A Handle-ized version of PreviousVersionNode.
class PreviousVersionInfo : public ResourceObj {
private:
constantPoolHandle _prev_constant_pool_handle;
// If the previous version of the InstanceKlass doesn't have any
// EMCP methods, then _prev_EMCP_methods will be NULL. Since the
// methods cannot be collected while we hold a handle,
// _prev_EMCP_methods should never have a length of zero.
GrowableArray<methodHandle>* _prev_EMCP_method_handles;
public:
PreviousVersionInfo(PreviousVersionNode *pv_node);
~PreviousVersionInfo();
constantPoolHandle prev_constant_pool_handle() const {
return _prev_constant_pool_handle;
}
GrowableArray<methodHandle>* prev_EMCP_method_handles() const {
return _prev_EMCP_method_handles;
}
};
// Helper object for walking previous versions. This helper cleans up
// the Handles that it allocates when the helper object is destroyed.
// The PreviousVersionInfo object returned by next_previous_version()
// is only valid until a subsequent call to next_previous_version() or
// the helper object is destroyed.
// Helper object for walking previous versions.
class PreviousVersionWalker : public StackObj {
private:
Thread* _thread;
GrowableArray<PreviousVersionNode *>* _previous_versions;
int _current_index;
// Fields for cleaning up when we are done walking the previous versions:
// A HandleMark for the PreviousVersionInfo handles:
HandleMark _hm;
// It would be nice to have a ResourceMark field in this helper also,
// but the ResourceMark code says to be careful to delete handles held
// in GrowableArrays _before_ deleting the GrowableArray. Since we
// can't guarantee the order in which the fields are destroyed, we
// have to let the creator of the PreviousVersionWalker object do
// the right thing. Also, adding a ResourceMark here causes an
// include loop.
// A pointer to the current node object so we can handle the deletes.
PreviousVersionNode* _current_p;
// A pointer to the current info object so we can handle the deletes.
PreviousVersionInfo * _current_p;
// The constant pool handle keeps all the methods in this class from being
// deallocated from the metaspace during class unloading.
constantPoolHandle _current_constant_pool_handle;
public:
PreviousVersionWalker(InstanceKlass *ik);
~PreviousVersionWalker();
PreviousVersionWalker(Thread* thread, InstanceKlass *ik);
// Return the interesting information for the next previous version
// of the klass. Returns NULL if there are no more previous versions.
PreviousVersionInfo* next_previous_version();
PreviousVersionNode* next_previous_version();
};