39 static bool _biased_locking_enabled = false;
40 BiasedLockingCounters BiasedLocking::_counters;
41
42 static GrowableArray<Handle>* _preserved_oop_stack = NULL;
43 static GrowableArray<markOop>* _preserved_mark_stack = NULL;
44
45 static void enable_biased_locking(InstanceKlass* k) {
46 k->set_prototype_header(markOopDesc::biased_locking_prototype());
47 }
48
49 class VM_EnableBiasedLocking: public VM_Operation {
50 private:
51 bool _is_cheap_allocated;
52 public:
53 VM_EnableBiasedLocking(bool is_cheap_allocated) { _is_cheap_allocated = is_cheap_allocated; }
54 VMOp_Type type() const { return VMOp_EnableBiasedLocking; }
55 Mode evaluation_mode() const { return _is_cheap_allocated ? _async_safepoint : _safepoint; }
56 bool is_cheap_allocated() const { return _is_cheap_allocated; }
57
58 void doit() {
59 // Iterate the system dictionary enabling biased locking for all
60 // currently loaded classes
61 ClassLoaderDataGraph::dictionary_classes_do(enable_biased_locking);
62 // Indicate that future instances should enable it as well
63 _biased_locking_enabled = true;
64
65 log_info(biasedlocking)("Biased locking enabled");
66 }
67
68 bool allow_nested_vm_operations() const { return false; }
69 };
70
71
72 // One-shot PeriodicTask subclass for enabling biased locking
73 class EnableBiasedLockingTask : public PeriodicTask {
74 public:
75 EnableBiasedLockingTask(size_t interval_time) : PeriodicTask(interval_time) {}
76
77 virtual void task() {
78 // Use async VM operation to avoid blocking the Watcher thread.
79 // VM Thread will free C heap storage.
80 VM_EnableBiasedLocking *op = new VM_EnableBiasedLocking(true);
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39 static bool _biased_locking_enabled = false;
40 BiasedLockingCounters BiasedLocking::_counters;
41
42 static GrowableArray<Handle>* _preserved_oop_stack = NULL;
43 static GrowableArray<markOop>* _preserved_mark_stack = NULL;
44
45 static void enable_biased_locking(InstanceKlass* k) {
46 k->set_prototype_header(markOopDesc::biased_locking_prototype());
47 }
48
49 class VM_EnableBiasedLocking: public VM_Operation {
50 private:
51 bool _is_cheap_allocated;
52 public:
53 VM_EnableBiasedLocking(bool is_cheap_allocated) { _is_cheap_allocated = is_cheap_allocated; }
54 VMOp_Type type() const { return VMOp_EnableBiasedLocking; }
55 Mode evaluation_mode() const { return _is_cheap_allocated ? _async_safepoint : _safepoint; }
56 bool is_cheap_allocated() const { return _is_cheap_allocated; }
57
58 void doit() {
59 // Iterate the class loader data dictionaries enabling biased locking for all
60 // currently loaded classes.
61 ClassLoaderDataGraph::dictionary_classes_do(enable_biased_locking);
62 // Indicate that future instances should enable it as well
63 _biased_locking_enabled = true;
64
65 log_info(biasedlocking)("Biased locking enabled");
66 }
67
68 bool allow_nested_vm_operations() const { return false; }
69 };
70
71
72 // One-shot PeriodicTask subclass for enabling biased locking
73 class EnableBiasedLockingTask : public PeriodicTask {
74 public:
75 EnableBiasedLockingTask(size_t interval_time) : PeriodicTask(interval_time) {}
76
77 virtual void task() {
78 // Use async VM operation to avoid blocking the Watcher thread.
79 // VM Thread will free C heap storage.
80 VM_EnableBiasedLocking *op = new VM_EnableBiasedLocking(true);
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