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24 
25 #ifndef SHARE_VM_GC_G1_SATBMARKQUEUE_HPP
26 #define SHARE_VM_GC_G1_SATBMARKQUEUE_HPP
27 
28 #include "gc/g1/ptrQueue.hpp"
29 #include "memory/allocation.hpp"
30 
31 class JavaThread;
32 class SATBMarkQueueSet;
33 
34 // Base class for processing the contents of a SATB buffer.
35 class SATBBufferClosure : public StackObj {
36 protected:
~SATBBufferClosure()37   ~SATBBufferClosure() { }
38 
39 public:
40   // Process the SATB entries in the designated buffer range.
41   virtual void do_buffer(void** buffer, size_t size) = 0;
42 };
43 
44 // A PtrQueue whose elements are (possibly stale) pointers to object heads.
45 class SATBMarkQueue: public PtrQueue {
46   friend class SATBMarkQueueSet;
47 
48 private:
49   // Filter out unwanted entries from the buffer.
50   void filter();
51 
52 public:
53   SATBMarkQueue(SATBMarkQueueSet* qset, bool permanent = false);
54 
55   // Process queue entries and free resources.
56   void flush();
57 
58   // Apply cl to the active part of the buffer.
59   // Prerequisite: Must be at a safepoint.
60   void apply_closure_and_empty(SATBBufferClosure* cl);
61 
62   // Overrides PtrQueue::should_enqueue_buffer(). See the method's
63   // definition for more information.
64   virtual bool should_enqueue_buffer();
65 
66 #ifndef PRODUCT
67   // Helpful for debugging
68   void print(const char* name);
69 #endif // PRODUCT
70 
71   // Compiler support.
byte_offset_of_index()72   static ByteSize byte_offset_of_index() {
73     return PtrQueue::byte_offset_of_index<SATBMarkQueue>();
74   }
75   using PtrQueue::byte_width_of_index;
76 
byte_offset_of_buf()77   static ByteSize byte_offset_of_buf() {
78     return PtrQueue::byte_offset_of_buf<SATBMarkQueue>();
79   }
80   using PtrQueue::byte_width_of_buf;
81 
byte_offset_of_active()82   static ByteSize byte_offset_of_active() {
83     return PtrQueue::byte_offset_of_active<SATBMarkQueue>();
84   }
85   using PtrQueue::byte_width_of_active;
86 
87 };
88 
89 class SATBMarkQueueSet: public PtrQueueSet {
90   SATBMarkQueue _shared_satb_queue;
91 
92 #ifdef ASSERT
93   void dump_active_states(bool expected_active);
94   void verify_active_states(bool expected_active);
95 #endif // ASSERT
96 
97 public:
98   SATBMarkQueueSet();
99 
100   void initialize(Monitor* cbl_mon, Mutex* fl_lock,
101                   int process_completed_threshold,
102                   Mutex* lock);
103 
104   static void handle_zero_index_for_thread(JavaThread* t);
105 
106   // Apply "set_active(active)" to all SATB queues in the set. It should be
107   // called only with the world stopped. The method will assert that the
108   // SATB queues of all threads it visits, as well as the SATB queue
109   // set itself, has an active value same as expected_active.
110   void set_active_all_threads(bool active, bool expected_active);
111 
112   // Filter all the currently-active SATB buffers.
113   void filter_thread_buffers();
114 
115   // If there exists some completed buffer, pop and process it, and
116   // return true.  Otherwise return false.  Processing a buffer
117   // consists of applying the closure to the active range of the
118   // buffer; the leading entries may be excluded due to filtering.
119   bool apply_closure_to_completed_buffer(SATBBufferClosure* cl);
120 
121 #ifndef PRODUCT
122   // Helpful for debugging
123   void print_all(const char* msg);
124 #endif // PRODUCT
125 
shared_satb_queue()126   SATBMarkQueue* shared_satb_queue() { return &_shared_satb_queue; }
127 
128   // If a marking is being abandoned, reset any unprocessed log buffers.
129   void abandon_partial_marking();
130 };
131 
132 #endif // SHARE_VM_GC_G1_SATBMARKQUEUE_HPP
133