sweeper.hpp revision 1879:f95d63e2154a 
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24
25#ifndef SHARE_VM_RUNTIME_SWEEPER_HPP
26#define SHARE_VM_RUNTIME_SWEEPER_HPP
27
28// An NmethodSweeper is an incremental cleaner for:
29//    - cleanup inline caches
30//    - reclamation of unreferences zombie nmethods
31//
32
33class NMethodSweeper : public AllStatic {
34  static long      _traversals;   // Stack traversal count
35  static nmethod*  _current;      // Current nmethod
36  static int       _seen;         // Nof. nmethod we have currently processed in current pass of CodeCache
37
38  static volatile int      _invocations;   // No. of invocations left until we are completed with this pass
39  static volatile int      _sweep_started; // Flag to control conc sweeper
40
41  static bool      _rescan;          // Indicates that we should do a full rescan of the
42                                     // of the code cache looking for work to do.
43  static bool      _do_sweep;        // Flag to skip the conc sweep if no stack scan happened
44  static int       _locked_seen;     // Number of locked nmethods encountered during the scan
45  static int       _not_entrant_seen_on_stack; // Number of not entrant nmethod were are still on stack
46
47  static bool      _was_full;        // remember if we did emergency unloading
48  static jint      _advise_to_sweep; // flag to indicate code cache getting full
49  static jlong     _last_was_full;   // timestamp of last emergency unloading
50  static uint      _highest_marked;   // highest compile id dumped at last emergency unloading
51  static long      _was_full_traversal;   // trav number at last emergency unloading
52
53  static void process_nmethod(nmethod *nm);
54
55  static void log_sweep(const char* msg, const char* format = NULL, ...);
56
57 public:
58  static long traversal_count() { return _traversals; }
59
60  static void scan_stacks();      // Invoked at the end of each safepoint
61  static void sweep_code_cache(); // Concurrent part of sweep job
62  static void possibly_sweep();   // Compiler threads call this to sweep
63
64  static void notify(nmethod* nm) {
65    // Perform a full scan of the code cache from the beginning.  No
66    // need to synchronize the setting of this flag since it only
67    // changes to false at safepoint so we can never overwrite it with false.
68     _rescan = true;
69  }
70
71  static void handle_full_code_cache(bool is_full); // Called by compilers who fail to allocate
72  static void speculative_disconnect_nmethods(bool was_full);   // Called by vm op to deal with alloc failure
73
74  static void set_was_full(bool state) { _was_full = state; }
75  static bool was_full() { return _was_full; }
76};
77
78#endif // SHARE_VM_RUNTIME_SWEEPER_HPP
79