Mon, 18 Mar 2013 13:19:06 +0100
8008555: Debugging code in compiled method sometimes leaks memory
Summary: support for strings that have same life-time as code that uses them.
Reviewed-by: kvn, twisti
1 /*
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25 #ifndef SHARE_VM_RUNTIME_SWEEPER_HPP
26 #define SHARE_VM_RUNTIME_SWEEPER_HPP
28 // An NmethodSweeper is an incremental cleaner for:
29 // - cleanup inline caches
30 // - reclamation of unreferences zombie nmethods
31 //
33 class 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
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
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
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
53 static void process_nmethod(nmethod *nm);
55 static void release_nmethod(nmethod* nm);
57 static void log_sweep(const char* msg, const char* format = NULL, ...);
59 public:
60 static long traversal_count() { return _traversals; }
62 #ifdef ASSERT
63 // Keep track of sweeper activity in the ring buffer
64 static void record_sweep(nmethod* nm, int line);
65 static void report_events(int id, address entry);
66 static void report_events();
67 #endif
69 static void scan_stacks(); // Invoked at the end of each safepoint
70 static void sweep_code_cache(); // Concurrent part of sweep job
71 static void possibly_sweep(); // Compiler threads call this to sweep
73 static void notify(nmethod* nm) {
74 // Perform a full scan of the code cache from the beginning. No
75 // need to synchronize the setting of this flag since it only
76 // changes to false at safepoint so we can never overwrite it with false.
77 _rescan = true;
78 }
80 static void handle_full_code_cache(bool is_full); // Called by compilers who fail to allocate
81 static void speculative_disconnect_nmethods(bool was_full); // Called by vm op to deal with alloc failure
83 static void set_was_full(bool state) { _was_full = state; }
84 static bool was_full() { return _was_full; }
85 };
87 #endif // SHARE_VM_RUNTIME_SWEEPER_HPP