events.hpp revision 1472:c18cbe5936b8 
1/*
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24
25// Events and EventMark provide interfaces to log events taking place in the vm.
26// This facility is extremly useful for post-mortem debugging. The eventlog
27// often provides crucial information about events leading up to the crash.
28//
29// All arguments past the format string must be passed as an intptr_t.
30//
31// To log a single event use:
32//    Events::log("New nmethod has been created " INTPTR_FORMAT, nm);
33//
34// To log a block of events use:
35//    EventMark m("GarbageCollecting %d", (intptr_t)gc_number);
36//
37// The constructor to eventlog indents the eventlog until the
38// destructor has been executed.
39//
40// IMPLEMENTATION RESTRICTION:
41//   Max 3 arguments are saved for each logged event.
42//
43
44class Events : AllStatic {
45 public:
46  // Logs an event, format as printf
47  static void log(const char* format, ...) PRODUCT_RETURN;
48
49  // Prints all events in the buffer
50  static void print_all(outputStream* st) PRODUCT_RETURN;
51
52  // Prints last number events from the event buffer
53  static void print_last(outputStream *st, int number) PRODUCT_RETURN;
54};
55
56class EventMark : public StackObj {
57 public:
58  // log a begin event, format as printf
59  EventMark(const char* format, ...) PRODUCT_RETURN;
60  // log an end event
61  ~EventMark() PRODUCT_RETURN;
62};
63
64int print_all_events(outputStream *st);
65