1 /*
2 * Copyright (c) 1997, 2006, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "incls/_precompiled.incl"
26 #include "incls/_events.cpp.incl"
27
28
29 #ifndef PRODUCT
30
31 ////////////////////////////////////////////////////////////////////////////
32 // Event
33
34 typedef u4 EventID;
35
36 class Event VALUE_OBJ_CLASS_SPEC {
37 private:
38 jlong _time_tick;
39 intx _thread_id;
40 const char* _format;
41 int _indent;
42 intptr_t _arg_1;
43 intptr_t _arg_2;
44 intptr_t _arg_3;
45
46 // only EventBuffer::add_event() can assign event id
47 friend class EventBuffer;
48 EventID _id;
49
50 public:
51
52 void clear() { _format = NULL; }
53
54 EventID id() const { return _id; }
55
56 void fill(int indent, const char* format, intptr_t arg_1, intptr_t arg_2, intptr_t arg_3) {
57 _format = format;
58 _arg_1 = arg_1;
59 _arg_2 = arg_2;
60 _arg_3 = arg_3;
61
62 _indent = indent;
63
64 _thread_id = os::current_thread_id();
65 _time_tick = os::elapsed_counter();
66 }
67
68 void print_on(outputStream *st) {
69 if (_format == NULL) return;
70 st->print(" %d", _thread_id);
71 st->print(" %3.2g ", (double)_time_tick / os::elapsed_frequency());
72 st->fill_to(20);
73 for (int index = 0; index < _indent; index++) {
74 st->print("| ");
75 }
76 st->print_cr(_format, _arg_1, _arg_2, _arg_3);
77 }
78 };
79
80 ////////////////////////////////////////////////////////////////////////////
81 // EventBuffer
82 //
83 // Simple lock-free event queue. Every event has a unique 32-bit id.
84 // It's fine if two threads add events at the same time, because they
85 // will get different event id, and then write to different buffer location.
86 // However, it is assumed that add_event() is quick enough (or buffer size
87 // is big enough), so when one thread is adding event, there can't be more
88 // than "size" events created by other threads; otherwise we'll end up having
89 // two threads writing to the same location.
90
91 class EventBuffer : AllStatic {
92 private:
93 static Event* buffer;
94 static int size;
95 static jint indent;
96 static volatile EventID _current_event_id;
97
98 static EventID get_next_event_id() {
99 return (EventID)Atomic::add(1, (jint*)&_current_event_id);
100 }
101
102 public:
103 static void inc_indent() { Atomic::inc(&indent); }
104 static void dec_indent() { Atomic::dec(&indent); }
105
106 static bool get_event(EventID id, Event* event) {
107 int index = (int)(id % size);
108 if (buffer[index].id() == id) {
109 memcpy(event, &buffer[index], sizeof(Event));
110 // check id again; if buffer[index] is being updated by another thread,
111 // event->id() will contain different value.
112 return (event->id() == id);
113 } else {
114 // id does not match - id is invalid, or event is overwritten
115 return false;
116 }
117 }
118
119 // add a new event to the queue; if EventBuffer is full, this call will
120 // overwrite the oldest event in the queue
121 static EventID add_event(const char* format,
122 intptr_t arg_1, intptr_t arg_2, intptr_t arg_3) {
123 // assign a unique id
124 EventID id = get_next_event_id();
125
126 // event will be copied to buffer[index]
127 int index = (int)(id % size);
128
129 // first, invalidate id, buffer[index] can't have event with id = index + 2
130 buffer[index]._id = index + 2;
131
132 // make sure everyone has seen that buffer[index] is invalid
133 OrderAccess::fence();
134
135 // ... before updating its value
136 buffer[index].fill(indent, format, arg_1, arg_2, arg_3);
137
138 // finally, set up real event id, now buffer[index] contains valid event
139 OrderAccess::release_store(&(buffer[index]._id), id);
140
141 return id;
142 }
143
144 static void print_last(outputStream *st, int number) {
145 st->print_cr("[Last %d events in the event buffer]", number);
146 st->print_cr("-<thd>-<elapsed sec>-<description>---------------------");
147
148 int count = 0;
149 EventID id = _current_event_id;
150 while (count < number) {
151 Event event;
152 if (get_event(id, &event)) {
153 event.print_on(st);
154 }
155 id--;
156 count++;
157 }
158 }
159
160 static void print_all(outputStream* st) {
161 print_last(st, size);
162 }
163
164 static void init() {
165 // Allocate the event buffer
166 size = EventLogLength;
167 buffer = NEW_C_HEAP_ARRAY(Event, size);
168
169 _current_event_id = 0;
170
171 // Clear the event buffer
172 for (int index = 0; index < size; index++) {
173 buffer[index]._id = index + 1; // index + 1 is invalid id
174 buffer[index].clear();
175 }
176 }
177 };
178
179 Event* EventBuffer::buffer;
180 int EventBuffer::size;
181 volatile EventID EventBuffer::_current_event_id;
182 int EventBuffer::indent;
183
184 ////////////////////////////////////////////////////////////////////////////
185 // Events
186
187 // Events::log() is safe for signal handlers
188 void Events::log(const char* format, ...) {
189 if (LogEvents) {
190 va_list ap;
191 va_start(ap, format);
192 intptr_t arg_1 = va_arg(ap, intptr_t);
193 intptr_t arg_2 = va_arg(ap, intptr_t);
194 intptr_t arg_3 = va_arg(ap, intptr_t);
195 va_end(ap);
196
197 EventBuffer::add_event(format, arg_1, arg_2, arg_3);
198 }
199 }
200
201 void Events::print_all(outputStream *st) {
202 EventBuffer::print_all(st);
203 }
204
205 void Events::print_last(outputStream *st, int number) {
206 EventBuffer::print_last(st, number);
207 }
208
209 ///////////////////////////////////////////////////////////////////////////
210 // EventMark
211
212 EventMark::EventMark(const char* format, ...) {
213 if (LogEvents) {
214 va_list ap;
215 va_start(ap, format);
216 intptr_t arg_1 = va_arg(ap, intptr_t);
217 intptr_t arg_2 = va_arg(ap, intptr_t);
218 intptr_t arg_3 = va_arg(ap, intptr_t);
219 va_end(ap);
220
221 EventBuffer::add_event(format, arg_1, arg_2, arg_3);
222 EventBuffer::inc_indent();
223 }
224 }
225
226 EventMark::~EventMark() {
227 if (LogEvents) {
228 EventBuffer::dec_indent();
229 EventBuffer::add_event("done", 0, 0, 0);
230 }
231 }
232
233 ///////////////////////////////////////////////////////////////////////////
234
235 void eventlog_init() {
236 EventBuffer::init();
237 }
238
239 int print_all_events(outputStream *st) {
240 EventBuffer::print_all(st);
241 return 1;
242 }
243
244 #else
245
246 void eventlog_init() {}
247 int print_all_events(outputStream *st) { return 0; }
248
249 #endif // PRODUCT