1 /*
2 * Copyright (c) 2001, 2014, 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 "precompiled.hpp"
26 #include "memory/allocation.inline.hpp"
27 #include "runtime/arguments.hpp"
28 #include "runtime/java.hpp"
29 #include "runtime/mutex.hpp"
30 #include "runtime/mutexLocker.hpp"
31 #include "runtime/os.hpp"
32 #include "runtime/perfData.hpp"
33 #include "runtime/perfMemory.hpp"
34 #include "runtime/statSampler.hpp"
35 #include "utilities/globalDefinitions.hpp"
36
37 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
38
39 // Prefix of performance data file.
40 const char PERFDATA_NAME[] = "hsperfdata";
41
42 // Add 1 for the '_' character between PERFDATA_NAME and pid. The '\0' terminating
43 // character will be included in the sizeof(PERFDATA_NAME) operation.
44 static const size_t PERFDATA_FILENAME_LEN = sizeof(PERFDATA_NAME) +
45 UINT_CHARS + 1;
46
47 char* PerfMemory::_start = NULL;
48 char* PerfMemory::_end = NULL;
49 char* PerfMemory::_top = NULL;
50 size_t PerfMemory::_capacity = 0;
51 jint PerfMemory::_initialized = false;
52 PerfDataPrologue* PerfMemory::_prologue = NULL;
53
54 void perfMemory_init() {
55
56 if (!UsePerfData) return;
57
58 PerfMemory::initialize();
59 }
60
61 void perfMemory_exit() {
62
63 if (!UsePerfData) return;
64 if (!PerfMemory::is_initialized()) return;
65
66 // if the StatSampler is active, then we don't want to remove
67 // resources it may be dependent on. Typically, the StatSampler
68 // is disengaged from the watcher thread when this method is called,
69 // but it is not disengaged if this method is invoked during a
70 // VM abort.
71 //
72 if (!StatSampler::is_active())
73 PerfDataManager::destroy();
74
75 // remove the persistent external resources, if any. this method
76 // does not unmap or invalidate any virtual memory allocated during
77 // initialization.
78 //
79 PerfMemory::destroy();
80 }
81
82 void PerfMemory::initialize() {
83
84 if (_prologue != NULL)
85 // initialization already performed
86 return;
87
88 size_t capacity = align_size_up(PerfDataMemorySize,
89 os::vm_allocation_granularity());
90
91 if (PerfTraceMemOps) {
92 tty->print("PerfDataMemorySize = " SIZE_FORMAT ","
93 " os::vm_allocation_granularity = " SIZE_FORMAT ","
94 " adjusted size = " SIZE_FORMAT "\n",
95 PerfDataMemorySize,
96 os::vm_allocation_granularity(),
97 capacity);
98 }
99
100 // allocate PerfData memory region
101 create_memory_region(capacity);
102
103 if (_start == NULL) {
104
105 // the PerfMemory region could not be created as desired. Rather
106 // than terminating the JVM, we revert to creating the instrumentation
107 // on the C heap. When running in this mode, external monitoring
108 // clients cannot attach to and monitor this JVM.
109 //
110 // the warning is issued only in debug mode in order to avoid
111 // additional output to the stdout or stderr output streams.
112 //
113 if (PrintMiscellaneous && Verbose) {
114 warning("Could not create PerfData Memory region, reverting to malloc");
115 }
116
117 _prologue = NEW_C_HEAP_OBJ(PerfDataPrologue, mtInternal);
118 }
119 else {
120
121 // the PerfMemory region was created as expected.
122
123 if (PerfTraceMemOps) {
124 tty->print("PerfMemory created: address = " INTPTR_FORMAT ","
125 " size = " SIZE_FORMAT "\n",
126 (void*)_start,
127 _capacity);
128 }
129
130 _prologue = (PerfDataPrologue *)_start;
131 _end = _start + _capacity;
132 _top = _start + sizeof(PerfDataPrologue);
133 }
134
135 assert(_prologue != NULL, "prologue pointer must be initialized");
136
137 #ifdef VM_LITTLE_ENDIAN
138 _prologue->magic = (jint)0xc0c0feca;
139 _prologue->byte_order = PERFDATA_LITTLE_ENDIAN;
140 #else
141 _prologue->magic = (jint)0xcafec0c0;
142 _prologue->byte_order = PERFDATA_BIG_ENDIAN;
143 #endif
144
145 _prologue->major_version = PERFDATA_MAJOR_VERSION;
146 _prologue->minor_version = PERFDATA_MINOR_VERSION;
147 _prologue->accessible = 0;
148
149 _prologue->entry_offset = sizeof(PerfDataPrologue);
150 _prologue->num_entries = 0;
151 _prologue->used = 0;
152 _prologue->overflow = 0;
153 _prologue->mod_time_stamp = 0;
154
155 OrderAccess::release_store(&_initialized, 1);
156 }
157
158 void PerfMemory::destroy() {
159
160 if (_prologue == NULL) return;
161
162 if (_start != NULL && _prologue->overflow != 0) {
163
164 // This state indicates that the contiguous memory region exists and
165 // that it wasn't large enough to hold all the counters. In this case,
166 // we output a warning message to the user on exit if the -XX:+Verbose
167 // flag is set (a debug only flag). External monitoring tools can detect
168 // this condition by monitoring the _prologue->overflow word.
169 //
170 // There are two tunables that can help resolve this issue:
171 // - increase the size of the PerfMemory with -XX:PerfDataMemorySize=<n>
172 // - decrease the maximum string constant length with
173 // -XX:PerfMaxStringConstLength=<n>
174 //
175 if (PrintMiscellaneous && Verbose) {
176 warning("PerfMemory Overflow Occurred.\n"
177 "\tCapacity = " SIZE_FORMAT " bytes"
178 " Used = " SIZE_FORMAT " bytes"
179 " Overflow = " INT32_FORMAT " bytes"
180 "\n\tUse -XX:PerfDataMemorySize=<size> to specify larger size.",
181 PerfMemory::capacity(),
182 PerfMemory::used(),
183 _prologue->overflow);
184 }
185 }
186
187 if (_start != NULL) {
188
189 // this state indicates that the contiguous memory region was successfully
190 // and that persistent resources may need to be cleaned up. This is
191 // expected to be the typical condition.
192 //
193 delete_memory_region();
194 }
195
196 _start = NULL;
197 _end = NULL;
198 _top = NULL;
199 _prologue = NULL;
200 _capacity = 0;
201 }
202
203 // allocate an aligned block of memory from the PerfData memory
204 // region. This method assumes that the PerfData memory region
205 // was aligned on a double word boundary when created.
206 //
207 char* PerfMemory::alloc(size_t size) {
208
209 if (!UsePerfData) return NULL;
210
211 MutexLocker ml(PerfDataMemAlloc_lock);
212
213 assert(_prologue != NULL, "called before initialization");
214
215 // check that there is enough memory for this request
216 if ((_top + size) >= _end) {
217
218 _prologue->overflow += (jint)size;
219
220 return NULL;
221 }
222
223 char* result = _top;
224
225 _top += size;
226
227 assert(contains(result), "PerfData memory pointer out of range");
228
229 _prologue->used = (jint)used();
230 _prologue->num_entries = _prologue->num_entries + 1;
231
232 return result;
233 }
234
235 void PerfMemory::mark_updated() {
236 if (!UsePerfData) return;
237
238 _prologue->mod_time_stamp = os::elapsed_counter();
239 }
240
241 // Returns the complete path including the file name of performance data file.
242 // Caller is expected to release the allocated memory.
243 char* PerfMemory::get_perfdata_file_path() {
244 char* dest_file = NULL;
245
246 if (PerfDataSaveFile != NULL) {
247 // dest_file_name stores the validated file name if file_name
248 // contains %p which will be replaced by pid.
249 dest_file = NEW_C_HEAP_ARRAY(char, JVM_MAXPATHLEN, mtInternal);
250 if(!Arguments::copy_expand_pid(PerfDataSaveFile, strlen(PerfDataSaveFile),
251 dest_file, JVM_MAXPATHLEN)) {
252 FREE_C_HEAP_ARRAY(char, dest_file, mtInternal);
253 if (PrintMiscellaneous && Verbose) {
254 warning("Invalid performance data file path name specified, "\
255 "fall back to a default name");
256 }
257 } else {
258 return dest_file;
259 }
260 }
261 // create the name of the file for retaining the instrumentation memory.
262 dest_file = NEW_C_HEAP_ARRAY(char, PERFDATA_FILENAME_LEN, mtInternal);
263 jio_snprintf(dest_file, PERFDATA_FILENAME_LEN,
264 "%s_%d", PERFDATA_NAME, os::current_process_id());
265
266 return dest_file;
267 }