1 /*
2 * Copyright 2001-2006 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
24
25 # include "incls/_precompiled.incl"
26 # include "incls/_perfMemory.cpp.incl"
27
28 char* PerfMemory::_start = NULL;
29 char* PerfMemory::_end = NULL;
30 char* PerfMemory::_top = NULL;
31 size_t PerfMemory::_capacity = 0;
32 jint PerfMemory::_initialized = false;
33 PerfDataPrologue* PerfMemory::_prologue = NULL;
34
35 void perfMemory_init() {
36
37 if (!UsePerfData) return;
38
39 PerfMemory::initialize();
40 }
41
42 void perfMemory_exit() {
43
44 if (!UsePerfData) return;
45 if (!PerfMemory::is_initialized()) return;
46
47 // if the StatSampler is active, then we don't want to remove
48 // resources it may be dependent on. Typically, the StatSampler
49 // is disengaged from the watcher thread when this method is called,
50 // but it is not disengaged if this method is invoked during a
51 // VM abort.
52 //
53 if (!StatSampler::is_active())
54 PerfDataManager::destroy();
55
56 // remove the persistent external resources, if any. this method
57 // does not unmap or invalidate any virtual memory allocated during
58 // initialization.
59 //
60 PerfMemory::destroy();
61 }
62
63 void PerfMemory::initialize() {
64
65 if (_prologue != NULL)
66 // initialization already performed
67 return;
68
69 size_t capacity = align_size_up(PerfDataMemorySize,
70 os::vm_allocation_granularity());
71
72 if (PerfTraceMemOps) {
73 tty->print("PerfDataMemorySize = " SIZE_FORMAT ","
74 " os::vm_allocation_granularity = " SIZE_FORMAT ","
75 " adjusted size = " SIZE_FORMAT "\n",
76 PerfDataMemorySize,
77 os::vm_allocation_granularity(),
78 capacity);
79 }
80
81 // allocate PerfData memory region
82 create_memory_region(capacity);
83
84 if (_start == NULL) {
85
86 // the PerfMemory region could not be created as desired. Rather
87 // than terminating the JVM, we revert to creating the instrumentation
88 // on the C heap. When running in this mode, external monitoring
89 // clients cannot attach to and monitor this JVM.
90 //
91 // the warning is issued only in debug mode in order to avoid
92 // additional output to the stdout or stderr output streams.
93 //
94 if (PrintMiscellaneous && Verbose) {
95 warning("Could not create PerfData Memory region, reverting to malloc");
96 }
97
98 _prologue = NEW_C_HEAP_OBJ(PerfDataPrologue);
99 }
100 else {
101
102 // the PerfMemory region was created as expected.
103
104 if (PerfTraceMemOps) {
105 tty->print("PerfMemory created: address = " INTPTR_FORMAT ","
106 " size = " SIZE_FORMAT "\n",
107 (void*)_start,
108 _capacity);
109 }
110
111 _prologue = (PerfDataPrologue *)_start;
112 _end = _start + _capacity;
113 _top = _start + sizeof(PerfDataPrologue);
114 }
115
116 assert(_prologue != NULL, "prologue pointer must be initialized");
117
118 #ifdef VM_LITTLE_ENDIAN
119 _prologue->magic = (jint)0xc0c0feca;
120 _prologue->byte_order = PERFDATA_LITTLE_ENDIAN;
121 #else
122 _prologue->magic = (jint)0xcafec0c0;
123 _prologue->byte_order = PERFDATA_BIG_ENDIAN;
124 #endif
125
126 _prologue->major_version = PERFDATA_MAJOR_VERSION;
127 _prologue->minor_version = PERFDATA_MINOR_VERSION;
128 _prologue->accessible = 0;
129
130 _prologue->entry_offset = sizeof(PerfDataPrologue);
131 _prologue->num_entries = 0;
132 _prologue->used = 0;
133 _prologue->overflow = 0;
134 _prologue->mod_time_stamp = 0;
135
136 OrderAccess::release_store(&_initialized, 1);
137 }
138
139 void PerfMemory::destroy() {
140
141 assert(_prologue != NULL, "prologue pointer must be initialized");
142
143 if (_start != NULL && _prologue->overflow != 0) {
144
145 // This state indicates that the contiguous memory region exists and
146 // that it wasn't large enough to hold all the counters. In this case,
147 // we output a warning message to the user on exit if the -XX:+Verbose
148 // flag is set (a debug only flag). External monitoring tools can detect
149 // this condition by monitoring the _prologue->overflow word.
150 //
151 // There are two tunables that can help resolve this issue:
152 // - increase the size of the PerfMemory with -XX:PerfDataMemorySize=<n>
153 // - decrease the maximum string constant length with
154 // -XX:PerfMaxStringConstLength=<n>
155 //
156 if (PrintMiscellaneous && Verbose) {
157 warning("PerfMemory Overflow Occurred.\n"
158 "\tCapacity = " SIZE_FORMAT " bytes"
159 " Used = " SIZE_FORMAT " bytes"
160 " Overflow = " INT32_FORMAT " bytes"
161 "\n\tUse -XX:PerfDataMemorySize=<size> to specify larger size.",
162 PerfMemory::capacity(),
163 PerfMemory::used(),
164 _prologue->overflow);
165 }
166 }
167
168 if (_start != NULL) {
169
170 // this state indicates that the contiguous memory region was successfully
171 // and that persistent resources may need to be cleaned up. This is
172 // expected to be the typical condition.
173 //
174 delete_memory_region();
175 }
176
177 _start = NULL;
178 _end = NULL;
179 _top = NULL;
180 _prologue = NULL;
181 _capacity = 0;
182 }
183
184 // allocate an aligned block of memory from the PerfData memory
185 // region. This method assumes that the PerfData memory region
186 // was aligned on a double word boundary when created.
187 //
188 char* PerfMemory::alloc(size_t size) {
189
190 if (!UsePerfData) return NULL;
191
192 MutexLocker ml(PerfDataMemAlloc_lock);
193
194 assert(_prologue != NULL, "called before initialization");
195
196 // check that there is enough memory for this request
197 if ((_top + size) >= _end) {
198
199 _prologue->overflow += (jint)size;
200
201 return NULL;
202 }
203
204 char* result = _top;
205
206 _top += size;
207
208 assert(contains(result), "PerfData memory pointer out of range");
209
210 _prologue->used = (jint)used();
211 _prologue->num_entries = _prologue->num_entries + 1;
212
213 return result;
214 }
215
216 void PerfMemory::mark_updated() {
217 if (!UsePerfData) return;
218
219 _prologue->mod_time_stamp = os::elapsed_counter();
220 }
221
222 // Returns the complete path including the file name of performance data file.
223 // Caller is expected to release the allocated memory.
224 char* PerfMemory::get_perfdata_file_path() {
225 char* dest_file = NULL;
226
227 if (PerfDataSaveFile != NULL) {
228 // dest_file_name stores the validated file name if file_name
229 // contains %p which will be replaced by pid.
230 dest_file = NEW_C_HEAP_ARRAY(char, JVM_MAXPATHLEN);
231 if(!Arguments::copy_expand_pid(PerfDataSaveFile, strlen(PerfDataSaveFile),
232 dest_file, JVM_MAXPATHLEN)) {
233 FREE_C_HEAP_ARRAY(char, dest_file);
234 if (PrintMiscellaneous && Verbose) {
235 warning("Invalid performance data file path name specified, "\
236 "fall back to a default name");
237 }
238 } else {
239 return dest_file;
240 }
241 }
242 // create the name of the file for retaining the instrumentation memory.
243 dest_file = NEW_C_HEAP_ARRAY(char, PERFDATA_FILENAME_LEN);
244 jio_snprintf(dest_file, PERFDATA_FILENAME_LEN,
245 "%s_%d", PERFDATA_NAME, os::current_process_id());
246
247 return dest_file;
248 }