1 /* 2 * Copyright (c) 1997, 2011, 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 "gc_implementation/shared/markSweep.hpp" 27 #include "gc_interface/collectedHeap.hpp" 28 #include "gc_interface/collectedHeap.inline.hpp" 29 #include "memory/genCollectedHeap.hpp" 30 #include "memory/resourceArea.hpp" 31 #include "runtime/init.hpp" 32 #include "runtime/interfaceSupport.hpp" 33 #include "runtime/threadLocalStorage.hpp" 34 #include "runtime/vframe.hpp" 35 #include "utilities/preserveException.hpp" 36 37 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC 38 39 // Implementation of InterfaceSupport 40 41 #ifdef ASSERT 42 43 long InterfaceSupport::_number_of_calls = 0; 44 long InterfaceSupport::_scavenge_alot_counter = 1; 45 long InterfaceSupport::_fullgc_alot_counter = 1; 46 long InterfaceSupport::_fullgc_alot_invocation = 0; 47 48 Histogram* RuntimeHistogram; 49 50 RuntimeHistogramElement::RuntimeHistogramElement(const char* elementName) { 51 static volatile jint RuntimeHistogram_lock = 0; 52 _name = elementName; 53 uintx count = 0; 54 55 while (Atomic::cmpxchg(1, &RuntimeHistogram_lock, 0) != 0) { 56 while (OrderAccess::load_acquire(&RuntimeHistogram_lock) != 0) { 57 count +=1; 58 if ( (WarnOnStalledSpinLock > 0) 59 && (count % WarnOnStalledSpinLock == 0)) { 60 warning("RuntimeHistogram_lock seems to be stalled"); 61 } 62 } 63 } 64 65 if (RuntimeHistogram == NULL) { 66 RuntimeHistogram = new Histogram("VM Runtime Call Counts",200); 67 } 68 69 RuntimeHistogram->add_element(this); 70 Atomic::dec(&RuntimeHistogram_lock); 71 } 72 73 void InterfaceSupport::trace(const char* result_type, const char* header) { 74 tty->print_cr("%6d %s", _number_of_calls, header); 75 } 76 77 void InterfaceSupport::gc_alot() { 78 Thread *thread = Thread::current(); 79 if (!thread->is_Java_thread()) return; // Avoid concurrent calls 80 // Check for new, not quite initialized thread. A thread in new mode cannot initiate a GC. 81 JavaThread *current_thread = (JavaThread *)thread; 82 if (current_thread->active_handles() == NULL) return; 83 84 // Short-circuit any possible re-entrant gc-a-lot attempt 85 if (thread->skip_gcalot()) return; 86 87 if (is_init_completed()) { 88 89 if (++_fullgc_alot_invocation < FullGCALotStart) { 90 return; 91 } 92 93 // Use this line if you want to block at a specific point, 94 // e.g. one number_of_calls/scavenge/gc before you got into problems 95 if (FullGCALot) _fullgc_alot_counter--; 96 97 // Check if we should force a full gc 98 if (_fullgc_alot_counter == 0) { 99 // Release dummy so objects are forced to move 100 if (!Universe::release_fullgc_alot_dummy()) { 101 warning("FullGCALot: Unable to release more dummies at bottom of heap"); 102 } 103 HandleMark hm(thread); 104 Universe::heap()->collect(GCCause::_full_gc_alot); 105 unsigned int invocations = Universe::heap()->total_full_collections(); 106 // Compute new interval 107 if (FullGCALotInterval > 1) { 108 _fullgc_alot_counter = 1+(long)((double)FullGCALotInterval*os::random()/(max_jint+1.0)); 109 if (PrintGCDetails && Verbose) { 110 tty->print_cr("Full gc no: %u\tInterval: %d", invocations, 111 _fullgc_alot_counter); 112 } 113 } else { 114 _fullgc_alot_counter = 1; 115 } 116 // Print progress message 117 if (invocations % 100 == 0) { 118 if (PrintGCDetails && Verbose) tty->print_cr("Full gc no: %u", invocations); 119 } 120 } else { 121 if (ScavengeALot) _scavenge_alot_counter--; 122 // Check if we should force a scavenge 123 if (_scavenge_alot_counter == 0) { 124 HandleMark hm(thread); 125 Universe::heap()->collect(GCCause::_scavenge_alot); 126 unsigned int invocations = Universe::heap()->total_collections() - Universe::heap()->total_full_collections(); 127 // Compute new interval 128 if (ScavengeALotInterval > 1) { 129 _scavenge_alot_counter = 1+(long)((double)ScavengeALotInterval*os::random()/(max_jint+1.0)); 130 if (PrintGCDetails && Verbose) { 131 tty->print_cr("Scavenge no: %u\tInterval: %d", invocations, 132 _scavenge_alot_counter); 133 } 134 } else { 135 _scavenge_alot_counter = 1; 136 } 137 // Print progress message 138 if (invocations % 1000 == 0) { 139 if (PrintGCDetails && Verbose) tty->print_cr("Scavenge no: %u", invocations); 140 } 141 } 142 } 143 } 144 } 145 146 147 vframe* vframe_array[50]; 148 int walk_stack_counter = 0; 149 150 void InterfaceSupport::walk_stack_from(vframe* start_vf) { 151 // walk 152 int i = 0; 153 for (vframe* f = start_vf; f; f = f->sender() ) { 154 if (i < 50) vframe_array[i++] = f; 155 } 156 } 157 158 159 void InterfaceSupport::walk_stack() { 160 JavaThread* thread = JavaThread::current(); 161 walk_stack_counter++; 162 if (!thread->has_last_Java_frame()) return; 163 ResourceMark rm(thread); 164 RegisterMap reg_map(thread); 165 walk_stack_from(thread->last_java_vframe(®_map)); 166 } 167 168 169 # ifdef ENABLE_ZAP_DEAD_LOCALS 170 171 static int zap_traversals = 0; 172 173 void InterfaceSupport::zap_dead_locals_old() { 174 JavaThread* thread = JavaThread::current(); 175 if (zap_traversals == -1) // edit constant for debugging 176 warning("I am here"); 177 int zap_frame_count = 0; // count frames to help debugging 178 for (StackFrameStream sfs(thread); !sfs.is_done(); sfs.next()) { 179 sfs.current()->zap_dead_locals(thread, sfs.register_map()); 180 ++zap_frame_count; 181 } 182 ++zap_traversals; 183 } 184 185 # endif 186 187 188 int deoptimizeAllCounter = 0; 189 int zombieAllCounter = 0; 190 191 192 void InterfaceSupport::zombieAll() { 193 if (is_init_completed() && zombieAllCounter > ZombieALotInterval) { 194 zombieAllCounter = 0; 195 VM_ZombieAll op; 196 VMThread::execute(&op); 197 } else { 198 zombieAllCounter++; 199 } 200 } 201 202 void InterfaceSupport::unlinkSymbols() { 203 VM_UnlinkSymbols op; 204 VMThread::execute(&op); 205 } 206 207 void InterfaceSupport::deoptimizeAll() { 208 if (is_init_completed() ) { 209 if (DeoptimizeALot && deoptimizeAllCounter > DeoptimizeALotInterval) { 210 deoptimizeAllCounter = 0; 211 VM_DeoptimizeAll op; 212 VMThread::execute(&op); 213 } else if (DeoptimizeRandom && (deoptimizeAllCounter & 0x1f) == (os::random() & 0x1f)) { 214 VM_DeoptimizeAll op; 215 VMThread::execute(&op); 216 } 217 } 218 deoptimizeAllCounter++; 219 } 220 221 222 void InterfaceSupport::stress_derived_pointers() { 223 #ifdef COMPILER2 224 JavaThread *thread = JavaThread::current(); 225 if (!is_init_completed()) return; 226 ResourceMark rm(thread); 227 bool found = false; 228 for (StackFrameStream sfs(thread); !sfs.is_done() && !found; sfs.next()) { 229 CodeBlob* cb = sfs.current()->cb(); 230 if (cb != NULL && cb->oop_maps() ) { 231 // Find oopmap for current method 232 OopMap* map = cb->oop_map_for_return_address(sfs.current()->pc()); 233 assert(map != NULL, "no oopmap found for pc"); 234 found = map->has_derived_pointer(); 235 } 236 } 237 if (found) { 238 // $$$ Not sure what to do here. 239 /* 240 Scavenge::invoke(0); 241 */ 242 } 243 #endif 244 } 245 246 247 void InterfaceSupport::verify_stack() { 248 JavaThread* thread = JavaThread::current(); 249 ResourceMark rm(thread); 250 // disabled because it throws warnings that oop maps should only be accessed 251 // in VM thread or during debugging 252 253 if (!thread->has_pending_exception()) { 254 // verification does not work if there are pending exceptions 255 StackFrameStream sfs(thread); 256 CodeBlob* cb = sfs.current()->cb(); 257 // In case of exceptions we might not have a runtime_stub on 258 // top of stack, hence, all callee-saved registers are not going 259 // to be setup correctly, hence, we cannot do stack verify 260 if (cb != NULL && !(cb->is_runtime_stub() || cb->is_uncommon_trap_stub())) return; 261 262 for (; !sfs.is_done(); sfs.next()) { 263 sfs.current()->verify(sfs.register_map()); 264 } 265 } 266 } 267 268 269 void InterfaceSupport::verify_last_frame() { 270 JavaThread* thread = JavaThread::current(); 271 ResourceMark rm(thread); 272 RegisterMap reg_map(thread); 273 frame fr = thread->last_frame(); 274 fr.verify(®_map); 275 } 276 277 278 #endif // ASSERT 279 280 281 void InterfaceSupport_init() { 282 #ifdef ASSERT 283 if (ScavengeALot || FullGCALot) { 284 srand(ScavengeALotInterval * FullGCALotInterval); 285 } 286 #endif 287 }