1 /* 2 * Copyright (c) 1997, 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 "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/atomic.inline.hpp" 32 #include "runtime/init.hpp" 33 #include "runtime/interfaceSupport.hpp" 34 #include "runtime/orderAccess.inline.hpp" 35 #include "runtime/os.inline.hpp" 36 #include "runtime/threadLocalStorage.hpp" 37 #include "runtime/vframe.hpp" 38 #include "utilities/preserveException.hpp" 39 40 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC 41 42 // Implementation of InterfaceSupport 43 44 #ifdef ASSERT 45 46 long InterfaceSupport::_number_of_calls = 0; 47 long InterfaceSupport::_scavenge_alot_counter = 1; 48 long InterfaceSupport::_fullgc_alot_counter = 1; 49 long InterfaceSupport::_fullgc_alot_invocation = 0; 50 51 Histogram* RuntimeHistogram; 52 53 RuntimeHistogramElement::RuntimeHistogramElement(const char* elementName) { 54 static volatile jint RuntimeHistogram_lock = 0; 55 _name = elementName; 56 uintx count = 0; 57 58 while (Atomic::cmpxchg(1, &RuntimeHistogram_lock, 0) != 0) { 59 while (OrderAccess::load_acquire(&RuntimeHistogram_lock) != 0) { 60 count +=1; 61 if ( (WarnOnStalledSpinLock > 0) 62 && (count % WarnOnStalledSpinLock == 0)) { 63 warning("RuntimeHistogram_lock seems to be stalled"); 64 } 65 } 66 } 67 68 if (RuntimeHistogram == NULL) { 69 RuntimeHistogram = new Histogram("VM Runtime Call Counts",200); 70 } 71 72 RuntimeHistogram->add_element(this); 73 Atomic::dec(&RuntimeHistogram_lock); 74 } 75 76 void InterfaceSupport::trace(const char* result_type, const char* header) { 77 tty->print_cr("%6d %s", _number_of_calls, header); 78 } 79 80 void InterfaceSupport::gc_alot() { 81 Thread *thread = Thread::current(); 82 if (!thread->is_Java_thread()) return; // Avoid concurrent calls 83 // Check for new, not quite initialized thread. A thread in new mode cannot initiate a GC. 84 JavaThread *current_thread = (JavaThread *)thread; 85 if (current_thread->active_handles() == NULL) return; 86 87 // Short-circuit any possible re-entrant gc-a-lot attempt 88 if (thread->skip_gcalot()) return; 89 90 if (is_init_completed()) { 91 92 if (++_fullgc_alot_invocation < FullGCALotStart) { 93 return; 94 } 95 96 // Use this line if you want to block at a specific point, 97 // e.g. one number_of_calls/scavenge/gc before you got into problems 98 if (FullGCALot) _fullgc_alot_counter--; 99 100 // Check if we should force a full gc 101 if (_fullgc_alot_counter == 0) { 102 // Release dummy so objects are forced to move 103 if (!Universe::release_fullgc_alot_dummy()) { 104 warning("FullGCALot: Unable to release more dummies at bottom of heap"); 105 } 106 HandleMark hm(thread); 107 Universe::heap()->collect(GCCause::_full_gc_alot); 108 unsigned int invocations = Universe::heap()->total_full_collections(); 109 // Compute new interval 110 if (FullGCALotInterval > 1) { 111 _fullgc_alot_counter = 1+(long)((double)FullGCALotInterval*os::random()/(max_jint+1.0)); 112 if (PrintGCDetails && Verbose) { 113 tty->print_cr("Full gc no: %u\tInterval: %d", invocations, 114 _fullgc_alot_counter); 115 } 116 } else { 117 _fullgc_alot_counter = 1; 118 } 119 // Print progress message 120 if (invocations % 100 == 0) { 121 if (PrintGCDetails && Verbose) tty->print_cr("Full gc no: %u", invocations); 122 } 123 } else { 124 if (ScavengeALot) _scavenge_alot_counter--; 125 // Check if we should force a scavenge 126 if (_scavenge_alot_counter == 0) { 127 HandleMark hm(thread); 128 Universe::heap()->collect(GCCause::_scavenge_alot); 129 unsigned int invocations = Universe::heap()->total_collections() - Universe::heap()->total_full_collections(); 130 // Compute new interval 131 if (ScavengeALotInterval > 1) { 132 _scavenge_alot_counter = 1+(long)((double)ScavengeALotInterval*os::random()/(max_jint+1.0)); 133 if (PrintGCDetails && Verbose) { 134 tty->print_cr("Scavenge no: %u\tInterval: %d", invocations, 135 _scavenge_alot_counter); 136 } 137 } else { 138 _scavenge_alot_counter = 1; 139 } 140 // Print progress message 141 if (invocations % 1000 == 0) { 142 if (PrintGCDetails && Verbose) tty->print_cr("Scavenge no: %u", invocations); 143 } 144 } 145 } 146 } 147 } 148 149 150 vframe* vframe_array[50]; 151 int walk_stack_counter = 0; 152 153 void InterfaceSupport::walk_stack_from(vframe* start_vf) { 154 // walk 155 int i = 0; 156 for (vframe* f = start_vf; f; f = f->sender() ) { 157 if (i < 50) vframe_array[i++] = f; 158 } 159 } 160 161 162 void InterfaceSupport::walk_stack() { 163 JavaThread* thread = JavaThread::current(); 164 walk_stack_counter++; 165 if (!thread->has_last_Java_frame()) return; 166 ResourceMark rm(thread); 167 RegisterMap reg_map(thread); 168 walk_stack_from(thread->last_java_vframe(®_map)); 169 } 170 171 172 # ifdef ENABLE_ZAP_DEAD_LOCALS 173 174 static int zap_traversals = 0; 175 176 void InterfaceSupport::zap_dead_locals_old() { 177 JavaThread* thread = JavaThread::current(); 178 if (zap_traversals == -1) // edit constant for debugging 179 warning("I am here"); 180 int zap_frame_count = 0; // count frames to help debugging 181 for (StackFrameStream sfs(thread); !sfs.is_done(); sfs.next()) { 182 sfs.current()->zap_dead_locals(thread, sfs.register_map()); 183 ++zap_frame_count; 184 } 185 ++zap_traversals; 186 } 187 188 # endif 189 190 191 int deoptimizeAllCounter = 0; 192 int zombieAllCounter = 0; 193 194 195 void InterfaceSupport::zombieAll() { 196 if (is_init_completed() && zombieAllCounter > ZombieALotInterval) { 197 zombieAllCounter = 0; 198 VM_ZombieAll op; 199 VMThread::execute(&op); 200 } else { 201 zombieAllCounter++; 202 } 203 } 204 205 void InterfaceSupport::unlinkSymbols() { 206 VM_UnlinkSymbols op; 207 VMThread::execute(&op); 208 } 209 210 void InterfaceSupport::deoptimizeAll() { 211 if (is_init_completed() ) { 212 if (DeoptimizeALot && deoptimizeAllCounter > DeoptimizeALotInterval) { 213 deoptimizeAllCounter = 0; 214 VM_DeoptimizeAll op; 215 VMThread::execute(&op); 216 } else if (DeoptimizeRandom && (deoptimizeAllCounter & 0x1f) == (os::random() & 0x1f)) { 217 VM_DeoptimizeAll op; 218 VMThread::execute(&op); 219 } 220 } 221 deoptimizeAllCounter++; 222 } 223 224 225 void InterfaceSupport::stress_derived_pointers() { 226 #ifdef COMPILER2 227 JavaThread *thread = JavaThread::current(); 228 if (!is_init_completed()) return; 229 ResourceMark rm(thread); 230 bool found = false; 231 for (StackFrameStream sfs(thread); !sfs.is_done() && !found; sfs.next()) { 232 CodeBlob* cb = sfs.current()->cb(); 233 if (cb != NULL && cb->oop_maps() ) { 234 // Find oopmap for current method 235 OopMap* map = cb->oop_map_for_return_address(sfs.current()->pc()); 236 assert(map != NULL, "no oopmap found for pc"); 237 found = map->has_derived_pointer(); 238 } 239 } 240 if (found) { 241 // $$$ Not sure what to do here. 242 /* 243 Scavenge::invoke(0); 244 */ 245 } 246 #endif 247 } 248 249 250 void InterfaceSupport::verify_stack() { 251 JavaThread* thread = JavaThread::current(); 252 ResourceMark rm(thread); 253 // disabled because it throws warnings that oop maps should only be accessed 254 // in VM thread or during debugging 255 256 if (!thread->has_pending_exception()) { 257 // verification does not work if there are pending exceptions 258 StackFrameStream sfs(thread); 259 CodeBlob* cb = sfs.current()->cb(); 260 // In case of exceptions we might not have a runtime_stub on 261 // top of stack, hence, all callee-saved registers are not going 262 // to be setup correctly, hence, we cannot do stack verify 263 if (cb != NULL && !(cb->is_runtime_stub() || cb->is_uncommon_trap_stub())) return; 264 265 for (; !sfs.is_done(); sfs.next()) { 266 sfs.current()->verify(sfs.register_map()); 267 } 268 } 269 } 270 271 272 void InterfaceSupport::verify_last_frame() { 273 JavaThread* thread = JavaThread::current(); 274 ResourceMark rm(thread); 275 RegisterMap reg_map(thread); 276 frame fr = thread->last_frame(); 277 fr.verify(®_map); 278 } 279 280 281 #endif // ASSERT 282 283 284 void InterfaceSupport_init() { 285 #ifdef ASSERT 286 if (ScavengeALot || FullGCALot) { 287 srand(ScavengeALotInterval * FullGCALotInterval); 288 } 289 #endif 290 }