1 /* 2 * Copyright (c) 1997, 2016, 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/shared/collectedHeap.hpp" 27 #include "gc/shared/collectedHeap.inline.hpp" 28 #include "gc/shared/genCollectedHeap.hpp" 29 #include "memory/resourceArea.hpp" 30 #include "runtime/atomic.hpp" 31 #include "runtime/init.hpp" 32 #include "runtime/interfaceSupport.hpp" 33 #include "runtime/orderAccess.inline.hpp" 34 #include "runtime/os.inline.hpp" 35 #include "runtime/vframe.hpp" 36 #include "utilities/preserveException.hpp" 37 38 // Implementation of InterfaceSupport 39 40 #ifdef ASSERT 41 42 long InterfaceSupport::_number_of_calls = 0; 43 long InterfaceSupport::_scavenge_alot_counter = 1; 44 long InterfaceSupport::_fullgc_alot_counter = 1; 45 long InterfaceSupport::_fullgc_alot_invocation = 0; 46 47 Histogram* RuntimeHistogram; 48 49 RuntimeHistogramElement::RuntimeHistogramElement(const char* elementName) { 50 static volatile jint RuntimeHistogram_lock = 0; 51 _name = elementName; 52 uintx count = 0; 53 54 while (Atomic::cmpxchg(1, &RuntimeHistogram_lock, 0) != 0) { 55 while (OrderAccess::load_acquire(&RuntimeHistogram_lock) != 0) { 56 count +=1; 57 if ( (WarnOnStalledSpinLock > 0) 58 && (count % WarnOnStalledSpinLock == 0)) { 59 warning("RuntimeHistogram_lock seems to be stalled"); 60 } 61 } 62 } 63 64 if (RuntimeHistogram == NULL) { 65 RuntimeHistogram = new Histogram("VM Runtime Call Counts",200); 66 } 67 68 RuntimeHistogram->add_element(this); 69 Atomic::dec(&RuntimeHistogram_lock); 70 } 71 72 void InterfaceSupport::gc_alot() { 73 Thread *thread = Thread::current(); 74 if (!thread->is_Java_thread()) return; // Avoid concurrent calls 75 // Check for new, not quite initialized thread. A thread in new mode cannot initiate a GC. 76 JavaThread *current_thread = (JavaThread *)thread; 77 if (current_thread->active_handles() == NULL) return; 78 79 // Short-circuit any possible re-entrant gc-a-lot attempt 80 if (thread->skip_gcalot()) return; 81 82 if (Threads::is_vm_complete()) { 83 84 if (++_fullgc_alot_invocation < FullGCALotStart) { 85 return; 86 } 87 88 // Use this line if you want to block at a specific point, 89 // e.g. one number_of_calls/scavenge/gc before you got into problems 90 if (FullGCALot) _fullgc_alot_counter--; 91 92 // Check if we should force a full gc 93 if (_fullgc_alot_counter == 0) { 94 // Release dummy so objects are forced to move 95 if (!Universe::release_fullgc_alot_dummy()) { 96 warning("FullGCALot: Unable to release more dummies at bottom of heap"); 97 } 98 HandleMark hm(thread); 99 Universe::heap()->collect(GCCause::_full_gc_alot); 100 unsigned int invocations = Universe::heap()->total_full_collections(); 101 // Compute new interval 102 if (FullGCALotInterval > 1) { 103 _fullgc_alot_counter = 1+(long)((double)FullGCALotInterval*os::random()/(max_jint+1.0)); 104 log_trace(gc)("Full gc no: %u\tInterval: %ld", invocations, _fullgc_alot_counter); 105 } else { 106 _fullgc_alot_counter = 1; 107 } 108 // Print progress message 109 if (invocations % 100 == 0) { 110 log_trace(gc)("Full gc no: %u", invocations); 111 } 112 } else { 113 if (ScavengeALot) _scavenge_alot_counter--; 114 // Check if we should force a scavenge 115 if (_scavenge_alot_counter == 0) { 116 HandleMark hm(thread); 117 Universe::heap()->collect(GCCause::_scavenge_alot); 118 unsigned int invocations = Universe::heap()->total_collections() - Universe::heap()->total_full_collections(); 119 // Compute new interval 120 if (ScavengeALotInterval > 1) { 121 _scavenge_alot_counter = 1+(long)((double)ScavengeALotInterval*os::random()/(max_jint+1.0)); 122 log_trace(gc)("Scavenge no: %u\tInterval: %ld", invocations, _scavenge_alot_counter); 123 } else { 124 _scavenge_alot_counter = 1; 125 } 126 // Print progress message 127 if (invocations % 1000 == 0) { 128 log_trace(gc)("Scavenge no: %u", invocations); 129 } 130 } 131 } 132 } 133 } 134 135 136 vframe* vframe_array[50]; 137 int walk_stack_counter = 0; 138 139 void InterfaceSupport::walk_stack_from(vframe* start_vf) { 140 // walk 141 int i = 0; 142 for (vframe* f = start_vf; f; f = f->sender() ) { 143 if (i < 50) vframe_array[i++] = f; 144 } 145 } 146 147 148 void InterfaceSupport::walk_stack() { 149 JavaThread* thread = JavaThread::current(); 150 walk_stack_counter++; 151 if (!thread->has_last_Java_frame()) return; 152 ResourceMark rm(thread); 153 RegisterMap reg_map(thread); 154 walk_stack_from(thread->last_java_vframe(®_map)); 155 } 156 157 // invocation counter for InterfaceSupport::deoptimizeAll/zombieAll functions 158 int deoptimizeAllCounter = 0; 159 int zombieAllCounter = 0; 160 161 void InterfaceSupport::zombieAll() { 162 // This method is called by all threads when a thread make 163 // transition to VM state (for example, runtime calls). 164 // Divide number of calls by number of threads to avoid 165 // dependence of ZombieAll events frequency on number of threads. 166 int value = zombieAllCounter / Threads::number_of_threads(); 167 if (is_init_completed() && value > ZombieALotInterval) { 168 zombieAllCounter = 0; 169 VM_ZombieAll op; 170 VMThread::execute(&op); 171 } 172 zombieAllCounter++; 173 } 174 175 void InterfaceSupport::unlinkSymbols() { 176 VM_UnlinkSymbols op; 177 VMThread::execute(&op); 178 } 179 180 void InterfaceSupport::deoptimizeAll() { 181 // This method is called by all threads when a thread make 182 // transition to VM state (for example, runtime calls). 183 // Divide number of calls by number of threads to avoid 184 // dependence of DeoptimizeAll events frequency on number of threads. 185 int value = deoptimizeAllCounter / Threads::number_of_threads(); 186 if (is_init_completed()) { 187 if (DeoptimizeALot && value > DeoptimizeALotInterval) { 188 deoptimizeAllCounter = 0; 189 VM_DeoptimizeAll op; 190 VMThread::execute(&op); 191 } else if (DeoptimizeRandom && (value & 0x1F) == (os::random() & 0x1F)) { 192 VM_DeoptimizeAll op; 193 VMThread::execute(&op); 194 } 195 } 196 deoptimizeAllCounter++; 197 } 198 199 200 void InterfaceSupport::stress_derived_pointers() { 201 #ifdef COMPILER2 202 JavaThread *thread = JavaThread::current(); 203 if (!is_init_completed()) return; 204 ResourceMark rm(thread); 205 bool found = false; 206 for (StackFrameStream sfs(thread); !sfs.is_done() && !found; sfs.next()) { 207 CodeBlob* cb = sfs.current()->cb(); 208 if (cb != NULL && cb->oop_maps() ) { 209 // Find oopmap for current method 210 const ImmutableOopMap* map = cb->oop_map_for_return_address(sfs.current()->pc()); 211 assert(map != NULL, "no oopmap found for pc"); 212 found = map->has_derived_pointer(); 213 } 214 } 215 if (found) { 216 // $$$ Not sure what to do here. 217 /* 218 Scavenge::invoke(0); 219 */ 220 } 221 #endif 222 } 223 224 225 void InterfaceSupport::verify_stack() { 226 JavaThread* thread = JavaThread::current(); 227 ResourceMark rm(thread); 228 // disabled because it throws warnings that oop maps should only be accessed 229 // in VM thread or during debugging 230 231 if (!thread->has_pending_exception()) { 232 // verification does not work if there are pending exceptions 233 StackFrameStream sfs(thread); 234 CodeBlob* cb = sfs.current()->cb(); 235 // In case of exceptions we might not have a runtime_stub on 236 // top of stack, hence, all callee-saved registers are not going 237 // to be setup correctly, hence, we cannot do stack verify 238 if (cb != NULL && !(cb->is_runtime_stub() || cb->is_uncommon_trap_stub())) return; 239 240 for (; !sfs.is_done(); sfs.next()) { 241 sfs.current()->verify(sfs.register_map()); 242 } 243 } 244 } 245 246 247 void InterfaceSupport::verify_last_frame() { 248 JavaThread* thread = JavaThread::current(); 249 ResourceMark rm(thread); 250 RegisterMap reg_map(thread); 251 frame fr = thread->last_frame(); 252 fr.verify(®_map); 253 } 254 255 256 #endif // ASSERT 257 258 259 void InterfaceSupport_init() { 260 #ifdef ASSERT 261 if (ScavengeALot || FullGCALot) { 262 srand(ScavengeALotInterval * FullGCALotInterval); 263 } 264 #endif 265 }