/* * Copyright (c) 1997, 2021, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. *
*/
void InterfaceSupport::gc_alot() {
Thread *thread = Thread::current(); if (!thread->is_Java_thread()) return; // Avoid concurrent calls // Check for new, not quite initialized thread. A thread in new mode cannot initiate a GC.
JavaThread *current_thread = JavaThread::cast(thread); if (current_thread->active_handles() == NULL) return;
// Short-circuit any possible re-entrant gc-a-lot attempt if (thread->skip_gcalot()) return;
if (Threads::is_vm_complete()) {
if (++_fullgc_alot_invocation < FullGCALotStart) { return;
}
// Use this line if you want to block at a specific point, // e.g. one number_of_calls/scavenge/gc before you got into problems if (FullGCALot) _fullgc_alot_counter--;
// Check if we should force a full gc if (_fullgc_alot_counter == 0) { // Release dummy so objects are forced to move if (!Universe::release_fullgc_alot_dummy()) {
warning("FullGCALot: Unable to release more dummies at bottom of heap");
}
HandleMark hm(thread);
Universe::heap()->collect(GCCause::_full_gc_alot); unsignedint invocations = Universe::heap()->total_full_collections(); // Compute new interval if (FullGCALotInterval > 1) {
_fullgc_alot_counter = 1+(unsignedint)((double)FullGCALotInterval*os::random()/(max_jint+1.0));
log_trace(gc)("Full gc no: %u\tInterval: %u", invocations, _fullgc_alot_counter);
} else {
_fullgc_alot_counter = 1;
} // Print progress message if (invocations % 100 == 0) {
log_trace(gc)("Full gc no: %u", invocations);
}
} else { if (ScavengeALot) _scavenge_alot_counter--; // Check if we should force a scavenge if (_scavenge_alot_counter == 0) {
HandleMark hm(thread);
Universe::heap()->collect(GCCause::_scavenge_alot); unsignedint invocations = Universe::heap()->total_collections() - Universe::heap()->total_full_collections(); // Compute new interval if (ScavengeALotInterval > 1) {
_scavenge_alot_counter = 1+(unsignedint)((double)ScavengeALotInterval*os::random()/(max_jint+1.0));
log_trace(gc)("Scavenge no: %u\tInterval: %u", invocations, _scavenge_alot_counter);
} else {
_scavenge_alot_counter = 1;
} // Print progress message if (invocations % 1000 == 0) {
log_trace(gc)("Scavenge no: %u", invocations);
}
}
}
}
}
vframe* vframe_array[50]; int walk_stack_counter = 0;
void InterfaceSupport::walk_stack_from(vframe* start_vf) { // walk int i = 0; for (vframe* f = start_vf; f; f = f->sender() ) { if (i < 50) vframe_array[i++] = f;
}
}
// invocation counter for InterfaceSupport::deoptimizeAll/zombieAll functions int deoptimizeAllCounter = 0; int zombieAllCounter = 0;
void InterfaceSupport::zombieAll() { // This method is called by all threads when a thread make // transition to VM state (for example, runtime calls). // Divide number of calls by number of threads to avoid // dependence of ZombieAll events frequency on number of threads. int value = zombieAllCounter / Threads::number_of_threads(); if (is_init_completed() && value > ZombieALotInterval) {
zombieAllCounter = 0;
VM_ZombieAll op;
VMThread::execute(&op);
}
zombieAllCounter++;
}
void InterfaceSupport::deoptimizeAll() { // This method is called by all threads when a thread make // transition to VM state (for example, runtime calls). // Divide number of calls by number of threads to avoid // dependence of DeoptimizeAll events frequency on number of threads. int value = deoptimizeAllCounter / Threads::number_of_threads(); if (is_init_completed()) { if (DeoptimizeALot && value > DeoptimizeALotInterval) {
deoptimizeAllCounter = 0;
VM_DeoptimizeAll op;
VMThread::execute(&op);
} elseif (DeoptimizeRandom && (value & 0x1F) == (os::random() & 0x1F)) {
VM_DeoptimizeAll op;
VMThread::execute(&op);
}
}
deoptimizeAllCounter++;
}
void InterfaceSupport::verify_stack() {
JavaThread* thread = JavaThread::current();
ResourceMark rm(thread); // disabled because it throws warnings that oop maps should only be accessed // in VM thread or during debugging
if (!thread->has_pending_exception()) { // verification does not work if there are pending exceptions
StackFrameStream sfs(thread, true/* update */, true /* process_frames */);
CodeBlob* cb = sfs.current()->cb(); // In case of exceptions we might not have a runtime_stub on // top of stack, hence, all callee-saved registers are not going // to be setup correctly, hence, we cannot do stack verify if (cb != NULL && !(cb->is_runtime_stub() || cb->is_uncommon_trap_stub())) return;
for (; !sfs.is_done(); sfs.next()) {
sfs.current()->verify(sfs.register_map());
}
}
}
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