/* * Copyright (c) 2003, 2022, 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
JvmtiFramePops::clear(JvmtiFramePop& fp) {
assert(_pops->length() > 0, "No more frame pops");
_pops->remove(fp.frame_number());
}
int
JvmtiFramePops::clear_to(JvmtiFramePop& fp) { int cleared = 0; int index = 0; while (index < _pops->length()) {
JvmtiFramePop pop = JvmtiFramePop(_pops->at(index)); if (pop.above_on_stack(fp)) {
_pops->remove_at(index);
++cleared;
} else {
++index;
}
} return cleared;
}
/////////////////////////////////////////////////////////////// // // class JvmtiFramePops - public methods //
JvmtiFramePops::JvmtiFramePops() {
_pops = new (mtServiceability) GrowableArray<int> (2, mtServiceability);
}
JvmtiFramePops::~JvmtiFramePops() { // return memory to c_heap. delete _pops;
}
int n = _pops->length(); for (int i=0; i<n; i++) {
JvmtiFramePop fp = JvmtiFramePop(_pops->at(i));
tty->print("%d: ", i);
fp.print();
tty->cr();
}
} #endif
/////////////////////////////////////////////////////////////// // // class JvmtiEnvThreadState // // Instances of JvmtiEnvThreadState hang off of each JvmtiThreadState, // one per JvmtiEnv. //
// Use _thread_saved if cthread is detached from JavaThread (_thread == NULL).
JavaThread* JvmtiEnvThreadState::get_thread_or_saved() { return _state->get_thread_or_saved();
}
// Given that a new (potential) event has come in, // maintain the current JVMTI location on a per-thread per-env basis // and use it to filter out duplicate events: // - instruction rewrites // - breakpoint followed by single step // - single step at a breakpoint void JvmtiEnvThreadState::compare_and_set_current_location(Method* new_method,
address new_location, jvmtiEvent event) {
int new_bci = new_location - new_method->code_base();
// The method is identified and stored as a jmethodID which is safe in this // case because the class cannot be unloaded while a method is executing.
jmethodID new_method_id = new_method->jmethod_id();
// the last breakpoint or single step was at this same location if (_current_bci == new_bci && _current_method_id == new_method_id) { switch (event) { case JVMTI_EVENT_BREAKPOINT: // Repeat breakpoint is complicated. If we previously posted a breakpoint // event at this location and if we also single stepped at this location // then we skip the duplicate breakpoint.
_breakpoint_posted = _breakpoint_posted && _single_stepping_posted; break; case JVMTI_EVENT_SINGLE_STEP: // Repeat single step is easy: just don't post it again. // If step is pending for popframe then it may not be // a repeat step. The new_bci and method_id is same as current_bci // and current method_id after pop and step for recursive calls. // This has been handled by clearing the location
_single_stepping_posted = true; break; default:
assert(false, "invalid event value passed"); break;
} return;
}
JvmtiFramePops* JvmtiEnvThreadState::get_frame_pops() { #ifdef ASSERT
Thread *current = Thread::current(); #endif
assert(get_thread() == NULL || get_thread()->is_handshake_safe_for(current), "frame pop data only accessible from same or detached thread or direct handshake"); if (_frame_pops == NULL) {
_frame_pops = new JvmtiFramePops();
assert(_frame_pops != NULL, "_frame_pops != NULL");
} return _frame_pops;
}
void JvmtiEnvThreadState::set_frame_pop(int frame_number) { #ifdef ASSERT
Thread *current = Thread::current(); #endif
assert(get_thread() == NULL || get_thread()->is_handshake_safe_for(current), "frame pop data only accessible from same or detached thread or direct handshake");
JvmtiFramePop fpop(frame_number);
JvmtiEventController::set_frame_pop(this, fpop);
}
void JvmtiEnvThreadState::clear_frame_pop(int frame_number) { #ifdef ASSERT
Thread *current = Thread::current(); #endif
assert(get_thread() == NULL || get_thread()->is_handshake_safe_for(current), "frame pop data only accessible from same or detached thread or direct handshake");
JvmtiFramePop fpop(frame_number);
JvmtiEventController::clear_frame_pop(this, fpop);
}
bool JvmtiEnvThreadState::is_frame_pop(int cur_frame_number) { #ifdef ASSERT
Thread *current = Thread::current(); #endif
assert(get_thread() == NULL || get_thread()->is_handshake_safe_for(current), "frame pop data only accessible from same or detached thread or direct handshake"); if (!jvmti_thread_state()->is_interp_only_mode() || _frame_pops == NULL) { returnfalse;
}
JvmtiFramePop fp(cur_frame_number); return get_frame_pops()->contains(fp);
}
class VM_VirtualThreadGetCurrentLocation : public VM_Operation { private:
Handle _vthread_h;
jmethodID _method_id; int _bci; bool _completed;
if (jvf != NULL) { // jvf can be NULL, when the native enterSpecial frame is on the top.
Method* method = jvf->method();
_method_id = method->jmethod_id();
_bci = jvf->bci();
}
_completed = true;
} void get_current_location(jmethodID *method_id, int *bci) {
*method_id = _method_id;
*bci = _bci;
} bool completed() { return _completed;
}
};
class GetCurrentLocationClosure : public HandshakeClosure { private:
jmethodID _method_id; int _bci; bool _completed; public:
GetCurrentLocationClosure()
: HandshakeClosure("GetCurrentLocation"),
_method_id(NULL),
_bci(0),
_completed(false) {} void do_thread(Thread *target) {
JavaThread *jt = JavaThread::cast(target);
ResourceMark rmark; // jt != Thread::current()
RegisterMap rm(jt,
RegisterMap::UpdateMap::skip,
RegisterMap::ProcessFrames::include,
RegisterMap::WalkContinuation::skip); // There can be a race condition between a handshake // and the target thread exiting from Java execution. // We must recheck that the last Java frame still exists. if (!jt->is_exiting() && jt->has_last_Java_frame()) {
javaVFrame* vf = jt->last_java_vframe(&rm); if (vf != NULL) {
Method* method = vf->method();
_method_id = method->jmethod_id();
_bci = vf->bci();
}
}
_completed = true;
} void get_current_location(jmethodID *method_id, int *bci) {
*method_id = _method_id;
*bci = _bci;
} bool completed() { return _completed;
}
};
void JvmtiEnvThreadState::reset_current_location(jvmtiEvent event_type, bool enabled) {
assert(event_type == JVMTI_EVENT_SINGLE_STEP || event_type == JVMTI_EVENT_BREAKPOINT, "must be single-step or breakpoint event");
// Current location is used to detect the following: // 1) a breakpoint event followed by single-stepping to the same bci // 2) single-step to a bytecode that will be transformed to a fast version // We skip to avoid posting the duplicate single-stepping event.
// If single-stepping is disabled, clear current location so that // single-stepping to the same method and bcp at a later time will be // detected if single-stepping is enabled at that time (see 4388912).
// If single-stepping is enabled, set the current location to the // current method and bcp. This covers the following type of case, // e.g., the debugger stepi command: // - bytecode single stepped // - SINGLE_STEP event posted and SINGLE_STEP event disabled // - SINGLE_STEP event re-enabled // - bytecode rewritten to fast version
// If breakpoint event is disabled, clear current location only if // single-stepping is not enabled. Otherwise, keep the thread location // to detect any duplicate events.
if (enabled) { // If enabling breakpoint, no need to reset. // Can't do anything if empty stack.
if (thread == NULL && event_type == JVMTI_EVENT_SINGLE_STEP && is_virtual()) { // Handle the unmounted virtual thread case.
jmethodID method_id; int bci;
JavaThread* cur_thread = JavaThread::current();
HandleMark hm(cur_thread);
VM_VirtualThreadGetCurrentLocation op(Handle(cur_thread, thread_oop));
VMThread::execute(&op); if (op.completed()) { // Do nothing if virtual thread has been already terminated.
op.get_current_location(&method_id, &bci);
set_current_location(method_id, bci);
} return;
} if (event_type == JVMTI_EVENT_SINGLE_STEP && thread->has_last_Java_frame()) {
jmethodID method_id; int bci; // The java thread stack may not be walkable for a running thread // so get current location with direct handshake.
GetCurrentLocationClosure op;
Thread *current = Thread::current(); if (thread->is_handshake_safe_for(current)) {
op.do_thread(thread);
} else {
Handshake::execute(&op, thread);
guarantee(op.completed(), "Handshake failed. Target thread is not alive?");
}
op.get_current_location(&method_id, &bci);
set_current_location(method_id, bci);
}
} elseif (event_type == JVMTI_EVENT_SINGLE_STEP || !is_enabled(JVMTI_EVENT_SINGLE_STEP)) { // If this is to disable breakpoint, also check if single-step is not enabled
clear_current_location();
}
}
¤ Dauer der Verarbeitung: 0.26 Sekunden
(vorverarbeitet)
¤
Die Informationen auf dieser Webseite wurden
nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit,
noch Qualität der bereit gestellten Informationen zugesichert.
Bemerkung:
Die farbliche Syntaxdarstellung ist noch experimentell.
