Mercurial > hg > truffle
diff src/share/vm/prims/jvmtiImpl.cpp @ 0:a61af66fc99e jdk7-b24
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author | duke |
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date | Sat, 01 Dec 2007 00:00:00 +0000 |
parents | |
children | 2f716c0acb64 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/prims/jvmtiImpl.cpp Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,912 @@ +/* + * Copyright 2003-2007 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.com if you need additional information or + * have any questions. + * + */ + +# include "incls/_precompiled.incl" +# include "incls/_jvmtiImpl.cpp.incl" + +GrowableArray<JvmtiRawMonitor*> *JvmtiPendingMonitors::_monitors = new (ResourceObj::C_HEAP) GrowableArray<JvmtiRawMonitor*>(1,true); + +void JvmtiPendingMonitors::transition_raw_monitors() { + assert((Threads::number_of_threads()==1), + "Java thread has not created yet or more than one java thread \ +is running. Raw monitor transition will not work"); + JavaThread *current_java_thread = JavaThread::current(); + assert(current_java_thread->thread_state() == _thread_in_vm, "Must be in vm"); + { + ThreadBlockInVM __tbivm(current_java_thread); + for(int i=0; i< count(); i++) { + JvmtiRawMonitor *rmonitor = monitors()->at(i); + int r = rmonitor->raw_enter(current_java_thread); + assert(r == ObjectMonitor::OM_OK, "raw_enter should have worked"); + } + } + // pending monitors are converted to real monitor so delete them all. + dispose(); +} + +// +// class JvmtiAgentThread +// +// JavaThread used to wrap a thread started by an agent +// using the JVMTI method RunAgentThread. +// + +JvmtiAgentThread::JvmtiAgentThread(JvmtiEnv* env, jvmtiStartFunction start_fn, const void *start_arg) + : JavaThread(start_function_wrapper) { + _env = env; + _start_fn = start_fn; + _start_arg = start_arg; +} + +void +JvmtiAgentThread::start_function_wrapper(JavaThread *thread, TRAPS) { + // It is expected that any Agent threads will be created as + // Java Threads. If this is the case, notification of the creation + // of the thread is given in JavaThread::thread_main(). + assert(thread->is_Java_thread(), "debugger thread should be a Java Thread"); + assert(thread == JavaThread::current(), "sanity check"); + + JvmtiAgentThread *dthread = (JvmtiAgentThread *)thread; + dthread->call_start_function(); +} + +void +JvmtiAgentThread::call_start_function() { + ThreadToNativeFromVM transition(this); + _start_fn(_env->jvmti_external(), jni_environment(), (void*)_start_arg); +} + + +// +// class GrowableCache - private methods +// + +void GrowableCache::recache() { + int len = _elements->length(); + + FREE_C_HEAP_ARRAY(address, _cache); + _cache = NEW_C_HEAP_ARRAY(address,len+1); + + for (int i=0; i<len; i++) { + _cache[i] = _elements->at(i)->getCacheValue(); + // + // The cache entry has gone bad. Without a valid frame pointer + // value, the entry is useless so we simply delete it in product + // mode. The call to remove() will rebuild the cache again + // without the bad entry. + // + if (_cache[i] == NULL) { + assert(false, "cannot recache NULL elements"); + remove(i); + return; + } + } + _cache[len] = NULL; + + _listener_fun(_this_obj,_cache); +} + +bool GrowableCache::equals(void* v, GrowableElement *e2) { + GrowableElement *e1 = (GrowableElement *) v; + assert(e1 != NULL, "e1 != NULL"); + assert(e2 != NULL, "e2 != NULL"); + + return e1->equals(e2); +} + +// +// class GrowableCache - public methods +// + +GrowableCache::GrowableCache() { + _this_obj = NULL; + _listener_fun = NULL; + _elements = NULL; + _cache = NULL; +} + +GrowableCache::~GrowableCache() { + clear(); + delete _elements; + FREE_C_HEAP_ARRAY(address, _cache); +} + +void GrowableCache::initialize(void *this_obj, void listener_fun(void *, address*) ) { + _this_obj = this_obj; + _listener_fun = listener_fun; + _elements = new (ResourceObj::C_HEAP) GrowableArray<GrowableElement*>(5,true); + recache(); +} + +// number of elements in the collection +int GrowableCache::length() { + return _elements->length(); +} + +// get the value of the index element in the collection +GrowableElement* GrowableCache::at(int index) { + GrowableElement *e = (GrowableElement *) _elements->at(index); + assert(e != NULL, "e != NULL"); + return e; +} + +int GrowableCache::find(GrowableElement* e) { + return _elements->find(e, GrowableCache::equals); +} + +// append a copy of the element to the end of the collection +void GrowableCache::append(GrowableElement* e) { + GrowableElement *new_e = e->clone(); + _elements->append(new_e); + recache(); +} + +// insert a copy of the element using lessthan() +void GrowableCache::insert(GrowableElement* e) { + GrowableElement *new_e = e->clone(); + _elements->append(new_e); + + int n = length()-2; + for (int i=n; i>=0; i--) { + GrowableElement *e1 = _elements->at(i); + GrowableElement *e2 = _elements->at(i+1); + if (e2->lessThan(e1)) { + _elements->at_put(i+1, e1); + _elements->at_put(i, e2); + } + } + + recache(); +} + +// remove the element at index +void GrowableCache::remove (int index) { + GrowableElement *e = _elements->at(index); + assert(e != NULL, "e != NULL"); + _elements->remove(e); + delete e; + recache(); +} + +// clear out all elements, release all heap space and +// let our listener know that things have changed. +void GrowableCache::clear() { + int len = _elements->length(); + for (int i=0; i<len; i++) { + delete _elements->at(i); + } + _elements->clear(); + recache(); +} + +void GrowableCache::oops_do(OopClosure* f) { + int len = _elements->length(); + for (int i=0; i<len; i++) { + GrowableElement *e = _elements->at(i); + e->oops_do(f); + } +} + +void GrowableCache::gc_epilogue() { + int len = _elements->length(); + // recompute the new cache value after GC + for (int i=0; i<len; i++) { + _cache[i] = _elements->at(i)->getCacheValue(); + } +} + + +// +// class JvmtiRawMonitor +// + +JvmtiRawMonitor::JvmtiRawMonitor(const char *name) { +#ifdef ASSERT + _name = strcpy(NEW_C_HEAP_ARRAY(char, strlen(name) + 1), name); +#else + _name = NULL; +#endif + _magic = JVMTI_RM_MAGIC; +} + +JvmtiRawMonitor::~JvmtiRawMonitor() { +#ifdef ASSERT + FreeHeap(_name); +#endif + _magic = 0; +} + + +// +// class JvmtiBreakpoint +// + +JvmtiBreakpoint::JvmtiBreakpoint() { + _method = NULL; + _bci = 0; +#ifdef CHECK_UNHANDLED_OOPS + // This one is always allocated with new, but check it just in case. + Thread *thread = Thread::current(); + if (thread->is_in_stack((address)&_method)) { + thread->allow_unhandled_oop((oop*)&_method); + } +#endif // CHECK_UNHANDLED_OOPS +} + +JvmtiBreakpoint::JvmtiBreakpoint(methodOop m_method, jlocation location) { + _method = m_method; + assert(_method != NULL, "_method != NULL"); + _bci = (int) location; +#ifdef CHECK_UNHANDLED_OOPS + // Could be allocated with new and wouldn't be on the unhandled oop list. + Thread *thread = Thread::current(); + if (thread->is_in_stack((address)&_method)) { + thread->allow_unhandled_oop(&_method); + } +#endif // CHECK_UNHANDLED_OOPS + + assert(_bci >= 0, "_bci >= 0"); +} + +void JvmtiBreakpoint::copy(JvmtiBreakpoint& bp) { + _method = bp._method; + _bci = bp._bci; +} + +bool JvmtiBreakpoint::lessThan(JvmtiBreakpoint& bp) { + Unimplemented(); + return false; +} + +bool JvmtiBreakpoint::equals(JvmtiBreakpoint& bp) { + return _method == bp._method + && _bci == bp._bci; +} + +bool JvmtiBreakpoint::is_valid() { + return _method != NULL && + _bci >= 0; +} + +address JvmtiBreakpoint::getBcp() { + return _method->bcp_from(_bci); +} + +void JvmtiBreakpoint::each_method_version_do(method_action meth_act) { + ((methodOopDesc*)_method->*meth_act)(_bci); + + // add/remove breakpoint to/from versions of the method that + // are EMCP. Directly or transitively obsolete methods are + // not saved in the PreviousVersionInfo. + Thread *thread = Thread::current(); + instanceKlassHandle ikh = instanceKlassHandle(thread, _method->method_holder()); + symbolOop m_name = _method->name(); + symbolOop m_signature = _method->signature(); + + { + ResourceMark rm(thread); + // PreviousVersionInfo objects returned via PreviousVersionWalker + // contain a GrowableArray of handles. We have to clean up the + // GrowableArray _after_ the PreviousVersionWalker destructor + // has destroyed the handles. + { + // search previous versions if they exist + PreviousVersionWalker pvw((instanceKlass *)ikh()->klass_part()); + for (PreviousVersionInfo * pv_info = pvw.next_previous_version(); + pv_info != NULL; pv_info = pvw.next_previous_version()) { + GrowableArray<methodHandle>* methods = + pv_info->prev_EMCP_method_handles(); + + if (methods == NULL) { + // We have run into a PreviousVersion generation where + // all methods were made obsolete during that generation's + // RedefineClasses() operation. At the time of that + // operation, all EMCP methods were flushed so we don't + // have to go back any further. + // + // A NULL methods array is different than an empty methods + // array. We cannot infer any optimizations about older + // generations from an empty methods array for the current + // generation. + break; + } + + for (int i = methods->length() - 1; i >= 0; i--) { + methodHandle method = methods->at(i); + if (method->name() == m_name && method->signature() == m_signature) { + RC_TRACE(0x00000800, ("%sing breakpoint in %s(%s)", + meth_act == &methodOopDesc::set_breakpoint ? "sett" : "clear", + method->name()->as_C_string(), + method->signature()->as_C_string())); + assert(!method->is_obsolete(), "only EMCP methods here"); + + ((methodOopDesc*)method()->*meth_act)(_bci); + break; + } + } + } + } // pvw is cleaned up + } // rm is cleaned up +} + +void JvmtiBreakpoint::set() { + each_method_version_do(&methodOopDesc::set_breakpoint); +} + +void JvmtiBreakpoint::clear() { + each_method_version_do(&methodOopDesc::clear_breakpoint); +} + +void JvmtiBreakpoint::print() { +#ifndef PRODUCT + const char *class_name = (_method == NULL) ? "NULL" : _method->klass_name()->as_C_string(); + const char *method_name = (_method == NULL) ? "NULL" : _method->name()->as_C_string(); + + tty->print("Breakpoint(%s,%s,%d,%p)",class_name, method_name, _bci, getBcp()); +#endif +} + + +// +// class VM_ChangeBreakpoints +// +// Modify the Breakpoints data structure at a safepoint +// + +void VM_ChangeBreakpoints::doit() { + switch (_operation) { + case SET_BREAKPOINT: + _breakpoints->set_at_safepoint(*_bp); + break; + case CLEAR_BREAKPOINT: + _breakpoints->clear_at_safepoint(*_bp); + break; + case CLEAR_ALL_BREAKPOINT: + _breakpoints->clearall_at_safepoint(); + break; + default: + assert(false, "Unknown operation"); + } +} + +void VM_ChangeBreakpoints::oops_do(OopClosure* f) { + // This operation keeps breakpoints alive + if (_breakpoints != NULL) { + _breakpoints->oops_do(f); + } + if (_bp != NULL) { + _bp->oops_do(f); + } +} + +// +// class JvmtiBreakpoints +// +// a JVMTI internal collection of JvmtiBreakpoint +// + +JvmtiBreakpoints::JvmtiBreakpoints(void listener_fun(void *,address *)) { + _bps.initialize(this,listener_fun); +} + +JvmtiBreakpoints:: ~JvmtiBreakpoints() {} + +void JvmtiBreakpoints::oops_do(OopClosure* f) { + _bps.oops_do(f); +} + +void JvmtiBreakpoints::gc_epilogue() { + _bps.gc_epilogue(); +} + +void JvmtiBreakpoints::print() { +#ifndef PRODUCT + ResourceMark rm; + + int n = _bps.length(); + for (int i=0; i<n; i++) { + JvmtiBreakpoint& bp = _bps.at(i); + tty->print("%d: ", i); + bp.print(); + tty->print_cr(""); + } +#endif +} + + +void JvmtiBreakpoints::set_at_safepoint(JvmtiBreakpoint& bp) { + assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); + + int i = _bps.find(bp); + if (i == -1) { + _bps.append(bp); + bp.set(); + } +} + +void JvmtiBreakpoints::clear_at_safepoint(JvmtiBreakpoint& bp) { + assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); + + int i = _bps.find(bp); + if (i != -1) { + _bps.remove(i); + bp.clear(); + } +} + +void JvmtiBreakpoints::clearall_at_safepoint() { + assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); + + int len = _bps.length(); + for (int i=0; i<len; i++) { + _bps.at(i).clear(); + } + _bps.clear(); +} + +int JvmtiBreakpoints::length() { return _bps.length(); } + +int JvmtiBreakpoints::set(JvmtiBreakpoint& bp) { + if ( _bps.find(bp) != -1) { + return JVMTI_ERROR_DUPLICATE; + } + VM_ChangeBreakpoints set_breakpoint(this,VM_ChangeBreakpoints::SET_BREAKPOINT, &bp); + VMThread::execute(&set_breakpoint); + return JVMTI_ERROR_NONE; +} + +int JvmtiBreakpoints::clear(JvmtiBreakpoint& bp) { + if ( _bps.find(bp) == -1) { + return JVMTI_ERROR_NOT_FOUND; + } + + VM_ChangeBreakpoints clear_breakpoint(this,VM_ChangeBreakpoints::CLEAR_BREAKPOINT, &bp); + VMThread::execute(&clear_breakpoint); + return JVMTI_ERROR_NONE; +} + +void JvmtiBreakpoints::clearall_in_class_at_safepoint(klassOop klass) { + bool changed = true; + // We are going to run thru the list of bkpts + // and delete some. This deletion probably alters + // the list in some implementation defined way such + // that when we delete entry i, the next entry might + // no longer be at i+1. To be safe, each time we delete + // an entry, we'll just start again from the beginning. + // We'll stop when we make a pass thru the whole list without + // deleting anything. + while (changed) { + int len = _bps.length(); + changed = false; + for (int i = 0; i < len; i++) { + JvmtiBreakpoint& bp = _bps.at(i); + if (bp.method()->method_holder() == klass) { + bp.clear(); + _bps.remove(i); + // This changed 'i' so we have to start over. + changed = true; + break; + } + } + } +} + +void JvmtiBreakpoints::clearall() { + VM_ChangeBreakpoints clearall_breakpoint(this,VM_ChangeBreakpoints::CLEAR_ALL_BREAKPOINT); + VMThread::execute(&clearall_breakpoint); +} + +// +// class JvmtiCurrentBreakpoints +// + +JvmtiBreakpoints *JvmtiCurrentBreakpoints::_jvmti_breakpoints = NULL; +address * JvmtiCurrentBreakpoints::_breakpoint_list = NULL; + + +JvmtiBreakpoints& JvmtiCurrentBreakpoints::get_jvmti_breakpoints() { + if (_jvmti_breakpoints != NULL) return (*_jvmti_breakpoints); + _jvmti_breakpoints = new JvmtiBreakpoints(listener_fun); + assert(_jvmti_breakpoints != NULL, "_jvmti_breakpoints != NULL"); + return (*_jvmti_breakpoints); +} + +void JvmtiCurrentBreakpoints::listener_fun(void *this_obj, address *cache) { + JvmtiBreakpoints *this_jvmti = (JvmtiBreakpoints *) this_obj; + assert(this_jvmti != NULL, "this_jvmti != NULL"); + + debug_only(int n = this_jvmti->length();); + assert(cache[n] == NULL, "cache must be NULL terminated"); + + set_breakpoint_list(cache); +} + + +void JvmtiCurrentBreakpoints::oops_do(OopClosure* f) { + if (_jvmti_breakpoints != NULL) { + _jvmti_breakpoints->oops_do(f); + } +} + +void JvmtiCurrentBreakpoints::gc_epilogue() { + if (_jvmti_breakpoints != NULL) { + _jvmti_breakpoints->gc_epilogue(); + } +} + + +/////////////////////////////////////////////////////////////// +// +// class VM_GetOrSetLocal +// + +// Constructor for non-object getter +VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, int index, BasicType type) + : _thread(thread) + , _calling_thread(NULL) + , _depth(depth) + , _index(index) + , _type(type) + , _set(false) + , _jvf(NULL) + , _result(JVMTI_ERROR_NONE) +{ +} + +// Constructor for object or non-object setter +VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, int index, BasicType type, jvalue value) + : _thread(thread) + , _calling_thread(NULL) + , _depth(depth) + , _index(index) + , _type(type) + , _value(value) + , _set(true) + , _jvf(NULL) + , _result(JVMTI_ERROR_NONE) +{ +} + +// Constructor for object getter +VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth, int index) + : _thread(thread) + , _calling_thread(calling_thread) + , _depth(depth) + , _index(index) + , _type(T_OBJECT) + , _set(false) + , _jvf(NULL) + , _result(JVMTI_ERROR_NONE) +{ +} + + +vframe *VM_GetOrSetLocal::get_vframe() { + if (!_thread->has_last_Java_frame()) { + return NULL; + } + RegisterMap reg_map(_thread); + vframe *vf = _thread->last_java_vframe(®_map); + int d = 0; + while ((vf != NULL) && (d < _depth)) { + vf = vf->java_sender(); + d++; + } + return vf; +} + +javaVFrame *VM_GetOrSetLocal::get_java_vframe() { + vframe* vf = get_vframe(); + if (vf == NULL) { + _result = JVMTI_ERROR_NO_MORE_FRAMES; + return NULL; + } + javaVFrame *jvf = (javaVFrame*)vf; + + if (!vf->is_java_frame() || jvf->method()->is_native()) { + _result = JVMTI_ERROR_OPAQUE_FRAME; + return NULL; + } + return jvf; +} + +// Check that the klass is assignable to a type with the given signature. +// Another solution could be to use the function Klass::is_subtype_of(type). +// But the type class can be forced to load/initialize eagerly in such a case. +// This may cause unexpected consequences like CFLH or class-init JVMTI events. +// It is better to avoid such a behavior. +bool VM_GetOrSetLocal::is_assignable(const char* ty_sign, Klass* klass, Thread* thread) { + assert(ty_sign != NULL, "type signature must not be NULL"); + assert(thread != NULL, "thread must not be NULL"); + assert(klass != NULL, "klass must not be NULL"); + + int len = (int) strlen(ty_sign); + if (ty_sign[0] == 'L' && ty_sign[len-1] == ';') { // Need pure class/interface name + ty_sign++; + len -= 2; + } + symbolHandle ty_sym = oopFactory::new_symbol_handle(ty_sign, len, thread); + if (klass->name() == ty_sym()) { + return true; + } + // Compare primary supers + int super_depth = klass->super_depth(); + int idx; + for (idx = 0; idx < super_depth; idx++) { + if (Klass::cast(klass->primary_super_of_depth(idx))->name() == ty_sym()) { + return true; + } + } + // Compare secondary supers + objArrayOop sec_supers = klass->secondary_supers(); + for (idx = 0; idx < sec_supers->length(); idx++) { + if (Klass::cast((klassOop) sec_supers->obj_at(idx))->name() == ty_sym()) { + return true; + } + } + return false; +} + +// Checks error conditions: +// JVMTI_ERROR_INVALID_SLOT +// JVMTI_ERROR_TYPE_MISMATCH +// Returns: 'true' - everything is Ok, 'false' - error code + +bool VM_GetOrSetLocal::check_slot_type(javaVFrame* jvf) { + methodOop method_oop = jvf->method(); + if (!method_oop->has_localvariable_table()) { + // Just to check index boundaries + jint extra_slot = (_type == T_LONG || _type == T_DOUBLE) ? 1 : 0; + if (_index < 0 || _index + extra_slot >= method_oop->max_locals()) { + _result = JVMTI_ERROR_INVALID_SLOT; + return false; + } + return true; + } + + jint num_entries = method_oop->localvariable_table_length(); + if (num_entries == 0) { + _result = JVMTI_ERROR_INVALID_SLOT; + return false; // There are no slots + } + int signature_idx = -1; + int vf_bci = jvf->bci(); + LocalVariableTableElement* table = method_oop->localvariable_table_start(); + for (int i = 0; i < num_entries; i++) { + int start_bci = table[i].start_bci; + int end_bci = start_bci + table[i].length; + + // Here we assume that locations of LVT entries + // with the same slot number cannot be overlapped + if (_index == (jint) table[i].slot && start_bci <= vf_bci && vf_bci <= end_bci) { + signature_idx = (int) table[i].descriptor_cp_index; + break; + } + } + if (signature_idx == -1) { + _result = JVMTI_ERROR_INVALID_SLOT; + return false; // Incorrect slot index + } + symbolOop sign_sym = method_oop->constants()->symbol_at(signature_idx); + const char* signature = (const char *) sign_sym->as_utf8(); + BasicType slot_type = char2type(signature[0]); + + switch (slot_type) { + case T_BYTE: + case T_SHORT: + case T_CHAR: + case T_BOOLEAN: + slot_type = T_INT; + break; + case T_ARRAY: + slot_type = T_OBJECT; + break; + }; + if (_type != slot_type) { + _result = JVMTI_ERROR_TYPE_MISMATCH; + return false; + } + + jobject jobj = _value.l; + if (_set && slot_type == T_OBJECT && jobj != NULL) { // NULL reference is allowed + // Check that the jobject class matches the return type signature. + JavaThread* cur_thread = JavaThread::current(); + HandleMark hm(cur_thread); + + Handle obj = Handle(cur_thread, JNIHandles::resolve_external_guard(jobj)); + NULL_CHECK(obj, (_result = JVMTI_ERROR_INVALID_OBJECT, false)); + KlassHandle ob_kh = KlassHandle(cur_thread, obj->klass()); + NULL_CHECK(ob_kh, (_result = JVMTI_ERROR_INVALID_OBJECT, false)); + + if (!is_assignable(signature, Klass::cast(ob_kh()), cur_thread)) { + _result = JVMTI_ERROR_TYPE_MISMATCH; + return false; + } + } + return true; +} + +static bool can_be_deoptimized(vframe* vf) { + return (vf->is_compiled_frame() && vf->fr().can_be_deoptimized()); +} + +bool VM_GetOrSetLocal::doit_prologue() { + _jvf = get_java_vframe(); + NULL_CHECK(_jvf, false); + + if (!check_slot_type(_jvf)) { + return false; + } + return true; +} + +void VM_GetOrSetLocal::doit() { + if (_set) { + // Force deoptimization of frame if compiled because it's + // possible the compiler emitted some locals as constant values, + // meaning they are not mutable. + if (can_be_deoptimized(_jvf)) { + + // Schedule deoptimization so that eventually the local + // update will be written to an interpreter frame. + VM_DeoptimizeFrame deopt(_jvf->thread(), _jvf->fr().id()); + VMThread::execute(&deopt); + + // Now store a new value for the local which will be applied + // once deoptimization occurs. Note however that while this + // write is deferred until deoptimization actually happens + // can vframe created after this point will have its locals + // reflecting this update so as far as anyone can see the + // write has already taken place. + + // If we are updating an oop then get the oop from the handle + // since the handle will be long gone by the time the deopt + // happens. The oop stored in the deferred local will be + // gc'd on its own. + if (_type == T_OBJECT) { + _value.l = (jobject) (JNIHandles::resolve_external_guard(_value.l)); + } + // Re-read the vframe so we can see that it is deoptimized + // [ Only need because of assert in update_local() ] + _jvf = get_java_vframe(); + ((compiledVFrame*)_jvf)->update_local(_type, _index, _value); + return; + } + StackValueCollection *locals = _jvf->locals(); + HandleMark hm; + + switch (_type) { + case T_INT: locals->set_int_at (_index, _value.i); break; + case T_LONG: locals->set_long_at (_index, _value.j); break; + case T_FLOAT: locals->set_float_at (_index, _value.f); break; + case T_DOUBLE: locals->set_double_at(_index, _value.d); break; + case T_OBJECT: { + Handle ob_h(JNIHandles::resolve_external_guard(_value.l)); + locals->set_obj_at (_index, ob_h); + break; + } + default: ShouldNotReachHere(); + } + _jvf->set_locals(locals); + } else { + StackValueCollection *locals = _jvf->locals(); + + if (locals->at(_index)->type() == T_CONFLICT) { + memset(&_value, 0, sizeof(_value)); + _value.l = NULL; + return; + } + + switch (_type) { + case T_INT: _value.i = locals->int_at (_index); break; + case T_LONG: _value.j = locals->long_at (_index); break; + case T_FLOAT: _value.f = locals->float_at (_index); break; + case T_DOUBLE: _value.d = locals->double_at(_index); break; + case T_OBJECT: { + // Wrap the oop to be returned in a local JNI handle since + // oops_do() no longer applies after doit() is finished. + oop obj = locals->obj_at(_index)(); + _value.l = JNIHandles::make_local(_calling_thread, obj); + break; + } + default: ShouldNotReachHere(); + } + } +} + + +bool VM_GetOrSetLocal::allow_nested_vm_operations() const { + return true; // May need to deoptimize +} + + +///////////////////////////////////////////////////////////////////////////////////////// + +// +// class JvmtiSuspendControl - see comments in jvmtiImpl.hpp +// + +bool JvmtiSuspendControl::suspend(JavaThread *java_thread) { + // external suspend should have caught suspending a thread twice + + // Immediate suspension required for JPDA back-end so JVMTI agent threads do + // not deadlock due to later suspension on transitions while holding + // raw monitors. Passing true causes the immediate suspension. + // java_suspend() will catch threads in the process of exiting + // and will ignore them. + java_thread->java_suspend(); + + // It would be nice to have the following assertion in all the time, + // but it is possible for a racing resume request to have resumed + // this thread right after we suspended it. Temporarily enable this + // assertion if you are chasing a different kind of bug. + // + // assert(java_lang_Thread::thread(java_thread->threadObj()) == NULL || + // java_thread->is_being_ext_suspended(), "thread is not suspended"); + + if (java_lang_Thread::thread(java_thread->threadObj()) == NULL) { + // check again because we can get delayed in java_suspend(): + // the thread is in process of exiting. + return false; + } + + return true; +} + +bool JvmtiSuspendControl::resume(JavaThread *java_thread) { + // external suspend should have caught resuming a thread twice + assert(java_thread->is_being_ext_suspended(), "thread should be suspended"); + + // resume thread + { + // must always grab Threads_lock, see JVM_SuspendThread + MutexLocker ml(Threads_lock); + java_thread->java_resume(); + } + + return true; +} + + +void JvmtiSuspendControl::print() { +#ifndef PRODUCT + MutexLocker mu(Threads_lock); + ResourceMark rm; + + tty->print("Suspended Threads: ["); + for (JavaThread *thread = Threads::first(); thread != NULL; thread = thread->next()) { +#if JVMTI_TRACE + const char *name = JvmtiTrace::safe_get_thread_name(thread); +#else + const char *name = ""; +#endif /*JVMTI_TRACE */ + tty->print("%s(%c ", name, thread->is_being_ext_suspended() ? 'S' : '_'); + if (!thread->has_last_Java_frame()) { + tty->print("no stack"); + } + tty->print(") "); + } + tty->print_cr("]"); +#endif +}