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dragonwell8_hotspot
提交 0e2e6b55 编写于 作者: K kevinw
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8055008: Clean up code that saves the previous versions of redefined classes 

8156137: SIGSEGV in ReceiverTypeData::clean_weak_klass_links
8057570: RedefineClasses() tests fail assert(((Metadata*)obj)->is_valid()) failed: obj is valid
Reviewed-by: coleenp
上级 52b31d47
隐藏空白更改
内联 并排
Showing with 345 addition and 371 deletion
src/share/vm/classfile/metadataOnStackMark.cpp
浏览文件 @ 0e2e6b55
......@@ -41,13 +41,13 @@ NOT_PRODUCT(bool MetadataOnStackMark::_is_active = false;)
// Walk metadata on the stack and mark it so that redefinition doesn't delete
// it. Class unloading also walks the previous versions and might try to
// delete it, so this class is used by class unloading also.
MetadataOnStackMark::MetadataOnStackMark(bool visit_code_cache) {
MetadataOnStackMark::MetadataOnStackMark(bool has_redefined_a_class) {
assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
assert(_used_buffers == NULL, "sanity check");
NOT_PRODUCT(_is_active = true;)
Threads::metadata_do(Metadata::mark_on_stack);
if (visit_code_cache) {
if (has_redefined_a_class) {
CodeCache::alive_nmethods_do(nmethod::mark_on_stack);
}
CompileBroker::mark_on_stack();
......
src/share/vm/classfile/metadataOnStackMark.hpp
浏览文件 @ 0e2e6b55
......@@ -47,7 +47,7 @@ class MetadataOnStackMark : public StackObj {
static void retire_buffer(MetadataOnStackBuffer* buffer);
public:
MetadataOnStackMark(bool visit_code_cache);
MetadataOnStackMark(bool has_redefined_a_class);
~MetadataOnStackMark();
static void record(Metadata* m, Thread* thread);
......
src/share/vm/code/nmethod.cpp
浏览文件 @ 0e2e6b55
......@@ -2173,7 +2173,7 @@ void nmethod::metadata_do(void f(Metadata*)) {
"metadata must be found in exactly one place");
if (r->metadata_is_immediate() && r->metadata_value() != NULL) {
Metadata* md = r->metadata_value();
f(md);
if (md != _method) f(md);
}
} else if (iter.type() == relocInfo::virtual_call_type) {
// Check compiledIC holders associated with this nmethod
......@@ -2199,7 +2199,7 @@ void nmethod::metadata_do(void f(Metadata*)) {
f(md);
}
// Visit metadata not embedded in the other places.
// Call function Method*, not embedded in these other places.
if (_method != NULL) f(_method);
}
......
src/share/vm/oops/instanceKlass.cpp
浏览文件 @ 0e2e6b55
......@@ -2582,16 +2582,6 @@ void InstanceKlass::release_C_heap_structures() {
assert(breakpoints() == 0x0, "should have cleared breakpoints");
}
// deallocate information about previous versions
if (_previous_versions != NULL) {
for (int i = _previous_versions->length() - 1; i >= 0; i--) {
PreviousVersionNode * pv_node = _previous_versions->at(i);
delete pv_node;
}
delete _previous_versions;
_previous_versions = NULL;
}
// deallocate the cached class file
if (_cached_class_file != NULL) {
os::free(_cached_class_file, mtClass);
......@@ -3187,16 +3177,17 @@ void InstanceKlass::print_on(outputStream* st) const {
st->print(BULLET"field type annotations: "); fields_type_annotations()->print_value_on(st); st->cr();
{
bool have_pv = false;
PreviousVersionWalker pvw(Thread::current(), (InstanceKlass*)this);
for (PreviousVersionNode * pv_node = pvw.next_previous_version();
pv_node != NULL; pv_node = pvw.next_previous_version()) {
// previous versions are linked together through the InstanceKlass
for (InstanceKlass* pv_node = _previous_versions;
pv_node != NULL;
pv_node = pv_node->previous_versions()) {
if (!have_pv)
st->print(BULLET"previous version: ");
have_pv = true;
pv_node->prev_constant_pool()->print_value_on(st);
pv_node->constants()->print_value_on(st);
}
if (have_pv) st->cr();
} // pvw is cleaned up
}
if (generic_signature() != NULL) {
st->print(BULLET"generic signature: ");
......@@ -3610,92 +3601,93 @@ void InstanceKlass::set_init_state(ClassState state) {
// RedefineClasses() support for previous versions:
// Purge previous versions
static void purge_previous_versions_internal(InstanceKlass* ik, int emcp_method_count) {
void InstanceKlass::purge_previous_versions(InstanceKlass* ik) {
if (ik->previous_versions() != NULL) {
// This klass has previous versions so see what we can cleanup
// while it is safe to do so.
int deleted_count = 0; // leave debugging breadcrumbs
int live_count = 0;
ClassLoaderData* loader_data = ik->class_loader_data() == NULL ?
ClassLoaderData::the_null_class_loader_data() :
ik->class_loader_data();
ClassLoaderData* loader_data = ik->class_loader_data();
assert(loader_data != NULL, "should never be null");
// RC_TRACE macro has an embedded ResourceMark
RC_TRACE(0x00000200, ("purge: %s: previous version length=%d",
ik->external_name(), ik->previous_versions()->length()));
RC_TRACE(0x00000200, ("purge: %s: previous versions", ik->external_name()));
// previous versions are linked together through the InstanceKlass
InstanceKlass* pv_node = ik->previous_versions();
InstanceKlass* last = ik;
int version = 0;
// check the previous versions list
for (; pv_node != NULL; ) {
ConstantPool* pvcp = pv_node->constants();
assert(pvcp != NULL, "cp ref was unexpectedly cleared");
for (int i = ik->previous_versions()->length() - 1; i >= 0; i--) {
// check the previous versions array
PreviousVersionNode * pv_node = ik->previous_versions()->at(i);
ConstantPool* cp_ref = pv_node->prev_constant_pool();
assert(cp_ref != NULL, "cp ref was unexpectedly cleared");
ConstantPool* pvcp = cp_ref;
if (!pvcp->on_stack()) {
// If the constant pool isn't on stack, none of the methods
// are executing. Delete all the methods, the constant pool and
// and this previous version node.
GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
if (method_refs != NULL) {
for (int j = method_refs->length() - 1; j >= 0; j--) {
Method* method = method_refs->at(j);
assert(method != NULL, "method ref was unexpectedly cleared");
method_refs->remove_at(j);
// method will be freed with associated class.
}
}
// Remove the constant pool
delete pv_node;
// Since we are traversing the array backwards, we don't have to
// do anything special with the index.
ik->previous_versions()->remove_at(i);
// are executing. Unlink this previous_version.
// The previous version InstanceKlass is on the ClassLoaderData deallocate list
// so will be deallocated during the next phase of class unloading.
pv_node = pv_node->previous_versions();
last->link_previous_versions(pv_node);
deleted_count++;
version++;
continue;
} else {
RC_TRACE(0x00000200, ("purge: previous version @%d is alive", i));
RC_TRACE(0x00000200, ("purge: previous version " INTPTR_FORMAT " is alive",
pv_node));
assert(pvcp->pool_holder() != NULL, "Constant pool with no holder");
guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
live_count++;
}
// At least one method is live in this previous version, clean out
// the others or mark them as obsolete.
GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
// At least one method is live in this previous version so clean its MethodData.
// Reset dead EMCP methods not to get breakpoints.
// All methods are deallocated when all of the methods for this class are no
// longer running.
Array<Method*>* method_refs = pv_node->methods();
if (method_refs != NULL) {
RC_TRACE(0x00000200, ("purge: previous methods length=%d",
method_refs->length()));
for (int j = method_refs->length() - 1; j >= 0; j--) {
for (int j = 0; j < method_refs->length(); j++) {
Method* method = method_refs->at(j);
assert(method != NULL, "method ref was unexpectedly cleared");
// Remove the emcp method if it's not executing
// If it's been made obsolete by a redefinition of a non-emcp
// method, mark it as obsolete but leave it to clean up later.
if (!method->on_stack()) {
method_refs->remove_at(j);
} else if (emcp_method_count == 0) {
method->set_is_obsolete();
// no breakpoints for non-running methods
if (method->is_running_emcp()) {
method->set_running_emcp(false);
}
} else {
assert (method->is_obsolete() || method->is_running_emcp(),
"emcp method cannot run after emcp bit is cleared");
// RC_TRACE macro has an embedded ResourceMark
RC_TRACE(0x00000200,
("purge: %s(%s): prev method @%d in version @%d is alive",
method->name()->as_C_string(),
method->signature()->as_C_string(), j, i));
method->signature()->as_C_string(), j, version));
if (method->method_data() != NULL) {
// Clean out any weak method links
// Clean out any weak method links for running methods
// (also should include not EMCP methods)
method->method_data()->clean_weak_method_links();
}
}
}
}
// next previous version
last = pv_node;
pv_node = pv_node->previous_versions();
version++;
}
assert(ik->previous_versions()->length() == live_count, "sanity check");
RC_TRACE(0x00000200,
("purge: previous version stats: live=%d, deleted=%d", live_count,
deleted_count));
}
// Clean MethodData of this class's methods so they don't refer to
// old methods that are no longer running.
Array<Method*>* methods = ik->methods();
int num_methods = methods->length();
for (int index2 = 0; index2 < num_methods; ++index2) {
......@@ -3705,122 +3697,30 @@ static void purge_previous_versions_internal(InstanceKlass* ik, int emcp_method_
}
}
// External interface for use during class unloading.
void InstanceKlass::purge_previous_versions(InstanceKlass* ik) {
// Call with >0 emcp methods since they are not currently being redefined.
purge_previous_versions_internal(ik, 1);
}
// Potentially add an information node that contains pointers to the
// interesting parts of the previous version of the_class.
// This is also where we clean out any unused references.
// Note that while we delete nodes from the _previous_versions
// array, we never delete the array itself until the klass is
// unloaded. The has_been_redefined() query depends on that fact.
//
void InstanceKlass::add_previous_version(instanceKlassHandle ikh,
BitMap* emcp_methods, int emcp_method_count) {
assert(Thread::current()->is_VM_thread(),
"only VMThread can add previous versions");
if (_previous_versions == NULL) {
// This is the first previous version so make some space.
// Start with 2 elements under the assumption that the class
// won't be redefined much.
_previous_versions = new (ResourceObj::C_HEAP, mtClass)
GrowableArray<PreviousVersionNode *>(2, true);
}
ConstantPool* cp_ref = ikh->constants();
// RC_TRACE macro has an embedded ResourceMark
RC_TRACE(0x00000400, ("adding previous version ref for %s @%d, EMCP_cnt=%d "
"on_stack=%d",
ikh->external_name(), _previous_versions->length(), emcp_method_count,
cp_ref->on_stack()));
// If the constant pool for this previous version of the class
// is not marked as being on the stack, then none of the methods
// in this previous version of the class are on the stack so
// we don't need to create a new PreviousVersionNode. However,
// we still need to examine older previous versions below.
Array<Method*>* old_methods = ikh->methods();
if (cp_ref->on_stack()) {
PreviousVersionNode * pv_node = NULL;
if (emcp_method_count == 0) {
// non-shared ConstantPool gets a reference
pv_node = new PreviousVersionNode(cp_ref, NULL);
RC_TRACE(0x00000400,
("add: all methods are obsolete; flushing any EMCP refs"));
} else {
int local_count = 0;
GrowableArray<Method*>* method_refs = new (ResourceObj::C_HEAP, mtClass)
GrowableArray<Method*>(emcp_method_count, true);
for (int i = 0; i < old_methods->length(); i++) {
if (emcp_methods->at(i)) {
// this old method is EMCP. Save it only if it's on the stack
Method* old_method = old_methods->at(i);
if (old_method->on_stack()) {
method_refs->append(old_method);
}
if (++local_count >= emcp_method_count) {
// no more EMCP methods so bail out now
break;
}
}
}
// non-shared ConstantPool gets a reference
pv_node = new PreviousVersionNode(cp_ref, method_refs);
}
// append new previous version.
_previous_versions->append(pv_node);
}
// Since the caller is the VMThread and we are at a safepoint, this
// is a good time to clear out unused references.
RC_TRACE(0x00000400, ("add: previous version length=%d",
_previous_versions->length()));
// Purge previous versions not executing on the stack
purge_previous_versions_internal(this, emcp_method_count);
void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
int emcp_method_count) {
int obsolete_method_count = old_methods->length() - emcp_method_count;
if (emcp_method_count != 0 && obsolete_method_count != 0 &&
_previous_versions->length() > 0) {
_previous_versions != NULL) {
// We have a mix of obsolete and EMCP methods so we have to
// clear out any matching EMCP method entries the hard way.
int local_count = 0;
for (int i = 0; i < old_methods->length(); i++) {
if (!emcp_methods->at(i)) {
Method* old_method = old_methods->at(i);
if (old_method->is_obsolete()) {
// only obsolete methods are interesting
Method* old_method = old_methods->at(i);
Symbol* m_name = old_method->name();
Symbol* m_signature = old_method->signature();
// we might not have added the last entry
for (int j = _previous_versions->length() - 1; j >= 0; j--) {
// check the previous versions array for non executing obsolete methods
PreviousVersionNode * pv_node = _previous_versions->at(j);
GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
if (method_refs == 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 method_refs is different than an empty method_refs.
// We cannot infer any optimizations about older generations
// from an empty method_refs for the current generation.
break;
}
// previous versions are linked together through the InstanceKlass
int j = 0;
for (InstanceKlass* prev_version = _previous_versions;
prev_version != NULL;
prev_version = prev_version->previous_versions(), j++) {
for (int k = method_refs->length() - 1; k >= 0; k--) {
Array<Method*>* method_refs = prev_version->methods();
for (int k = 0; k < method_refs->length(); k++) {
Method* method = method_refs->at(k);
if (!method->is_obsolete() &&
......@@ -3828,14 +3728,11 @@ void InstanceKlass::add_previous_version(instanceKlassHandle ikh,
method->signature() == m_signature) {
// The current RedefineClasses() call has made all EMCP
// versions of this method obsolete so mark it as obsolete
// and remove the reference.
RC_TRACE(0x00000400,
("add: %s(%s): flush obsolete method @%d in version @%d",
m_name->as_C_string(), m_signature->as_C_string(), k, j));
method->set_is_obsolete();
// Leave obsolete methods on the previous version list to
// clean up later.
break;
}
}
......@@ -3843,9 +3740,9 @@ void InstanceKlass::add_previous_version(instanceKlassHandle ikh,
// The previous loop may not find a matching EMCP method, but
// that doesn't mean that we can optimize and not go any
// further back in the PreviousVersion generations. The EMCP
// method for this generation could have already been deleted,
// method for this generation could have already been made obsolete,
// but there still may be an older EMCP method that has not
// been deleted.
// been made obsolete.
}
if (++local_count >= obsolete_method_count) {
......@@ -3855,30 +3752,67 @@ void InstanceKlass::add_previous_version(instanceKlassHandle ikh,
}
}
}
} // end add_previous_version()
}
// Save the scratch_class as the previous version if any of the methods are running.
// The previous_versions are used to set breakpoints in EMCP methods and they are
// also used to clean MethodData links to redefined methods that are no longer running.
void InstanceKlass::add_previous_version(instanceKlassHandle scratch_class,
int emcp_method_count) {
assert(Thread::current()->is_VM_thread(),
"only VMThread can add previous versions");
// RC_TRACE macro has an embedded ResourceMark
RC_TRACE(0x00000400, ("adding previous version ref for %s, EMCP_cnt=%d",
scratch_class->external_name(), emcp_method_count));
// Determine if InstanceKlass has a previous version.
bool InstanceKlass::has_previous_version() const {
return (_previous_versions != NULL && _previous_versions->length() > 0);
} // end has_previous_version()
// Clean out old previous versions
purge_previous_versions(this);
// Mark newly obsolete methods in remaining previous versions. An EMCP method from
// a previous redefinition may be made obsolete by this redefinition.
Array<Method*>* old_methods = scratch_class->methods();
mark_newly_obsolete_methods(old_methods, emcp_method_count);
InstanceKlass* InstanceKlass::get_klass_version(int version) {
if (constants()->version() == version) {
return this;
// If the constant pool for this previous version of the class
// is not marked as being on the stack, then none of the methods
// in this previous version of the class are on the stack so
// we don't need to add this as a previous version.
ConstantPool* cp_ref = scratch_class->constants();
if (!cp_ref->on_stack()) {
RC_TRACE(0x00000400, ("add: scratch class not added; no methods are running"));
return;
}
PreviousVersionWalker pvw(Thread::current(), (InstanceKlass*)this);
for (PreviousVersionNode * pv_node = pvw.next_previous_version();
pv_node != NULL; pv_node = pvw.next_previous_version()) {
ConstantPool* prev_cp = pv_node->prev_constant_pool();
if (prev_cp->version() == version) {
return prev_cp->pool_holder();
if (emcp_method_count != 0) {
// At least one method is still running, check for EMCP methods
for (int i = 0; i < old_methods->length(); i++) {
Method* old_method = old_methods->at(i);
if (!old_method->is_obsolete() && old_method->on_stack()) {
// if EMCP method (not obsolete) is on the stack, mark as EMCP so that
// we can add breakpoints for it.
// We set the method->on_stack bit during safepoints for class redefinition and
// class unloading and use this bit to set the is_running_emcp bit.
// After the safepoint, the on_stack bit is cleared and the running emcp
// method may exit. If so, we would set a breakpoint in a method that
// is never reached, but this won't be noticeable to the programmer.
old_method->set_running_emcp(true);
RC_TRACE(0x00000400, ("add: EMCP method %s is on_stack " INTPTR_FORMAT,
old_method->name_and_sig_as_C_string(), old_method));
} else if (!old_method->is_obsolete()) {
RC_TRACE(0x00000400, ("add: EMCP method %s is NOT on_stack " INTPTR_FORMAT,
old_method->name_and_sig_as_C_string(), old_method));
}
}
}
return NULL; // None found
}
// Add previous version if any methods are still running.
RC_TRACE(0x00000400, ("add: scratch class added; one of its methods is on_stack"));
assert(scratch_class->previous_versions() == NULL, "shouldn't have a previous version");
scratch_class->link_previous_versions(previous_versions());
link_previous_versions(scratch_class());
} // end add_previous_version()
Method* InstanceKlass::method_with_idnum(int idnum) {
Method* m = NULL;
......@@ -3936,61 +3870,3 @@ jint InstanceKlass::get_cached_class_file_len() {
unsigned char * InstanceKlass::get_cached_class_file_bytes() {
return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
}
// Construct a PreviousVersionNode entry for the array hung off
// the InstanceKlass.
PreviousVersionNode::PreviousVersionNode(ConstantPool* prev_constant_pool,
GrowableArray<Method*>* prev_EMCP_methods) {
_prev_constant_pool = prev_constant_pool;
_prev_EMCP_methods = prev_EMCP_methods;
}
// Destroy a PreviousVersionNode
PreviousVersionNode::~PreviousVersionNode() {
if (_prev_constant_pool != NULL) {
_prev_constant_pool = NULL;
}
if (_prev_EMCP_methods != NULL) {
delete _prev_EMCP_methods;
}
}
// Construct a helper for walking the previous versions array
PreviousVersionWalker::PreviousVersionWalker(Thread* thread, InstanceKlass *ik) {
_thread = thread;
_previous_versions = ik->previous_versions();
_current_index = 0;
_current_p = NULL;
_current_constant_pool_handle = constantPoolHandle(thread, ik->constants());
}
// Return the interesting information for the next previous version
// of the klass. Returns NULL if there are no more previous versions.
PreviousVersionNode* PreviousVersionWalker::next_previous_version() {
if (_previous_versions == NULL) {
// no previous versions so nothing to return
return NULL;
}
_current_p = NULL; // reset to NULL
_current_constant_pool_handle = NULL;
int length = _previous_versions->length();
while (_current_index < length) {
PreviousVersionNode * pv_node = _previous_versions->at(_current_index++);
// Save a handle to the constant pool for this previous version,
// which keeps all the methods from being deallocated.
_current_constant_pool_handle = constantPoolHandle(_thread, pv_node->prev_constant_pool());
_current_p = pv_node;
return pv_node;
}
return NULL;
} // end next_previous_version()
src/share/vm/oops/instanceKlass.hpp
浏览文件 @ 0e2e6b55
......@@ -88,7 +88,6 @@ class BreakpointInfo;
class fieldDescriptor;
class DepChange;
class nmethodBucket;
class PreviousVersionNode;
class JvmtiCachedClassFieldMap;
class MemberNameTable;
......@@ -235,7 +234,8 @@ class InstanceKlass: public Klass {
_misc_is_anonymous = 1 << 3, // has embedded _host_klass field
_misc_is_contended = 1 << 4, // marked with contended annotation
_misc_has_default_methods = 1 << 5, // class/superclass/implemented interfaces has default methods
_misc_declares_default_methods = 1 << 6 // directly declares default methods (any access)
_misc_declares_default_methods = 1 << 6, // directly declares default methods (any access)
_misc_has_been_redefined = 1 << 7 // class has been redefined
};
u2 _misc_flags;
u2 _minor_version; // minor version number of class file
......@@ -250,9 +250,8 @@ class InstanceKlass: public Klass {
nmethodBucket* _dependencies; // list of dependent nmethods
nmethod* _osr_nmethods_head; // Head of list of on-stack replacement nmethods for this class
BreakpointInfo* _breakpoints; // bpt lists, managed by Method*
// Array of interesting part(s) of the previous version(s) of this
// InstanceKlass. See PreviousVersionWalker below.
GrowableArray<PreviousVersionNode *>* _previous_versions;
// Linked instanceKlasses of previous versions
InstanceKlass* _previous_versions;
// JVMTI fields can be moved to their own structure - see 6315920
// JVMTI: cached class file, before retransformable agent modified it in CFLH
JvmtiCachedClassFileData* _cached_class_file;
......@@ -664,21 +663,31 @@ class InstanceKlass: public Klass {
}
// RedefineClasses() support for previous versions:
void add_previous_version(instanceKlassHandle ikh, BitMap *emcp_methods,
int emcp_method_count);
// If the _previous_versions array is non-NULL, then this klass
// has been redefined at least once even if we aren't currently
// tracking a previous version.
bool has_been_redefined() const { return _previous_versions != NULL; }
bool has_previous_version() const;
void add_previous_version(instanceKlassHandle ikh, int emcp_method_count);
InstanceKlass* previous_versions() const { return _previous_versions; }
bool has_been_redefined() const {
return (_misc_flags & _misc_has_been_redefined) != 0;
}
void set_has_been_redefined() {
_misc_flags |= _misc_has_been_redefined;
}
void init_previous_versions() {
_previous_versions = NULL;
}
GrowableArray<PreviousVersionNode *>* previous_versions() const {
return _previous_versions;
InstanceKlass* get_klass_version(int version) {
for (InstanceKlass* ik = this; ik != NULL; ik = ik->previous_versions()) {
if (ik->constants()->version() == version) {
return ik;
}
}
return NULL;
}
InstanceKlass* get_klass_version(int version);
static void purge_previous_versions(InstanceKlass* ik);
// JVMTI: Support for caching a class file before it is modified by an agent that can do retransformation
......@@ -1119,6 +1128,10 @@ private:
// Free CHeap allocated fields.
void release_C_heap_structures();
// RedefineClasses support
void link_previous_versions(InstanceKlass* pv) { _previous_versions = pv; }
void mark_newly_obsolete_methods(Array<Method*>* old_methods, int emcp_method_count);
public:
// CDS support - remove and restore oops from metadata. Oops are not shared.
virtual void remove_unshareable_info();
......@@ -1217,62 +1230,6 @@ class JNIid: public CHeapObj<mtClass> {
};
// If breakpoints are more numerous than just JVMTI breakpoints,
// consider compressing this data structure.
// It is currently a simple linked list defined in method.hpp.
class BreakpointInfo;
// A collection point for interesting information about the previous
// version(s) of an InstanceKlass. A GrowableArray of PreviousVersionNodes
// is attached to the InstanceKlass as needed. See PreviousVersionWalker below.
class PreviousVersionNode : public CHeapObj<mtClass> {
private:
ConstantPool* _prev_constant_pool;
// If the previous version of the InstanceKlass doesn't have any
// EMCP methods, then _prev_EMCP_methods will be NULL. If all the
// EMCP methods have been collected, then _prev_EMCP_methods can
// have a length of zero.
GrowableArray<Method*>* _prev_EMCP_methods;
public:
PreviousVersionNode(ConstantPool* prev_constant_pool,
GrowableArray<Method*>* prev_EMCP_methods);
~PreviousVersionNode();
ConstantPool* prev_constant_pool() const {
return _prev_constant_pool;
}
GrowableArray<Method*>* prev_EMCP_methods() const {
return _prev_EMCP_methods;
}
};
// Helper object for walking previous versions.
class PreviousVersionWalker : public StackObj {
private:
Thread* _thread;
GrowableArray<PreviousVersionNode *>* _previous_versions;
int _current_index;
// A pointer to the current node object so we can handle the deletes.
PreviousVersionNode* _current_p;
// The constant pool handle keeps all the methods in this class from being
// deallocated from the metaspace during class unloading.
constantPoolHandle _current_constant_pool_handle;
public:
PreviousVersionWalker(Thread* thread, InstanceKlass *ik);
// Return the interesting information for the next previous version
// of the klass. Returns NULL if there are no more previous versions.
PreviousVersionNode* next_previous_version();
};
//
// nmethodBucket is used to record dependent nmethods for
// deoptimization. nmethod dependencies are actually <klass, method>
......
src/share/vm/oops/klass.cpp
浏览文件 @ 0e2e6b55
......@@ -455,6 +455,12 @@ void Klass::clean_weak_klass_links(BoolObjectClosure* is_alive, bool clean_alive
if (clean_alive_klasses && current->oop_is_instance()) {
InstanceKlass* ik = InstanceKlass::cast(current);
ik->clean_weak_instanceklass_links(is_alive);
// JVMTI RedefineClasses creates previous versions that are not in
// the class hierarchy, so process them here.
while ((ik = ik->previous_versions()) != NULL) {
ik->clean_weak_instanceklass_links(is_alive);
}
}
}
}
......
src/share/vm/oops/method.cpp
浏览文件 @ 0e2e6b55
......@@ -91,6 +91,7 @@ Method::Method(ConstMethod* xconst, AccessFlags access_flags, int size) {
set_hidden(false);
set_dont_inline(false);
set_has_injected_profile(false);
set_running_emcp(false);
set_method_data(NULL);
clear_method_counters();
set_vtable_index(Method::garbage_vtable_index);
......
src/share/vm/oops/method.hpp
浏览文件 @ 0e2e6b55
......@@ -111,6 +111,7 @@ class Method : public Metadata {
_caller_sensitive : 1,
_force_inline : 1,
_hidden : 1,
_running_emcp : 1,
_dont_inline : 1,
_has_injected_profile : 1,
: 2;
......@@ -711,6 +712,21 @@ class Method : public Metadata {
void set_is_obsolete() { _access_flags.set_is_obsolete(); }
bool is_deleted() const { return access_flags().is_deleted(); }
void set_is_deleted() { _access_flags.set_is_deleted(); }
bool is_running_emcp() const {
// EMCP methods are old but not obsolete or deleted. Equivalent
// Modulo Constant Pool means the method is equivalent except
// the constant pool and instructions that access the constant
// pool might be different.
// If a breakpoint is set in a redefined method, its EMCP methods that are
// still running must have a breakpoint also.
return _running_emcp;
}
void set_running_emcp(bool x) {
_running_emcp = x;
}
bool on_stack() const { return access_flags().on_stack(); }
void set_on_stack(const bool value);
......
src/share/vm/prims/jvmtiImpl.cpp
浏览文件 @ 0e2e6b55
......@@ -282,39 +282,22 @@ address JvmtiBreakpoint::getBcp() {
void JvmtiBreakpoint::each_method_version_do(method_action meth_act) {
((Method*)_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 PreviousVersionNodes.
// add/remove breakpoint to/from versions of the method that are EMCP.
Thread *thread = Thread::current();
instanceKlassHandle ikh = instanceKlassHandle(thread, _method->method_holder());
Symbol* m_name = _method->name();
Symbol* m_signature = _method->signature();
// search previous versions if they exist
PreviousVersionWalker pvw(thread, (InstanceKlass *)ikh());
for (PreviousVersionNode * pv_node = pvw.next_previous_version();
pv_node != NULL; pv_node = pvw.next_previous_version()) {
GrowableArray<Method*>* methods = pv_node->prev_EMCP_methods();
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 (InstanceKlass* pv_node = ikh->previous_versions();
pv_node != NULL;
pv_node = pv_node->previous_versions()) {
Array<Method*>* methods = pv_node->methods();
for (int i = methods->length() - 1; i >= 0; i--) {
Method* method = methods->at(i);
// obsolete methods that are running are not deleted from
// previous version array, but they are skipped here.
if (!method->is_obsolete() &&
// Only set breakpoints in running EMCP methods.
if (method->is_running_emcp() &&
method->name() == m_name &&
method->signature() == m_signature) {
RC_TRACE(0x00000800, ("%sing breakpoint in %s(%s)",
......
src/share/vm/prims/jvmtiRedefineClasses.cpp
浏览文件 @ 0e2e6b55
......@@ -3435,13 +3435,12 @@ void VM_RedefineClasses::AdjustCpoolCacheAndVtable::do_klass(Klass* k) {
}
// the previous versions' constant pool caches may need adjustment
PreviousVersionWalker pvw(_thread, ik);
for (PreviousVersionNode * pv_node = pvw.next_previous_version();
pv_node != NULL; pv_node = pvw.next_previous_version()) {
other_cp = pv_node->prev_constant_pool();
cp_cache = other_cp->cache();
for (InstanceKlass* pv_node = ik->previous_versions();
pv_node != NULL;
pv_node = pv_node->previous_versions()) {
cp_cache = pv_node->constants()->cache();
if (cp_cache != NULL) {
cp_cache->adjust_method_entries(other_cp->pool_holder(), &trace_name_printed);
cp_cache->adjust_method_entries(pv_node, &trace_name_printed);
}
}
}
......@@ -3461,9 +3460,8 @@ void VM_RedefineClasses::update_jmethod_ids() {
}
}
void VM_RedefineClasses::check_methods_and_mark_as_obsolete(
BitMap *emcp_methods, int * emcp_method_count_p) {
*emcp_method_count_p = 0;
int VM_RedefineClasses::check_methods_and_mark_as_obsolete() {
int emcp_method_count = 0;
int obsolete_count = 0;
int old_index = 0;
for (int j = 0; j < _matching_methods_length; ++j, ++old_index) {
......@@ -3537,9 +3535,9 @@ void VM_RedefineClasses::check_methods_and_mark_as_obsolete(
// that we get from effectively overwriting the old methods
// when the new methods are attached to the_class.
// track which methods are EMCP for add_previous_version() call
emcp_methods->set_bit(old_index);
(*emcp_method_count_p)++;
// Count number of methods that are EMCP. The method will be marked
// old but not obsolete if it is EMCP.
emcp_method_count++;
// An EMCP method is _not_ obsolete. An obsolete method has a
// different jmethodID than the current method. An EMCP method
......@@ -3589,10 +3587,11 @@ void VM_RedefineClasses::check_methods_and_mark_as_obsolete(
old_method->name()->as_C_string(),
old_method->signature()->as_C_string()));
}
assert((*emcp_method_count_p + obsolete_count) == _old_methods->length(),
assert((emcp_method_count + obsolete_count) == _old_methods->length(),
"sanity check");
RC_TRACE(0x00000100, ("EMCP_cnt=%d, obsolete_cnt=%d", *emcp_method_count_p,
RC_TRACE(0x00000100, ("EMCP_cnt=%d, obsolete_cnt=%d", emcp_method_count,
obsolete_count));
return emcp_method_count;
}
// This internal class transfers the native function registration from old methods
......@@ -3973,11 +3972,8 @@ void VM_RedefineClasses::redefine_single_class(jclass the_jclass,
old_constants->set_pool_holder(scratch_class());
#endif
// track which methods are EMCP for add_previous_version() call below
BitMap emcp_methods(_old_methods->length());
int emcp_method_count = 0;
emcp_methods.clear(); // clears 0..(length() - 1)
check_methods_and_mark_as_obsolete(&emcp_methods, &emcp_method_count);
// track number of methods that are EMCP for add_previous_version() call below
int emcp_method_count = check_methods_and_mark_as_obsolete();
transfer_old_native_function_registrations(the_class);
// The class file bytes from before any retransformable agents mucked
......@@ -4064,9 +4060,10 @@ void VM_RedefineClasses::redefine_single_class(jclass the_jclass,
scratch_class->enclosing_method_method_index());
scratch_class->set_enclosing_method_indices(old_class_idx, old_method_idx);
the_class->set_has_been_redefined();
// keep track of previous versions of this class
the_class->add_previous_version(scratch_class, &emcp_methods,
emcp_method_count);
the_class->add_previous_version(scratch_class, emcp_method_count);
RC_TIMER_STOP(_timer_rsc_phase1);
RC_TIMER_START(_timer_rsc_phase2);
......
src/share/vm/prims/jvmtiRedefineClasses.hpp
浏览文件 @ 0e2e6b55
......@@ -403,14 +403,9 @@ class VM_RedefineClasses: public VM_Operation {
// Change jmethodIDs to point to the new methods
void update_jmethod_ids();
// In addition to marking methods as obsolete, this routine
// records which methods are EMCP (Equivalent Module Constant
// Pool) in the emcp_methods BitMap and returns the number of
// EMCP methods via emcp_method_count_p. This information is
// used when information about the previous version of the_class
// is squirreled away.
void check_methods_and_mark_as_obsolete(BitMap *emcp_methods,
int * emcp_method_count_p);
// In addition to marking methods as old and/or obsolete, this routine
// counts the number of methods that are EMCP (Equivalent Module Constant Pool).
int check_methods_and_mark_as_obsolete();
void transfer_old_native_function_registrations(instanceKlassHandle the_class);
// Install the redefinition of a class
......
test/runtime/RedefineFinalizer/RedefineFinalizer.java → test/runtime/RedefineTests/RedefineFinalizer.java
浏览文件 @ 0e2e6b55
/*
* Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2014, 2018, 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
......
test/runtime/RedefineTests/RedefineRunningMethods.java 0 → 100644
浏览文件 @ 0e2e6b55
/*
* Copyright (c) 2014, 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.
*/
/*
* @test
* @bug 8055008
* @summary Redefine EMCP and non-EMCP methods that are running in an infinite loop
* @library /testlibrary
* @build RedefineClassHelper
* @run main RedefineClassHelper
* @run main/othervm -javaagent:redefineagent.jar RedefineRunningMethods
*/
public class RedefineRunningMethods {
public static String newB =
"class RedefineRunningMethods$B {" +
" static int count1 = 0;" +
" static int count2 = 0;" +
" public static volatile boolean stop = false;" +
" static void localSleep() { " +
" try{ " +
" Thread.currentThread().sleep(10);" +
" } catch(InterruptedException ie) { " +
" } " +
" } " +
" public static void infinite() { " +
" System.out.println(\"infinite called\");" +
" }" +
" public static void infinite_emcp() { " +
" while (!stop) { count2++; localSleep(); }" +
" }" +
"}";
public static String evenNewerB =
"class RedefineRunningMethods$B {" +
" static int count1 = 0;" +
" static int count2 = 0;" +
" public static volatile boolean stop = false;" +
" static void localSleep() { " +
" try{ " +
" Thread.currentThread().sleep(1);" +
" } catch(InterruptedException ie) { " +
" } " +
" } " +
" public static void infinite() { }" +
" public static void infinite_emcp() { " +
" System.out.println(\"infinite_emcp now obsolete called\");" +
" }" +
"}";
static class B {
static int count1 = 0;
static int count2 = 0;
public static volatile boolean stop = false;
static void localSleep() {
try{
Thread.currentThread().sleep(10);//sleep for 10 ms
} catch(InterruptedException ie) {
}
}
public static void infinite() {
while (!stop) { count1++; localSleep(); }
}
public static void infinite_emcp() {
while (!stop) { count2++; localSleep(); }
}
}
public static void main(String[] args) throws Exception {
new Thread() {
public void run() {
B.infinite();
}
}.start();
new Thread() {
public void run() {
B.infinite_emcp();
}
}.start();
RedefineClassHelper.redefineClass(B.class, newB);
System.gc();
B.infinite();
// Start a thread with the second version of infinite_emcp running
new Thread() {
public void run() {
B.infinite_emcp();
}
}.start();
for (int i = 0; i < 20 ; i++) {
String s = new String("some garbage");
System.gc();
}
RedefineClassHelper.redefineClass(B.class, evenNewerB);
System.gc();
for (int i = 0; i < 20 ; i++) {
B.infinite();
String s = new String("some garbage");
System.gc();
}
B.infinite_emcp();
// purge should clean everything up.
B.stop = true;
for (int i = 0; i < 20 ; i++) {
B.infinite();
String s = new String("some garbage");
System.gc();
}
}
}
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