/* * Copyright (c) 1997, 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. *
*/
/* NOTE about use of any ctor or function call that can trigger a safepoint/GC: such ctors and calls MUST NOT come between an oop declaration/init and its usage because if objects are move this may cause various memory stomps, bus errors and segfaults. Here is a cookbook for causing so called "naked oop failures":
JVM_ENTRY(jobjectArray, JVM_GetClassDeclaredFields<etc> { // Object address to be held directly in mirror & not visible to GC oop mirror = JNIHandles::resolve_non_null(ofClass);
// If this ctor can hit a safepoint, moving objects around, then ComplexConstructor foo;
// Boom! mirror may point to JUNK instead of the intended object (some dereference of mirror)
// Here's another call that may block for GC, making mirror stale MutexLocker ml(some_lock);
// And here's an initializer that can result in a stale oop // all in one step. oop o = call_that_can_throw_exception(TRAPS);
The solution is to keep the oop declaration BELOW the ctor or function call that might cause a GC, do another resolve to reassign the oop, or consider use of a Handle instead of an oop so there is immunity from object motion. But note that the "QUICK" entries below do not have a handlemark and thus can only support use of handles passed in.
*/
while (!vfst.at_end()) {
Method* m = vfst.method(); if (!vfst.method()->method_holder()->is_subclass_of(vmClasses::ClassLoader_klass())&&
!vfst.method()->method_holder()->is_subclass_of(access_controller_klass) &&
!vfst.method()->method_holder()->is_subclass_of(privileged_action_klass)) { break;
}
last_caller = m;
vfst.next();
} // if this is called from Class.forName0 and that is called from Class.forName, // then print the caller of Class.forName. If this is Class.loadClass, then print // that caller, otherwise keep quiet since this should be picked up elsewhere. bool found_it = false; if (!vfst.at_end() &&
vfst.method()->method_holder()->name() == vmSymbols::java_lang_Class() &&
vfst.method()->name() == vmSymbols::forName0_name()) {
vfst.next(); if (!vfst.at_end() &&
vfst.method()->method_holder()->name() == vmSymbols::java_lang_Class() &&
vfst.method()->name() == vmSymbols::forName_name()) {
vfst.next();
found_it = true;
}
} elseif (last_caller != NULL &&
last_caller->method_holder()->name() ==
vmSymbols::java_lang_ClassLoader() &&
last_caller->name() == vmSymbols::loadClass_name()) {
found_it = true;
} elseif (!vfst.at_end()) { if (vfst.method()->is_native()) { // JNI call
found_it = true;
}
} if (found_it && !vfst.at_end()) { // found the caller
caller = vfst.method()->method_holder();
line_number = vfst.method()->line_number_from_bci(vfst.bci()); if (line_number == -1) { // show method name if it's a native method
trace = vfst.method()->name_and_sig_as_C_string();
}
Symbol* s = caller->source_file_name(); if (s != NULL) {
source_file = s->as_C_string();
}
}
} if (caller != NULL) { if (to_class != caller) { constchar * from = caller->external_name(); constchar * to = to_class->external_name(); // print in a single call to reduce interleaving between threads if (source_file != NULL) {
log_debug(class, resolve)("%s %s %s:%d (%s)", from, to, source_file, line_number, trace);
} else {
log_debug(class, resolve)("%s %s (%s)", from, to, trace);
}
}
}
}
// The function below is actually exposed by jdk.internal.misc.VM and not // java.lang.System, but we choose to keep it here so that it stays next // to JVM_CurrentTimeMillis and JVM_NanoTime
// We're going to verify that the result can fit in a long. // For that we need the difference in seconds between 'seconds' // and 'offset_secs' to be such that: // |seconds - offset_secs| < (2^63/10^9) // We're going to approximate 10^9 ~< 2^30 (1000^3 ~< 1024^3) // which makes |seconds - offset_secs| < 2^33 // and we will prefer +/- 2^32 as the maximum acceptable diff // as 2^32 has a more natural feel than 2^33... // // So if |seconds - offset_secs| >= 2^32 - we return a special // sentinel value (-1) which the caller should take as an // exception value indicating that the offset given to us is // too far from range of the current time - leading to too big // a nano adjustment. The caller is expected to recover by // computing a more accurate offset and calling this method // again. (For the record 2^32 secs is ~136 years, so that // should rarely happen) //
jlong diff = seconds - offset_secs; if (diff >= MAX_DIFF_SECS || diff <= MIN_DIFF_SECS) { return -1; // sentinel value: the offset is too far off the target
}
// return the adjustment. If you compute a time by adding // this number of nanoseconds along with the number of seconds // in the offset you should get the current UTC time. return (diff * (jlong)1000000000) + nanos;
JVM_END
JVM_ENTRY(void, JVM_ArrayCopy(JNIEnv *env, jclass ignored, jobject src, jint src_pos,
jobject dst, jint dst_pos, jint length)) // Check if we have null pointers if (src == NULL || dst == NULL) { THROW(vmSymbols::java_lang_NullPointerException());
}
arrayOop s = arrayOop(JNIHandles::resolve_non_null(src));
arrayOop d = arrayOop(JNIHandles::resolve_non_null(dst));
assert(oopDesc::is_oop(s), "JVM_ArrayCopy: src not an oop");
assert(oopDesc::is_oop(d), "JVM_ArrayCopy: dst not an oop"); // Do copy
s->klass()->copy_array(s, src_pos, d, dst_pos, length, thread);
JVM_END
/* * Return all of the system properties in a Java String array with alternating * names and values from the jvm SystemProperty. * Which includes some internal and all commandline -D defined properties.
*/
JVM_ENTRY(jobjectArray, JVM_GetProperties(JNIEnv *env))
ResourceMark rm(THREAD);
HandleMark hm(THREAD); int ndx = 0; int fixedCount = 2;
SystemProperty* p = Arguments::system_properties(); int count = Arguments::PropertyList_count(p);
// Allocate result String array
InstanceKlass* ik = vmClasses::String_klass();
objArrayOop r = oopFactory::new_objArray(ik, (count + fixedCount) * 2, CHECK_NULL);
objArrayHandle result_h(THREAD, r);
// Convert the -XX:MaxDirectMemorySize= command line flag // to the sun.nio.MaxDirectMemorySize property. // Do this after setting user properties to prevent people // from setting the value with a -D option, as requested. // Leave empty if not supplied if (!FLAG_IS_DEFAULT(MaxDirectMemorySize)) { char as_chars[256];
jio_snprintf(as_chars, sizeof(as_chars), JULONG_FORMAT, MaxDirectMemorySize);
Handle key_str = java_lang_String::create_from_platform_dependent_str("sun.nio.MaxDirectMemorySize", CHECK_NULL);
Handle value_str = java_lang_String::create_from_platform_dependent_str(as_chars, CHECK_NULL);
result_h->obj_at_put(ndx * 2, key_str());
result_h->obj_at_put(ndx * 2 + 1, value_str());
ndx++;
}
// JVM monitoring and management support // Add the sun.management.compiler property for the compiler's name
{ #undef CSIZE #ifdefined(_LP64) || defined(_WIN64) #define CSIZE "64-Bit " #else #define CSIZE #endif// 64bit
/* * Return the temporary directory that the VM uses for the attach * and perf data files. * * It is important that this directory is well-known and the * same for all VM instances. It cannot be affected by configuration * variables such as java.io.tmpdir.
*/
JVM_ENTRY(jstring, JVM_GetTemporaryDirectory(JNIEnv *env))
HandleMark hm(THREAD); constchar* temp_dir = os::get_temp_directory();
Handle h = java_lang_String::create_from_platform_dependent_str(temp_dir, CHECK_NULL); return (jstring) JNIHandles::make_local(THREAD, h());
JVM_END
JVM_ENTRY_NO_ENV(void, JVM_BeforeHalt()) #if INCLUDE_CDS // Link all classes for dynamic CDS dumping before vm exit. if (DynamicArchive::should_dump_at_vm_exit()) {
DynamicArchive::prepare_for_dump_at_exit();
} #endif
EventShutdown event; if (event.should_commit()) {
event.set_reason("Shutdown requested from Java");
event.commit();
}
JVM_END
staticinline jlong convert_size_t_to_jlong(size_t val) { // In the 64-bit vm, a size_t can overflow a jlong (which is signed).
NOT_LP64 (return (jlong)val;)
LP64_ONLY(return (jlong)MIN2(val, (size_t)max_jlong);)
}
JVM_ENTRY_NO_ENV(jlong, JVM_TotalMemory(void))
size_t n = Universe::heap()->capacity(); return convert_size_t_to_jlong(n);
JVM_END
JVM_ENTRY_NO_ENV(jlong, JVM_FreeMemory(void))
size_t n = Universe::heap()->unused(); return convert_size_t_to_jlong(n);
JVM_END
JVM_ENTRY_NO_ENV(jlong, JVM_MaxMemory(void))
size_t n = Universe::heap()->max_capacity(); return convert_size_t_to_jlong(n);
JVM_END
Handle stackStream_h(THREAD, JNIHandles::resolve_non_null(stackStream));
Handle contScope_h(THREAD, JNIHandles::resolve(contScope));
Handle cont_h(THREAD, JNIHandles::resolve(cont)); // frames array is a Class<?>[] array when only getting caller reference, // and a StackFrameInfo[] array (or derivative) otherwise. It should never // be null.
objArrayOop fa = objArrayOop(JNIHandles::resolve_non_null(frames));
objArrayHandle frames_array_h(THREAD, fa);
int limit = start_index + frame_count; if (frames_array_h->length() < limit) {
THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(), "not enough space in buffers", NULL);
}
JVM_ENTRY(jint, JVM_MoreStackWalk(JNIEnv *env, jobject stackStream, jlong mode, jlong anchor,
jint frame_count, jint start_index,
jobjectArray frames)) // frames array is a Class<?>[] array when only getting caller reference, // and a StackFrameInfo[] array (or derivative) otherwise. It should never // be null.
objArrayOop fa = objArrayOop(JNIHandles::resolve_non_null(frames));
objArrayHandle frames_array_h(THREAD, fa);
int limit = start_index+frame_count; if (frames_array_h->length() < limit) {
THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(), "not enough space in buffers");
}
// The current thread already owns the monitor and it has not yet // been added to the wait queue so the current thread cannot be // made the successor. This means that the JVMTI_EVENT_MONITOR_WAIT // event handler cannot accidentally consume an unpark() meant for // the ParkEvent associated with this ObjectMonitor.
}
ObjectSynchronizer::wait(obj, ms, CHECK);
JVM_END
#ifdef ASSERT // Just checking that the cloneable flag is set correct if (obj->is_array()) {
guarantee(klass->is_cloneable(), "all arrays are cloneable");
} else {
guarantee(obj->is_instance(), "should be instanceOop"); bool cloneable = klass->is_subtype_of(vmClasses::Cloneable_klass());
guarantee(cloneable == klass->is_cloneable(), "incorrect cloneable flag");
} #endif
// Check if class of obj supports the Cloneable interface. // All arrays are considered to be cloneable (See JLS 20.1.5). // All j.l.r.Reference classes are considered non-cloneable. if (!klass->is_cloneable() ||
(klass->is_instance_klass() &&
InstanceKlass::cast(klass)->reference_type() != REF_NONE)) {
ResourceMark rm(THREAD);
THROW_MSG_0(vmSymbols::java_lang_CloneNotSupportedException(), klass->external_name());
}
Handle new_obj(THREAD, new_obj_oop); // Caution: this involves a java upcall, so the clone should be // "gc-robust" by this stage. if (klass->has_finalizer()) {
assert(obj->is_instance(), "should be instanceOop");
new_obj_oop = InstanceKlass::register_finalizer(instanceOop(new_obj()), CHECK_NULL);
new_obj = Handle(THREAD, new_obj_oop);
}
// Misc. class handling ///////////////////////////////////////////////////////////
JVM_ENTRY(jclass, JVM_GetCallerClass(JNIEnv* env)) // Getting the class of the caller frame. // // The call stack at this point looks something like this: // // [0] [ @CallerSensitive public sun.reflect.Reflection.getCallerClass ] // [1] [ @CallerSensitive API.method ] // [.] [ (skipped intermediate frames) ] // [n] [ caller ]
vframeStream vfst(thread); // Cf. LibraryCallKit::inline_native_Reflection_getCallerClass for (int n = 0; !vfst.at_end(); vfst.security_next(), n++) {
Method* m = vfst.method();
assert(m != NULL, "sanity"); switch (n) { case 0: // This must only be called from Reflection.getCallerClass if (m->intrinsic_id() != vmIntrinsics::_getCallerClass) {
THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), "JVM_GetCallerClass must only be called from Reflection.getCallerClass");
} // fall-through case 1: // Frame 0 and 1 must be caller sensitive. if (!m->caller_sensitive()) {
THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), err_msg("CallerSensitive annotation expected at frame %d", n));
} break; default: if (!m->is_ignored_by_security_stack_walk()) { // We have reached the desired frame; return the holder class. return (jclass) JNIHandles::make_local(THREAD, m->method_holder()->java_mirror());
} break;
}
} return NULL;
JVM_END
// Returns a class loaded by the bootstrap class loader; or null // if not found. ClassNotFoundException is not thrown. // FindClassFromBootLoader is exported to the launcher for windows.
JVM_ENTRY(jclass, JVM_FindClassFromBootLoader(JNIEnv* env, constchar* name)) // Java libraries should ensure that name is never null or illegal. if (name == NULL || (int)strlen(name) > Symbol::max_length()) { // It's impossible to create this class; the name cannot fit // into the constant pool. return NULL;
}
assert(UTF8::is_legal_utf8((constunsignedchar*)name, (int)strlen(name), false), "illegal UTF name");
TempNewSymbol h_name = SymbolTable::new_symbol(name);
Klass* k = SystemDictionary::resolve_or_null(h_name, CHECK_NULL); if (k == NULL) { return NULL;
}
// Find a class with this name in this loader, using the caller's protection domain.
JVM_ENTRY(jclass, JVM_FindClassFromCaller(JNIEnv* env, constchar* name,
jboolean init, jobject loader,
jclass caller))
TempNewSymbol h_name =
SystemDictionary::class_name_symbol(name, vmSymbols::java_lang_ClassNotFoundException(),
CHECK_NULL);
oop loader_oop = JNIHandles::resolve(loader);
oop from_class = JNIHandles::resolve(caller);
oop protection_domain = NULL; // If loader is null, shouldn't call ClassLoader.checkPackageAccess; otherwise get // NPE. Put it in another way, the bootstrap class loader has all permission and // thus no checkPackageAccess equivalence in the VM class loader. // The caller is also passed as NULL by the java code if there is no security // manager to avoid the performance cost of getting the calling class. if (from_class != NULL && loader_oop != NULL) {
protection_domain = java_lang_Class::as_Klass(from_class)->protection_domain();
}
if (log_is_enabled(Debug, class, resolve) && result != NULL) {
trace_class_resolution(java_lang_Class::as_Klass(JNIHandles::resolve_non_null(result)));
} return result;
JVM_END
// Currently only called from the old verifier.
JVM_ENTRY(jclass, JVM_FindClassFromClass(JNIEnv *env, constchar *name,
jboolean init, jclass from))
TempNewSymbol h_name =
SystemDictionary::class_name_symbol(name, vmSymbols::java_lang_ClassNotFoundException(),
CHECK_NULL);
oop from_class_oop = JNIHandles::resolve(from);
Klass* from_class = (from_class_oop == NULL)
? (Klass*)NULL
: java_lang_Class::as_Klass(from_class_oop);
oop class_loader = NULL;
oop protection_domain = NULL; if (from_class != NULL) {
class_loader = from_class->class_loader();
protection_domain = from_class->protection_domain();
}
Handle h_loader(THREAD, class_loader);
Handle h_prot (THREAD, protection_domain);
jclass result = find_class_from_class_loader(env, h_name, init, h_loader,
h_prot, true, thread);
if (log_is_enabled(Debug, class, resolve) && result != NULL) { // this function is generally only used for class loading during verification.
ResourceMark rm;
oop from_mirror = JNIHandles::resolve_non_null(from);
Klass* from_class = java_lang_Class::as_Klass(from_mirror); constchar * from_name = from_class->external_name();
if (UsePerfData) {
ClassLoader::perf_app_classfile_bytes_read()->inc(len);
}
// Class resolution will get the class name from the .class stream if the name is null.
TempNewSymbol class_name = name == NULL ? NULL :
SystemDictionary::class_name_symbol(name, vmSymbols::java_lang_NoClassDefFoundError(),
CHECK_NULL);
/* * Define a class with the specified flags that indicates if it's a nestmate, * hidden, or strongly referenced from class loader.
*/ static jclass jvm_lookup_define_class(jclass lookup, constchar *name, const jbyte *buf, jsize len, jobject pd,
jboolean init, int flags, jobject classData, TRAPS) {
ResourceMark rm(THREAD);
Klass* lookup_k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(lookup)); // Lookup class must be a non-null instance if (lookup_k == NULL) {
THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(), "Lookup class is null");
}
assert(lookup_k->is_instance_klass(), "Lookup class must be an instance klass");
if (!is_hidden) { // classData is only applicable for hidden classes if (classData != NULL) {
THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(), "classData is only applicable for hidden classes");
} if (is_nestmate) {
THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(), "dynamic nestmate is only applicable for hidden classes");
} if (!is_strong) {
THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(), "an ordinary class must be strongly referenced by its defining loader");
} if (vm_annotations) {
THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(), "vm annotations only allowed for hidden classes");
} if (flags != STRONG_LOADER_LINK) {
THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(),
err_msg("invalid flag 0x%x", flags));
}
}
// Class resolution will get the class name from the .class stream if the name is null.
TempNewSymbol class_name = name == NULL ? NULL :
SystemDictionary::class_name_symbol(name, vmSymbols::java_lang_NoClassDefFoundError(),
CHECK_NULL);
// The hidden class loader data has been artificially been kept alive to // this point. The mirror and any instances of this class have to keep // it alive afterwards.
ik->class_loader_data()->dec_keep_alive();
if (is_nestmate && log_is_enabled(Debug, class, nestmates)) {
ModuleEntry* module = ik->module(); constchar * module_name = module->is_named() ? module->name()->as_C_string() : UNNAMED_MODULE;
log_debug(class, nestmates)("Dynamic nestmate: %s/%s, nest_host %s, %s",
module_name,
ik->external_name(),
host_class->external_name(),
ik->is_hidden() ? "is hidden" : "is not hidden");
}
}
assert(Reflection::is_same_class_package(lookup_k, ik), "lookup class and defined class are in different packages");
if (init) {
ik->initialize(CHECK_NULL);
} else {
ik->link_class(CHECK_NULL);
}
/* * Define a class with the specified lookup class. * lookup: Lookup class * name: the name of the class * buf: class bytes * len: length of class bytes * pd: protection domain * init: initialize the class * flags: properties of the class * classData: private static pre-initialized field
*/
JVM_ENTRY(jclass, JVM_LookupDefineClass(JNIEnv *env, jclass lookup, constchar *name, const jbyte *buf,
jsize len, jobject pd, jboolean initialize, int flags, jobject classData))
if (lookup == NULL) {
THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(), "Lookup class is null");
}
// Internalize the string, converting '.' to '/' in string. char* p = (char*)str; while (*p != '\0') { if (*p == '.') {
*p = '/';
}
p++;
}
constint str_len = (int)(p - str); if (str_len > Symbol::max_length()) { // It's impossible to create this class; the name cannot fit // into the constant pool. return NULL;
}
TempNewSymbol klass_name = SymbolTable::new_symbol(str, str_len);
// Security Note: // The Java level wrapper will perform the necessary security check allowing // us to pass the NULL as the initiating class loader.
Handle h_loader(THREAD, JNIHandles::resolve(loader));
Klass* k = SystemDictionary::find_instance_or_array_klass(THREAD, klass_name,
h_loader,
Handle()); #if INCLUDE_CDS if (k == NULL) { // If the class is not already loaded, try to see if it's in the shared // archive for the current classloader (h_loader).
k = SystemDictionaryShared::find_or_load_shared_class(klass_name, h_loader, CHECK_NULL);
} #endif return (k == NULL) ? NULL :
(jclass) JNIHandles::make_local(THREAD, k->java_mirror());
JVM_END
// Module support //////////////////////////////////////////////////////////////////////////////
// Special handling for primitive objects if (java_lang_Class::is_primitive(mirror)) { // Primitive objects does not have any interfaces
objArrayOop r = oopFactory::new_objArray(vmClasses::Class_klass(), 0, CHECK_NULL); return (jobjectArray) JNIHandles::make_local(THREAD, r);
}
Klass* klass = java_lang_Class::as_Klass(mirror); // Figure size of result array int size; if (klass->is_instance_klass()) {
size = InstanceKlass::cast(klass)->local_interfaces()->length();
} else {
assert(klass->is_objArray_klass() || klass->is_typeArray_klass(), "Illegal mirror klass");
size = 2;
}
// Allocate result array
objArrayOop r = oopFactory::new_objArray(vmClasses::Class_klass(), size, CHECK_NULL);
objArrayHandle result (THREAD, r); // Fill in result if (klass->is_instance_klass()) { // Regular instance klass, fill in all local interfaces for (int index = 0; index < size; index++) {
Klass* k = InstanceKlass::cast(klass)->local_interfaces()->at(index);
result->obj_at_put(index, k->java_mirror());
}
} else { // All arrays implement java.lang.Cloneable and java.io.Serializable
result->obj_at_put(0, vmClasses::Cloneable_klass()->java_mirror());
result->obj_at_put(1, vmClasses::Serializable_klass()->java_mirror());
} return (jobjectArray) JNIHandles::make_local(THREAD, result());
JVM_END
JVM_ENTRY(jboolean, JVM_IsInterface(JNIEnv *env, jclass cls))
oop mirror = JNIHandles::resolve_non_null(cls); if (java_lang_Class::is_primitive(mirror)) { return JNI_FALSE;
}
Klass* k = java_lang_Class::as_Klass(mirror);
jboolean result = k->is_interface();
assert(!result || k->is_instance_klass(), "all interfaces are instance types"); // The compiler intrinsic for isInterface tests the // Klass::_access_flags bits in the same way. return result;
JVM_END
JVM_ENTRY(jobjectArray, JVM_GetClassSigners(JNIEnv *env, jclass cls))
JvmtiVMObjectAllocEventCollector oam;
oop mirror = JNIHandles::resolve_non_null(cls); if (java_lang_Class::is_primitive(mirror)) { // There are no signers for primitive types return NULL;
}
// If there are no signers set in the class, or if the class // is an array, return NULL. if (signers == NULL) return NULL;
// copy of the signers array
Klass* element = ObjArrayKlass::cast(signers->klass())->element_klass();
objArrayOop signers_copy = oopFactory::new_objArray(element, signers->length(), CHECK_NULL); for (int index = 0; index < signers->length(); index++) {
signers_copy->obj_at_put(index, signers->obj_at(index));
}
// return the copy return (jobjectArray) JNIHandles::make_local(THREAD, signers_copy);
JVM_END
JVM_ENTRY(void, JVM_SetClassSigners(JNIEnv *env, jclass cls, jobjectArray signers))
oop mirror = JNIHandles::resolve_non_null(cls); if (!java_lang_Class::is_primitive(mirror)) { // This call is ignored for primitive types and arrays. // Signers are only set once, ClassLoader.java, and thus shouldn't // be called with an array. Only the bootstrap loader creates arrays.
Klass* k = java_lang_Class::as_Klass(mirror); if (k->is_instance_klass()) {
java_lang_Class::set_signers(k->java_mirror(), objArrayOop(JNIHandles::resolve(signers)));
}
}
JVM_END
// Returns the inherited_access_control_context field of the running thread.
JVM_ENTRY(jobject, JVM_GetInheritedAccessControlContext(JNIEnv *env, jclass cls))
oop result = java_lang_Thread::inherited_access_control_context(thread->threadObj()); return JNIHandles::make_local(THREAD, result);
JVM_END
JVM_ENTRY(jobject, JVM_GetStackAccessControlContext(JNIEnv *env, jclass cls)) if (!UsePrivilegedStack) return NULL;
ResourceMark rm(THREAD);
GrowableArray<Handle>* local_array = new GrowableArray<Handle>(12);
JvmtiVMObjectAllocEventCollector oam;
// count the protection domains on the execution stack. We collapse // duplicate consecutive protection domains into a single one, as // well as stopping when we hit a privileged frame.
// Iterate through Java frames
vframeStream vfst(thread); for(; !vfst.at_end(); vfst.next()) { // get method of frame
Method* method = vfst.method();
// stop at the first privileged frame if (method->method_holder() == vmClasses::AccessController_klass() &&
method->name() == vmSymbols::executePrivileged_name())
{ // this frame is privileged
is_privileged = true;
// either all the domains on the stack were system domains, or // we had a privileged system domain if (local_array->is_empty()) { if (is_privileged && privileged_context.is_null()) return NULL;
// Iterate through Java frames
vframeStream vfst(thread); for(; !vfst.at_end(); vfst.next()) { int loc = -1; // get method of frame
Method* method = vfst.method();
Symbol *name = method->name();
InstanceKlass* holder = method->method_holder(); if (name == vmSymbols::runWith_method_name()) { if ((holder == resolver.Carrier_klass
|| holder == vmClasses::VirtualThread_klass()
|| holder == vmClasses::Thread_klass())) {
loc = 1;
}
}
Klass* k = java_lang_Class::as_Klass(mirror);
debug_only(int computed_modifiers = k->compute_modifier_flags());
assert(k->modifier_flags() == computed_modifiers, "modifiers cache is OK"); return k->modifier_flags();
JVM_END
// Inner class reflection ///////////////////////////////////////////////////////////////////////////////
JVM_ENTRY(jobjectArray, JVM_GetDeclaredClasses(JNIEnv *env, jclass ofClass))
JvmtiVMObjectAllocEventCollector oam; // ofClass is a reference to a java_lang_Class object. The mirror object // of an InstanceKlass
oop ofMirror = JNIHandles::resolve_non_null(ofClass); if (java_lang_Class::is_primitive(ofMirror) ||
! java_lang_Class::as_Klass(ofMirror)->is_instance_klass()) {
oop result = oopFactory::new_objArray(vmClasses::Class_klass(), 0, CHECK_NULL); return (jobjectArray)JNIHandles::make_local(THREAD, result);
}
InstanceKlass* k = InstanceKlass::cast(java_lang_Class::as_Klass(ofMirror));
InnerClassesIterator iter(k);
if (iter.length() == 0) { // Neither an inner nor outer class
oop result = oopFactory::new_objArray(vmClasses::Class_klass(), 0, CHECK_NULL); return (jobjectArray)JNIHandles::make_local(THREAD, result);
}
// find inner class info
constantPoolHandle cp(thread, k->constants()); int length = iter.length();
// Allocate temp. result array
objArrayOop r = oopFactory::new_objArray(vmClasses::Class_klass(), length/4, CHECK_NULL);
objArrayHandle result (THREAD, r); int members = 0;
for (; !iter.done(); iter.next()) { int ioff = iter.inner_class_info_index(); int ooff = iter.outer_class_info_index();
if (ioff != 0 && ooff != 0) { // Check to see if the name matches the class we're looking for // before attempting to find the class. if (cp->klass_name_at_matches(k, ooff)) {
Klass* outer_klass = cp->klass_at(ooff, CHECK_NULL); if (outer_klass == k) {
Klass* ik = cp->klass_at(ioff, CHECK_NULL);
InstanceKlass* inner_klass = InstanceKlass::cast(ik);
// Throws an exception if outer klass has not declared k as // an inner klass
Reflection::check_for_inner_class(k, inner_klass, true, CHECK_NULL);
JVM_ENTRY(jclass, JVM_GetDeclaringClass(JNIEnv *env, jclass ofClass))
{ // ofClass is a reference to a java_lang_Class object.
oop ofMirror = JNIHandles::resolve_non_null(ofClass); if (java_lang_Class::is_primitive(ofMirror)) { return NULL;
}
Klass* klass = java_lang_Class::as_Klass(ofMirror); if (!klass->is_instance_klass()) { return NULL;
}
bool inner_is_member = false;
Klass* outer_klass
= InstanceKlass::cast(klass)->compute_enclosing_class(&inner_is_member, CHECK_NULL); if (outer_klass == NULL) return NULL; // already a top-level class if (!inner_is_member) return NULL; // a hidden class (inside a method) return (jclass) JNIHandles::make_local(THREAD, outer_klass->java_mirror());
}
JVM_END
JVM_ENTRY(jstring, JVM_GetSimpleBinaryName(JNIEnv *env, jclass cls))
{
oop mirror = JNIHandles::resolve_non_null(cls); if (java_lang_Class::is_primitive(mirror)) { return NULL;
}
Klass* klass = java_lang_Class::as_Klass(mirror); if (!klass->is_instance_klass()) { return NULL;
}
InstanceKlass* k = InstanceKlass::cast(klass); int ooff = 0, noff = 0; if (k->find_inner_classes_attr(&ooff, &noff, THREAD)) { if (noff != 0) {
constantPoolHandle i_cp(thread, k->constants());
Symbol* name = i_cp->symbol_at(noff);
Handle str = java_lang_String::create_from_symbol(name, CHECK_NULL); return (jstring) JNIHandles::make_local(THREAD, str());
}
} return NULL;
}
JVM_END
JVM_ENTRY(jstring, JVM_GetClassSignature(JNIEnv *env, jclass cls))
assert (cls != NULL, "illegal class");
JvmtiVMObjectAllocEventCollector oam;
ResourceMark rm(THREAD);
oop mirror = JNIHandles::resolve_non_null(cls); // Return null for arrays and primitives if (!java_lang_Class::is_primitive(mirror)) {
Klass* k = java_lang_Class::as_Klass(mirror); if (k->is_instance_klass()) {
Symbol* sym = InstanceKlass::cast(k)->generic_signature(); if (sym == NULL) return NULL;
Handle str = java_lang_String::create_from_symbol(sym, CHECK_NULL); return (jstring) JNIHandles::make_local(THREAD, str());
}
} return NULL;
JVM_END
JVM_ENTRY(jbyteArray, JVM_GetClassAnnotations(JNIEnv *env, jclass cls))
assert (cls != NULL, "illegal class");
oop mirror = JNIHandles::resolve_non_null(cls); // Return null for arrays and primitives if (!java_lang_Class::is_primitive(mirror)) {
Klass* k = java_lang_Class::as_Klass(mirror); if (k->is_instance_klass()) {
typeArrayOop a = Annotations::make_java_array(InstanceKlass::cast(k)->class_annotations(), CHECK_NULL); return (jbyteArray) JNIHandles::make_local(THREAD, a);
}
} return NULL;
JVM_END
staticbool jvm_get_field_common(jobject field, fieldDescriptor& fd) { // some of this code was adapted from from jni_FromReflectedField
oop reflected = JNIHandles::resolve_non_null(field);
oop mirror = java_lang_reflect_Field::clazz(reflected);
Klass* k = java_lang_Class::as_Klass(mirror); int slot = java_lang_reflect_Field::slot(reflected); int modifiers = java_lang_reflect_Field::modifiers(reflected);
InstanceKlass* ik = InstanceKlass::cast(k);
intptr_t offset = ik->field_offset(slot);
if (modifiers & JVM_ACC_STATIC) { // for static fields we only look in the current class if (!ik->find_local_field_from_offset(offset, true, &fd)) {
assert(false, "cannot find static field"); returnfalse;
}
} else { // for instance fields we start with the current class and work // our way up through the superclass chain if (!ik->find_field_from_offset(offset, false, &fd)) {
assert(false, "cannot find instance field"); returnfalse;
}
} returntrue;
}
static Method* jvm_get_method_common(jobject method) { // some of this code was adapted from from jni_FromReflectedMethod
Method* m = InstanceKlass::cast(k)->method_with_idnum(slot);
assert(m != NULL, "cannot find method"); return m; // caller has to deal with NULL in product mode
}
/* Type use annotations support (JDK 1.8) */
JVM_ENTRY(jbyteArray, JVM_GetClassTypeAnnotations(JNIEnv *env, jclass cls))
assert (cls != NULL, "illegal class");
ResourceMark rm(THREAD); // Return null for arrays and primitives if (!java_lang_Class::is_primitive(JNIHandles::resolve(cls))) {
Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve(cls)); if (k->is_instance_klass()) {
AnnotationArray* type_annotations = InstanceKlass::cast(k)->class_type_annotations(); if (type_annotations != NULL) {
typeArrayOop a = Annotations::make_java_array(type_annotations, CHECK_NULL); return (jbyteArray) JNIHandles::make_local(THREAD, a);
}
}
} return NULL;
JVM_END
JVM_ENTRY(jbyteArray, JVM_GetMethodTypeAnnotations(JNIEnv *env, jobject method))
assert (method != NULL, "illegal method"); // method is a handle to a java.lang.reflect.Method object
Method* m = jvm_get_method_common(method); if (m == NULL) { return NULL;
}
AnnotationArray* type_annotations = m->type_annotations(); if (type_annotations != NULL) {
typeArrayOop a = Annotations::make_java_array(type_annotations, CHECK_NULL); return (jbyteArray) JNIHandles::make_local(THREAD, a);
}
staticvoid bounds_check(const constantPoolHandle& cp, jint index, TRAPS) { if (!cp->is_within_bounds(index)) {
THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), "Constant pool index out of bounds");
}
}
JVM_ENTRY(jobjectArray, JVM_GetMethodParameters(JNIEnv *env, jobject method))
{ // method is a handle to a java.lang.reflect.Method object
Method* method_ptr = jvm_get_method_common(method);
methodHandle mh (THREAD, method_ptr);
Handle reflected_method (THREAD, JNIHandles::resolve_non_null(method)); constint num_params = mh->method_parameters_length();
if (num_params < 0) { // A -1 return value from method_parameters_length means there is no // parameter data. Return null to indicate this to the reflection // API.
assert(num_params == -1, "num_params should be -1 if it is less than zero"); return (jobjectArray)NULL;
} else { // Otherwise, we return something up to reflection, even if it is // a zero-length array. Why? Because in some cases this can // trigger a MalformedParametersException.
// make sure all the symbols are properly formatted for (int i = 0; i < num_params; i++) {
MethodParametersElement* params = mh->method_parameters_start(); int index = params[i].name_cp_index;
--> --------------------
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