1 /* 2 * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #ifndef SHARE_RUNTIME_JNIHANDLES_INLINE_HPP 26 #define SHARE_RUNTIME_JNIHANDLES_INLINE_HPP 27 28 #include "runtime/jniHandles.hpp" 29 30 #include "oops/access.inline.hpp" 31 #include "oops/oop.hpp" 32 #include "utilities/debug.hpp" 33 #include "utilities/globalDefinitions.hpp" 34 35 inline bool JNIHandles::is_tagged_with(jobject handle, TypeTag tag) { 36 return (reinterpret_cast<uintptr_t>(handle) & tag_mask) == tag; 37 } 38 39 inline bool JNIHandles::is_local_tagged(jobject handle) { 40 return is_tagged_with(handle, TypeTag::local); 41 } 42 43 inline bool JNIHandles::is_weak_global_tagged(jobject handle) { 44 return is_tagged_with(handle, TypeTag::weak_global); 45 } 46 47 inline bool JNIHandles::is_global_tagged(jobject handle) { 48 return is_tagged_with(handle, TypeTag::global); 49 } 50 51 inline oop* JNIHandles::local_ptr(jobject handle) { 52 assert(is_local_tagged(handle), "precondition"); 53 STATIC_ASSERT(TypeTag::local == 0); 54 return reinterpret_cast<oop*>(handle); 55 } 56 57 inline oop* JNIHandles::global_ptr(jobject handle) { 58 assert(is_global_tagged(handle), "precondition"); 59 char* ptr = reinterpret_cast<char*>(handle) - TypeTag::global; 60 return reinterpret_cast<oop*>(ptr); 61 } 62 63 inline oop* JNIHandles::weak_global_ptr(jweak handle) { 64 assert(is_weak_global_tagged(handle), "precondition"); 65 char* ptr = reinterpret_cast<char*>(handle) - TypeTag::weak_global; 66 return reinterpret_cast<oop*>(ptr); 67 } 68 69 // external_guard is true if called from resolve_external_guard. 70 template <DecoratorSet decorators, bool external_guard> 71 inline oop JNIHandles::resolve_impl(jobject handle) { 72 assert(handle != nullptr, "precondition"); 73 assert(!current_thread_in_native(), "must not be in native"); 74 oop result; 75 if (is_weak_global_tagged(handle)) { // Unlikely 76 result = NativeAccess<ON_PHANTOM_OOP_REF|decorators>::oop_load(weak_global_ptr(handle)); 77 } else if (is_global_tagged(handle)) { 78 result = NativeAccess<decorators>::oop_load(global_ptr(handle)); 79 // Construction of jobjects canonicalize a null value into a null 80 // jobject, so for non-jweak the pointee should never be null. 81 assert(external_guard || result != nullptr, "Invalid JNI handle"); 82 } else { 83 result = *local_ptr(handle); 84 // Construction of jobjects canonicalize a null value into a null 85 // jobject, so for non-jweak the pointee should never be null. 86 assert(external_guard || result != nullptr, "Invalid JNI handle"); 87 } 88 return result; 89 } 90 91 inline oop JNIHandles::resolve(jobject handle) { 92 oop result = nullptr; 93 if (handle != nullptr) { 94 result = resolve_impl<DECORATORS_NONE, false /* external_guard */>(handle); 95 } 96 return result; 97 } 98 99 inline oop JNIHandles::resolve_no_keepalive(jobject handle) { 100 oop result = nullptr; 101 if (handle != nullptr) { 102 result = resolve_impl<AS_NO_KEEPALIVE, false /* external_guard */>(handle); 103 } 104 return result; 105 } 106 107 inline bool JNIHandles::is_same_object(jobject handle1, jobject handle2) { 108 oop obj1 = resolve_no_keepalive(handle1); 109 oop obj2 = resolve_no_keepalive(handle2); 110 return obj1 == obj2; 111 } 112 113 inline oop JNIHandles::resolve_non_null(jobject handle) { 114 assert(handle != nullptr, "JNI handle should not be null"); 115 oop result = resolve_impl<DECORATORS_NONE, false /* external_guard */>(handle); 116 assert(result != nullptr, "null read from jni handle"); 117 return result; 118 } 119 120 inline void JNIHandles::destroy_local(jobject handle) { 121 if (handle != nullptr) { 122 *local_ptr(handle) = nullptr; 123 } 124 } 125 126 #endif // SHARE_RUNTIME_JNIHANDLES_INLINE_HPP --- EOF ---