1 /* 2 * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved. 3 * Copyright (c) 2018, Google and/or its affiliates. All rights reserved. 4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 5 * 6 * This code is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 only, as 8 * published by the Free Software Foundation. 9 * 10 * This code is distributed in the hope that it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 13 * version 2 for more details (a copy is included in the LICENSE file that 14 * accompanied this code). 15 * 16 * You should have received a copy of the GNU General Public License version 17 * 2 along with this work; if not, write to the Free Software Foundation, 18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 19 * 20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 21 * or visit www.oracle.com if you need additional information or have any 22 * questions. 23 */ 24 #ifndef NSK_EXCEPTIONCHECKINGJNIENV_DEFINED 25 #define NSK_EXCEPTIONCHECKINGJNIENV_DEFINED 26 27 #include <jni.h> 28 29 /** 30 * ExceptionCheckingJniEnv wraps around the JNIEnv data structure and 31 * methods to enable automatic exception checking. This allows test writers 32 * and readers to concentrate on what the test is to do and leave the 33 * error checking and throwing to this data structure and subsystem. 34 * 35 * For example: 36 * 37 * ... JNIEnv* env ... 38 * jclass klass = env->GetObjectClass(o); 39 * if (klass == NULL) { 40 * printf("Error: GetObjectClass returned NULL\n"); 41 * return; 42 * } 43 * if (env->ExceptionCheck()) { 44 * ... 45 * } 46 * 47 * Can be simplified to: 48 * ... ExceptionCheckingJniEnv* env ... 49 * jclass klass = env->GetObjectClass(o); 50 * 51 * Where now the JNI Exception checking and the NULL return checking are done 52 * internally and will perform whatever action the ErrorHandler requires. 53 * 54 * By default, the error handler describes the exception via the JNI 55 * ExceptionDescribe method and calls FatalError. 56 * 57 * Note: at a future date, this will also include the tracing mechanism done in 58 * NSK_VERIFY, which will thus embed its logic into the ExceptionCheckingJniEnv 59 * and clearing that up for the code readers and writers. 60 */ 61 class ExceptionCheckingJniEnv { 62 public: 63 // JNIEnv API redefinitions. 64 jfieldID GetFieldID(jclass klass, const char *name, const char* type); 65 jclass GetObjectClass(jobject obj); 66 jobject GetObjectField(jobject obj, jfieldID field); 67 void SetObjectField(jobject obj, jfieldID field, jobject value); 68 69 jobject NewGlobalRef(jobject obj); 70 void DeleteGlobalRef(jobject obj); 71 72 // ExceptionCheckingJniEnv methods. 73 JNIEnv* GetJNIEnv() { 74 return _jni_env; 75 } 76 77 void HandleError(const char* msg) { 78 if (_error_handler) { 79 _error_handler(_jni_env, msg); 80 } 81 } 82 83 typedef void (*ErrorHandler)(JNIEnv* env, const char* error_message); 84 85 static void FatalError(JNIEnv* env, const char* message) { 86 if (env->ExceptionCheck()) { 87 env->ExceptionDescribe(); 88 } 89 env->FatalError(message); 90 } 91 92 ExceptionCheckingJniEnv(JNIEnv* jni_env, ErrorHandler error_handler) : 93 _jni_env(jni_env), _error_handler(error_handler) {} 94 95 private: 96 JNIEnv* _jni_env; 97 ErrorHandler _error_handler; 98 }; 99 100 // We cannot use unique_ptr due to this being gnu98++, so use this instead: 101 class ExceptionCheckingJniEnvPtr { 102 private: 103 ExceptionCheckingJniEnv _env; 104 105 public: 106 ExceptionCheckingJniEnv* operator->() { 107 return &_env; 108 } 109 110 ExceptionCheckingJniEnvPtr( 111 JNIEnv* jni_env, 112 ExceptionCheckingJniEnv::ErrorHandler error_handler = ExceptionCheckingJniEnv::FatalError) : 113 _env(jni_env, error_handler) { 114 } 115 }; 116 117 #endif