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      1 /*
      2  * Copyright (c) 1997, 2010, 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.  Oracle designates this
      8  * particular file as subject to the "Classpath" exception as provided
      9  * by Oracle in the LICENSE file that accompanied this code.
     10  *
     11  * This code is distributed in the hope that it will be useful, but WITHOUT
     12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
     13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
     14  * version 2 for more details (a copy is included in the LICENSE file that
     15  * accompanied this code).
     16  *
     17  * You should have received a copy of the GNU General Public License version
     18  * 2 along with this work; if not, write to the Free Software Foundation,
     19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
     20  *
     21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
     22  * or visit www.oracle.com if you need additional information or have any
     23  * questions.
     24  */
     25 
     26 #include "jni.h"
     27 #include "jni_util.h"
     28 
     29 extern jfieldID IO_fd_fdID;
     30 extern jfieldID IO_handle_fdID;
     31 
     32 #ifdef _ALLBSD_SOURCE
     33 #include <fcntl.h>
     34 #ifndef O_SYNC
     35 #define O_SYNC  O_FSYNC
     36 #endif
     37 #ifndef O_DSYNC
     38 #define O_DSYNC O_FSYNC
     39 #endif
     40 #elif !defined(O_DSYNC) || !defined(O_SYNC)
     41 #define O_SYNC  (0x0800)
     42 #define O_DSYNC (0x2000)
     43 #endif
     44 
     45 /*
     46  * IO helper functions
     47  */
     48 
     49 jint readSingle(JNIEnv *env, jobject this, jfieldID fid);
     50 jint readBytes(JNIEnv *env, jobject this, jbyteArray bytes, jint off,
     51                jint len, jfieldID fid);
     52 void writeSingle(JNIEnv *env, jobject this, jint byte, jboolean append, jfieldID fid);
     53 void writeBytes(JNIEnv *env, jobject this, jbyteArray bytes, jint off,
     54                 jint len, jboolean append, jfieldID fid);
     55 void fileOpen(JNIEnv *env, jobject this, jstring path, jfieldID fid, int flags);
     56 void throwFileNotFoundException(JNIEnv *env, jstring path);
     57 
     58 
     59 /*
     60  * Macros for managing platform strings.  The typical usage pattern is:
     61  *
     62  *     WITH_PLATFORM_STRING(env, string, var) {
     63  *         doSomethingWith(var);
     64  *     } END_PLATFORM_STRING(env, var);
     65  *
     66  *  where  env      is the prevailing JNIEnv,
     67  *         string   is a JNI reference to a java.lang.String object, and
     68  *         var      is the char * variable that will point to the string,
     69  *                  after being converted into the platform encoding.
     70  *
     71  * The related macro WITH_FIELD_PLATFORM_STRING first extracts the string from
     72  * a given field of a given object:
     73  *
     74  *     WITH_FIELD_PLATFORM_STRING(env, object, id, var) {
     75  *         doSomethingWith(var);
     76  *     } END_PLATFORM_STRING(env, var);
     77  *
     78  *  where  env      is the prevailing JNIEnv,
     79  *         object   is a jobject,
     80  *         id       is the field ID of the String field to be extracted, and
     81  *         var      is the char * variable that will point to the string.
     82  *
     83  * Uses of these macros may be nested as long as each WITH_.._STRING macro
     84  * declares a unique variable.
     85  */
     86 
     87 #define WITH_PLATFORM_STRING(env, strexp, var)                                \
     88     if (1) {                                                                  \
     89         const char *var;                                                      \
     90         jstring _##var##str = (strexp);                                       \
     91         if (_##var##str == NULL) {                                            \
     92             JNU_ThrowNullPointerException((env), NULL);                       \
     93             goto _##var##end;                                                 \
     94         }                                                                     \
     95         var = JNU_GetStringPlatformChars((env), _##var##str, NULL);           \
     96         if (var == NULL) goto _##var##end;
     97 
     98 #define WITH_FIELD_PLATFORM_STRING(env, object, id, var)                      \
     99     WITH_PLATFORM_STRING(env,                                                 \
    100                          ((object == NULL)                                    \
    101                           ? NULL                                              \
    102                           : (*(env))->GetObjectField((env), (object), (id))), \
    103                          var)
    104 
    105 #define END_PLATFORM_STRING(env, var)                                         \
    106         JNU_ReleaseStringPlatformChars(env, _##var##str, var);                \
    107     _##var##end: ;                                                            \
    108     } else ((void)NULL)
    109 
    110 
    111 /* Macros for transforming Java Strings into native Unicode strings.
    112  * Works analogously to WITH_PLATFORM_STRING.
    113  */
    114 
    115 #define WITH_UNICODE_STRING(env, strexp, var)                                 \
    116     if (1) {                                                                  \
    117         const jchar *var;                                                     \
    118         jstring _##var##str = (strexp);                                       \
    119         if (_##var##str == NULL) {                                            \
    120             JNU_ThrowNullPointerException((env), NULL);                       \
    121             goto _##var##end;                                                 \
    122         }                                                                     \
    123         var = (*(env))->GetStringChars((env), _##var##str, NULL);             \
    124         if (var == NULL) goto _##var##end;
    125 
    126 #define END_UNICODE_STRING(env, var)                                          \
    127         (*(env))->ReleaseStringChars(env, _##var##str, var);                  \
    128     _##var##end: ;                                                            \
    129     } else ((void)NULL)
    130