1 /*
2 * Copyright (c) 2000, 2018, 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 <sys/types.h>
27 #include <string.h>
28 #include <sys/resource.h>
29
30 #include "jni.h"
31 #include "jni_util.h"
32 #include "jvm.h"
33 #include "jlong.h"
34 #include "sun_nio_ch_IOUtil.h"
35 #include "java_lang_Integer.h"
36 #include "nio.h"
37 #include "nio_util.h"
38
39 static jfieldID fd_fdID; /* for jint 'fd' in java.io.FileDescriptor */
40
41
42 JNIEXPORT void JNICALL
43 Java_sun_nio_ch_IOUtil_initIDs(JNIEnv *env, jclass clazz)
44 {
45 CHECK_NULL(clazz = (*env)->FindClass(env, "java/io/FileDescriptor"));
46 CHECK_NULL(fd_fdID = (*env)->GetFieldID(env, clazz, "fd", "I"));
47 }
48
49 JNIEXPORT jboolean JNICALL
50 Java_sun_nio_ch_IOUtil_randomBytes(JNIEnv *env, jclass clazz,
51 jbyteArray randArray)
52 {
53 JNU_ThrowByName(env, "java/lang/UnsupportedOperationException", NULL);
54 return JNI_FALSE;
55 }
56
57 JNIEXPORT jint JNICALL
58 Java_sun_nio_ch_IOUtil_fdVal(JNIEnv *env, jclass clazz, jobject fdo)
59 {
60 return (*env)->GetIntField(env, fdo, fd_fdID);
61 }
62
63 JNIEXPORT void JNICALL
64 Java_sun_nio_ch_IOUtil_setfdVal(JNIEnv *env, jclass clazz, jobject fdo, jint val)
65 {
66 (*env)->SetIntField(env, fdo, fd_fdID, val);
67 }
68
69 static int
70 configureBlocking(int fd, jboolean blocking)
71 {
72 int flags = fcntl(fd, F_GETFL);
73 int newflags = blocking ? (flags & ~O_NONBLOCK) : (flags | O_NONBLOCK);
74
75 return (flags == newflags) ? 0 : fcntl(fd, F_SETFL, newflags);
76 }
77
78 JNIEXPORT void JNICALL
79 Java_sun_nio_ch_IOUtil_configureBlocking(JNIEnv *env, jclass clazz,
80 jobject fdo, jboolean blocking)
81 {
82 if (configureBlocking(fdval(env, fdo), blocking) < 0)
83 JNU_ThrowIOExceptionWithLastError(env, "Configure blocking failed");
84 }
85
86 JNIEXPORT jlong JNICALL
87 Java_sun_nio_ch_IOUtil_makePipe(JNIEnv *env, jobject this, jboolean blocking)
88 {
89 int fd[2];
90
91 if (pipe(fd) < 0) {
92 JNU_ThrowIOExceptionWithLastError(env, "Pipe failed");
93 return 0;
94 }
95 if (blocking == JNI_FALSE) {
96 if ((configureBlocking(fd[0], JNI_FALSE) < 0)
97 || (configureBlocking(fd[1], JNI_FALSE) < 0)) {
98 JNU_ThrowIOExceptionWithLastError(env, "Configure blocking failed");
99 close(fd[0]);
100 close(fd[1]);
101 return 0;
102 }
103 }
104 return ((jlong) fd[0] << 32) | (jlong) fd[1];
105 }
106
107
108 JNIEXPORT jint JNICALL
109 Java_sun_nio_ch_IOUtil_write1(JNIEnv *env, jclass cl, jint fd, jbyte b)
110 {
111 char c = (char)b;
112 return convertReturnVal(env, write(fd, &c, 1), JNI_FALSE);
113 }
114
115
116 JNIEXPORT jboolean JNICALL
117 Java_sun_nio_ch_IOUtil_drain(JNIEnv *env, jclass cl, jint fd)
118 {
119 char buf[16];
120 int tn = 0;
121
122 for (;;) {
123 int n = read(fd, buf, sizeof(buf));
124 tn += n;
125 if ((n < 0) && (errno != EAGAIN))
126 JNU_ThrowIOExceptionWithLastError(env, "Drain");
127 if (n == (int)sizeof(buf))
128 continue;
129 return (tn > 0) ? JNI_TRUE : JNI_FALSE;
130 }
131 }
132
133 JNIEXPORT jint JNICALL
134 Java_sun_nio_ch_IOUtil_fdLimit(JNIEnv *env, jclass this)
135 {
136 struct rlimit rlp;
137 if (getrlimit(RLIMIT_NOFILE, &rlp) < 0) {
138 JNU_ThrowIOExceptionWithLastError(env, "getrlimit failed");
139 return -1;
140 }
141 if (rlp.rlim_max == RLIM_INFINITY ||
142 rlp.rlim_max > (rlim_t)java_lang_Integer_MAX_VALUE) {
143 return java_lang_Integer_MAX_VALUE;
144 } else {
145 return (jint)rlp.rlim_max;
146 }
147 }
148
149 JNIEXPORT jint JNICALL
150 Java_sun_nio_ch_IOUtil_iovMax(JNIEnv *env, jclass this)
151 {
152 jlong iov_max = sysconf(_SC_IOV_MAX);
153 if (iov_max == -1)
154 iov_max = 16;
155 return (jint)iov_max;
156 }
157
158 /* Declared in nio_util.h for use elsewhere in NIO */
159
160 jint
161 convertReturnVal(JNIEnv *env, jint n, jboolean reading)
162 {
163 if (n > 0) /* Number of bytes written */
164 return n;
165 else if (n == 0) {
166 if (reading) {
167 return IOS_EOF; /* EOF is -1 in javaland */
168 } else {
169 return 0;
170 }
171 }
172 else if (errno == EAGAIN)
173 return IOS_UNAVAILABLE;
174 else if (errno == EINTR)
175 return IOS_INTERRUPTED;
176 else {
177 const char *msg = reading ? "Read failed" : "Write failed";
178 JNU_ThrowIOExceptionWithLastError(env, msg);
179 return IOS_THROWN;
180 }
181 }
182
183 /* Declared in nio_util.h for use elsewhere in NIO */
184
185 jlong
186 convertLongReturnVal(JNIEnv *env, jlong n, jboolean reading)
187 {
188 if (n > 0) /* Number of bytes written */
189 return n;
190 else if (n == 0) {
191 if (reading) {
192 return IOS_EOF; /* EOF is -1 in javaland */
193 } else {
194 return 0;
195 }
196 }
197 else if (errno == EAGAIN)
198 return IOS_UNAVAILABLE;
199 else if (errno == EINTR)
200 return IOS_INTERRUPTED;
201 else {
202 const char *msg = reading ? "Read failed" : "Write failed";
203 JNU_ThrowIOExceptionWithLastError(env, msg);
204 return IOS_THROWN;
205 }
206 }
207
208 jint
209 fdval(JNIEnv *env, jobject fdo)
210 {
211 return (*env)->GetIntField(env, fdo, fd_fdID);
212 }