1 /*

     2  * Copyright (c) 2011, 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 /*

    27  * KQueueArrayWrapper.c

    28  * Implementation of Selector using FreeBSD / Mac OS X kqueues

    29  * Derived from Sun's DevPollArrayWrapper

    30  */

    31 

    32 

    33 #include "jni.h"

    34 #include "jni_util.h"

    35 #include "jvm.h"

    36 #include "jlong.h"

    37 #include "nio_util.h"

    38 

    39 #include <sys/types.h>

    40 #include <sys/event.h>

    41 #include <sys/time.h>

    42 

    43 JNIEXPORT void JNICALL

    44 Java_sun_nio_ch_KQueueArrayWrapper_initStructSizes(JNIEnv *env, jclass clazz)

    45 {

    46 #define CHECK_EXCEPTION() { \

    47     if ((*env)->ExceptionCheck(env)) { \

    48         goto exceptionOccurred; \

    49     } \

    50 }

    51 

    52 #define CHECK_ERROR_AND_EXCEPTION(_field) { \

    53     if (_field == NULL) { \

    54         goto badField; \

    55     } \

    56     CHECK_EXCEPTION(); \

    57 }

    58 

    59 

    60     jfieldID field;

    61 

    62     field = (*env)->GetStaticFieldID(env, clazz, "EVFILT_READ", "S");

    63     CHECK_ERROR_AND_EXCEPTION(field);

    64     (*env)->SetStaticShortField(env, clazz, field, EVFILT_READ);

    65     CHECK_EXCEPTION();

    66 

    67     field = (*env)->GetStaticFieldID(env, clazz, "EVFILT_WRITE", "S");

    68     CHECK_ERROR_AND_EXCEPTION(field);

    69     (*env)->SetStaticShortField(env, clazz, field, EVFILT_WRITE);

    70     CHECK_EXCEPTION();

    71 

    72     field = (*env)->GetStaticFieldID(env, clazz, "SIZEOF_KEVENT", "S");

    73     CHECK_ERROR_AND_EXCEPTION(field);

    74     (*env)->SetStaticShortField(env, clazz, field, (short) sizeof(struct kevent));

    75     CHECK_EXCEPTION();

    76 

    77     field = (*env)->GetStaticFieldID(env, clazz, "FD_OFFSET", "S");

    78     CHECK_ERROR_AND_EXCEPTION(field);

    79     (*env)->SetStaticShortField(env, clazz, field, (short) offsetof(struct kevent, ident));

    80     CHECK_EXCEPTION();

    81 

    82     field = (*env)->GetStaticFieldID(env, clazz, "FILTER_OFFSET", "S");

    83     CHECK_ERROR_AND_EXCEPTION(field);

    84     (*env)->SetStaticShortField(env, clazz, field, (short) offsetof(struct kevent, filter));

    85     CHECK_EXCEPTION();

    86     return;

    87 

    88 badField:

    89     return;

    90 

    91 exceptionOccurred:

    92     return;

    93 

    94 #undef CHECK_EXCEPTION

    95 #undef CHECK_ERROR_AND_EXCEPTION

    96 }

    97 

    98 JNIEXPORT jint JNICALL

    99 Java_sun_nio_ch_KQueueArrayWrapper_init(JNIEnv *env, jobject this)

   100 {

   101     int kq = kqueue();

   102     if (kq < 0) {

   103         JNU_ThrowIOExceptionWithLastError(env, "KQueueArrayWrapper: kqueue() failed");

   104     }

   105     return kq;

   106 }

   107 

   108 

   109 JNIEXPORT void JNICALL

   110 Java_sun_nio_ch_KQueueArrayWrapper_register0(JNIEnv *env, jobject this,

   111                                              jint kq, jint fd, jint r, jint w)

   112 {

   113     struct kevent changes[2];

   114     struct kevent errors[2];

   115     struct timespec dontBlock = {0, 0};

   116 

   117     // if (r) then { register for read } else { unregister for read }

   118     // if (w) then { register for write } else { unregister for write }

   119     // Ignore errors - they're probably complaints about deleting non-

   120     //   added filters - but provide an error array anyway because

   121     //   kqueue behaves erratically if some of its registrations fail.

   122     EV_SET(&changes[0], fd, EVFILT_READ,  r ? EV_ADD : EV_DELETE, 0, 0, 0);

   123     EV_SET(&changes[1], fd, EVFILT_WRITE, w ? EV_ADD : EV_DELETE, 0, 0, 0);

   124     kevent(kq, changes, 2, errors, 2, &dontBlock);

   125 }

   126 

   127 JNIEXPORT jint JNICALL

   128 Java_sun_nio_ch_KQueueArrayWrapper_kevent0(JNIEnv *env, jobject this, jint kq,

   129                                            jlong kevAddr, jint kevCount,

   130                                            jlong timeout)

   131 {

   132     struct kevent *kevs = (struct kevent *)jlong_to_ptr(kevAddr);

   133     struct timespec ts;

   134     struct timespec *tsp;

   135     int result;

   136 

   137     // Java timeout is in milliseconds. Convert to struct timespec.

   138     // Java timeout == -1 : wait forever : timespec timeout of NULL

   139     // Java timeout == 0  : return immediately : timespec timeout of zero

   140     if (timeout >= 0) {

   141         // For some indeterminate reason kevent(2) has been found to fail with

   142         // an EINVAL error for timeout values greater than or equal to

   143         // 100000001000L. To avoid this problem, clamp the timeout arbitrarily

   144         // to the maximum value of a 32-bit signed integer which is

   145         // approximately 25 days in milliseconds.

   146         const jlong timeoutMax = 0x7fffffff; // java.lang.Integer.MAX_VALUE

   147         if (timeout > timeoutMax) {

   148             timeout = timeoutMax;

   149         }

   150         ts.tv_sec = timeout / 1000;

   151         ts.tv_nsec = (timeout % 1000) * 1000000; //nanosec = 1 million millisec

   152         tsp = &ts;

   153     } else {

   154         tsp = NULL;

   155     }

   156 

   157     RESTARTABLE(kevent(kq, NULL, 0, kevs, kevCount, tsp), result);

   158     if (result < 0) {

   159         JNU_ThrowIOExceptionWithLastError(env,

   160             "KQueueArrayWrapper: kevent poll failed");

   161     }

   162 

   163     return result;

   164 }

   165 

   166 

   167 JNIEXPORT void JNICALL

   168 Java_sun_nio_ch_KQueueArrayWrapper_interrupt(JNIEnv *env, jclass cls, jint fd)

   169 {

   170     char c = 1;

   171     if (1 != write(fd, &c, 1)) {

   172         JNU_ThrowIOExceptionWithLastError(env, "KQueueArrayWrapper: interrupt failed");

   173     }

   174 }

   175