1 /*
   2  * Copyright (c) 2002, 2006, 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 "jni.h"
  29 #include "jni_util.h"
  30 #include "jvm.h"
  31 #include "jlong.h"
  32 #include "sun_nio_ch_NativeThread.h"
  33 #include "nio_util.h"
  34 
  35 
  36 #ifdef __linux__
  37 #include <pthread.h>
  38 #include <sys/signal.h>
  39 
  40 /* Also defined in src/solaris/native/java/net/linux_close.c */
  41 #define INTERRUPT_SIGNAL (__SIGRTMAX - 2)
  42 
  43 static void
  44 nullHandler(int sig)
  45 {
  46 }
  47 
  48 #endif
  49 
  50 
  51 JNIEXPORT void JNICALL
  52 Java_sun_nio_ch_NativeThread_init(JNIEnv *env, jclass cl)
  53 {
  54 #ifdef __linux__
  55 
  56     /* Install the null handler for INTERRUPT_SIGNAL.  This might overwrite the
  57      * handler previously installed by java/net/linux_close.c, but that's okay
  58      * since neither handler actually does anything.  We install our own
  59      * handler here simply out of paranoia; ultimately the two mechanisms
  60      * should somehow be unified, perhaps within the VM.
  61      */
  62 
  63     sigset_t ss;
  64     struct sigaction sa, osa;
  65     sa.sa_handler = nullHandler;
  66     sa.sa_flags = 0;
  67     sigemptyset(&sa.sa_mask);
  68     if (sigaction(INTERRUPT_SIGNAL, &sa, &osa) < 0)
  69         JNU_ThrowIOExceptionWithLastError(env, "sigaction");
  70 
  71 #endif
  72 }
  73 
  74 JNIEXPORT jlong JNICALL
  75 Java_sun_nio_ch_NativeThread_current(JNIEnv *env, jclass cl)
  76 {
  77 #ifdef __linux__
  78     return (long)pthread_self();
  79 #else
  80     return -1;
  81 #endif
  82 }
  83 
  84 JNIEXPORT void JNICALL
  85 Java_sun_nio_ch_NativeThread_signal(JNIEnv *env, jclass cl, jlong thread)
  86 {
  87 #ifdef __linux__
  88     if (pthread_kill((pthread_t)thread, INTERRUPT_SIGNAL))
  89         JNU_ThrowIOExceptionWithLastError(env, "Thread signal failed");
  90 #endif
  91 }