1 /*
   2  * Copyright (c) 2002, 2020, 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 #include <signal.h>
  35 #include <pthread.h>
  36 
  37 #ifdef __linux__
  38   /* Also defined in net/linux_close.c */
  39   #define INTERRUPT_SIGNAL (SIGRTMAX - 2)
  40 #elif defined(_AIX)
  41   /* Also defined in net/aix_close.c */
  42   #define INTERRUPT_SIGNAL (SIGRTMAX - 1)
  43 #elif defined(_ALLBSD_SOURCE)
  44   /* Also defined in net/bsd_close.c */
  45   #define INTERRUPT_SIGNAL SIGIO
  46 #else
  47   #error "missing platform-specific definition here"
  48 #endif
  49 
  50 static void
  51 nullHandler(int sig)
  52 {
  53 }
  54 
  55 JNIEXPORT void JNICALL
  56 Java_sun_nio_ch_NativeThread_init(JNIEnv *env, jclass cl)
  57 {
  58     /* Install the null handler for INTERRUPT_SIGNAL.  This might overwrite the
  59      * handler previously installed by <platform>_close.c, but that's okay
  60      * since neither handler actually does anything.  We install our own
  61      * handler here simply out of paranoia; ultimately the two mechanisms
  62      * should somehow be unified, perhaps within the VM.
  63      */
  64 
  65     sigset_t ss;
  66     struct sigaction sa, osa;
  67     sa.sa_handler = nullHandler;
  68     sa.sa_flags = 0;
  69     sigemptyset(&sa.sa_mask);
  70     if (sigaction(INTERRUPT_SIGNAL, &sa, &osa) < 0)
  71         JNU_ThrowIOExceptionWithLastError(env, "sigaction");
  72 }
  73 
  74 JNIEXPORT jlong JNICALL
  75 Java_sun_nio_ch_NativeThread_current(JNIEnv *env, jclass cl)
  76 {
  77     return (jlong)pthread_self();
  78 }
  79 
  80 JNIEXPORT void JNICALL
  81 Java_sun_nio_ch_NativeThread_signal(JNIEnv *env, jclass cl, jlong thread)
  82 {
  83     int ret;
  84     ret = pthread_kill((pthread_t)thread, INTERRUPT_SIGNAL);
  85 #ifdef MACOSX
  86     if (ret != 0 && ret != ESRCH)
  87 #else
  88     if (ret != 0)
  89 #endif
  90         JNU_ThrowIOExceptionWithLastError(env, "Thread signal failed");
  91 }