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 
  36 #ifdef __linux__
  37   #include <pthread.h>
  38   /* Also defined in net/linux_close.c */
  39   #define INTERRUPT_SIGNAL (__SIGRTMAX - 2)
  40 #elif defined(_AIX)
  41   #include <pthread.h>
  42   /* Also defined in net/aix_close.c */
  43   #define INTERRUPT_SIGNAL (SIGRTMAX - 1)
  44 #elif defined(_ALLBSD_SOURCE)
  45   #include <pthread.h>
  46   /* Also defined in net/bsd_close.c */
  47   #define INTERRUPT_SIGNAL SIGIO
  48 #else
  49   #error "missing platform-specific definition here"
  50 #endif
  51 
  52 static void
  53 nullHandler(int sig)
  54 {
  55 }
  56 
  57 JNIEXPORT void JNICALL
  58 Java_sun_nio_ch_NativeThread_init(JNIEnv *env, jclass cl)
  59 {
  60     /* Install the null handler for INTERRUPT_SIGNAL.  This might overwrite the
  61      * handler previously installed by <platform>_close.c, but that's okay
  62      * since neither handler actually does anything.  We install our own
  63      * handler here simply out of paranoia; ultimately the two mechanisms
  64      * should somehow be unified, perhaps within the VM.
  65      */
  66 
  67     sigset_t ss;
  68     struct sigaction sa, osa;
  69     sa.sa_handler = nullHandler;
  70     sa.sa_flags = 0;
  71     sigemptyset(&sa.sa_mask);
  72     if (sigaction(INTERRUPT_SIGNAL, &sa, &osa) < 0)
  73         JNU_ThrowIOExceptionWithLastError(env, "sigaction");
  74 }
  75 
  76 JNIEXPORT jlong JNICALL
  77 Java_sun_nio_ch_NativeThread_current(JNIEnv *env, jclass cl)
  78 {
  79     return (jlong)pthread_self();
  80 }
  81 
  82 JNIEXPORT void JNICALL
  83 Java_sun_nio_ch_NativeThread_signal(JNIEnv *env, jclass cl, jlong thread)
  84 {
  85     int ret;
  86     ret = pthread_kill((pthread_t)thread, INTERRUPT_SIGNAL);
  87 #ifdef MACOSX
  88     if (ret != 0 && ret != ESRCH)
  89 #else
  90     if (ret != 0)
  91 #endif
  92         JNU_ThrowIOExceptionWithLastError(env, "Thread signal failed");
  93 }