diff options
Diffstat (limited to 'libjava/classpath/native/jni/java-nio/gnu_java_nio_VMSelector.c')
| -rw-r--r-- | libjava/classpath/native/jni/java-nio/gnu_java_nio_VMSelector.c | 303 |
1 files changed, 303 insertions, 0 deletions
diff --git a/libjava/classpath/native/jni/java-nio/gnu_java_nio_VMSelector.c b/libjava/classpath/native/jni/java-nio/gnu_java_nio_VMSelector.c new file mode 100644 index 000000000..19a6f244d --- /dev/null +++ b/libjava/classpath/native/jni/java-nio/gnu_java_nio_VMSelector.c @@ -0,0 +1,303 @@ +/* gnu_java_nio_VMSelector.c - Native methods for SelectorImpl class + Copyright (C) 2004, 2005 Free Software Foundation, Inc. + +This file is part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath is distributed in the hope that it will be useful, but +WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301 USA. + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + +#include "config.h" + +/* <sys/types.h> needs to be included on OSX before <sys/select.h> */ +#if defined(HAVE_SYS_TYPES_H) +#include <sys/types.h> +#endif +#if defined(HAVE_SYS_SELECT_H) +#include <sys/select.h> +#endif +#include <sys/time.h> + +#include <string.h> + +#include <errno.h> + +#include <jni.h> +#include <jcl.h> + +#include "gnu_java_nio_VMSelector.h" + +/* Amount of characters in the error message buffer for strerror_r. */ +#define BUF_SIZE 250 + +void helper_put_filedescriptors (JNIEnv *, jintArray, fd_set *, int *); + +void helper_get_filedescriptors (JNIEnv *, jintArray *, fd_set *); + +void helper_reset (JNIEnv *, jintArray *); + +int +helper_select (JNIEnv *, jclass, jmethodID, + int, fd_set *, fd_set *, fd_set *, struct timeval *); + +void +helper_put_filedescriptors (JNIEnv * env, jintArray fdArray, fd_set * fds, + int *max_fd) +{ + jint *tmpFDArray = (*env)->GetIntArrayElements (env, fdArray, 0); + int size = (*env)->GetArrayLength (env, fdArray); + int index, fd; + + for (index = 0; index < size; index++) + { + fd = tmpFDArray[index]; + + if (fd > 0) + { + FD_SET (tmpFDArray[index], fds); + + if (tmpFDArray[index] > (*max_fd)) + (*max_fd) = tmpFDArray[index]; + } + } +} + +void +helper_get_filedescriptors (JNIEnv * env, jintArray * fdArray, fd_set * fds) +{ + jint *tmpFDArray = (*env)->GetIntArrayElements (env, fdArray, 0); + int size = (*env)->GetArrayLength (env, fdArray); + int index, fd; + + for (index = 0; index < size; index++) + { + fd = tmpFDArray[index]; + if (fd < 0 || !FD_ISSET (fd, fds)) + tmpFDArray[index] = 0; + } +} + +void +helper_reset (JNIEnv * env, jintArray * fdArray) +{ + jint *tmpFDArray = (*env)->GetIntArrayElements (env, fdArray, 0); + int size = (*env)->GetArrayLength (env, fdArray); + int index; + + for (index = 0; index < size; index++) + tmpFDArray[index] = 0; +} + +/* A wrapper for select() which ignores EINTR. + * Taken from gclib's posix.cc + */ +int +helper_select (JNIEnv * env, jclass thread_class, + jmethodID thread_interrupted, int n, fd_set * readfds, + fd_set * writefds, fd_set * exceptfds, struct timeval *timeout) +{ +#ifdef HAVE_SYS_SELECT_H + /* If we have a timeout, compute the absolute ending time. */ + struct timeval end, delay, after; + int r; + + if (timeout) + { + gettimeofday (&end, NULL); + + end.tv_usec += timeout->tv_usec; + + if (end.tv_usec >= 1000000) + { + ++end.tv_sec; + end.tv_usec -= 1000000; + } + + end.tv_sec += timeout->tv_sec; + delay = *timeout; + } + else + { + /* Placate compiler. */ + delay.tv_sec = delay.tv_usec = 0; + } + + while (1) + { + r = select (n, readfds, writefds, exceptfds, timeout ? &delay : NULL); + + if (r < 0 && errno != EINTR) + return -errno; + else if (r >= 0) + return r; + + /* Here we know we got EINTR. */ + if ((*env)-> + CallStaticBooleanMethod (env, thread_class, thread_interrupted)) + { + return -EINTR; + } + + if (timeout) + { + gettimeofday (&after, NULL); + + /* Now compute new timeout argument. */ + delay.tv_usec = end.tv_usec - after.tv_usec; + delay.tv_sec = end.tv_sec - after.tv_sec; + + if (delay.tv_usec < 0) + { + --delay.tv_sec; + delay.tv_usec += 1000000; + } + + if (delay.tv_sec < 0) + { + /* We assume that the user wants a valid select() call + * more than precise timing. So if we get a series of + * EINTR we just keep trying with delay 0 until we get a + * valid result. + */ + delay.tv_sec = 0; + } + } + } +#else /* HAVE_SYS_SELECT_H */ + return 0; +#endif + +} + +JNIEXPORT jint JNICALL +Java_gnu_java_nio_VMSelector_select (JNIEnv * env, + jclass obj __attribute__ ((__unused__)), + jintArray read, + jintArray write, + jintArray except, jlong timeout) +{ + jint result; + jclass thread_class = (*env)->FindClass (env, "java/lang/Thread"); + jmethodID thread_current_thread = + (*env)->GetStaticMethodID (env, thread_class, "currentThread", + "()Ljava/lang/Thread;"); + jmethodID thread_interrupt = + (*env)->GetMethodID (env, thread_class, "interrupt", "()V"); + jmethodID thread_interrupted = + (*env)->GetStaticMethodID (env, thread_class, "interrupted", "()Z"); + jobject current_thread; + int max_fd = 0; + fd_set read_fds; + fd_set write_fds; + fd_set except_fds; + struct timeval real_time_data; + struct timeval *time_data = NULL; + char *message; + + /* If a legal timeout value isn't given, use NULL. + * This means an infinite timeout. The specification + * also says that a zero timeout should be treated + * as infinite. Otherwise (if the timeout value is legal), + * fill our timeval struct and use it for the select. + */ + if (timeout > 0) + { + real_time_data.tv_sec = timeout / 1000; + real_time_data.tv_usec = (timeout % 1000) * 1000; + time_data = &real_time_data; + } + + /* Reset all fd_set structures */ + FD_ZERO (&read_fds); + FD_ZERO (&write_fds); + FD_ZERO (&except_fds); + + /* Fill the fd_set data structures for the _Jv_select() call. */ + helper_put_filedescriptors (env, read, &read_fds, &max_fd); + helper_put_filedescriptors (env, write, &write_fds, &max_fd); + helper_put_filedescriptors (env, except, &except_fds, &max_fd); + + /* Actually do the select */ + result = + helper_select (env, thread_class, thread_interrupted, max_fd + 1, + &read_fds, &write_fds, &except_fds, time_data); + + if (result == -EINTR) + { + /* The behavior of JRE 1.4.1 is that no exception is thrown + * when the thread is interrupted, but the thread's interrupt + * status is set. Clear all of our select sets and return 0, + * indicating that nothing was selected. + */ + current_thread = + (*env)->CallStaticObjectMethod (env, thread_class, + thread_current_thread); + (*env)->CallVoidMethod (env, current_thread, thread_interrupt); + + helper_reset (env, read); + helper_reset (env, write); + helper_reset (env, except); + + return 0; + } + + if (result < 0) + { +#if defined(HAVE_STRERROR_R) + char message_buf[BUF_SIZE+1]; + int errorcode = -result; + + if (strerror_r (errorcode, message_buf, BUF_SIZE)) + { + /* This would mean that message_buf was to small + * to hold the error message. + */ + JCL_ThrowException (env, "java/lang/InternalError", + "Not enough space in message buffer."); + return 0; + } + + message = message_buf; +#else + message = strerror(errno); +#endif + + JCL_ThrowException (env, "java/io/IOException", message); + return 0; + } + + /* Set the file descriptors according to the values returned from select(). */ + helper_get_filedescriptors (env, read, &read_fds); + helper_get_filedescriptors (env, write, &write_fds); + helper_get_filedescriptors (env, except, &except_fds); + + return result; +} |