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Java example source code file (UnixNativeDispatcher.c)

This example Java source code file (UnixNativeDispatcher.c) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

dir, eintr, enoent, ent_buf_size, esrch, file, fstatat64_syscall_available, jnicall, jniexport, jnu_throwinternalerror, jnu_throwoutofmemoryerror, null, restartable, restartable_return_ptr

The UnixNativeDispatcher.c Java example source code

/*
 * Copyright (c) 2008, 2013, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
#include <fcntl.h>
#include <dirent.h>
#include <unistd.h>
#include <pwd.h>
#include <grp.h>
#include <errno.h>
#include <dlfcn.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/statvfs.h>
#include <sys/time.h>

#ifdef __solaris__
#include <strings.h>
#endif

#ifdef __linux__
#include <string.h>
#endif

#ifdef _ALLBSD_SOURCE
#include <string.h>

#define stat64 stat
#define statvfs64 statvfs

#define open64 open
#define fstat64 fstat
#define lstat64 lstat
#define dirent64 dirent
#define readdir64_r readdir_r
#endif

#include "jni.h"
#include "jni_util.h"
#include "jlong.h"

#include "sun_nio_fs_UnixNativeDispatcher.h"

/**
 * Size of password or group entry when not available via sysconf
 */
#define ENT_BUF_SIZE   1024

#define RESTARTABLE(_cmd, _result) do { \
  do { \
    _result = _cmd; \
  } while((_result == -1) && (errno == EINTR)); \
} while(0)

#define RESTARTABLE_RETURN_PTR(_cmd, _result) do { \
  do { \
    _result = _cmd; \
  } while((_result == NULL) && (errno == EINTR)); \
} while(0)

static jfieldID attrs_st_mode;
static jfieldID attrs_st_ino;
static jfieldID attrs_st_dev;
static jfieldID attrs_st_rdev;
static jfieldID attrs_st_nlink;
static jfieldID attrs_st_uid;
static jfieldID attrs_st_gid;
static jfieldID attrs_st_size;
static jfieldID attrs_st_atime_sec;
static jfieldID attrs_st_atime_nsec;
static jfieldID attrs_st_mtime_sec;
static jfieldID attrs_st_mtime_nsec;
static jfieldID attrs_st_ctime_sec;
static jfieldID attrs_st_ctime_nsec;

#ifdef _DARWIN_FEATURE_64_BIT_INODE
static jfieldID attrs_st_birthtime_sec;
#endif

static jfieldID attrs_f_frsize;
static jfieldID attrs_f_blocks;
static jfieldID attrs_f_bfree;
static jfieldID attrs_f_bavail;

static jfieldID entry_name;
static jfieldID entry_dir;
static jfieldID entry_fstype;
static jfieldID entry_options;
static jfieldID entry_dev;

/**
 * System calls that may not be available at run time.
 */
typedef int openat64_func(int, const char *, int, ...);
typedef int fstatat64_func(int, const char *, struct stat64 *, int);
typedef int unlinkat_func(int, const char*, int);
typedef int renameat_func(int, const char*, int, const char*);
typedef int futimesat_func(int, const char *, const struct timeval *);
typedef DIR* fdopendir_func(int);

static openat64_func* my_openat64_func = NULL;
static fstatat64_func* my_fstatat64_func = NULL;
static unlinkat_func* my_unlinkat_func = NULL;
static renameat_func* my_renameat_func = NULL;
static futimesat_func* my_futimesat_func = NULL;
static fdopendir_func* my_fdopendir_func = NULL;

/**
 * fstatat missing from glibc on Linux. Temporary workaround
 * for x86/x64.
 */
#if defined(__linux__) && defined(__i386)
#define FSTATAT64_SYSCALL_AVAILABLE
static int fstatat64_wrapper(int dfd, const char *path,
                             struct stat64 *statbuf, int flag)
{
    #ifndef __NR_fstatat64
    #define __NR_fstatat64  300
    #endif
    return syscall(__NR_fstatat64, dfd, path, statbuf, flag);
}
#endif

#if defined(__linux__) && defined(__x86_64__)
#define FSTATAT64_SYSCALL_AVAILABLE
static int fstatat64_wrapper(int dfd, const char *path,
                             struct stat64 *statbuf, int flag)
{
    #ifndef __NR_newfstatat
    #define __NR_newfstatat  262
    #endif
    return syscall(__NR_newfstatat, dfd, path, statbuf, flag);
}
#endif

/**
 * Call this to throw an internal UnixException when a system/library
 * call fails
 */
static void throwUnixException(JNIEnv* env, int errnum) {
    jobject x = JNU_NewObjectByName(env, "sun/nio/fs/UnixException",
        "(I)V", errnum);
    if (x != NULL) {
        (*env)->Throw(env, x);
    }
}

/**
 * Initialization
 */
JNIEXPORT jint JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_init(JNIEnv* env, jclass this)
{
    jint capabilities = 0;
    jclass clazz;

    clazz = (*env)->FindClass(env, "sun/nio/fs/UnixFileAttributes");
    if (clazz == NULL) {
        return 0;
    }
    attrs_st_mode = (*env)->GetFieldID(env, clazz, "st_mode", "I");
    attrs_st_ino = (*env)->GetFieldID(env, clazz, "st_ino", "J");
    attrs_st_dev = (*env)->GetFieldID(env, clazz, "st_dev", "J");
    attrs_st_rdev = (*env)->GetFieldID(env, clazz, "st_rdev", "J");
    attrs_st_nlink = (*env)->GetFieldID(env, clazz, "st_nlink", "I");
    attrs_st_uid = (*env)->GetFieldID(env, clazz, "st_uid", "I");
    attrs_st_gid = (*env)->GetFieldID(env, clazz, "st_gid", "I");
    attrs_st_size = (*env)->GetFieldID(env, clazz, "st_size", "J");
    attrs_st_atime_sec = (*env)->GetFieldID(env, clazz, "st_atime_sec", "J");
    attrs_st_atime_nsec = (*env)->GetFieldID(env, clazz, "st_atime_nsec", "J");
    attrs_st_mtime_sec = (*env)->GetFieldID(env, clazz, "st_mtime_sec", "J");
    attrs_st_mtime_nsec = (*env)->GetFieldID(env, clazz, "st_mtime_nsec", "J");
    attrs_st_ctime_sec = (*env)->GetFieldID(env, clazz, "st_ctime_sec", "J");
    attrs_st_ctime_nsec = (*env)->GetFieldID(env, clazz, "st_ctime_nsec", "J");

#ifdef _DARWIN_FEATURE_64_BIT_INODE
    attrs_st_birthtime_sec = (*env)->GetFieldID(env, clazz, "st_birthtime_sec", "J");
#endif

    clazz = (*env)->FindClass(env, "sun/nio/fs/UnixFileStoreAttributes");
    if (clazz == NULL) {
        return 0;
    }
    attrs_f_frsize = (*env)->GetFieldID(env, clazz, "f_frsize", "J");
    attrs_f_blocks = (*env)->GetFieldID(env, clazz, "f_blocks", "J");
    attrs_f_bfree = (*env)->GetFieldID(env, clazz, "f_bfree", "J");
    attrs_f_bavail = (*env)->GetFieldID(env, clazz, "f_bavail", "J");

    clazz = (*env)->FindClass(env, "sun/nio/fs/UnixMountEntry");
    if (clazz == NULL) {
        return 0;
    }
    entry_name = (*env)->GetFieldID(env, clazz, "name", "[B");
    entry_dir = (*env)->GetFieldID(env, clazz, "dir", "[B");
    entry_fstype = (*env)->GetFieldID(env, clazz, "fstype", "[B");
    entry_options = (*env)->GetFieldID(env, clazz, "opts", "[B");
    entry_dev = (*env)->GetFieldID(env, clazz, "dev", "J");

    /* system calls that might not be available at run time */

#if (defined(__solaris__) && defined(_LP64)) || defined(_ALLBSD_SOURCE)
    /* Solaris 64-bit does not have openat64/fstatat64 */
    my_openat64_func = (openat64_func*)dlsym(RTLD_DEFAULT, "openat");
    my_fstatat64_func = (fstatat64_func*)dlsym(RTLD_DEFAULT, "fstatat");
#else
    my_openat64_func = (openat64_func*) dlsym(RTLD_DEFAULT, "openat64");
    my_fstatat64_func = (fstatat64_func*) dlsym(RTLD_DEFAULT, "fstatat64");
#endif
    my_unlinkat_func = (unlinkat_func*) dlsym(RTLD_DEFAULT, "unlinkat");
    my_renameat_func = (renameat_func*) dlsym(RTLD_DEFAULT, "renameat");
    my_futimesat_func = (futimesat_func*) dlsym(RTLD_DEFAULT, "futimesat");
    my_fdopendir_func = (fdopendir_func*) dlsym(RTLD_DEFAULT, "fdopendir");

#if defined(FSTATAT64_SYSCALL_AVAILABLE)
    /* fstatat64 missing from glibc */
    if (my_fstatat64_func == NULL)
        my_fstatat64_func = (fstatat64_func*)&fstatat64_wrapper;
#endif

    /* supports futimes or futimesat */

#ifdef _ALLBSD_SOURCE
    capabilities |= sun_nio_fs_UnixNativeDispatcher_SUPPORTS_FUTIMES;
#else
    if (my_futimesat_func != NULL)
        capabilities |= sun_nio_fs_UnixNativeDispatcher_SUPPORTS_FUTIMES;
#endif

    /* supports openat, etc. */

    if (my_openat64_func != NULL &&  my_fstatat64_func != NULL &&
        my_unlinkat_func != NULL && my_renameat_func != NULL &&
        my_futimesat_func != NULL && my_fdopendir_func != NULL)
    {
        capabilities |= sun_nio_fs_UnixNativeDispatcher_SUPPORTS_OPENAT;
    }

    /* supports file birthtime */

#ifdef _DARWIN_FEATURE_64_BIT_INODE
    capabilities |= sun_nio_fs_UnixNativeDispatcher_SUPPORTS_BIRTHTIME;
#endif

    return capabilities;
}

JNIEXPORT jbyteArray JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_getcwd(JNIEnv* env, jclass this) {
    jbyteArray result = NULL;
    char buf[PATH_MAX+1];

    /* EINTR not listed as a possible error */
    char* cwd = getcwd(buf, sizeof(buf));
    if (cwd == NULL) {
        throwUnixException(env, errno);
    } else {
        jsize len = (jsize)strlen(buf);
        result = (*env)->NewByteArray(env, len);
        if (result != NULL) {
            (*env)->SetByteArrayRegion(env, result, 0, len, (jbyte*)buf);
        }
    }
    return result;
}

JNIEXPORT jbyteArray
Java_sun_nio_fs_UnixNativeDispatcher_strerror(JNIEnv* env, jclass this, jint error)
{
    char* msg;
    jsize len;
    jbyteArray bytes;

    msg = strerror((int)error);
    len = strlen(msg);
    bytes = (*env)->NewByteArray(env, len);
    if (bytes != NULL) {
        (*env)->SetByteArrayRegion(env, bytes, 0, len, (jbyte*)msg);
    }
    return bytes;
}

JNIEXPORT jint
Java_sun_nio_fs_UnixNativeDispatcher_dup(JNIEnv* env, jclass this, jint fd) {

    int res = -1;

    RESTARTABLE(dup((int)fd), res);
    if (fd == -1) {
        throwUnixException(env, errno);
    }
    return (jint)res;
}

JNIEXPORT jlong JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_fopen0(JNIEnv* env, jclass this,
    jlong pathAddress, jlong modeAddress)
{
    FILE* fp = NULL;
    const char* path = (const char*)jlong_to_ptr(pathAddress);
    const char* mode = (const char*)jlong_to_ptr(modeAddress);

    do {
        fp = fopen(path, mode);
    } while (fp == NULL && errno == EINTR);

    if (fp == NULL) {
        throwUnixException(env, errno);
    }

    return ptr_to_jlong(fp);
}

JNIEXPORT void JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_fclose(JNIEnv* env, jclass this, jlong stream)
{
    int res;
    FILE* fp = jlong_to_ptr(stream);

    do {
        res = fclose(fp);
    } while (res == EOF && errno == EINTR);
    if (res == EOF) {
        throwUnixException(env, errno);
    }
}

JNIEXPORT jint JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_open0(JNIEnv* env, jclass this,
    jlong pathAddress, jint oflags, jint mode)
{
    jint fd;
    const char* path = (const char*)jlong_to_ptr(pathAddress);

    RESTARTABLE(open64(path, (int)oflags, (mode_t)mode), fd);
    if (fd == -1) {
        throwUnixException(env, errno);
    }
    return fd;
}

JNIEXPORT jint JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_openat0(JNIEnv* env, jclass this, jint dfd,
    jlong pathAddress, jint oflags, jint mode)
{
    jint fd;
    const char* path = (const char*)jlong_to_ptr(pathAddress);

    if (my_openat64_func == NULL) {
        JNU_ThrowInternalError(env, "should not reach here");
        return -1;
    }

    RESTARTABLE((*my_openat64_func)(dfd, path, (int)oflags, (mode_t)mode), fd);
    if (fd == -1) {
        throwUnixException(env, errno);
    }
    return fd;
}

JNIEXPORT void JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_close(JNIEnv* env, jclass this, jint fd) {
    int err;
    /* TDB - need to decide if EIO and other errors should cause exception */
    RESTARTABLE(close((int)fd), err);
}

JNIEXPORT jint JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_read(JNIEnv* env, jclass this, jint fd,
    jlong address, jint nbytes)
{
    ssize_t n;
    void* bufp = jlong_to_ptr(address);
    RESTARTABLE(read((int)fd, bufp, (size_t)nbytes), n);
    if (n == -1) {
        throwUnixException(env, errno);
    }
    return (jint)n;
}

JNIEXPORT jint JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_write(JNIEnv* env, jclass this, jint fd,
    jlong address, jint nbytes)
{
    ssize_t n;
    void* bufp = jlong_to_ptr(address);
    RESTARTABLE(write((int)fd, bufp, (size_t)nbytes), n);
    if (n == -1) {
        throwUnixException(env, errno);
    }
    return (jint)n;
}

/**
 * Copy stat64 members into sun.nio.fs.UnixFileAttributes
 */
static void prepAttributes(JNIEnv* env, struct stat64* buf, jobject attrs) {
    (*env)->SetIntField(env, attrs, attrs_st_mode, (jint)buf->st_mode);
    (*env)->SetLongField(env, attrs, attrs_st_ino, (jlong)buf->st_ino);
    (*env)->SetLongField(env, attrs, attrs_st_dev, (jlong)buf->st_dev);
    (*env)->SetLongField(env, attrs, attrs_st_rdev, (jlong)buf->st_rdev);
    (*env)->SetIntField(env, attrs, attrs_st_nlink, (jint)buf->st_nlink);
    (*env)->SetIntField(env, attrs, attrs_st_uid, (jint)buf->st_uid);
    (*env)->SetIntField(env, attrs, attrs_st_gid, (jint)buf->st_gid);
    (*env)->SetLongField(env, attrs, attrs_st_size, (jlong)buf->st_size);
    (*env)->SetLongField(env, attrs, attrs_st_atime_sec, (jlong)buf->st_atime);
    (*env)->SetLongField(env, attrs, attrs_st_mtime_sec, (jlong)buf->st_mtime);
    (*env)->SetLongField(env, attrs, attrs_st_ctime_sec, (jlong)buf->st_ctime);

#ifdef _DARWIN_FEATURE_64_BIT_INODE
    (*env)->SetLongField(env, attrs, attrs_st_birthtime_sec, (jlong)buf->st_birthtime);
#endif

#if (_POSIX_C_SOURCE >= 200809L) || defined(__solaris__)
    (*env)->SetLongField(env, attrs, attrs_st_atime_nsec, (jlong)buf->st_atim.tv_nsec);
    (*env)->SetLongField(env, attrs, attrs_st_mtime_nsec, (jlong)buf->st_mtim.tv_nsec);
    (*env)->SetLongField(env, attrs, attrs_st_ctime_nsec, (jlong)buf->st_ctim.tv_nsec);
#endif
}

JNIEXPORT void JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_stat0(JNIEnv* env, jclass this,
    jlong pathAddress, jobject attrs)
{
    int err;
    struct stat64 buf;
    const char* path = (const char*)jlong_to_ptr(pathAddress);

    RESTARTABLE(stat64(path, &buf), err);
    if (err == -1) {
        throwUnixException(env, errno);
    } else {
        prepAttributes(env, &buf, attrs);
    }
}

JNIEXPORT void JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_lstat0(JNIEnv* env, jclass this,
    jlong pathAddress, jobject attrs)
{
    int err;
    struct stat64 buf;
    const char* path = (const char*)jlong_to_ptr(pathAddress);

    RESTARTABLE(lstat64(path, &buf), err);
    if (err == -1) {
        throwUnixException(env, errno);
    } else {
        prepAttributes(env, &buf, attrs);
    }
}

JNIEXPORT void JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_fstat(JNIEnv* env, jclass this, jint fd,
    jobject attrs)
{
    int err;
    struct stat64 buf;

    RESTARTABLE(fstat64((int)fd, &buf), err);
    if (err == -1) {
        throwUnixException(env, errno);
    } else {
        prepAttributes(env, &buf, attrs);
    }
}

JNIEXPORT void JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_fstatat0(JNIEnv* env, jclass this, jint dfd,
    jlong pathAddress, jint flag, jobject attrs)
{
    int err;
    struct stat64 buf;
    const char* path = (const char*)jlong_to_ptr(pathAddress);

    if (my_fstatat64_func == NULL) {
        JNU_ThrowInternalError(env, "should not reach here");
        return;
    }
    RESTARTABLE((*my_fstatat64_func)((int)dfd, path, &buf, (int)flag), err);
    if (err == -1) {
        throwUnixException(env, errno);
    } else {
        prepAttributes(env, &buf, attrs);
    }
}

JNIEXPORT void JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_chmod0(JNIEnv* env, jclass this,
    jlong pathAddress, jint mode)
{
    int err;
    const char* path = (const char*)jlong_to_ptr(pathAddress);

    RESTARTABLE(chmod(path, (mode_t)mode), err);
    if (err == -1) {
        throwUnixException(env, errno);
    }
}

JNIEXPORT void JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_fchmod(JNIEnv* env, jclass this, jint filedes,
    jint mode)
{
    int err;

    RESTARTABLE(fchmod((int)filedes, (mode_t)mode), err);
    if (err == -1) {
        throwUnixException(env, errno);
    }
}


JNIEXPORT void JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_chown0(JNIEnv* env, jclass this,
    jlong pathAddress, jint uid, jint gid)
{
    int err;
    const char* path = (const char*)jlong_to_ptr(pathAddress);

    RESTARTABLE(chown(path, (uid_t)uid, (gid_t)gid), err);
    if (err == -1) {
        throwUnixException(env, errno);
    }
}

JNIEXPORT void JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_lchown0(JNIEnv* env, jclass this, jlong pathAddress, jint uid, jint gid)
{
    int err;
    const char* path = (const char*)jlong_to_ptr(pathAddress);

    RESTARTABLE(lchown(path, (uid_t)uid, (gid_t)gid), err);
    if (err == -1) {
        throwUnixException(env, errno);
    }
}

JNIEXPORT void JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_fchown(JNIEnv* env, jclass this, jint filedes, jint uid, jint gid)
{
    int err;

    RESTARTABLE(fchown(filedes, (uid_t)uid, (gid_t)gid), err);
    if (err == -1) {
        throwUnixException(env, errno);
    }
}

JNIEXPORT void JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_utimes0(JNIEnv* env, jclass this,
    jlong pathAddress, jlong accessTime, jlong modificationTime)
{
    int err;
    struct timeval times[2];
    const char* path = (const char*)jlong_to_ptr(pathAddress);

    times[0].tv_sec = accessTime / 1000000;
    times[0].tv_usec = accessTime % 1000000;

    times[1].tv_sec = modificationTime / 1000000;
    times[1].tv_usec = modificationTime % 1000000;

    RESTARTABLE(utimes(path, ×[0]), err);
    if (err == -1) {
        throwUnixException(env, errno);
    }
}

JNIEXPORT void JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_futimes(JNIEnv* env, jclass this, jint filedes,
    jlong accessTime, jlong modificationTime)
{
    struct timeval times[2];
    int err = 0;

    times[0].tv_sec = accessTime / 1000000;
    times[0].tv_usec = accessTime % 1000000;

    times[1].tv_sec = modificationTime / 1000000;
    times[1].tv_usec = modificationTime % 1000000;

#ifdef _ALLBSD_SOURCE
    RESTARTABLE(futimes(filedes, ×[0]), err);
#else
    if (my_futimesat_func == NULL) {
        JNU_ThrowInternalError(env, "my_ftimesat_func is NULL");
        return;
    }
    RESTARTABLE((*my_futimesat_func)(filedes, NULL, ×[0]), err);
#endif
    if (err == -1) {
        throwUnixException(env, errno);
    }
}

JNIEXPORT jlong JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_opendir0(JNIEnv* env, jclass this,
    jlong pathAddress)
{
    DIR* dir;
    const char* path = (const char*)jlong_to_ptr(pathAddress);

    /* EINTR not listed as a possible error */
    dir = opendir(path);
    if (dir == NULL) {
        throwUnixException(env, errno);
    }
    return ptr_to_jlong(dir);
}

JNIEXPORT jlong JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_fdopendir(JNIEnv* env, jclass this, int dfd) {
    DIR* dir;

    if (my_fdopendir_func == NULL) {
        JNU_ThrowInternalError(env, "should not reach here");
        return (jlong)-1;
    }

    /* EINTR not listed as a possible error */
    dir = (*my_fdopendir_func)((int)dfd);
    if (dir == NULL) {
        throwUnixException(env, errno);
    }
    return ptr_to_jlong(dir);
}

JNIEXPORT void JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_closedir(JNIEnv* env, jclass this, jlong dir) {
    int err;
    DIR* dirp = jlong_to_ptr(dir);

    RESTARTABLE(closedir(dirp), err);
    if (errno == -1) {
        throwUnixException(env, errno);
    }
}

JNIEXPORT jbyteArray JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_readdir(JNIEnv* env, jclass this, jlong value) {
    struct dirent64* result;
    struct {
        struct dirent64 buf;
        char name_extra[PATH_MAX + 1 - sizeof result->d_name];
    } entry;
    struct dirent64* ptr = &entry.buf;
    int res;
    DIR* dirp = jlong_to_ptr(value);

    /* EINTR not listed as a possible error */
    /* TDB: reentrant version probably not required here */
    res = readdir64_r(dirp, ptr, &result);
    if (res != 0) {
        throwUnixException(env, res);
        return NULL;
    } else {
        if (result == NULL) {
            return NULL;
        } else {
            jsize len = strlen(ptr->d_name);
            jbyteArray bytes = (*env)->NewByteArray(env, len);
            if (bytes != NULL) {
                (*env)->SetByteArrayRegion(env, bytes, 0, len, (jbyte*)(ptr->d_name));
            }
            return bytes;
        }
    }
}

JNIEXPORT void JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_mkdir0(JNIEnv* env, jclass this,
    jlong pathAddress, jint mode)
{
    const char* path = (const char*)jlong_to_ptr(pathAddress);

    /* EINTR not listed as a possible error */
    if (mkdir(path, (mode_t)mode) == -1) {
        throwUnixException(env, errno);
    }
}

JNIEXPORT void JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_rmdir0(JNIEnv* env, jclass this,
    jlong pathAddress)
{
    const char* path = (const char*)jlong_to_ptr(pathAddress);

    /* EINTR not listed as a possible error */
    if (rmdir(path) == -1) {
        throwUnixException(env, errno);
    }
}

JNIEXPORT void JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_link0(JNIEnv* env, jclass this,
    jlong existingAddress, jlong newAddress)
{
    int err;
    const char* existing = (const char*)jlong_to_ptr(existingAddress);
    const char* newname = (const char*)jlong_to_ptr(newAddress);

    RESTARTABLE(link(existing, newname), err);
    if (err == -1) {
        throwUnixException(env, errno);
    }
}


JNIEXPORT void JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_unlink0(JNIEnv* env, jclass this,
    jlong pathAddress)
{
    const char* path = (const char*)jlong_to_ptr(pathAddress);

    /* EINTR not listed as a possible error */
    if (unlink(path) == -1) {
        throwUnixException(env, errno);
    }
}

JNIEXPORT void JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_unlinkat0(JNIEnv* env, jclass this, jint dfd,
                                               jlong pathAddress, jint flags)
{
    const char* path = (const char*)jlong_to_ptr(pathAddress);

    if (my_unlinkat_func == NULL) {
        JNU_ThrowInternalError(env, "should not reach here");
        return;
    }

    /* EINTR not listed as a possible error */
    if ((*my_unlinkat_func)((int)dfd, path, (int)flags) == -1) {
        throwUnixException(env, errno);
    }
}

JNIEXPORT void JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_rename0(JNIEnv* env, jclass this,
    jlong fromAddress, jlong toAddress)
{
    const char* from = (const char*)jlong_to_ptr(fromAddress);
    const char* to = (const char*)jlong_to_ptr(toAddress);

    /* EINTR not listed as a possible error */
    if (rename(from, to) == -1) {
        throwUnixException(env, errno);
    }
}

JNIEXPORT void JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_renameat0(JNIEnv* env, jclass this,
    jint fromfd, jlong fromAddress, jint tofd, jlong toAddress)
{
    const char* from = (const char*)jlong_to_ptr(fromAddress);
    const char* to = (const char*)jlong_to_ptr(toAddress);

    if (my_renameat_func == NULL) {
        JNU_ThrowInternalError(env, "should not reach here");
        return;
    }

    /* EINTR not listed as a possible error */
    if ((*my_renameat_func)((int)fromfd, from, (int)tofd, to) == -1) {
        throwUnixException(env, errno);
    }
}

JNIEXPORT void JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_symlink0(JNIEnv* env, jclass this,
    jlong targetAddress, jlong linkAddress)
{
    const char* target = (const char*)jlong_to_ptr(targetAddress);
    const char* link = (const char*)jlong_to_ptr(linkAddress);

    /* EINTR not listed as a possible error */
    if (symlink(target, link) == -1) {
        throwUnixException(env, errno);
    }
}

JNIEXPORT jbyteArray JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_readlink0(JNIEnv* env, jclass this,
    jlong pathAddress)
{
    jbyteArray result = NULL;
    char target[PATH_MAX+1];
    const char* path = (const char*)jlong_to_ptr(pathAddress);

    /* EINTR not listed as a possible error */
    int n = readlink(path, target, sizeof(target));
    if (n == -1) {
        throwUnixException(env, errno);
    } else {
        jsize len;
        if (n == sizeof(target)) {
            n--;
        }
        target[n] = '\0';
        len = (jsize)strlen(target);
        result = (*env)->NewByteArray(env, len);
        if (result != NULL) {
            (*env)->SetByteArrayRegion(env, result, 0, len, (jbyte*)target);
        }
    }
    return result;
}

JNIEXPORT jbyteArray JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_realpath0(JNIEnv* env, jclass this,
    jlong pathAddress)
{
    jbyteArray result = NULL;
    char resolved[PATH_MAX+1];
    const char* path = (const char*)jlong_to_ptr(pathAddress);

    /* EINTR not listed as a possible error */
    if (realpath(path, resolved) == NULL) {
        throwUnixException(env, errno);
    } else {
        jsize len = (jsize)strlen(resolved);
        result = (*env)->NewByteArray(env, len);
        if (result != NULL) {
            (*env)->SetByteArrayRegion(env, result, 0, len, (jbyte*)resolved);
        }
    }
    return result;
}

JNIEXPORT void JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_access0(JNIEnv* env, jclass this,
    jlong pathAddress, jint amode)
{
    int err;
    const char* path = (const char*)jlong_to_ptr(pathAddress);

    RESTARTABLE(access(path, (int)amode), err);
    if (err == -1) {
        throwUnixException(env, errno);
    }
}

JNIEXPORT void JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_statvfs0(JNIEnv* env, jclass this,
    jlong pathAddress, jobject attrs)
{
    int err;
    struct statvfs64 buf;
    const char* path = (const char*)jlong_to_ptr(pathAddress);


    RESTARTABLE(statvfs64(path, &buf), err);
    if (err == -1) {
        throwUnixException(env, errno);
    } else {
        (*env)->SetLongField(env, attrs, attrs_f_frsize, long_to_jlong(buf.f_frsize));
        (*env)->SetLongField(env, attrs, attrs_f_blocks, long_to_jlong(buf.f_blocks));
        (*env)->SetLongField(env, attrs, attrs_f_bfree,  long_to_jlong(buf.f_bfree));
        (*env)->SetLongField(env, attrs, attrs_f_bavail, long_to_jlong(buf.f_bavail));
    }
}

JNIEXPORT jlong JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_pathconf0(JNIEnv* env, jclass this,
    jlong pathAddress, jint name)
{
    long err;
    const char* path = (const char*)jlong_to_ptr(pathAddress);

    err = pathconf(path, (int)name);
    if (err == -1) {
        throwUnixException(env, errno);
    }
    return (jlong)err;
}

JNIEXPORT jlong JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_fpathconf(JNIEnv* env, jclass this,
    jint fd, jint name)
{
    long err;

    err = fpathconf((int)fd, (int)name);
    if (err == -1) {
        throwUnixException(env, errno);
    }
    return (jlong)err;
}

JNIEXPORT void JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_mknod0(JNIEnv* env, jclass this,
    jlong pathAddress, jint mode, jlong dev)
{
    int err;
    const char* path = (const char*)jlong_to_ptr(pathAddress);

    RESTARTABLE(mknod(path, (mode_t)mode, (dev_t)dev), err);
    if (err == -1) {
        throwUnixException(env, errno);
    }
}

JNIEXPORT jbyteArray JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_getpwuid(JNIEnv* env, jclass this, jint uid)
{
    jbyteArray result = NULL;
    int buflen;
    char* pwbuf;

    /* allocate buffer for password record */
    buflen = (int)sysconf(_SC_GETPW_R_SIZE_MAX);
    if (buflen == -1)
        buflen = ENT_BUF_SIZE;
    pwbuf = (char*)malloc(buflen);
    if (pwbuf == NULL) {
        JNU_ThrowOutOfMemoryError(env, "native heap");
    } else {
        struct passwd pwent;
        struct passwd* p = NULL;
        int res = 0;

        errno = 0;
        #ifdef __solaris__
            RESTARTABLE_RETURN_PTR(getpwuid_r((uid_t)uid, &pwent, pwbuf, (size_t)buflen), p);
        #else
            RESTARTABLE(getpwuid_r((uid_t)uid, &pwent, pwbuf, (size_t)buflen, &p), res);
        #endif

        if (res != 0 || p == NULL || p->pw_name == NULL || *(p->pw_name) == '\0') {
            /* not found or error */
            if (errno == 0)
                errno = ENOENT;
            throwUnixException(env, errno);
        } else {
            jsize len = strlen(p->pw_name);
            result = (*env)->NewByteArray(env, len);
            if (result != NULL) {
                (*env)->SetByteArrayRegion(env, result, 0, len, (jbyte*)(p->pw_name));
            }
        }
        free(pwbuf);
    }

    return result;
}


JNIEXPORT jbyteArray JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_getgrgid(JNIEnv* env, jclass this, jint gid)
{
    jbyteArray result = NULL;
    int buflen;
    int retry;

    /* initial size of buffer for group record */
    buflen = (int)sysconf(_SC_GETGR_R_SIZE_MAX);
    if (buflen == -1)
        buflen = ENT_BUF_SIZE;

    do {
        struct group grent;
        struct group* g = NULL;
        int res = 0;

        char* grbuf = (char*)malloc(buflen);
        if (grbuf == NULL) {
            JNU_ThrowOutOfMemoryError(env, "native heap");
            return NULL;
        }

        errno = 0;
        #ifdef __solaris__
            RESTARTABLE_RETURN_PTR(getgrgid_r((gid_t)gid, &grent, grbuf, (size_t)buflen), g);
        #else
            RESTARTABLE(getgrgid_r((gid_t)gid, &grent, grbuf, (size_t)buflen, &g), res);
        #endif

        retry = 0;
        if (res != 0 || g == NULL || g->gr_name == NULL || *(g->gr_name) == '\0') {
            /* not found or error */
            if (errno == ERANGE) {
                /* insufficient buffer size so need larger buffer */
                buflen += ENT_BUF_SIZE;
                retry = 1;
            } else {
                if (errno == 0)
                    errno = ENOENT;
                throwUnixException(env, errno);
            }
        } else {
            jsize len = strlen(g->gr_name);
            result = (*env)->NewByteArray(env, len);
            if (result != NULL) {
                (*env)->SetByteArrayRegion(env, result, 0, len, (jbyte*)(g->gr_name));
            }
        }

        free(grbuf);

    } while (retry);

    return result;
}

JNIEXPORT jint JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_getpwnam0(JNIEnv* env, jclass this,
    jlong nameAddress)
{
    jint uid = -1;
    int buflen;
    char* pwbuf;

    /* allocate buffer for password record */
    buflen = (int)sysconf(_SC_GETPW_R_SIZE_MAX);
    if (buflen == -1)
        buflen = ENT_BUF_SIZE;
    pwbuf = (char*)malloc(buflen);
    if (pwbuf == NULL) {
        JNU_ThrowOutOfMemoryError(env, "native heap");
    } else {
        struct passwd pwent;
        struct passwd* p = NULL;
        int res = 0;
        const char* name = (const char*)jlong_to_ptr(nameAddress);

        errno = 0;
        #ifdef __solaris__
            RESTARTABLE_RETURN_PTR(getpwnam_r(name, &pwent, pwbuf, (size_t)buflen), p);
        #else
            RESTARTABLE(getpwnam_r(name, &pwent, pwbuf, (size_t)buflen, &p), res);
        #endif

        if (res != 0 || p == NULL || p->pw_name == NULL || *(p->pw_name) == '\0') {
            /* not found or error */
            if (errno != 0 && errno != ENOENT && errno != ESRCH)
                throwUnixException(env, errno);
        } else {
            uid = p->pw_uid;
        }
        free(pwbuf);
    }

    return uid;
}

JNIEXPORT jint JNICALL
Java_sun_nio_fs_UnixNativeDispatcher_getgrnam0(JNIEnv* env, jclass this,
    jlong nameAddress)
{
    jint gid = -1;
    int buflen, retry;

    /* initial size of buffer for group record */
    buflen = (int)sysconf(_SC_GETGR_R_SIZE_MAX);
    if (buflen == -1)
        buflen = ENT_BUF_SIZE;

    do {
        struct group grent;
        struct group* g = NULL;
        int res = 0;
        char *grbuf;
        const char* name = (const char*)jlong_to_ptr(nameAddress);

        grbuf = (char*)malloc(buflen);
        if (grbuf == NULL) {
            JNU_ThrowOutOfMemoryError(env, "native heap");
            return -1;
        }

        errno = 0;
        #ifdef __solaris__
            RESTARTABLE_RETURN_PTR(getgrnam_r(name, &grent, grbuf, (size_t)buflen), g);
        #else
            RESTARTABLE(getgrnam_r(name, &grent, grbuf, (size_t)buflen, &g), res);
        #endif

        retry = 0;
        if (res != 0 || g == NULL || g->gr_name == NULL || *(g->gr_name) == '\0') {
            /* not found or error */
            if (errno != 0 && errno != ENOENT && errno != ESRCH) {
                if (errno == ERANGE) {
                    /* insufficient buffer size so need larger buffer */
                    buflen += ENT_BUF_SIZE;
                    retry = 1;
                } else {
                    throwUnixException(env, errno);
                }
            }
        } else {
            gid = g->gr_gid;
        }

        free(grbuf);

    } while (retry);

    return gid;
}

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