changeset 832:b89125f34e15

. Implement the virtual machine interface for BSD. This allows jmap -histo and jmap -dump to work. Based on work by: Brian Gardner <brian@experts-exchange.com>
author glewis@misty.eyesbeyond.com
date Wed, 11 Feb 2009 21:25:20 -0800
parents 1075888098ed
children 70336f995c2c d3f7b6d2dfc5
files make/com/sun/tools/attach/Exportedfiles.gmk make/com/sun/tools/attach/FILES_java.gmk make/com/sun/tools/attach/Makefile make/com/sun/tools/attach/mapfile-bsd src/share/classes/sun/tools/attach/META-INF/services/com.sun.tools.attach.spi.AttachProvider src/solaris/classes/sun/tools/attach/BsdAttachProvider.java src/solaris/classes/sun/tools/attach/BsdVirtualMachine.java src/solaris/native/sun/tools/attach/BsdVirtualMachine.c
diffstat 8 files changed, 646 insertions(+), 6 deletions(-) [+]
line wrap: on
line diff
--- a/make/com/sun/tools/attach/Exportedfiles.gmk	Wed Feb 11 07:56:01 2009 -0800
+++ b/make/com/sun/tools/attach/Exportedfiles.gmk	Wed Feb 11 21:25:20 2009 -0800
@@ -43,5 +43,7 @@
 	sun/tools/attach/LinuxVirtualMachine.java
 endif
 
-
-
+ifeq ($(PLATFORM), bsd)
+FILES_export = \
+	sun/tools/attach/BsdVirtualMachine.java
+endif
--- a/make/com/sun/tools/attach/FILES_java.gmk	Wed Feb 11 07:56:01 2009 -0800
+++ b/make/com/sun/tools/attach/FILES_java.gmk	Wed Feb 11 21:25:20 2009 -0800
@@ -45,7 +45,7 @@
 
 ifeq ($(PLATFORM), bsd)
 FILES_java += \
-	$(TARGDIR)/sun/tools/attach/BsdAttachProvider.java
+	sun/tools/attach/BsdAttachProvider.java
 endif
 
 #
--- a/make/com/sun/tools/attach/Makefile	Wed Feb 11 07:56:01 2009 -0800
+++ b/make/com/sun/tools/attach/Makefile	Wed Feb 11 21:25:20 2009 -0800
@@ -36,6 +36,9 @@
 ifeq ($(PLATFORM), linux)
 FILES_m = mapfile-linux
 endif
+ifeq ($(PLATFORM), bsd)
+FILES_m = mapfile-bsd
+endif
 include $(BUILDDIR)/common/Mapfile-vers.gmk
 
 #
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/make/com/sun/tools/attach/mapfile-bsd	Wed Feb 11 21:25:20 2009 -0800
@@ -0,0 +1,41 @@
+#
+# Copyright 2005 Sun Microsystems, Inc.  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.  Sun designates this
+# particular file as subject to the "Classpath" exception as provided
+# by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+# CA 95054 USA or visit www.sun.com if you need additional information or
+# have any questions.
+#
+
+# Define public interface.
+
+SUNWprivate_1.1 {
+	global:
+	    Java_sun_tools_attach_BsdVirtualMachine_checkPermissions;
+	    Java_sun_tools_attach_BsdVirtualMachine_close;
+	    Java_sun_tools_attach_BsdVirtualMachine_connect;
+	    Java_sun_tools_attach_BsdVirtualMachine_open;
+	    Java_sun_tools_attach_BsdVirtualMachine_sendQuitTo;
+	    Java_sun_tools_attach_BsdVirtualMachine_socket;
+	    Java_sun_tools_attach_BsdVirtualMachine_read;
+	    Java_sun_tools_attach_BsdVirtualMachine_write;
+	    Java_sun_tools_attach_BsdVirtualMachine_createAttachFile;
+	local:
+		*;
+};
--- a/src/share/classes/sun/tools/attach/META-INF/services/com.sun.tools.attach.spi.AttachProvider	Wed Feb 11 07:56:01 2009 -0800
+++ b/src/share/classes/sun/tools/attach/META-INF/services/com.sun.tools.attach.spi.AttachProvider	Wed Feb 11 21:25:20 2009 -0800
@@ -30,3 +30,4 @@
 #[solaris]sun.tools.attach.SolarisAttachProvider
 #[windows]sun.tools.attach.WindowsAttachProvider
 #[linux]sun.tools.attach.LinuxAttachProvider
+#[bsd]sun.tools.attach.BsdAttachProvider
--- a/src/solaris/classes/sun/tools/attach/BsdAttachProvider.java	Wed Feb 11 07:56:01 2009 -0800
+++ b/src/solaris/classes/sun/tools/attach/BsdAttachProvider.java	Wed Feb 11 21:25:20 2009 -0800
@@ -54,13 +54,31 @@
     public VirtualMachine attachVirtualMachine(String vmid)
         throws AttachNotSupportedException, IOException
     {
-        throw new AttachNotSupportedException("Attach not yet supported on BSD");
+        checkAttachPermission();
+
+        // AttachNotSupportedException will be thrown if the target VM can be determined
+        // to be not attachable.
+        testAttachable(vmid);
+
+        return new BsdVirtualMachine(this, vmid);
     }
 
     public VirtualMachine attachVirtualMachine(VirtualMachineDescriptor vmd)
         throws AttachNotSupportedException, IOException
     {
-        throw new AttachNotSupportedException("Attach not yet supported on BSD");
+        if (vmd.provider() != this) {
+            throw new AttachNotSupportedException("provider mismatch");
+        }
+        // To avoid re-checking if the VM if attachable, we check if the descriptor
+        // is for a hotspot VM - these descriptors are created by the listVirtualMachines
+        // implementation which only returns a list of attachable VMs.
+        if (vmd instanceof HotSpotVirtualMachineDescriptor) {
+            assert ((HotSpotVirtualMachineDescriptor)vmd).isAttachable();
+            checkAttachPermission();
+            return new BsdVirtualMachine(this, vmd.id());
+        } else {
+            return attachVirtualMachine(vmd.id());
+        }
     }
 
 }
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/solaris/classes/sun/tools/attach/BsdVirtualMachine.java	Wed Feb 11 21:25:20 2009 -0800
@@ -0,0 +1,299 @@
+/*
+ * Copyright 2005-2006 Sun Microsystems, Inc.  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.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+package sun.tools.attach;
+
+import com.sun.tools.attach.VirtualMachine;
+import com.sun.tools.attach.AgentLoadException;
+import com.sun.tools.attach.AttachNotSupportedException;
+import com.sun.tools.attach.spi.AttachProvider;
+import java.io.InputStream;
+import java.io.IOException;
+import java.io.File;
+import java.util.Properties;
+
+/*
+ * BSD implementation of HotSpotVirtualMachine
+ */
+public class BsdVirtualMachine extends HotSpotVirtualMachine {
+
+    // The patch to the socket file created by the target VM
+    String path;
+
+    /**
+     * Attaches to the target VM
+     */
+    BsdVirtualMachine(AttachProvider provider, String vmid)
+        throws AttachNotSupportedException, IOException
+    {
+        super(provider, vmid);
+
+        // This provider only understands pids
+        int pid;
+        try {
+            pid = Integer.parseInt(vmid);
+        } catch (NumberFormatException x) {
+            throw new AttachNotSupportedException("Invalid process identifier");
+        }
+
+        // Find the socket file. If not found then we attempt to start the
+        // attach mechanism in the target VM by sending it a QUIT signal.
+        // Then we attempt to find the socket file again.
+        path = findSocketFile(pid);
+        if (path == null) {
+            File f = new File("/tmp/.attach_pid" + pid);
+	    createAttachFile(f.getPath());
+            try {
+                sendQuitTo(pid);
+
+                // give the target VM time to start the attach mechanism
+                int i = 0;
+                long delay = 200;
+                int retries = (int)(attachTimeout() / delay);
+                do {
+                    try {
+                        Thread.sleep(delay);
+                    } catch (InterruptedException x) { }
+                    path = findSocketFile(pid);
+                    i++;
+                } while (i <= retries && path == null);
+                if (path == null) {
+                    throw new AttachNotSupportedException(
+                        "Unable to open socket file: target process not responding " +
+                        "or HotSpot VM not loaded");
+                }
+            } finally {
+                f.delete();
+            }
+        }
+
+        // Check that the file owner/permission to avoid attaching to
+        // bogus process
+        checkPermissions(path);
+
+        // Check that we can connect to the process
+        // - this ensures we throw the permission denied error now rather than
+        // later when we attempt to enqueue a command.
+        int s = socket();
+        try {
+            connect(s, path);
+        } finally {
+            close(s);
+        }
+    }
+
+    /**
+     * Detach from the target VM
+     */
+    public void detach() throws IOException {
+        synchronized (this) {
+            if (this.path != null) {
+                this.path = null;
+            }
+        }
+    }
+
+    // protocol version
+    private final static String PROTOCOL_VERSION = "1";
+
+    // known errors
+    private final static int ATTACH_ERROR_BADVERSION = 101;
+
+    /**
+     * Execute the given command in the target VM.
+     */
+    InputStream execute(String cmd, Object ... args) throws AgentLoadException, IOException {
+        assert args.length <= 3;                // includes null
+
+        // did we detach?
+        String p;
+        synchronized (this) {
+            if (this.path == null) {
+                throw new IOException("Detached from target VM");
+            }
+            p = this.path;
+        }
+
+        // create UNIX socket
+        int s = socket();
+
+        // connect to target VM
+        try {
+            connect(s, p);
+        } catch (IOException x) {
+            close(s);
+            throw x;
+        }
+
+        IOException ioe = null;
+
+        // connected - write request
+        // <ver> <cmd> <args...>
+        try {
+            writeString(s, PROTOCOL_VERSION);
+            writeString(s, cmd);
+
+            for (int i=0; i<3; i++) {
+                if (i < args.length && args[i] != null) {
+                    writeString(s, (String)args[i]);
+                } else {
+                    writeString(s, "");
+                }
+            }
+        } catch (IOException x) {
+            ioe = x;
+        }
+
+
+        // Create an input stream to read reply
+        SocketInputStream sis = new SocketInputStream(s);
+
+        // Read the command completion status
+        int completionStatus;
+        try {
+            completionStatus = readInt(sis);
+        } catch (IOException x) {
+            sis.close();
+            if (ioe != null) {
+                throw ioe;
+            } else {
+                throw x;
+            }
+        }
+
+        if (completionStatus != 0) {
+            sis.close();
+
+            // In the event of a protocol mismatch then the target VM
+            // returns a known error so that we can throw a reasonable
+            // error.
+            if (completionStatus == ATTACH_ERROR_BADVERSION) {
+                throw new IOException("Protocol mismatch with target VM");
+            }
+
+            // Special-case the "load" command so that the right exception is
+            // thrown.
+            if (cmd.equals("load")) {
+                throw new AgentLoadException("Failed to load agent library");
+            } else {
+                throw new IOException("Command failed in target VM");
+            }
+        }
+
+        // Return the input stream so that the command output can be read
+        return sis;
+    }
+
+    /*
+     * InputStream for the socket connection to get target VM
+     */
+    private class SocketInputStream extends InputStream {
+        int s;
+
+        public SocketInputStream(int s) {
+            this.s = s;
+        }
+
+        public synchronized int read() throws IOException {
+            byte b[] = new byte[1];
+            int n = this.read(b, 0, 1);
+            if (n == 1) {
+                return b[0] & 0xff;
+            } else {
+                return -1;
+            }
+        }
+
+        public synchronized int read(byte[] bs, int off, int len) throws IOException {
+            if ((off < 0) || (off > bs.length) || (len < 0) ||
+                ((off + len) > bs.length) || ((off + len) < 0)) {
+                throw new IndexOutOfBoundsException();
+            } else if (len == 0)
+                return 0;
+
+            return BsdVirtualMachine.read(s, bs, off, len);
+        }
+
+        public void close() throws IOException {
+            BsdVirtualMachine.close(s);
+        }
+    }
+
+    // Return the socket file for the given process.
+    // Checks working directory of process for .java_pid<pid>. If not
+    // found it looks in /tmp.
+    private String findSocketFile(int pid) {
+        // First check for a .java_pid<pid> file in the working directory
+        // of the target process
+        String fn = ".java_pid" + pid;
+        String path = "/tmp/" + fn;
+        File f = new File(path);
+        if (!f.exists()) {
+            return null;            // not found
+        }
+        return path;
+    }
+
+    /*
+     * Write/sends the given to the target VM. String is transmitted in
+     * UTF-8 encoding.
+     */
+    private void writeString(int fd, String s) throws IOException {
+        if (s.length() > 0) {
+            byte b[];
+            try {
+                b = s.getBytes("UTF-8");
+            } catch (java.io.UnsupportedEncodingException x) {
+                throw new InternalError();
+            }
+            BsdVirtualMachine.write(fd, b, 0, b.length);
+        }
+        byte b[] = new byte[1];
+        b[0] = 0;
+        write(fd, b, 0, 1);
+    }
+
+
+    //-- native methods
+
+    static native void sendQuitTo(int pid) throws IOException;
+
+    static native void checkPermissions(String path) throws IOException;
+
+    static native int socket() throws IOException;
+
+    static native void connect(int fd, String path) throws IOException;
+
+    static native void close(int fd) throws IOException;
+
+    static native int read(int fd, byte buf[], int off, int bufLen) throws IOException;
+
+    static native void write(int fd, byte buf[], int off, int bufLen) throws IOException;
+
+    static native void createAttachFile(String path);
+
+    static {
+        System.loadLibrary("attach");
+    }
+}
--- a/src/solaris/native/sun/tools/attach/BsdVirtualMachine.c	Wed Feb 11 07:56:01 2009 -0800
+++ b/src/solaris/native/sun/tools/attach/BsdVirtualMachine.c	Wed Feb 11 21:25:20 2009 -0800
@@ -1,3 +1,279 @@
 /*
- * Dummy file - needs to be implemented for bsd
+ * Copyright 2005 Sun Microsystems, Inc.  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.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
  */
+
+#include "jni.h"
+#include "jni_util.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <signal.h>
+#include <dirent.h>
+#include <ctype.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/un.h>
+#include <fcntl.h>
+
+#include "sun_tools_attach_BsdVirtualMachine.h"
+
+#define RESTARTABLE(_cmd, _result) do { \
+  do { \
+    _result = _cmd; \
+  } while((_result == -1) && (errno == EINTR)); \
+} while(0)
+
+/*
+ * Class:     sun_tools_attach_BsdVirtualMachine
+ * Method:    socket
+ * Signature: ()I
+ */
+JNIEXPORT jint JNICALL Java_sun_tools_attach_BsdVirtualMachine_socket
+  (JNIEnv *env, jclass cls)
+{
+    int fd = socket(PF_UNIX, SOCK_STREAM, 0);
+    if (fd == -1) {
+        JNU_ThrowIOExceptionWithLastError(env, "socket");
+    }
+    return (jint)fd;
+}
+
+/*
+ * Class:     sun_tools_attach_BsdVirtualMachine
+ * Method:    connect
+ * Signature: (ILjava/lang/String;)I
+ */
+JNIEXPORT void JNICALL Java_sun_tools_attach_BsdVirtualMachine_connect
+  (JNIEnv *env, jclass cls, jint fd, jstring path)
+{
+    jboolean isCopy;
+    const char* p = GetStringPlatformChars(env, path, &isCopy);
+    if (p != NULL) {
+        struct sockaddr_un addr;
+        int err = 0;
+
+        addr.sun_family = AF_UNIX;
+        strcpy(addr.sun_path, p);
+
+        if (connect(fd, (struct sockaddr*)&addr, sizeof(addr)) == -1) {
+            err = errno;
+        }
+
+        if (isCopy) {
+            JNU_ReleaseStringPlatformChars(env, path, p);
+        }
+
+        /*
+         * If the connect failed then we throw the appropriate exception
+         * here (can't throw it before releasing the string as can't call
+         * JNI with pending exception)
+         */
+        if (err != 0) {
+            if (err == ENOENT) {
+                JNU_ThrowByName(env, "java/io/FileNotFoundException", NULL);
+            } else {
+                char* msg = strdup(strerror(err));
+                JNU_ThrowIOException(env, msg);
+                if (msg != NULL) {
+                    free(msg);
+                }
+            }
+        }
+    }
+}
+
+/*
+ * Class:     sun_tools_attach_BsdVirtualMachine
+ * Method:    sendQuitTo
+ * Signature: (I)V
+ */
+JNIEXPORT void JNICALL Java_sun_tools_attach_BsdVirtualMachine_sendQuitTo
+  (JNIEnv *env, jclass cls, jint pid)
+{
+    if (kill((pid_t)pid, SIGQUIT)) {
+        JNU_ThrowIOExceptionWithLastError(env, "kill");
+    }
+}
+
+/*
+ * Class:     sun_tools_attach_BsdVirtualMachine
+ * Method:    checkPermissions
+ * Signature: (Ljava/lang/String;)V
+ */
+JNIEXPORT void JNICALL Java_sun_tools_attach_BsdVirtualMachine_checkPermissions
+  (JNIEnv *env, jclass cls, jstring path)
+{
+    jboolean isCopy;
+    const char* p = GetStringPlatformChars(env, path, &isCopy);
+    if (p != NULL) {
+        struct stat sb;
+        uid_t uid, gid;
+        int res;
+
+        /*
+         * Check that the path is owned by the effective uid/gid of this
+         * process. Also check that group/other access is not allowed.
+         */
+        uid = geteuid();
+        gid = getegid();
+
+        res = stat(p, &sb);
+        if (res != 0) {
+            /* save errno */
+            res = errno;
+        }
+
+        /* release p here before we throw an I/O exception */
+        if (isCopy) {
+            JNU_ReleaseStringPlatformChars(env, path, p);
+        }
+
+        if (res == 0) {
+            if ( (sb.st_uid != uid) || (sb.st_gid != gid) ||
+                 ((sb.st_mode & (S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH)) != 0) ) {
+                JNU_ThrowIOException(env, "well-known file is not secure");
+            }
+        } else {
+            char* msg = strdup(strerror(res));
+            JNU_ThrowIOException(env, msg);
+            if (msg != NULL) {
+                free(msg);
+            }
+        }
+    }
+}
+
+/*
+ * Class:     sun_tools_attach_BsdVirtualMachine
+ * Method:    close
+ * Signature: (I)V
+ */
+JNIEXPORT void JNICALL Java_sun_tools_attach_BsdVirtualMachine_close
+  (JNIEnv *env, jclass cls, jint fd)
+{
+    int res;
+    RESTARTABLE(close(fd), res);
+}
+
+/*
+ * Class:     sun_tools_attach_BsdVirtualMachine
+ * Method:    read
+ * Signature: (I[BI)I
+ */
+JNIEXPORT jint JNICALL Java_sun_tools_attach_BsdVirtualMachine_read
+  (JNIEnv *env, jclass cls, jint fd, jbyteArray ba, jint off, jint baLen)
+{
+    unsigned char buf[128];
+    size_t len = sizeof(buf);
+    ssize_t n;
+
+    size_t remaining = (size_t)(baLen - off);
+    if (len > remaining) {
+        len = remaining;
+    }
+
+    RESTARTABLE(read(fd, buf+off, len), n);
+    if (n == -1) {
+        JNU_ThrowIOExceptionWithLastError(env, "read");
+    } else {
+        if (n == 0) {
+            n = -1;     // EOF
+        } else {
+            (*env)->SetByteArrayRegion(env, ba, off, (jint)n, (jbyte *)(buf+off));
+        }
+    }
+    return n;
+}
+
+/*
+ * Class:     sun_tools_attach_BsdVirtualMachine
+ * Method:    write
+ * Signature: (I[B)V
+ */
+JNIEXPORT void JNICALL Java_sun_tools_attach_BsdVirtualMachine_write
+  (JNIEnv *env, jclass cls, jint fd, jbyteArray ba, jint off, jint bufLen)
+{
+    size_t remaining = bufLen;
+    do {
+        unsigned char buf[128];
+        size_t len = sizeof(buf);
+        int n;
+
+        if (len > remaining) {
+            len = remaining;
+        }
+        (*env)->GetByteArrayRegion(env, ba, off, len, (jbyte *)buf);
+
+        RESTARTABLE(write(fd, buf, len), n);
+        if (n > 0) {
+           off += n;
+           remaining -= n;
+        } else {
+            JNU_ThrowIOExceptionWithLastError(env, "write");
+            return;
+        }
+
+    } while (remaining > 0);
+}
+
+/*
+ * Class:     sun_tools_attach_BSDVirtualMachine
+ * Method:    createAttachFile
+ * Signature: (Ljava.lang.String;)V
+ */
+JNIEXPORT void JNICALL Java_sun_tools_attach_BsdVirtualMachine_createAttachFile(JNIEnv *env, jclass cls, jstring path)
+{
+    const char* _path;
+    jboolean isCopy;
+    int fd, rc;
+
+    _path = GetStringPlatformChars(env, path, &isCopy);
+    if (_path == NULL) {
+        JNU_ThrowIOException(env, "Must specify a path");
+        return;
+    }
+
+    RESTARTABLE(open(_path, O_CREAT | O_EXCL, S_IWUSR | S_IRUSR), fd);
+    if (fd == -1) {
+        /* release p here before we throw an I/O exception */
+        if (isCopy) {
+            JNU_ReleaseStringPlatformChars(env, path, _path);
+        }
+        JNU_ThrowIOExceptionWithLastError(env, "open");
+        return;
+    }
+
+    RESTARTABLE(chown(_path, geteuid(), getegid()), rc);
+
+    RESTARTABLE(close(fd), rc);
+
+    /* release p here */
+    if (isCopy) {
+        JNU_ReleaseStringPlatformChars(env, path, _path);
+    }
+}