# HG changeset patch
# User allwin
# Date 1373647407 -7200
# Node ID 5de3638104b4d7a27d3b36812f72fc04d035dbbf
# Parent  ac0163dd0a50f39d74914d49749d1a1f3a478437
7162400: Intermittent java.io.IOException: Bad file number during HotSpotVirtualMachine.executeCommand
Summary: Intermittent java.io.IOException: Bad file number during HotSpotVirtualMachine.executeCommand
Reviewed-by: dcubed, dholmes, sspitsyn, mgerdin, ctornqvi, dsamersoff

diff -r ac0163dd0a50 -r 5de3638104b4 hotspot/src/os/bsd/vm/attachListener_bsd.cpp
--- a/hotspot/src/os/bsd/vm/attachListener_bsd.cpp	Wed Jul 10 15:49:15 2013 +0000
+++ b/hotspot/src/os/bsd/vm/attachListener_bsd.cpp	Fri Jul 12 18:43:27 2013 +0200
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 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
@@ -437,6 +437,30 @@
   return op;
 }
 
+
+// Performs initialization at vm startup
+// For BSD we remove any stale .java_pid file which could cause
+// an attaching process to think we are ready to receive on the
+// domain socket before we are properly initialized
+
+void AttachListener::vm_start() {
+  char fn[UNIX_PATH_MAX];
+  struct stat64 st;
+  int ret;
+
+  int n = snprintf(fn, UNIX_PATH_MAX, "%s/.java_pid%d",
+           os::get_temp_directory(), os::current_process_id());
+  assert(n < (int)UNIX_PATH_MAX, "java_pid file name buffer overflow");
+
+  RESTARTABLE(::stat64(fn, &st), ret);
+  if (ret == 0) {
+    ret = ::unlink(fn);
+    if (ret == -1) {
+      debug_only(warning("failed to remove stale attach pid file at %s", fn));
+    }
+  }
+}
+
 int AttachListener::pd_init() {
   JavaThread* thread = JavaThread::current();
   ThreadBlockInVM tbivm(thread);
diff -r ac0163dd0a50 -r 5de3638104b4 hotspot/src/os/linux/vm/attachListener_linux.cpp
--- a/hotspot/src/os/linux/vm/attachListener_linux.cpp	Wed Jul 10 15:49:15 2013 +0000
+++ b/hotspot/src/os/linux/vm/attachListener_linux.cpp	Fri Jul 12 18:43:27 2013 +0200
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 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
@@ -432,6 +432,30 @@
   return op;
 }
 
+
+// Performs initialization at vm startup
+// For Linux we remove any stale .java_pid file which could cause
+// an attaching process to think we are ready to receive on the
+// domain socket before we are properly initialized
+
+void AttachListener::vm_start() {
+  char fn[UNIX_PATH_MAX];
+  struct stat64 st;
+  int ret;
+
+  int n = snprintf(fn, UNIX_PATH_MAX, "%s/.java_pid%d",
+           os::get_temp_directory(), os::current_process_id());
+  assert(n < (int)UNIX_PATH_MAX, "java_pid file name buffer overflow");
+
+  RESTARTABLE(::stat64(fn, &st), ret);
+  if (ret == 0) {
+    ret = ::unlink(fn);
+    if (ret == -1) {
+      debug_only(warning("failed to remove stale attach pid file at %s", fn));
+    }
+  }
+}
+
 int AttachListener::pd_init() {
   JavaThread* thread = JavaThread::current();
   ThreadBlockInVM tbivm(thread);
diff -r ac0163dd0a50 -r 5de3638104b4 hotspot/src/os/solaris/vm/attachListener_solaris.cpp
--- a/hotspot/src/os/solaris/vm/attachListener_solaris.cpp	Wed Jul 10 15:49:15 2013 +0000
+++ b/hotspot/src/os/solaris/vm/attachListener_solaris.cpp	Fri Jul 12 18:43:27 2013 +0200
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 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
@@ -576,6 +576,30 @@
   return op;
 }
 
+
+// Performs initialization at vm startup
+// For Solaris we remove any stale .java_pid file which could cause
+// an attaching process to think we are ready to receive a door_call
+// before we are properly initialized
+
+void AttachListener::vm_start() {
+  char fn[PATH_MAX+1];
+  struct stat64 st;
+  int ret;
+
+  int n = snprintf(fn, sizeof(fn), "%s/.java_pid%d",
+           os::get_temp_directory(), os::current_process_id());
+  assert(n < sizeof(fn), "java_pid file name buffer overflow");
+
+  RESTARTABLE(::stat64(fn, &st), ret);
+  if (ret == 0) {
+    ret = ::unlink(fn);
+    if (ret == -1) {
+      debug_only(warning("failed to remove stale attach pid file at %s", fn));
+    }
+  }
+}
+
 int AttachListener::pd_init() {
   JavaThread* thread = JavaThread::current();
   ThreadBlockInVM tbivm(thread);
diff -r ac0163dd0a50 -r 5de3638104b4 hotspot/src/os/windows/vm/attachListener_windows.cpp
--- a/hotspot/src/os/windows/vm/attachListener_windows.cpp	Wed Jul 10 15:49:15 2013 +0000
+++ b/hotspot/src/os/windows/vm/attachListener_windows.cpp	Fri Jul 12 18:43:27 2013 +0200
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 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
@@ -358,6 +358,10 @@
   return op;
 }
 
+void AttachListener::vm_start() {
+  // nothing to do
+}
+
 int AttachListener::pd_init() {
   return Win32AttachListener::init();
 }
diff -r ac0163dd0a50 -r 5de3638104b4 hotspot/src/share/vm/runtime/thread.cpp
--- a/hotspot/src/share/vm/runtime/thread.cpp	Wed Jul 10 15:49:15 2013 +0000
+++ b/hotspot/src/share/vm/runtime/thread.cpp	Fri Jul 12 18:43:27 2013 +0200
@@ -3637,6 +3637,7 @@
 
   // Start Attach Listener if +StartAttachListener or it can't be started lazily
   if (!DisableAttachMechanism) {
+    AttachListener::vm_start();
     if (StartAttachListener || AttachListener::init_at_startup()) {
       AttachListener::init();
     }
diff -r ac0163dd0a50 -r 5de3638104b4 hotspot/src/share/vm/services/attachListener.hpp
--- a/hotspot/src/share/vm/services/attachListener.hpp	Wed Jul 10 15:49:15 2013 +0000
+++ b/hotspot/src/share/vm/services/attachListener.hpp	Fri Jul 12 18:43:27 2013 +0200
@@ -50,6 +50,7 @@
 
 class AttachListener: AllStatic {
  public:
+  static void vm_start() NOT_SERVICES_RETURN;
   static void init()  NOT_SERVICES_RETURN;
   static void abort() NOT_SERVICES_RETURN;
 
diff -r ac0163dd0a50 -r 5de3638104b4 hotspot/test/serviceability/attach/AttachWithStalePidFile.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/serviceability/attach/AttachWithStalePidFile.java	Fri Jul 12 18:43:27 2013 +0200
@@ -0,0 +1,139 @@
+/*
+ * Copyright (c) 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.
+ *
+ * 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.
+ */
+
+/*
+ * @test
+ * @bug 7162400
+ * @key regression
+ * @summary Regression test for attach issue where stale pid files in /tmp lead to connection issues
+ * @library /testlibrary
+ * @compile AttachWithStalePidFileTarget.java
+ * @run main AttachWithStalePidFile
+ */
+
+import com.oracle.java.testlibrary.*;
+import com.sun.tools.attach.VirtualMachine;
+import sun.tools.attach.HotSpotVirtualMachine;
+import java.lang.reflect.Field;
+import java.nio.file.*;
+import java.nio.file.attribute.*;
+import java.io.*;
+
+public class AttachWithStalePidFile {
+  public static void main(String... args) throws Exception {
+
+    // this test is only valid on non-Windows platforms
+    if(Platform.isWindows()) {
+      System.out.println("This test is only valid on non-Windows platforms.");
+      return;
+    }
+
+    // Since there might be stale pid-files owned by different
+    // users on the system we may need to retry the test in case we
+    // are unable to remove the existing file.
+    int retries = 5;
+    while(!runTest() && --retries > 0);
+
+    if(retries == 0) {
+      throw new RuntimeException("Test failed after 5 retries. " +
+        "Remove any /tmp/.java_pid* files and retry.");
+    }
+  }
+
+  public static boolean runTest() throws Exception {
+    ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(
+      "-XX:+UnlockDiagnosticVMOptions", "-XX:+PauseAtStartup", "AttachWithStalePidFileTarget");
+    Process target = pb.start();
+    Path pidFile = null;
+
+    try {
+      int pid = getUnixProcessId(target);
+
+      // create the stale .java_pid file. use hard-coded /tmp path as in th VM
+      pidFile = createJavaPidFile(pid);
+      if(pidFile == null) {
+        return false;
+      }
+
+      // wait for vm.paused file to be created and delete it once we find it.
+      waitForAndResumeVM(pid);
+
+      // unfortunately there's no reliable way to know the VM is ready to receive the
+      // attach request so we have to do an arbitrary sleep.
+      Thread.sleep(5000);
+
+      HotSpotVirtualMachine vm = (HotSpotVirtualMachine)VirtualMachine.attach(((Integer)pid).toString());
+      BufferedReader remoteDataReader = new BufferedReader(new InputStreamReader(vm.remoteDataDump()));
+      String line = null;
+      while((line = remoteDataReader.readLine()) != null);
+
+      vm.detach();
+      return true;
+    }
+    finally {
+      target.destroy();
+      target.waitFor();
+
+      if(pidFile != null && Files.exists(pidFile)) {
+        Files.delete(pidFile);
+      }
+    }
+  }
+
+  private static Path createJavaPidFile(int pid) throws Exception {
+    Path pidFile = Paths.get("/tmp/.java_pid" + pid);
+    if(Files.exists(pidFile)) {
+      try {
+        Files.delete(pidFile);
+      }
+      catch(FileSystemException e) {
+        if(e.getReason().equals("Operation not permitted")) {
+          System.out.println("Unable to remove exisiting stale PID file" + pidFile);
+          return null;
+        }
+        throw e;
+      }
+    }
+    return Files.createFile(pidFile,
+      PosixFilePermissions.asFileAttribute(PosixFilePermissions.fromString("rw-------")));
+  }
+
+  private static void waitForAndResumeVM(int pid) throws Exception {
+    Path pauseFile = Paths.get("vm.paused." + pid);
+    int retries = 60;
+    while(!Files.exists(pauseFile) && --retries > 0) {
+      Thread.sleep(1000);
+    }
+    if(retries == 0) {
+      throw new RuntimeException("Timeout waiting for VM to start. " +
+        "vm.paused file not created within 60 seconds.");
+    }
+    Files.delete(pauseFile);
+  }
+
+  private static int getUnixProcessId(Process unixProcess) throws Exception {
+    Field pidField = unixProcess.getClass().getDeclaredField("pid");
+    pidField.setAccessible(true);
+    return (Integer)pidField.get(unixProcess);
+  }
+}
diff -r ac0163dd0a50 -r 5de3638104b4 hotspot/test/serviceability/attach/AttachWithStalePidFileTarget.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/serviceability/attach/AttachWithStalePidFileTarget.java	Fri Jul 12 18:43:27 2013 +0200
@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 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.
+ *
+ * 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.
+ */
+public class AttachWithStalePidFileTarget {
+  public static void main(String... args) throws Exception {
+    Thread.sleep(2*60*1000);
+  }
+}