From 22e9e06b9d5f9dfe308d012bf23a6244b2562ae7 Mon Sep 17 00:00:00 2001
From: Jon Travis <jtravis@p00p.org>
Date: Wed, 8 Jul 2009 14:54:51 -0700
Subject: [PATCH 1/3] (SIGAR-150) Wrapper class to synchronize Sigar method
 invocation

Signed-off-by: Doug MacEachern <dougm@hyperic.com>
---
 .../java/src/org/hyperic/sigar/Humidor.java   | 80 +++++++++++++++++++
 1 file changed, 80 insertions(+)
 create mode 100644 bindings/java/src/org/hyperic/sigar/Humidor.java

diff --git a/bindings/java/src/org/hyperic/sigar/Humidor.java b/bindings/java/src/org/hyperic/sigar/Humidor.java
new file mode 100644
index 00000000..7dd80b14
--- /dev/null
+++ b/bindings/java/src/org/hyperic/sigar/Humidor.java
@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) [2004-2009], Hyperic, Inc.
+ * This file is part of SIGAR.
+ * 
+ * SIGAR is free software; you can redistribute it and/or modify
+ * it under the terms version 2 of the GNU General Public License as
+ * published by the Free Software Foundation. This program 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 this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+ * USA.
+ */
+
+package org.hyperic.sigar;
+
+import java.lang.reflect.InvocationHandler;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.lang.reflect.Proxy;
+
+/**
+ * The Humidor provides access to a single Sigar instance.  Sigar has a
+ * high-cost setup/teardown and has a high amount of caching, used to determine
+ * things like the % of CPU used in-between calls.
+ *
+ * The Humidor also synchronizes access to all Sigar methods, so all
+ * calls will be serialized.
+ */
+public class Humidor {
+    private static final Humidor INSTANCE = new Humidor();
+    private Object LOCK = new Object();
+    private InvocationHandler _handler;
+    private SigarProxy _sigar;
+
+    private Humidor() {}
+
+    private static class MyHandler implements InvocationHandler {
+        private SigarProxy _sigar;
+        private Object _lock = new Object();
+
+        public MyHandler(SigarProxy sigar) {
+            _sigar = sigar;
+        }
+
+        public Object invoke(Object proxy, Method meth, Object[] args)
+            throws Throwable
+        {
+            try {
+                synchronized (_lock) {
+                    return meth.invoke(_sigar, args);
+                }
+            } catch(InvocationTargetException e) {
+                throw e.getTargetException();
+            }
+        }
+    }
+
+    public SigarProxy getSigar() {
+        synchronized(LOCK) {
+            if (_sigar == null) {
+                Sigar s = new Sigar();
+                _handler = new MyHandler(s);
+                _sigar = (SigarProxy)
+                    Proxy.newProxyInstance(Humidor.class.getClassLoader(),
+                                           new Class[] { SigarProxy.class },
+                                           _handler);
+            }
+            return _sigar;
+        }
+    }
+
+    public static Humidor getInstance() {
+        return INSTANCE;
+    }
+}

From ce39c1ad1e949326f3507d03f16cac5822f19f4c Mon Sep 17 00:00:00 2001
From: Doug MacEachern <dougm@hyperic.com>
Date: Wed, 8 Jul 2009 15:28:49 -0700
Subject: [PATCH 2/3] support for caller constructed Sigar object

---
 bindings/java/src/org/hyperic/sigar/Humidor.java | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/bindings/java/src/org/hyperic/sigar/Humidor.java b/bindings/java/src/org/hyperic/sigar/Humidor.java
index 7dd80b14..c039bded 100644
--- a/bindings/java/src/org/hyperic/sigar/Humidor.java
+++ b/bindings/java/src/org/hyperic/sigar/Humidor.java
@@ -36,9 +36,14 @@ public class Humidor {
     private Object LOCK = new Object();
     private InvocationHandler _handler;
     private SigarProxy _sigar;
+    private Sigar _impl;
 
     private Humidor() {}
 
+    public Humidor(Sigar sigar) {
+        _impl = sigar;
+    }
+
     private static class MyHandler implements InvocationHandler {
         private SigarProxy _sigar;
         private Object _lock = new Object();
@@ -63,8 +68,10 @@ public class Humidor {
     public SigarProxy getSigar() {
         synchronized(LOCK) {
             if (_sigar == null) {
-                Sigar s = new Sigar();
-                _handler = new MyHandler(s);
+                if (_impl == null) {
+                    _impl = new Sigar();
+                }
+                _handler = new MyHandler(_impl);
                 _sigar = (SigarProxy)
                     Proxy.newProxyInstance(Humidor.class.getClassLoader(),
                                            new Class[] { SigarProxy.class },

From 7d483e39820b3d296eecdb75028a97202511857e Mon Sep 17 00:00:00 2001
From: Doug MacEachern <dougm@hyperic.com>
Date: Wed, 8 Jul 2009 15:59:24 -0700
Subject: [PATCH 3/3] Humidor test

---
 .../hyperic/sigar/test/SigarTestRunner.java   |  1 +
 .../org/hyperic/sigar/test/TestHumidor.java   | 95 +++++++++++++++++++
 2 files changed, 96 insertions(+)
 create mode 100644 bindings/java/src/org/hyperic/sigar/test/TestHumidor.java

diff --git a/bindings/java/src/org/hyperic/sigar/test/SigarTestRunner.java b/bindings/java/src/org/hyperic/sigar/test/SigarTestRunner.java
index 31615f08..332e099b 100644
--- a/bindings/java/src/org/hyperic/sigar/test/SigarTestRunner.java
+++ b/bindings/java/src/org/hyperic/sigar/test/SigarTestRunner.java
@@ -79,6 +79,7 @@ public class SigarTestRunner extends SigarCommandBase {
         TestUptime.class,
         TestVMware.class,
         TestWho.class,
+        TestHumidor.class
     };
 
     private static final Class[] WIN32_TESTS = {
diff --git a/bindings/java/src/org/hyperic/sigar/test/TestHumidor.java b/bindings/java/src/org/hyperic/sigar/test/TestHumidor.java
new file mode 100644
index 00000000..1336908a
--- /dev/null
+++ b/bindings/java/src/org/hyperic/sigar/test/TestHumidor.java
@@ -0,0 +1,95 @@
+/*
+ * Copyright (C) [2004-2009], Hyperic, Inc.
+ * This file is part of SIGAR.
+ * 
+ * SIGAR is free software; you can redistribute it and/or modify
+ * it under the terms version 2 of the GNU General Public License as
+ * published by the Free Software Foundation. This program 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 this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+ * USA.
+ */
+
+package org.hyperic.sigar.test;
+
+import java.util.ArrayList;
+
+import org.hyperic.sigar.CpuPerc;
+import org.hyperic.sigar.Humidor;
+import org.hyperic.sigar.Sigar;
+import org.hyperic.sigar.SigarException;
+import org.hyperic.sigar.SigarProxy;
+
+public class TestHumidor extends SigarTestCase {
+
+    public TestHumidor(String name) {
+        super(name);
+    }
+
+    private static class HumidorThread extends Thread {
+        private SigarProxy sigar;
+        private HumidorThread(SigarProxy sigar) {
+            this.sigar = sigar;
+        }
+
+        public void run() {
+            try {
+                getProcCpu(this.sigar);
+            } catch (Exception e) {
+                throw new IllegalArgumentException(e.getMessage());
+            }
+        }
+    }
+
+    private static void getProcCpu(SigarProxy sigar) throws Exception {
+        long[] pids = sigar.getProcList();
+        for (int j=0; j<10; j++) {
+            for (int i=0; i<pids.length; i++) {
+                try {
+                    double cpu = sigar.getProcCpu(pids[i]).getPercent();
+                    if (SigarTestCase.getVerbose()) {
+                        System.out.println(Thread.currentThread().getName() + 
+                                           " " + pids[i] + "=" + CpuPerc.format(cpu));
+                    }
+                } catch (SigarException e) {
+                    //ok - process may have gone away or permission denied.
+                }
+            }
+        }
+    }
+
+    private void runTests(SigarProxy sigar) throws Exception {
+        ArrayList threads = new ArrayList();
+        for (int i=0; i<3; i++) {
+            Thread t = new HumidorThread(sigar);
+            threads.add(t);
+            t.start();
+        }
+        for (int i=0; i<threads.size(); i++) {
+            Thread t = (Thread)threads.get(i);
+            t.join();
+        }
+    }
+
+    public void testGlobalInstance() throws Exception {
+        runTests(Humidor.getInstance().getSigar());
+    }
+
+    public void testInstance() throws Exception {
+        Sigar sigar = new Sigar();
+        runTests(new Humidor(sigar).getSigar());
+        sigar.close();
+    }
+
+    //uncomment to see if this test will indeed cause a segfault
+    //without the protection of the Humidor
+    //public void testUnwrapped() throws Exception {
+    //    runTests(new Sigar());
+    //}
+}