From: Ben Soares <bsoares@dundee.ac.uk>
Date: Fri, 8 Feb 2019 15:53:28 +0000 (+0000)
Subject: JAL-3194 new launcher, use like: java -cp classes:lib/* jalview.bin.Launcher -maxMem
X-Git-Url: http://source.jalview.org/gitweb/?p=jalview.git;a=commitdiff_plain;h=refs%2Fheads%2Ffeature%2FJAL-3194_create_launcher_with_dynamic_memory_heap_setting

JAL-3194 new launcher, use like: java -cp classes:lib/* jalview.bin.Launcher -maxMem
---

diff --git a/src/jalview/bin/Launcher.java b/src/jalview/bin/Launcher.java
new file mode 100644
index 0000000..c91b812
--- /dev/null
+++ b/src/jalview/bin/Launcher.java
@@ -0,0 +1,103 @@
+package jalview.bin;
+
+import java.io.File;
+import java.lang.management.ManagementFactory;
+import java.util.ArrayList;
+
+public class Launcher
+{
+
+  private final static String startClass = "jalview.bin.Jalview";
+
+  private final static int maxHeapSizePerCent = 95;
+
+  private final static String maxMemArg = "-maxMem";
+
+  public static void main(String[] args)
+  {
+    final String javaBin = System.getProperty("java.home") + File.separator
+            + "bin" + File.separator + "java";
+
+    ArrayList<String> command = new ArrayList<>();
+    command.add(javaBin);
+
+    for (String jvmArg : ManagementFactory.getRuntimeMXBean()
+            .getInputArguments())
+    {
+      command.add(jvmArg);
+    }
+    command.add("-cp");
+    command.add(ManagementFactory.getRuntimeMXBean().getClassPath());
+    ArrayList<String> arguments = new ArrayList<>();
+    boolean maxMem = false;
+    for (String arg : args)
+    {
+      if (arg.equals(maxMemArg) && !maxMem)
+      {
+        maxMem = true;
+        // remove any existing max heap size argument
+        ARG: for (int i = 0; i < command.size(); i++)
+        {
+          if (command.get(i).startsWith("-Xmx"))
+          {
+            command.remove(i);
+            break ARG; // assuming at most one -Xmx
+          }
+        }
+        long maxMemLong = -1;
+        long physicalMem = getPhysicalMemory();
+        if (physicalMem > 0)
+        {
+          maxMemLong = physicalMem * maxHeapSizePerCent / 100;
+        }
+        if (maxMemLong > 0)
+        {
+          command.add("-Xmx" + Long.toString(maxMemLong));
+        }
+      }
+      else
+      {
+        arguments.add(arg);
+      }
+    }
+    command.add(startClass);
+    command.addAll(arguments);
+
+    final ProcessBuilder builder = new ProcessBuilder(command);
+
+    System.out.println("COMMAND: " + builder.command().toString());
+
+    try
+    {
+      builder.inheritIO();
+      builder.start();
+    } catch (Exception e)
+    {
+      e.printStackTrace();
+    }
+    System.exit(0);
+
+  }
+
+  public static long getPhysicalMemory()
+  {
+    final Object o = ManagementFactory.getOperatingSystemMXBean();
+
+    try
+    {
+      if (o instanceof com.sun.management.OperatingSystemMXBean)
+      {
+        final com.sun.management.OperatingSystemMXBean osb = (com.sun.management.OperatingSystemMXBean) o;
+        return osb.getTotalPhysicalMemorySize();
+      }
+    } catch (NoClassDefFoundError e)
+    {
+      // com.sun.management.OperatingSystemMXBean doesn't exist in this JVM
+      System.out.println("No com.sun.management.OperatingSystemMXBean");
+    }
+
+    // We didn't get a com.sun.management.OperatingSystemMXBean.
+    return -1;
+  }
+
+}