Merge branch 'develop' into trialMerge

[jalview.git] / src / jalview / bin / MemorySetting.java

diff --git a/src/jalview/bin/MemorySetting.java b/src/jalview/bin/MemorySetting.java
new file mode 100644 (file)
index 0000000..b3bae2d
--- /dev/null
+++ b/src/jalview/bin/MemorySetting.java
@@ -0,0 +1,51 @@
+package jalview.bin;
+
+import java.lang.management.ManagementFactory;
+import java.lang.management.OperatingSystemMXBean;
+
+public class MemorySetting
+{
+  public static final long leaveFreeMinMemory = 536870912; // 0.5 GB
+
+  public static final long applicationMinMemory = 536870912; // 0.5 GB
+
+  protected static long getPhysicalMemory()
+  {
+    final OperatingSystemMXBean 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;
+  }
+
+  public static long memPercent(int percent)
+  {
+    long memPercent = -1;
+
+    long physicalMem = getPhysicalMemory();
+    if (physicalMem > applicationMinMemory)
+    {
+      // try and set at least applicationMinMemory and thereafter ensure
+      // leaveFreeMinMemory is left for the OS
+      memPercent = Math.max(applicationMinMemory,
+              physicalMem - Math.max(physicalMem * (100 - percent) / 100,
+                      leaveFreeMinMemory));
+    }
+
+    return memPercent;
+  }
+
+}