Use the actual available free memory instead of the max possible

src/com/sheepit/client/os/FreeBSD.java

@@ -133,6 +133,11 @@ public class FreeBSD extends OS {
 		return 0;
 	}
 	
+	@Override
+	public int getFreeMemory() {
+		return -1;
+	}
+	
 	@Override
 	public String getCUDALib() {
 		return "cuda";

src/com/sheepit/client/os/Linux.java

@@ -116,6 +116,35 @@ public class Linux extends OS {
 		return 0;
 	}
 	
+	@Override
+	public int getFreeMemory() {
+		try {
+			String filePath = "/proc/meminfo";
+			Scanner scanner = new Scanner(new File(filePath));
+			
+			while (scanner.hasNextLine()) {
+				String line = scanner.nextLine();
+				
+				if (line.startsWith("MemFree")) {
+					String buf[] = line.split(":");
+					if (buf.length > 0) {
+						Integer buf2 = new Integer(buf[1].trim().split(" ")[0]);
+						return (((buf2 / 262144) + 1) * 262144); // 256*1024 = 262144
+					}
+				}
+			}
+			scanner.close();
+		}
+		catch (java.lang.NoClassDefFoundError e) {
+			System.err.println("OS::Linux::getFreeMemory error " + e + " mostly because Scanner class was introducted by Java 5 and you are running a lower version");
+		}
+		catch (Exception e) {
+			e.printStackTrace();
+		}
+		
+		return 0;
+	}
+	
 	@Override
 	public String getCUDALib() {
 		return "cuda";

src/com/sheepit/client/os/Mac.java

@@ -140,6 +140,11 @@ public class Mac extends OS {
 		return -1;
 	}
 	
+	@Override
+	public int getFreeMemory() {
+		return -1;
+	}
+	
 	@Override
 	public Process exec(List<String> command, Map<String, String> env) throws IOException {
 		List<String> actual_command = command;

src/com/sheepit/client/os/OS.java

@@ -33,6 +33,8 @@ public abstract class OS {
 	
 	public abstract int getMemory();
 	
+	public abstract int getFreeMemory();
+	
 	public abstract String getRenderBinaryPath();
 	
 	public String getCUDALib() {

src/com/sheepit/client/os/Windows.java

@@ -102,6 +102,21 @@ public class Windows extends OS {
 		return 0;
 	}
 	
+	@Override
+	public int getFreeMemory() {
+		try {
+			MEMORYSTATUSEX _memory = new MEMORYSTATUSEX();
+			if (Kernel32.INSTANCE.GlobalMemoryStatusEx(_memory)) {
+				return (int) (_memory.ullAvailPhys.longValue() / 1024); // size in KB
+			}
+		}
+		catch (Exception e) {
+			e.printStackTrace();
+		}	
+		 
+		return -1;
+	}
+	
 	@Override
 	public String getCUDALib() {
 		return "nvcuda";