public class Sizeof {
// this is our way of requesting garbage collection to be run:
// [how aggressive it is depends on the JVM to a large degree, but
// it is almost always better than a single Runtime.gc() call]
public static void runGC() {
// for whatever reason it helps to call Runtime.gc()
// using several method calls:
for (int r = 0; r < 4; ++r)
_runGC();
}
private static void _runGC() {
long usedMem1 = usedMemory(), usedMem2 = Long.MAX_VALUE;
for (int i = 0; (usedMem1 < usedMem2) && (i < 1000); ++i) {
s_runtime.runFinalization();
s_runtime.gc();
Thread.yield();
usedMem2 = usedMem1;
usedMem1 = usedMemory();
}
}
public static Long used() {
return new Long(usedMemory());
}
public static long maxToBeAttempted() {
return s_runtime.maxMemory();
}
public static long totalCommitted() {
return s_runtime.totalMemory();
}
static long usedMemory() {
return s_runtime.totalMemory() - s_runtime.freeMemory();
}
private static final Runtime s_runtime = Runtime.getRuntime();
}
