private static unsafe void DoEviction(object stateInfo)
{
while (true)
{
try
{
MEMORYSTATUSEX memStatus = new MEMORYSTATUSEX();
memStatus.dwLength = (UInt32)sizeof(MEMORYSTATUSEX);
HpcLinqNative.GlobalMemoryStatusEx(ref memStatus);
if (HpcLinqNative.GlobalMemoryStatusEx(ref memStatus) &&
memStatus.ullAvailPhys < 4 * 1024 * 1024 * 1024UL)
{
// Perform eviction only when feeling memory pressure
lock (s_cache)
{
var candidates = s_cache.Where(x => x.Value.RefCount == 0);
foreach (var rec in candidates)
{
s_cache.Remove(rec.Key);
}
}
}
}
catch (Exception e)
{
DryadLinqLog.Add("Exception occurred when performing cache eviction: {0}.",
e.Message);
}
}
}
internal static extern bool GlobalMemoryStatusEx(ref MEMORYSTATUSEX lpBuffer);
internal static extern bool GlobalMemoryStatusEx(ref MEMORYSTATUSEX lpBuffer);