soft-references

I am familiar with WeakReference , but I am looking for a reference type that is cleared only when memory is low, not simply every time when the gc runs (just like Java's SoftReference ). I'm looking for a way to implement a memory-sensitive cache. Andrew Hare No there isn't an equivalent. Is there a particular reason why WeakReference won't do the job? Here is a similar question to yours: Why doesn't .NET have a SoftReference as well as a WeakReference, like Java? Maybe the ASP.NET Cache class ( System.Web.Caching.Cache ) might help achieve what you want? It automatically remove objects if

In C++ I'm using boost::shared_ptr and boost::weak_ptr to automatically delete objects that are no longer needed. I know these work with reference counting. In Java, memory is managed by a garbage collector, which consideres the built-in object references as strong , WeakReference as weak and SoftReference as something in between (may be collected by the GC, but may as well survive the GC), which is really handy for caching objects for some time, but throwing them away as soon as free memory is getting low. So now I'm back in C++ and I miss the comfort of having soft references. I wonder if

Here's my use case. We are trying to narrow down a potential memory leak in an application, and we are using a memory analysis tool to snapshot the heap so we can look for object instances and references. (In case it helps, we're using YourKit.) This application makes extensive use of dynamic and CGLIB proxies, which end up storing tons of references to classes and classloaders in WeakHashMaps. After our test case runs, we are expecting all hard references to object X and its classloader to be gone, but since there were many proxies involved in the test case in the end we have many weak/soft

In other languages (e.g. Java), object references can be Strong, Weak, Soft or Phantom ( http://weblogs.java.net/blog/enicholas/archive/2006/05/understanding_w.html ). In Python, references are Strong by default and the WeakRef module allows weak references. Is it possible to have "soft references" in Python? In my particular case, I have a cache of objects that are time-consuming to create. Sometimes there may be no references to a cached object, but I don't want to throw the cached object away if I don't have to (i.e. if memory is plentiful). Python doesn't natively offer any flavors of

It seams that Dalvik's garbage collector doesn't respect SoftReferences and removes them as soon as possible, just like WeakReferences. I'm not 100% sure yet, but despite the fact that there is still ~3MB of free memory my SoftReferences get cleared after I see "GC freed bla-bla-bla bytes" in LogCat. Also, I saw a comment by Mark Murphy here : Except that it doesn't work on Android, at least in the 1.5 timeframe. I have no idea if the GC SoftReference bugs have been fixed. SoftReferences get GC'd too soon with this bug. Is it true? Are SoftReferences not respected? How to workaround this?

Per the documentation for Guava's MapMaker.softValues() : Warning: in most circumstances it is better to set a per-cache maximum size instead of using soft references. You should only use this method if you are well familiar with the practical consequences of soft references. I have an intermediate understanding of soft references - their behavior, uses, and their contract with garbage collection. However I'm wondering what these practical consequences are which the doc alludes to. Why exactly is it better to use maximum size rather than soft references? Don't the algorithms and behavior of