message: Document the goals of the shared CompiledFunctionCache.
diff: @@ -331,10 +331,11 @@ struct CacheEntry {
  };
  // A CompiledFunctionCache represents a cache of compiled functions that can be
  -// shared between one or more CompiledFunction objects. This allows the capacity
  -// of an LRU cache to be shared between many jit-compiled functions, rather than
  -// necessarily having a unique cache for each function with its own
  -// capacity limit. We assume the cache is protected by the GIL.
  +// shared between one or more CompiledFunction objects. It serves two goals:
  +// - reduce the number of lru caches (hash map) across multiple JITs.
  +// - make the cache global to increase cache hits (e.g. calling jit(f)(3) twice)
  +// keeping entries alive as long as the underlying function f is alive.
  +// Assume the cache is protected by the GIL.
  class CompiledFunctionCache {
  public:
  static constexpr int kDefaultCapacity = 4096;
  