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Cache::SharedMemoryCache(3pm) User Contributed Perl Documentation Cache::SharedMemoryCache(3pm)


Cache::SharedMemoryCache -- extends the MemoryCache.


The SharedMemoryCache extends the MemoryCache class and binds the data store to shared memory so that separate process can use the same cache.

The official recommendation is now to use FileCache instead of SharedMemoryCache. The reasons for this include:

1) FileCache provides equal or better performance in all cases that we've been able to test. This is due to all modern OS's ability to buffer and cache file system accesses very well.

2) FileCache has no real limits on cached object size or the number of cached objects, whereas the SharedMemoryCache has limits, and rather low ones at that.

3) FileCache works well on every OS, whereas the SharedMemoryCache works only on systems that support IPC::ShareLite. And IPC::ShareLite is an impressive effort -- but think about how hard it is to get shared memory working properly on *one* system. Now imagine writing a wrapper around shared memory for many operating systems.


  use Cache::SharedMemoryCache;
  my %cache_options_= ( 'namespace' => 'MyNamespace',
                        'default_expires_in' => 600 );
  my $shared_memory_cache = 
    new Cache::SharedMemoryCache( \%cache_options ) or
      croak( "Couldn't instantiate SharedMemoryCache" );


See Cache::Cache for the API documentation.


See Cache::Cache for the standard options.


See Cache::Cache for the default properties.


Cache::Cache, Cache::MemoryCache


Original author: DeWitt Clinton <>

Last author: $Author: dclinton $

Copyright (C) 2001-2003 DeWitt Clinton

2022-06-30 perl v5.34.0