Wolf -- a simple shared memory container

Module

Area

Area is the interface easy to create or load a shared memory buffer. It can be use in multi thread or process. To be simple and fast, when it allocate a buffer it will never use the buffer again.

usage:

 #include "area/shm_area.h"
 
 struct TestNode {
    int test_int;
    double test_double;
    char[10] test_char_array;
 };
 
 auto shm = area::ShmArea("test_shared_memory_dat2", // shared memory file path 
                          1000,                      // shared memory max size
                          true);                     // reset shared memory flag
                          
 TestNode* buffer = (TestNode*)shm.Allocate(sizeof(TestNode));     // allocate memory just like malloc

Container

Container if a set of structure base on area. For more easy to use, it's designed as template. Easy to use is the most important !

1. LockFreeSkipList

   Design for multi thread and process, it can be use by multi writer and multi reader. The algorithm is from The Art of Multiprocessor Programming By Maurice Herlihy, Nir Shavit Since use lock in shared memory is very very difficult so LockFreeSkipList is implement by atomic library from C++11 current random.h is copy from leveldb.

   Atomic library can be used in shared memory and you can test it by the code shared_memory_atomic_test.cpp in test folder.

   usage:

   #include "area/shm_area.h"
   #include "container/shm_manager.h"
   #include "container/lockfree_skiplist.h"
   
   auto area = area::ShmArea("test_shared_memory_dat", 
                             10000000,
                             true); // If you want to open from exist memory, just pass false
                             
   auto* shm_manager = new container::ShmManager(&area); 
   
   container::LockFreeSkipList<int> list(shm_manager, true); // If you want to open from exist skiplist, just pass false
   
   for (int i=0; i<20000; ++i) {
           list.Add(i);
   }
   
   list.FindLessThan(9999);