Utils for c/cpp

util includes:

• hashtable
• bitmap
• bloomfilter
• skiplist
• trie tree
• thread pool
• mempool(arena)
• event reactor(epoll)
• lru cache
• page cache
• spinlock/rwlock
• lockfree queue/ring
• etc...

test usage

cd test
mkdir build
cd build
cmake ..
make -j4
./test_main