cas lock
gcc -O2 lthread_mutex_test.c -lpthread -o lthread_mutex_test
gcc -O2 pthread_mutex_test.c -lpthread -o pthread_mutex_test
my centos7(vmware)
#time ./lthread_mutex_test
counter: 300000000
real 0m1.785s
user 0m1.942s
sys 0m1.347s
#time ./pthread_mutex_test
counter: 300000000
real 0m7.170s
user 0m8.224s
sys 0m4.472s