多个用 PTHREAD_MUTEX_INITIALIZER 初始化的 pthread_mutex_t 不是同一个 mutex

参考：http://stackoverflow.com/questions/6310746/initializing-pthread-mutexes

【结论】

static pthread_mutex_t m0 = PTHREAD_MUTEX_INITIALIZER;
static pthread_mutex_t m1 = PTHREAD_MUTEX_INITIALIZER;
static pthread_mutex_t m2 = PTHREAD_MUTEX_INITIALIZER;

像这样初始化的3个 pthread_mutex_t，并不是同一个 mutex，即在使用时，相互不影响。

【说明】

static pthread_mutex_t m0 = {0x32AAABA7, {0}};
static pthread_mutex_t m1 = {0x32AAABA7, {0}};
static pthread_mutex_t m2 = {0x32AAABA7, {0}};

尽管通过 gcc -E code.cpp，看似初始化成同样的东西，但

It is essentially an enum value, but with a Hamming code protection to (a) make it safe and (b) make it obscure. You have three distinct mutexes here