lock_pthread.lc

unix网络编程卷1：套接口API的全书源码

/* include my_lock_init */
#include    "unpthread.h"##  1 ##src/server/lock_pthread.c##
#include    <sys/mman.h>##  2 ##src/server/lock_pthread.c##

static pthread_mutex_t *mptr;   /* actual mutex will be in shared memory */##  3 ##src/server/lock_pthread.c##

void##  4 ##src/server/lock_pthread.c##
my_lock_init(char *pathname)##  5 ##src/server/lock_pthread.c##
{##  6 ##src/server/lock_pthread.c##
    int     fd;##  7 ##src/server/lock_pthread.c##
    pthread_mutexattr_t mattr;##  8 ##src/server/lock_pthread.c##

    fd = Open("/dev/zero", O_RDWR, 0);##  9 ##src/server/lock_pthread.c##

    mptr = Mmap(0, sizeof(pthread_mutex_t), PROT_READ | PROT_WRITE,## 10 ##src/server/lock_pthread.c##
                MAP_SHARED, fd, 0);## 11 ##src/server/lock_pthread.c##
    Close(fd);## 12 ##src/server/lock_pthread.c##

    Pthread_mutexattr_init(&mattr);## 13 ##src/server/lock_pthread.c##
    Pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED);## 14 ##src/server/lock_pthread.c##
    Pthread_mutex_init(mptr, &mattr);## 15 ##src/server/lock_pthread.c##
}## 16 ##src/server/lock_pthread.c##
/* end my_lock_init */

/* include my_lock_wait */
void## 17 ##src/server/lock_pthread.c##
my_lock_wait()## 18 ##src/server/lock_pthread.c##
{## 19 ##src/server/lock_pthread.c##
    Pthread_mutex_lock(mptr);## 20 ##src/server/lock_pthread.c##
}## 21 ##src/server/lock_pthread.c##

void## 22 ##src/server/lock_pthread.c##
my_lock_release()## 23 ##src/server/lock_pthread.c##
{## 24 ##src/server/lock_pthread.c##
    Pthread_mutex_unlock(mptr);## 25 ##src/server/lock_pthread.c##
}## 26 ##src/server/lock_pthread.c##
/* end my_lock_wait */