/* include my_lock_init */ #include "unp.h"## 1 ##src/server/lock_fcntl.c## static struct flock lock_it, unlock_it;## 2 ##src/server/lock_fcntl.c## static int lock_fd = -1;## 3 ##src/server/lock_fcntl.c## /* fcntl() will fail if my_lock_init() not called */## 4 ##src/server/lock_fcntl.c## void## 5 ##src/server/lock_fcntl.c## my_lock_init(char *pathname)## 6 ##src/server/lock_fcntl.c## {## 7 ##src/server/lock_fcntl.c## char lock_file[1024];## 8 ##src/server/lock_fcntl.c## /* 4must copy caller's string, in case it's a constant */## 9 ##src/server/lock_fcntl.c## strncpy(lock_file, pathname, sizeof(lock_file));## 10 ##src/server/lock_fcntl.c## lock_fd = Mkstemp(lock_file);## 11 ##src/server/lock_fcntl.c## Unlink(lock_file); /* but lock_fd remains open */## 12 ##src/server/lock_fcntl.c## lock_it.l_type = F_WRLCK;## 13 ##src/server/lock_fcntl.c## lock_it.l_whence = SEEK_SET;## 14 ##src/server/lock_fcntl.c## lock_it.l_start = 0;## 15 ##src/server/lock_fcntl.c## lock_it.l_len = 0;## 16 ##src/server/lock_fcntl.c## unlock_it.l_type = F_UNLCK;## 17 ##src/server/lock_fcntl.c## unlock_it.l_whence = SEEK_SET;## 18 ##src/server/lock_fcntl.c## unlock_it.l_start = 0;## 19 ##src/server/lock_fcntl.c## unlock_it.l_len = 0;## 20 ##src/server/lock_fcntl.c## }## 21 ##src/server/lock_fcntl.c## /* end my_lock_init */ /* include my_lock_wait */ void## 22 ##src/server/lock_fcntl.c## my_lock_wait()## 23 ##src/server/lock_fcntl.c## {## 24 ##src/server/lock_fcntl.c## int rc;## 25 ##src/server/lock_fcntl.c## while ((rc = fcntl(lock_fd, F_SETLKW, &lock_it)) < 0) {## 26 ##src/server/lock_fcntl.c## if (errno == EINTR)## 27 ##src/server/lock_fcntl.c## continue;## 28 ##src/server/lock_fcntl.c## else## 29 ##src/server/lock_fcntl.c## err_sys("fcntl error for my_lock_wait");## 30 ##src/server/lock_fcntl.c## }## 31 ##src/server/lock_fcntl.c## }## 32 ##src/server/lock_fcntl.c## void## 33 ##src/server/lock_fcntl.c## my_lock_release()## 34 ##src/server/lock_fcntl.c## {## 35 ##src/server/lock_fcntl.c## if (fcntl(lock_fd, F_SETLKW, &unlock_it) < 0)## 36 ##src/server/lock_fcntl.c## err_sys("fcntl error for my_lock_release");## 37 ##src/server/lock_fcntl.c## }## 38 ##src/server/lock_fcntl.c## /* end my_lock_wait */