mas01cr@496: #include "audioDB.h"
mas01cr@496: 
mas01cr@496: int acquire_lock(int fd, bool exclusive) {
mas01cr@496:   struct flock lock;
mas01cr@496:   int status;
mas01cr@496:   
mas01cr@496:   lock.l_type = exclusive ? F_WRLCK : F_RDLCK;
mas01cr@496:   lock.l_whence = SEEK_SET;
mas01cr@496:   lock.l_start = 0;
mas01cr@496:   lock.l_len = 0; /* "the whole file" */
mas01cr@496: 
mas01cr@496:  retry:
mas01cr@496:   do {
mas01cr@496:     status = fcntl(fd, F_SETLKW, &lock);
mas01cr@496:   } while (status != 0 && errno == EINTR);
mas01cr@496:   
mas01cr@496:   if (status) {
mas01cr@496:     if (errno == EAGAIN) {
mas01cr@496:       sleep(1);
mas01cr@496:       goto retry;
mas01cr@496:     } else {
mas01cr@496:       return status;
mas01cr@496:     }
mas01cr@496:   }
mas01cr@496:   return 0;
mas01cr@496: }
mas01cr@496: 
mas01cr@496: int divest_lock(int fd) {
mas01cr@496:   struct flock lock;
mas01cr@496: 
mas01cr@496:   lock.l_type = F_UNLCK;
mas01cr@496:   lock.l_whence = SEEK_SET;
mas01cr@496:   lock.l_start = 0;
mas01cr@496:   lock.l_len = 0;
mas01cr@496: 
mas01cr@496:   return fcntl(fd, F_SETLKW, &lock);
mas01cr@496: }