1 #include <sys/eventfd.h> 2 #include <unistd.h> 3 4 /* We duplicate the GLibc error semantics, which are poorly defined 5 * if the read() or write() does not return the proper number of bytes. 6 */ eventfd_read(int fd,eventfd_t * counter)7int eventfd_read(int fd, eventfd_t *counter) 8 { 9 int ret = read(fd, counter, sizeof(*counter)); 10 11 if (ret == sizeof(*counter)) 12 return 0; 13 14 return -1; 15 } 16 eventfd_write(int fd,eventfd_t counter)17int eventfd_write(int fd, eventfd_t counter) 18 { 19 int ret = write(fd, &counter, sizeof(counter)); 20 21 if (ret == sizeof(counter)) 22 return 0; 23 24 return -1; 25 } 26