Problem - Kevin Tafuro

the connections to the server. The increase in file descriptors could be done externally
by using setrlimit( ) before starting the server process (with the bash shell, the
command would be ulimit -n 512).
The proper way to deal with this problem is to allocate the array dynamically and
ensure that FD_SET( ) and FD_CLR( ) resize the array as necessary before modifying it.
Unfortunately, to do this, we need to create a new data type. We define the data type
such that it can be safely cast to an fd_set for passing it directly to select( ):
#include
typedef struct {
long int *fds_bits;
size_t fds_size;
} SPC_FD_SET;
With a new data type defined, we can replace FD_SET( ), FD_CLR( ), FD_ISSET( ), and
FD_ZERO( ), which are normally implemented as preprocessor macros. Instead, we
will implement them as functions because we need to do a little extra work, and it
also helps ensure type safety:
void spc_fd_zero(SPC_FD_SET *fdset) {
fdset->fds_bits = 0;
fdset->fds_size = 0;
}
void spc_fd_set(int fd, SPC_FD_SET *fdset) {
long *tmp_bits;
size_t new_size;
if (fd < 0) return;
if (fd > fdset->fds_size) {
new_size = sizeof(long) * ((fd + sizeof(long) - 1) / sizeof(long));
if (!(tmp_bits = (long *)realloc(fdset->fds_bits, new_size))) return;
fdset->fds_bits = tmp_bits;
fdset->fds_size = new_size;
}
fdset->fds_bits[fd / sizeof(long)] |= (1 fdset->fds_size) {
new_size = sizeof(long) * ((fd + sizeof(long) - 1) / sizeof(long));
if (!(tmp_bits = (long *)realloc(fdset->fds_bits, new_size))) return;
fdset->fds_bits = tmp_bits;
fdset->fds_size = new_size;
}
fdset->fds_bits[fd / sizeof(long)] |= (1