8 #include <botan/internal/dev_random.h>    10 #include <sys/types.h>    11 #include <sys/select.h>    21 int open_nonblocking(
const char* pathname)
    32    return ::open(pathname, flags);
    43    for(
size_t i = 0; i != fsnames.size(); ++i)
    45       fd_type fd = open_nonblocking(fsnames[i].c_str());
    46       if(fd >= 0 && fd < FD_SETSIZE)
    47          devices.push_back(fd);
    56    for(
size_t i = 0; i != devices.size(); ++i)
    68    const size_t ENTROPY_BITS_PER_BYTE = 8;
    69    const size_t MS_WAIT_TIME = 32;
    74    int max_fd = devices[0];
    77    for(
size_t i = 0; i != devices.size(); ++i)
    79       FD_SET(devices[i], &read_set);
    80       max_fd = 
std::max(devices[i], max_fd);
    83    struct ::timeval timeout;
    85    timeout.tv_sec = (MS_WAIT_TIME / 1000);
    86    timeout.tv_usec = (MS_WAIT_TIME % 1000) * 1000;
    88    if(::
select(max_fd + 1, &read_set, 0, 0, &timeout) < 0)
    91    for(
size_t i = 0; i != devices.size(); ++i)
    93       if(FD_ISSET(devices[i], &read_set))
    95          const ssize_t got = ::read(devices[i], &io_buffer[0], io_buffer.
size());
    97             accum.
add(&io_buffer[0], got, ENTROPY_BITS_PER_BYTE);
 Device_EntropySource(const std::vector< std::string > &fsnames)
size_t desired_remaining_bits() const
MemoryRegion< byte > & get_io_buffer(size_t size)
void add(const void *bytes, size_t length, double entropy_bits_per_byte)
void poll(Entropy_Accumulator &accum)
T select(T mask, T from0, T from1)