void
Selector::execute()
{
int nfds;
struct timeval timeout_copy;
struct timeval *tp;
memcpy( read_fds, save_read_fds, fd_set_size * sizeof(fd_set) );
memcpy( write_fds, save_write_fds, fd_set_size * sizeof(fd_set) );
memcpy( except_fds, save_except_fds, fd_set_size * sizeof(fd_set) );
if( timeout_wanted ) {
timeout_copy = timeout;
tp = &timeout_copy;
} else {
tp = NULL;
}
// select() ignores its first argument on Windows. We still track
// max_fd for the display() functions.
start_thread_safe("select");
if (m_single_shot == SINGLE_SHOT_OK)
{
nfds = poll(&m_poll, 1, tp ? (1000*tp->tv_sec + tp->tv_usec/1000) : -1);
}
else
{
nfds = select( max_fd + 1,
(SELECT_FDSET_PTR) read_fds,
(SELECT_FDSET_PTR) write_fds,
(SELECT_FDSET_PTR) except_fds,
tp );
}
_select_errno = errno;
stop_thread_safe("select");
_select_retval = nfds;
if( nfds < 0 ) {
#if !defined(WIN32)
if( _select_errno == EINTR ) {
state = SIGNALLED;
return;
}
#endif
state = FAILED;
return;
}
_select_errno = 0;
if( nfds == 0 ) {
state = TIMED_OUT;
} else {
state = FDS_READY;
}
return;
}
void
Selector::execute()
{
int nfds;
struct timeval *tp;
memcpy( read_fds, save_read_fds, fd_set_size * sizeof(fd_set) );
memcpy( write_fds, save_write_fds, fd_set_size * sizeof(fd_set) );
memcpy( except_fds, save_except_fds, fd_set_size * sizeof(fd_set) );
if( timeout_wanted ) {
tp = &timeout;
} else {
tp = NULL;
}
// select() ignores its first argument on Windows. We still track
// max_fd for the display() functions.
start_thread_safe("select");
nfds = select( max_fd + 1,
(SELECT_FDSET_PTR) read_fds,
(SELECT_FDSET_PTR) write_fds,
(SELECT_FDSET_PTR) except_fds,
tp );
stop_thread_safe("select");
_select_retval = nfds;
if( nfds < 0 ) {
_select_errno = errno;
#if !defined(WIN32)
if( errno == EINTR ) {
state = SIGNALLED;
return;
}
#endif
state = FAILED;
return;
}
_select_errno = 0;
if( nfds == 0 ) {
state = TIMED_OUT;
} else {
state = FDS_READY;
}
return;
}
/* Generic read/write wrappers for condor. These function emulate-ish the
* read/write system calls under unix except that they are portable, use
* a timeout, and make sure that all data is read or written.
*
* A few notes on the behavior differing from POSIX:
* - These will never fail due to EINTR.
* - If in non_blocking mode, there may be a short read or write returned.
* - The corresponding POSIX functon returns 0 bytes read when the peer closed
* the socket; these return -2.
* - If zero bytes were read/written in non-blocking mode, this will return 0. This differs
* from POSIX.
* - Providing a zero-sized argument to this function will cause the program to abort().
*
* Returns < 0 on failure. -1 = general error, -2 = peer closed socket
*/
int
condor_read( char const *peer_description, SOCKET fd, char *buf, int sz, int timeout, int flags, bool non_blocking )
{
Selector selector;
int nr = 0, nro;
unsigned int start_time=0, cur_time=0;
char sinbuf[SINFUL_STRING_BUF_SIZE];
if( IsDebugLevel(D_NETWORK) ) {
dprintf(D_NETWORK,
"condor_read(fd=%d %s,,size=%d,timeout=%d,flags=%d,non_blocking=%d)\n",
fd,
not_null_peer_description(peer_description,fd,sinbuf),
sz,
timeout,
flags,
non_blocking);
}
/* PRE Conditions. */
ASSERT(fd >= 0); /* Need valid file descriptor */
ASSERT(buf != NULL); /* Need real memory to put data into */
ASSERT(sz > 0); /* Need legit size on buffer */
if (non_blocking) {
#ifdef WIN32
unsigned long mode = 1; // nonblocking mode
if (ioctlsocket(fd, FIONBIO, &mode) < 0)
return -1;
#else
int fcntl_flags;
if ( (fcntl_flags=fcntl(fd, F_GETFL)) < 0 )
return -1;
// set nonblocking mode
if ( ((fcntl_flags & O_NONBLOCK) == 0) && fcntl(fd, F_SETFL, fcntl_flags | O_NONBLOCK) == -1 )
return -1;
#endif
nr = -2;
while (nr == -2 || (nr == -1 && errno == EINTR)) {
nr = recv(fd, buf, sz, flags);
}
if ( nr <= 0 ) {
int the_error;
char const *the_errorstr;
#ifdef WIN32
the_error = WSAGetLastError();
the_errorstr = "";
#else
the_error = errno;
the_errorstr = strerror(the_error);
#endif
if ( nr == 0 && !(flags & MSG_PEEK)) {
nr = -2;
dprintf( D_FULLDEBUG, "condor_read(): "
"Socket closed when trying to read %d bytes from %s in non-blocking mode\n",
sz,
not_null_peer_description(peer_description,fd,sinbuf) );
} else if ( !errno_is_temporary(the_error) ) {
dprintf( D_ALWAYS, "condor_read() failed: recv() %d bytes from %s "
"returned %d, "
"timeout=%d, errno=%d %s.\n",
sz,
not_null_peer_description(peer_description,fd,sinbuf),
nr, timeout, the_error, the_errorstr );
}
else
{
nr = 0;
}
}
#ifdef WIN32
mode = 0; // reset blocking mode
if (ioctlsocket(fd, FIONBIO, &mode) < 0)
return -1;
#else
// reset flags to prior value
if ( ((fcntl_flags & O_NONBLOCK) == 0) && (fcntl(fd, F_SETFL, fcntl_flags) == -1) )
return -1;
#endif
return nr;
}
selector.add_fd( fd, Selector::IO_READ );
if ( timeout > 0 ) {
start_time = time(NULL);
cur_time = start_time;
}
while( nr < sz ) {
if( timeout > 0 ) {
if( cur_time == 0 ) {
cur_time = time(NULL);
}
// If it hasn't yet been longer then we said we would wait...
if( start_time + timeout > cur_time ) {
selector.set_timeout( (start_time + timeout) - cur_time );
} else {
dprintf( D_ALWAYS,
"condor_read(): timeout reading %d bytes from %s.\n",
sz,
not_null_peer_description(peer_description,fd,sinbuf) );
return -1;
}
cur_time = 0;
if( IsDebugVerbose( D_NETWORK ) ) {
dprintf(D_NETWORK, "condor_read(): fd=%d\n", fd);
}
selector.execute();
if( IsDebugVerbose( D_NETWORK ) ) {
dprintf(D_NETWORK, "condor_read(): select returned %d\n",
selector.select_retval());
}
if ( selector.timed_out() ) {
dprintf( D_ALWAYS,
"condor_read(): timeout reading %d bytes from %s.\n",
sz,
not_null_peer_description(peer_description,fd,sinbuf) );
return -1;
} else if ( selector.signalled() ) {
continue;
} else if ( !selector.has_ready() ) {
int the_error;
char const *the_errorstr;
#ifdef WIN32
the_error = WSAGetLastError();
the_errorstr = "";
#else
the_error = errno;
the_errorstr = strerror(the_error);
#endif
dprintf( D_ALWAYS, "condor_read() failed: select() "
"returns %d, reading %d bytes from %s (errno=%d %s).\n",
selector.select_retval(),
sz,
not_null_peer_description(peer_description,fd,sinbuf),
the_error, the_errorstr );
return -1;
}
}
start_thread_safe("recv");
nro = recv(fd, &buf[nr], sz - nr, flags);
// Save the error value before stop_thread_safe(), as that may
// overwrite it.
int the_error;
#ifdef WIN32
the_error = WSAGetLastError();
#else
the_error = errno;
#endif
stop_thread_safe("recv");
if( nro <= 0 ) {
// If timeout > 0, and we made it here, then
// we know we were woken by select(). Now, if
// select() wakes up on a read fd, and then recv()
// subsequently returns 0, that means that the
// socket has been closed by our peer.
// If timeout == 0, then recv() should have
// blocked until 1 or more bytes arrived.
// Thus no matter what, if nro==0, then the
// socket must be closed.
if ( nro == 0 ) {
dprintf( D_FULLDEBUG, "condor_read(): "
"Socket closed when trying to read %d bytes from %s\n",
sz,
not_null_peer_description(peer_description,fd,sinbuf) );
return -2;
}
char const *the_errorstr;
#ifdef WIN32
the_errorstr = "";
#else
the_errorstr = strerror(the_error);
#endif
if ( errno_is_temporary(the_error) ) {
dprintf( D_FULLDEBUG, "condor_read(): "
"recv() returned temporary error %d %s,"
"still trying to read from %s\n",
the_error,the_errorstr,
not_null_peer_description(peer_description,fd,sinbuf) );
continue;
}
dprintf( D_ALWAYS, "condor_read() failed: recv(fd=%d) returned %d, "
"errno = %d %s, reading %d bytes from %s.\n",
fd, nro, the_error, the_errorstr, sz,
not_null_peer_description(peer_description,fd,sinbuf) );
if( the_error == ETIMEDOUT ) {
if( timeout <= 0 ) {
dprintf( D_ALWAYS,
"condor_read(): read timeout during blocking read from %s\n",
not_null_peer_description(peer_description,fd,sinbuf));
}
else {
int lapse = (int)(time(NULL)-start_time);
dprintf( D_ALWAYS,
"condor_read(): UNEXPECTED read timeout after %ds during non-blocking read from %s (desired timeout=%ds)\n",
lapse,
not_null_peer_description(peer_description,fd,sinbuf),
timeout);
}
}
return -1;
}
nr += nro;
}
/* Post Conditions */
ASSERT( nr == sz ); // we should have read *ALL* the data
return nr;
}
int
condor_write( char const *peer_description, SOCKET fd, const char *buf, int sz, int timeout, int flags, bool non_blocking )
{
int nw = 0, nwo = 0;
unsigned int start_time = 0, cur_time = 0;
char tmpbuf[1];
int nro;
bool select_for_read = true;
bool needs_select = true;
char sinbuf[SINFUL_STRING_BUF_SIZE];
if( IsDebugLevel( D_NETWORK ) ) {
dprintf(D_NETWORK,
"condor_write(fd=%d %s,,size=%d,timeout=%d,flags=%d,non_blocking=%d)\n",
fd,
not_null_peer_description(peer_description,fd,sinbuf),
sz,
timeout,
flags,
non_blocking);
}
/* Pre-conditions. */
ASSERT(sz > 0); /* Can't write buffers that are have no data */
ASSERT(fd >= 0); /* Need valid file descriptor */
ASSERT(buf != NULL); /* Need valid buffer to write */
if (non_blocking) {
#ifdef WIN32
unsigned long mode = 1; // nonblocking mode
if (ioctlsocket(fd, FIONBIO, &mode) < 0)
return -1;
#else
int fcntl_flags;
if ( (fcntl_flags=fcntl(fd, F_GETFL)) < 0 )
return -1;
// set nonblocking mode
if ( ((fcntl_flags & O_NONBLOCK) == 0) && fcntl(fd, F_SETFL, fcntl_flags | O_NONBLOCK) == -1 )
return -1;
#endif
nw = -2;
while (nw == -2 || (nw == -1 && errno == EINTR)) {
nw = send(fd, buf, sz, flags);
}
if ( nw <= 0 ) {
int the_error;
char const *the_errorstr;
#ifdef WIN32
the_error = WSAGetLastError();
the_errorstr = "";
#else
the_error = errno;
the_errorstr = strerror(the_error);
#endif
if ( !errno_is_temporary(the_error) ) {
dprintf( D_ALWAYS, "condor_write() failed: send() %d bytes to %s "
"returned %d, "
"timeout=%d, errno=%d %s.\n",
sz,
not_null_peer_description(peer_description,fd,sinbuf),
nw, timeout, the_error, the_errorstr );
}
else
{
nw = 0;
}
}
if (nw < 0) {
dprintf(D_NETWORK, "condor_write (non-blocking) wrote %d bytes.\n", nw);
}
#ifdef WIN32
mode = 0; // reset blocking mode
if (ioctlsocket(fd, FIONBIO, &mode) < 0)
return -1;
#else
// reset flags to prior value
if ( ((fcntl_flags & O_NONBLOCK) == 0) && fcntl(fd, F_SETFL, fcntl_flags) == -1 )
return -1;
#endif
return nw;
}
Selector selector;
selector.add_fd( fd, Selector::IO_READ );
selector.add_fd( fd, Selector::IO_WRITE );
selector.add_fd( fd, Selector::IO_EXCEPT );
if(timeout > 0) {
start_time = time(NULL);
cur_time = start_time;
}
while( nw < sz ) {
needs_select = true;
if( timeout > 0 ) {
while( needs_select ) {
if( cur_time == 0 ) {
cur_time = time(NULL);
}
if( start_time + timeout > cur_time ) {
selector.set_timeout( (start_time + timeout) - cur_time );
} else {
dprintf( D_ALWAYS, "condor_write(): "
"timed out writing %d bytes to %s\n",
sz,
not_null_peer_description(peer_description,fd,sinbuf) );
return -1;
}
cur_time = 0;
// The write and except sets are added at the top of
// this function, since we always want to select on
// them.
if( select_for_read ) {
// Also, put it in the read fds, so we'll wake
// up if the socket is closed
selector.add_fd( fd, Selector::IO_READ );
} else {
selector.delete_fd( fd, Selector::IO_READ );
}
selector.execute();
// unless we decide we need to select() again, we
// want to break out of our while() loop now that
// we've actually performed a select()
needs_select = false;
if ( selector.timed_out() ) {
dprintf( D_ALWAYS, "condor_write(): "
"timed out writing %d bytes to %s\n",
sz,
not_null_peer_description(peer_description,fd,sinbuf) );
return -1;
} else if ( selector.signalled() ) {
needs_select = true;
continue;
} else if ( selector.has_ready() ) {
if ( selector.fd_ready( fd, Selector::IO_READ ) ) {
dprintf(D_NETWORK, "condor_write(): socket %d is readable\n", fd);
// see if the socket was closed
nro = recv(fd, tmpbuf, 1, MSG_PEEK);
if( nro == -1 ) {
int the_error;
char const *the_errorstr;
#ifdef WIN32
the_error = WSAGetLastError();
the_errorstr = "";
#else
the_error = errno;
the_errorstr = strerror(the_error);
#endif
if(errno_is_temporary( the_error )) {
continue;
}
dprintf( D_ALWAYS, "condor_write(): "
"Socket closed when trying "
"to write %d bytes to %s, fd is %d, "
"errno=%d %s\n",
sz,
not_null_peer_description(peer_description,fd,sinbuf),
fd, the_error, the_errorstr );
return -1;
}
if( ! nro ) {
dprintf( D_ALWAYS, "condor_write(): "
"Socket closed when trying "
"to write %d bytes to %s, fd is %d\n",
sz,
not_null_peer_description(peer_description,fd,sinbuf),
fd );
return -1;
}
/*
otherwise, there's real data to consume
on the read side, and we don't want to
put our fd in the readfds anymore or
select() will never block. also, we
need to re-do the select()
*/
needs_select = true;
select_for_read = false;
}
} else {
dprintf( D_ALWAYS, "condor_write() failed: select() "
"returns %d, "
"writing %d bytes to %s.\n",
selector.select_retval(),
sz,
not_null_peer_description(peer_description,fd,sinbuf) );
return -1;
}
}
}
start_thread_safe("send");
nwo = send(fd, &buf[nw], sz - nw, flags);
// Save the error value before stop_thread_safe(), as that may
// overwrite it.
int the_error;
#ifdef WIN32
the_error = WSAGetLastError();
#else
the_error = errno;
#endif
stop_thread_safe("send");
if( nwo <= 0 ) {
char const *the_errorstr;
#ifdef WIN32
the_errorstr = "";
#else
the_errorstr = strerror(the_error);
#endif
if ( errno_is_temporary(the_error) ) {
dprintf( D_FULLDEBUG, "condor_write(): "
"send() returned temporary error %d %s,"
"still trying to write %d bytes to %s\n", the_error,
the_errorstr, sz,
not_null_peer_description(peer_description,fd,sinbuf) );
continue;
}
dprintf( D_ALWAYS, "condor_write() failed: send() %d bytes to %s "
"returned %d, "
"timeout=%d, errno=%d %s.\n",
sz,
not_null_peer_description(peer_description,fd,sinbuf),
nwo, timeout, the_error, the_errorstr );
return -1;
}
nw += nwo;
}
/* POST conditions. */
ASSERT( nw == sz ); /* Make sure that we wrote everything */
return nw;
}
