generic-library/libzmq
1
0
Fork 0
mirror of https://github.com/zeromq/libzmq.git synced 2025-11-03 19:40:39 +01:00
Code Issues Projects Releases Wiki Activity

Problem: FD set copying on Windows still not optimal on some places. Solution: Improved memcpy() of FD sets for Windows builds.

Browse Source
This commit is contained in:
bjovke
2017-04-14 16:31:05 +02:00
parent a3ad12f7fa
commit dc7bbe35b4
2 changed files with 30 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

20
src/select.cpp
View File

@@ -401,16 +401,36 @@ zmq::select_t::fds_set_t::fds_set_t ()
zmq::select_t::fds_set_t::fds_set_t (const fds_set_t& other_) zmq::select_t::fds_set_t::fds_set_t (const fds_set_t& other_)
{ {
#if defined ZMQ_HAVE_WINDOWS
// On Windows we don't need to copy the whole fd_set.
// SOCKETS are continuous from the beginning of fd_array in fd_set.
// We just need to copy fd_count elements of fd_array.
// We gain huge memcpy() improvement if number of used SOCKETs is much lower than FD_SETSIZE.
memcpy (&read, &other_.read, (char *) (other_.read.fd_array + other_.read.fd_count ) - (char *) &other_.read );
memcpy (&write, &other_.write, (char *) (other_.write.fd_array + other_.write.fd_count) - (char *) &other_.write);
memcpy (&error, &other_.error, (char *) (other_.error.fd_array + other_.error.fd_count) - (char *) &other_.error);
#else
memcpy (&read, &other_.read, sizeof other_.read); memcpy (&read, &other_.read, sizeof other_.read);
memcpy (&write, &other_.write, sizeof other_.write); memcpy (&write, &other_.write, sizeof other_.write);
memcpy (&error, &other_.error, sizeof other_.error); memcpy (&error, &other_.error, sizeof other_.error);
#endif
} }
zmq::select_t::fds_set_t& zmq::select_t::fds_set_t::operator= (const fds_set_t& other_) zmq::select_t::fds_set_t& zmq::select_t::fds_set_t::operator= (const fds_set_t& other_)
{ {
#if defined ZMQ_HAVE_WINDOWS
// On Windows we don't need to copy the whole fd_set.
// SOCKETS are continuous from the beginning of fd_array in fd_set.
// We just need to copy fd_count elements of fd_array.
// We gain huge memcpy() improvement if number of used SOCKETs is much lower than FD_SETSIZE.
memcpy (&read, &other_.read, (char *) (other_.read.fd_array + other_.read.fd_count ) - (char *) &other_.read );
memcpy (&write, &other_.write, (char *) (other_.write.fd_array + other_.write.fd_count) - (char *) &other_.write);
memcpy (&error, &other_.error, (char *) (other_.error.fd_array + other_.error.fd_count) - (char *) &other_.error);
#else
memcpy (&read, &other_.read, sizeof other_.read); memcpy (&read, &other_.read, sizeof other_.read);
memcpy (&write, &other_.write, sizeof other_.write); memcpy (&write, &other_.write, sizeof other_.write);
memcpy (&error, &other_.error, sizeof other_.error); memcpy (&error, &other_.error, sizeof other_.error);
#endif
return *this; return *this;
} }

13
src/zmq.cpp
View File

@@ -1110,10 +1110,14 @@ int zmq_poll (zmq_pollitem_t *items_, int nitems_, long timeout_)
// Wait for events. Ignore interrupts if there's infinite timeout. // Wait for events. Ignore interrupts if there's infinite timeout.
while (true) { while (true) {
memcpy (&inset, &pollset_in, sizeof (fd_set));
memcpy (&outset, &pollset_out, sizeof (fd_set));
memcpy (&errset, &pollset_err, sizeof (fd_set));
#if defined ZMQ_HAVE_WINDOWS #if defined ZMQ_HAVE_WINDOWS
// On Windows we don't need to copy the whole fd_set.
// SOCKETS are continuous from the beginning of fd_array in fd_set.
// We just need to copy fd_count elements of fd_array.
// We gain huge memcpy() improvement if number of used SOCKETs is much lower than FD_SETSIZE.
memcpy (&inset, &pollset_in , (char *) (pollset_in.fd_array + pollset_in.fd_count ) - (char *) &pollset_in );
memcpy (&outset, &pollset_out, (char *) (pollset_out.fd_array + pollset_out.fd_count) - (char *) &pollset_out);
memcpy (&errset, &pollset_err, (char *) (pollset_err.fd_array + pollset_err.fd_count) - (char *) &pollset_err);
int rc = select (0, &inset, &outset, &errset, ptimeout); int rc = select (0, &inset, &outset, &errset, ptimeout);
if (unlikely (rc == SOCKET_ERROR)) { if (unlikely (rc == SOCKET_ERROR)) {
errno = zmq::wsa_error_to_errno (WSAGetLastError ()); errno = zmq::wsa_error_to_errno (WSAGetLastError ());
@@ -1121,6 +1125,9 @@ int zmq_poll (zmq_pollitem_t *items_, int nitems_, long timeout_)
return -1; return -1;
} }
#else #else
memcpy (&inset, &pollset_in, sizeof (fd_set));
memcpy (&outset, &pollset_out, sizeof (fd_set));
memcpy (&errset, &pollset_err, sizeof (fd_set));
int rc = select (maxfd + 1, &inset, &outset, &errset, ptimeout); int rc = select (maxfd + 1, &inset, &outset, &errset, ptimeout);
if (unlikely (rc == -1)) { if (unlikely (rc == -1)) {
errno_assert (errno == EINTR || errno == EBADF); errno_assert (errno == EINTR || errno == EBADF);