-/* $Id$ */
-
/* rl_transport - RL specific functions for transport */
-/* Copyright (c) 2004 Martin Quinson. All rights reserved. */
+/* Copyright (c) 2004, 2005, 2006, 2007, 2009, 2010. The SimGrid Team.
+ * All rights reserved. */
/* This program is free software; you can redistribute it and/or modify it
* under the terms of the license (GNU LGPL) which comes with this package. */
+#include "xbt/ex.h"
#include "portable.h"
#include "gras/Transport/transport_private.h"
-XBT_LOG_EXTERNAL_CATEGORY(transport);
-XBT_LOG_DEFAULT_CATEGORY(transport);
+XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(gras_trp);
+
+/* check transport_private.h for an explanation of this variable */
+gras_socket_t _gras_lastly_selected_socket = NULL;
/**
* gras_trp_select:
*
- * Returns the next socket to service having a message awaiting.
+ * Returns the next socket to service because it receives a message.
*
* if timeout<0, we ought to implement the adaptative timeout (FIXME)
*
- * if timeout=0, do not wait for new message, only handle the ones already there.
*
* if timeout>0 and no message there, wait at most that amount of time before giving up.
*/
-xbt_error_t
-gras_trp_select(double timeout,
- gras_socket_t *dst) {
-
- xbt_error_t errcode;
- xbt_dynar_t sockets= gras_socketset_get();
+gras_socket_t gras_trp_select(double timeout)
+{
+ xbt_dynar_t sockets =
+ ((gras_trp_procdata_t)
+ gras_libdata_by_id(gras_trp_libdata_id))->sockets;
int done = -1;
- double wakeup = gras_os_time() + 1000000*timeout;
+ double wakeup = gras_os_time() + timeout;
double now = 0;
/* nextToService used to make sure socket with high number do not starve */
/* static int nextToService = 0; */
struct timeval tout, *p_tout;
- int max_fds=0; /* first arg of select: number of existing sockets */
+ int max_fds = 0; /* first arg of select: number of existing sockets */
/* but accept() of winsock returns sockets bigger than the limit, so don't bother
with this tiny optimisation on BillWare */
fd_set FDS;
- int ready; /* return of select: number of socket ready to be serviced */
- int fd_setsize; /* FD_SETSIZE not always defined. Get this portably */
-
- gras_socket_t sock_iter; /* iterating over all sockets */
- int cursor; /* iterating over all sockets */
+ int ready; /* return of select: number of socket ready to be serviced */
+ static int fd_setsize = -1; /* FD_SETSIZE not always defined. Get this portably */
+
+ gras_socket_t sock_iter; /* iterating over all sockets */
+ unsigned int cursor; /* iterating over all sockets */
+
+ /* Check whether there is more data to read from the socket we selected last time.
+ This can happen with tcp buffered sockets since we try to get as much data as we can for them */
+ if (_gras_lastly_selected_socket
+ && _gras_lastly_selected_socket->moredata) {
+ XBT_VERB
+ ("Returning _gras_lastly_selected_socket since there is more data on it");
+ return _gras_lastly_selected_socket;
+ }
-
- /* Compute FD_SETSIZE */
+ /* Compute FD_SETSIZE on need */
+ if (fd_setsize < 0) {
#ifdef HAVE_SYSCONF
- fd_setsize = sysconf( _SC_OPEN_MAX );
+ fd_setsize = sysconf(_SC_OPEN_MAX);
#else
-# ifdef HAVE_GETDTABLESIZE
- fd_setsize = getdtablesize();
+# ifdef HAVE_GETDTABLESIZE
+ fd_setsize = getdtablesize();
# else
- fd_setsize = FD_SETSIZE;
-# endif /* !USE_SYSCONF */
+ fd_setsize = FD_SETSIZE;
+# endif /* !USE_SYSCONF */
#endif
+ }
- *dst=NULL;
while (done == -1) {
- if (timeout > 0) { /* did we timeout already? */
+ if (timeout > 0) { /* did we timeout already? */
now = gras_os_time();
+ XBT_DEBUG("wakeup=%f now=%f", wakeup, now);
if (now == -1 || now >= wakeup) {
- done = 0; /* didn't find anything */
- break;
+ /* didn't find anything; no need to update _gras_lastly_selected_socket since its moredata is 0 (or we would have returned it directly) */
+ THROWF(timeout_error, 0,
+ "Timeout (%f) elapsed with selecting for incomming connexions",
+ timeout);
}
}
/* construct the set of socket to ear from */
FD_ZERO(&FDS);
- xbt_dynar_foreach(sockets,cursor,sock_iter) {
+ max_fds = -1;
+ xbt_dynar_foreach(sockets, cursor, sock_iter) {
+ if (!sock_iter->valid)
+ continue;
+
if (sock_iter->incoming) {
+ XBT_DEBUG("Considering socket %d for select", sock_iter->sd);
#ifndef HAVE_WINSOCK_H
- if (max_fds < sock_iter->sd)
- max_fds = sock_iter->sd;
+ if (max_fds < sock_iter->sd)
+ max_fds = sock_iter->sd;
+#else
+ max_fds = 0;
+
#endif
- FD_SET(sock_iter->sd, &FDS);
+ FD_SET(sock_iter->sd, &FDS);
} else {
- DEBUG1("Not considering socket %d for select",sock_iter->sd);
+ XBT_DEBUG("Not considering socket %d for select", sock_iter->sd);
}
}
+
+ if (max_fds == -1) {
+ if (timeout > 0) {
+ XBT_DEBUG("No socket to select onto. Sleep %f sec instead.", timeout);
+ gras_os_sleep(timeout);
+ THROWF(timeout_error, 0,
+ "No socket to select onto. Sleep %f sec instead", timeout);
+ } else {
+ XBT_DEBUG("No socket to select onto. Return directly.");
+ THROWF(timeout_error, 0,
+ "No socket to select onto. Return directly.");
+ }
+ }
#ifndef HAVE_WINSOCK_H
/* we cannot have more than FD_SETSIZE sockets
... but with WINSOCK which returns sockets higher than the limit (killing this optim) */
if (++max_fds > fd_setsize && fd_setsize > 0) {
- WARN1("too many open sockets (%d).",max_fds);
+ XBT_WARN("too many open sockets (%d).", max_fds);
done = 0;
break;
}
max_fds = fd_setsize;
#endif
- if (timeout > 0) {
+ tout.tv_sec = tout.tv_usec = 0;
+ if (timeout > 0) {
/* set the timeout */
- tout.tv_sec = (unsigned long)((wakeup - now)/1000000);
- tout.tv_usec = (unsigned long)(wakeup - now) % 1000000;
+ tout.tv_sec = (unsigned long) (wakeup - now);
+ tout.tv_usec =
+ ((wakeup - now) - ((unsigned long) (wakeup - now))) * 1000000;
p_tout = &tout;
} else if (timeout == 0) {
/* polling only */
p_tout = &tout;
/* we just do one loop around */
done = 0;
- } else {
+ } else {
/* no timeout: good luck! */
p_tout = NULL;
}
- DEBUG1("Selecting over %d socket(s)", max_fds-1);
+ XBT_DEBUG("Selecting over %d socket(s); timeout=%f", max_fds - 1,
+ timeout);
ready = select(max_fds, &FDS, NULL, NULL, p_tout);
+ XBT_DEBUG("select returned %d", ready);
if (ready == -1) {
switch (errno) {
- case EINTR: /* a signal we don't care about occured. we don't care */
- /* if we cared, we would have set an handler */
- continue;
- case EINVAL: /* invalid value */
- RAISE3(system_error,"invalid select: nb fds: %d, timeout: %d.%d",
- max_fds, (int)tout.tv_sec,(int) tout.tv_usec);
- case ENOMEM:
- xbt_assert0(0,"Malloc error during the select");
+ case EINTR: /* a signal we don't care about occured. we don't care */
+ /* if we cared, we would have set an handler */
+ continue;
+ case EINVAL: /* invalid value */
+ THROWF(system_error, EINVAL,
+ "invalid select: nb fds: %d, timeout: %d.%d", max_fds,
+ (int) tout.tv_sec, (int) tout.tv_usec);
+ case ENOMEM:
+ xbt_die("Malloc error during the select");
default:
- RAISE2(system_error,"Error during select: %s (%d)",
- strerror(errno),errno);
+ THROWF(system_error, errno, "Error during select: %s (%d)",
+ strerror(errno), errno);
}
- RAISE_IMPOSSIBLE;
+ THROW_IMPOSSIBLE;
} else if (ready == 0) {
- continue; /* this was a timeout */
+ continue; /* this was a timeout */
}
- xbt_dynar_foreach(sockets,cursor,sock_iter) {
- if(!FD_ISSET(sock_iter->sd, &FDS)) { /* this socket is not ready */
- continue;
- }
-
- /* Got a socket to serve */
- ready--;
-
- if ( sock_iter->accepting
- && sock_iter->plugin->socket_accept) {
- /* not a socket but an ear. accept on it and serve next socket */
- gras_socket_t accepted=NULL;
-
- DEBUG2("accepted=%p,&accepted=%p",accepted,&accepted);
- TRY((sock_iter->plugin->socket_accept)(sock_iter,&accepted));
- accepted->raw = sock_iter->raw;
- } else {
-#if 0
- FIXME: this fails of files. quite logical
- /* Make sure the socket is still alive by reading the first byte */
- char lookahead;
- int recvd;
-
- recvd = recv(sock_iter->sd, &lookahead, 1, MSG_PEEK);
- if (recvd < 0) {
- WARN2("socket %d failed: %s", sock_iter->sd, strerror(errno));
- /* done with this socket */
- gras_socket_close(&sock_iter);
- cursor--;
- } else if (recvd == 0) {
- /* Connection reset (=closed) by peer. */
- DEBUG1("Connection %d reset by peer", sock_iter->sd);
- gras_socket_close(&sock_iter);
- cursor--;
- } else {
-#endif
- /* Got a suited socket ! */
- *dst = sock_iter;
- XBT_OUT;
- return no_error;
-#if 0
- }
-#endif
- }
+ xbt_dynar_foreach(sockets, cursor, sock_iter) {
+ if (!FD_ISSET(sock_iter->sd, &FDS)) { /* this socket is not ready */
+ continue;
+ }
+
+ /* Got a socket to serve */
+ ready--;
+
+ if (sock_iter->accepting && sock_iter->plugin->socket_accept) {
+ /* not a socket but an ear. accept on it and serve next socket */
+ gras_socket_t accepted = NULL;
+
+ /* release mutex before accept; it will change the sockets dynar, so we have to break the foreach asap */
+ xbt_dynar_cursor_unlock(sockets);
+ accepted = (sock_iter->plugin->socket_accept) (sock_iter);
+
+ XBT_DEBUG("accepted=%p,&accepted=%p", accepted, &accepted);
+ accepted->meas = sock_iter->meas;
+ break;
-
- /* if we're here, the socket we found wasn't really ready to be served */
- if (ready == 0) /* exausted all sockets given by select. Request new ones */
- break;
+ } else {
+ /* Make sure the socket is still alive by reading the first byte */
+ int recvd;
+
+ if (sock_iter->recvd) {
+ /* Socket wasn't used since last time! Don't bother checking whether it's still alive */
+ recvd = 1;
+ } else {
+ recvd = read(sock_iter->sd, &sock_iter->recvd_val, 1);
+ }
+
+ if (recvd < 0) {
+ XBT_WARN("socket %d failed: %s", sock_iter->sd, strerror(errno));
+ /* done with this socket; remove it and break the foreach since it will change the dynar */
+ xbt_dynar_cursor_unlock(sockets);
+ gras_socket_close(sock_iter);
+ break;
+ } else if (recvd == 0) {
+ /* Connection reset (=closed) by peer. */
+ XBT_DEBUG("Connection %d reset by peer", sock_iter->sd);
+ sock_iter->valid = 0; /* don't close it. User may keep references to it */
+ } else {
+ /* Got a suited socket ! */
+ XBT_OUT();
+ sock_iter->recvd = 1;
+ XBT_DEBUG("Filled little buffer (%c %x %d)", sock_iter->recvd_val,
+ sock_iter->recvd_val, recvd);
+ _gras_lastly_selected_socket = sock_iter;
+ /* break sync dynar iteration */
+ xbt_dynar_cursor_unlock(sockets);
+ return sock_iter;
+ }
+ }
+
+ /* if we're here, the socket we found wasn't really ready to be served */
+ if (ready == 0) { /* exausted all sockets given by select. Request new ones */
+
+ xbt_dynar_cursor_unlock(sockets);
+ break;
+ }
}
}
- XBT_OUT;
- return timeout_error;
+ /* No socket found. Maybe we had timeout=0 and nothing to do */
+ XBT_DEBUG("TIMEOUT");
+ THROWF(timeout_error, 0, "Timeout");
}
-xbt_error_t gras_trp_sg_setup(gras_trp_plugin_t *plug) {
- return mismatch_error;
+void gras_trp_sg_setup(gras_trp_plugin_t plug)
+{
+ THROWF(mismatch_error, 0, "No SG transport on live platforms");
}
-