/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
* vim:expandtab:shiftwidth=8:tabstop=8:
*
- * lib/lib-eq.c
- * Library level Event queue management routines
+ * GPL HEADER START
+ *
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 only,
+ * as published by the Free Software Foundation.
*
- * Copyright (c) 2001-2003 Cluster File Systems, Inc.
- * Copyright (c) 2001-2002 Sandia National Laboratories
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License version 2 for more details (a copy is included
+ * in the LICENSE file that accompanied this code).
*
- * This file is part of Lustre, http://www.sf.net/projects/lustre/
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; If not, see
+ * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
*
- * Lustre is free software; you can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ * GPL HEADER END
+ */
+/*
+ * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Use is subject to license terms.
+ */
+/*
+ * This file is part of Lustre, http://www.lustre.org/
+ * Lustre is a trademark of Sun Microsystems, Inc.
*
- * Lustre is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
+ * lnet/lnet/lib-eq.c
*
- * You should have received a copy of the GNU General Public License
- * along with Lustre; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ * Library level Event queue management routines
*/
-#define DEBUG_SUBSYSTEM S_PORTALS
-#include <portals/lib-p30.h>
-#include <portals/arg-blocks.h>
+#define DEBUG_SUBSYSTEM S_LNET
+#include <lnet/lib-lnet.h>
-int do_PtlEQAlloc_internal(nal_cb_t * nal, void *private, void *v_args,
- void *v_ret)
+/**
+ * Create an event queue that has room for \a count number of events.
+ *
+ * The event queue is circular and older events will be overwritten by new
+ * ones if they are not removed in time by the user using the functions
+ * LNetEQGet(), LNetEQWait(), or LNetEQPoll(). It is up to the user to
+ * determine the appropriate size of the event queue to prevent this loss
+ * of events. Note that when EQ handler is specified in \a callback, no
+ * event loss can happen, since the handler is run for each event deposited
+ * into the EQ.
+ *
+ * \param count The number of events to be stored in the event queue. It
+ * will be rounded up to the next power of two.
+ * \param callback A handler function that runs when an event is deposited
+ * into the EQ. The constant value LNET_EQ_HANDLER_NONE can be used to
+ * indicate that no event handler is desired.
+ * \param handle On successful return, this location will hold a handle for
+ * the newly created EQ.
+ *
+ * \retval 0 On success.
+ * \retval -EINVAL If an parameter is not valid.
+ * \retval -ENOMEM If memory for the EQ can't be allocated.
+ *
+ * \see lnet_eq_handler_t for the discussion on EQ handler semantics.
+ */
+int
+LNetEQAlloc(unsigned int count, lnet_eq_handler_t callback,
+ lnet_handle_eq_t *handle)
{
- /*
- * Incoming:
- * ptl_handle_ni_t ni_in
- * ptl_size_t count_in
- * void * base_in
- *
- * Outgoing:
- * ptl_handle_eq_t * handle_out
- */
-
- PtlEQAlloc_in *args = v_args;
- PtlEQAlloc_out *ret = v_ret;
-
- lib_eq_t *eq;
- unsigned long flags;
-
- /* api should have rounded up */
- if (args->count_in != LOWEST_BIT_SET (args->count_in))
- return ret->rc = PTL_VAL_FAILED;
-
- eq = lib_eq_alloc (nal);
- if (eq == NULL)
- return (ret->rc = PTL_NOSPACE);
+ lnet_eq_t *eq;
- state_lock(nal, &flags);
+ LASSERT (the_lnet.ln_init);
+ LASSERT (the_lnet.ln_refcount > 0);
- if (nal->cb_map != NULL) {
- struct iovec iov = {
- .iov_base = args->base_in,
- .iov_len = args->count_in * sizeof (ptl_event_t) };
+ /* We need count to be a power of 2 so that when eq_{enq,deq}_seq
+ * overflow, they don't skip entries, so the queue has the same
+ * apparent capacity at all times */
- ret->rc = nal->cb_map (nal, 1, &iov, &eq->eq_addrkey);
- if (ret->rc != PTL_OK) {
- lib_eq_free (nal, eq);
-
- state_unlock (nal, &flags);
- return (ret->rc);
- }
+ if (count != LOWEST_BIT_SET(count)) { /* not a power of 2 already */
+ do { /* knock off all but the top bit... */
+ count &= ~LOWEST_BIT_SET (count);
+ } while (count != LOWEST_BIT_SET(count));
+
+ count <<= 1; /* ...and round up */
+ }
+
+ if (count == 0) /* catch bad parameter / overflow on roundup */
+ return (-EINVAL);
+
+ eq = lnet_eq_alloc();
+ if (eq == NULL)
+ return (-ENOMEM);
+
+ LIBCFS_ALLOC(eq->eq_events, count * sizeof(lnet_event_t));
+ if (eq->eq_events == NULL) {
+ LNET_LOCK();
+ lnet_eq_free (eq);
+ LNET_UNLOCK();
+
+ return -ENOMEM;
}
- eq->sequence = 1;
- eq->base = args->base_in;
- eq->size = args->count_in;
+ /* NB this resets all event sequence numbers to 0, to be earlier
+ * than eq_deq_seq */
+ memset(eq->eq_events, 0, count * sizeof(lnet_event_t));
+
+ eq->eq_deq_seq = 1;
+ eq->eq_enq_seq = 1;
+ eq->eq_size = count;
eq->eq_refcount = 0;
- eq->event_callback = args->callback_in;
+ eq->eq_callback = callback;
+
+ LNET_LOCK();
- lib_initialise_handle (nal, &eq->eq_lh, PTL_COOKIE_TYPE_EQ);
- list_add (&eq->eq_list, &nal->ni.ni_active_eqs);
+ lnet_initialise_handle (&eq->eq_lh, LNET_COOKIE_TYPE_EQ);
+ cfs_list_add (&eq->eq_list, &the_lnet.ln_active_eqs);
- state_unlock(nal, &flags);
+ LNET_UNLOCK();
- ptl_eq2handle(&ret->handle_out, eq);
- return (ret->rc = PTL_OK);
+ lnet_eq2handle(handle, eq);
+ return (0);
}
-int do_PtlEQFree_internal(nal_cb_t * nal, void *private, void *v_args,
- void *v_ret)
+/**
+ * Release the resources associated with an event queue if it's idle;
+ * otherwise do nothing and it's up to the user to try again.
+ *
+ * \param eqh A handle for the event queue to be released.
+ *
+ * \retval 0 If the EQ is not in use and freed.
+ * \retval -ENOENT If \a eqh does not point to a valid EQ.
+ * \retval -EBUSY If the EQ is still in use by some MDs.
+ */
+int
+LNetEQFree(lnet_handle_eq_t eqh)
{
- /*
- * Incoming:
- * ptl_handle_eq_t eventq_in
- *
- * Outgoing:
- */
+ lnet_eq_t *eq;
+ int size;
+ lnet_event_t *events;
- PtlEQFree_in *args = v_args;
- PtlEQFree_out *ret = v_ret;
- lib_eq_t *eq;
- long flags;
+ LASSERT (the_lnet.ln_init);
+ LASSERT (the_lnet.ln_refcount > 0);
- state_lock (nal, &flags);
+ LNET_LOCK();
- eq = ptl_handle2eq(&args->eventq_in, nal);
+ eq = lnet_handle2eq(&eqh);
if (eq == NULL) {
- ret->rc = PTL_INV_EQ;
- } else if (eq->eq_refcount != 0) {
- ret->rc = PTL_EQ_INUSE;
+ LNET_UNLOCK();
+ return (-ENOENT);
+ }
+
+ if (eq->eq_refcount != 0) {
+ CDEBUG(D_NET, "Event queue (%d) busy on destroy.\n",
+ eq->eq_refcount);
+ LNET_UNLOCK();
+ return (-EBUSY);
+ }
+
+ /* stash for free after lock dropped */
+ events = eq->eq_events;
+ size = eq->eq_size;
+
+ lnet_invalidate_handle (&eq->eq_lh);
+ cfs_list_del (&eq->eq_list);
+ lnet_eq_free (eq);
+
+ LNET_UNLOCK();
+
+ LIBCFS_FREE(events, size * sizeof (lnet_event_t));
+
+ return 0;
+}
+
+int
+lib_get_event (lnet_eq_t *eq, lnet_event_t *ev)
+{
+ int new_index = eq->eq_deq_seq & (eq->eq_size - 1);
+ lnet_event_t *new_event = &eq->eq_events[new_index];
+ int rc;
+ ENTRY;
+
+ CDEBUG(D_INFO, "event: %p, sequence: %lu, eq->size: %u\n",
+ new_event, eq->eq_deq_seq, eq->eq_size);
+
+ if (LNET_SEQ_GT (eq->eq_deq_seq, new_event->sequence)) {
+ RETURN(0);
+ }
+
+ /* We've got a new event... */
+ *ev = *new_event;
+
+ /* ...but did it overwrite an event we've not seen yet? */
+ if (eq->eq_deq_seq == new_event->sequence) {
+ rc = 1;
} else {
- if (nal->cb_unmap != NULL) {
- struct iovec iov = {
- .iov_base = eq->base,
- .iov_len = eq->size * sizeof (ptl_event_t) };
-
- nal->cb_unmap(nal, 1, &iov, &eq->eq_addrkey);
+ /* don't complain with CERROR: some EQs are sized small
+ * anyway; if it's important, the caller should complain */
+ CDEBUG(D_NET, "Event Queue Overflow: eq seq %lu ev seq %lu\n",
+ eq->eq_deq_seq, new_event->sequence);
+ rc = -EOVERFLOW;
+ }
+
+ eq->eq_deq_seq = new_event->sequence + 1;
+ RETURN(rc);
+}
+
+/**
+ * A nonblocking function that can be used to get the next event in an EQ.
+ * If an event handler is associated with the EQ, the handler will run before
+ * this function returns successfully. The event is removed from the queue.
+ *
+ * \param eventq A handle for the event queue.
+ * \param event On successful return (1 or -EOVERFLOW), this location will
+ * hold the next event in the EQ.
+ *
+ * \retval 0 No pending event in the EQ.
+ * \retval 1 Indicates success.
+ * \retval -ENOENT If \a eventq does not point to a valid EQ.
+ * \retval -EOVERFLOW Indicates success (i.e., an event is returned) and that
+ * at least one event between this event and the last event obtained from the
+ * EQ has been dropped due to limited space in the EQ.
+ */
+int
+LNetEQGet (lnet_handle_eq_t eventq, lnet_event_t *event)
+{
+ int which;
+
+ return LNetEQPoll(&eventq, 1, 0,
+ event, &which);
+}
+
+/**
+ * Block the calling process until there is an event in the EQ.
+ * If an event handler is associated with the EQ, the handler will run before
+ * this function returns successfully. This function returns the next event
+ * in the EQ and removes it from the EQ.
+ *
+ * \param eventq A handle for the event queue.
+ * \param event On successful return (1 or -EOVERFLOW), this location will
+ * hold the next event in the EQ.
+ *
+ * \retval 1 Indicates success.
+ * \retval -ENOENT If \a eventq does not point to a valid EQ.
+ * \retval -EOVERFLOW Indicates success (i.e., an event is returned) and that
+ * at least one event between this event and the last event obtained from the
+ * EQ has been dropped due to limited space in the EQ.
+ */
+int
+LNetEQWait (lnet_handle_eq_t eventq, lnet_event_t *event)
+{
+ int which;
+
+ return LNetEQPoll(&eventq, 1, LNET_TIME_FOREVER,
+ event, &which);
+}
+
+/**
+ * Block the calling process until there's an event from a set of EQs or
+ * timeout happens.
+ *
+ * If an event handler is associated with the EQ, the handler will run before
+ * this function returns successfully, in which case the corresponding event
+ * is consumed.
+ *
+ * LNetEQPoll() provides a timeout to allow applications to poll, block for a
+ * fixed period, or block indefinitely.
+ *
+ * \param eventqs,neq An array of EQ handles, and size of the array.
+ * \param timeout_ms Time in milliseconds to wait for an event to occur on
+ * one of the EQs. The constant LNET_TIME_FOREVER can be used to indicate an
+ * infinite timeout.
+ * \param event,which On successful return (1 or -EOVERFLOW), \a event will
+ * hold the next event in the EQs, and \a which will contain the index of the
+ * EQ from which the event was taken.
+ *
+ * \retval 0 No pending event in the EQs after timeout.
+ * \retval 1 Indicates success.
+ * \retval -EOVERFLOW Indicates success (i.e., an event is returned) and that
+ * at least one event between this event and the last event obtained from the
+ * EQ indicated by \a which has been dropped due to limited space in the EQ.
+ * \retval -ENOENT If there's an invalid handle in \a eventqs.
+ */
+int
+LNetEQPoll (lnet_handle_eq_t *eventqs, int neq, int timeout_ms,
+ lnet_event_t *event, int *which)
+{
+ int i;
+ int rc;
+#ifdef __KERNEL__
+ cfs_waitlink_t wl;
+ cfs_time_t now;
+#else
+ struct timeval then;
+ struct timeval now;
+# ifdef HAVE_LIBPTHREAD
+ struct timespec ts;
+# endif
+ lnet_ni_t *eqwaitni = the_lnet.ln_eqwaitni;
+#endif
+ ENTRY;
+
+ LASSERT (the_lnet.ln_init);
+ LASSERT (the_lnet.ln_refcount > 0);
+
+ if (neq < 1)
+ RETURN(-ENOENT);
+
+ LNET_LOCK();
+
+ for (;;) {
+#ifndef __KERNEL__
+ LNET_UNLOCK();
+
+ /* Recursion breaker */
+ if (the_lnet.ln_rc_state == LNET_RC_STATE_RUNNING &&
+ !LNetHandleIsEqual(eventqs[0], the_lnet.ln_rc_eqh))
+ lnet_router_checker();
+
+ LNET_LOCK();
+#endif
+ for (i = 0; i < neq; i++) {
+ lnet_eq_t *eq = lnet_handle2eq(&eventqs[i]);
+
+ if (eq == NULL) {
+ LNET_UNLOCK();
+ RETURN(-ENOENT);
+ }
+
+ rc = lib_get_event (eq, event);
+ if (rc != 0) {
+ LNET_UNLOCK();
+ *which = i;
+ RETURN(rc);
+ }
}
- lib_invalidate_handle (nal, &eq->eq_lh);
- list_del (&eq->eq_list);
- lib_eq_free (nal, eq);
- ret->rc = PTL_OK;
- }
+#ifdef __KERNEL__
+ if (timeout_ms == 0) {
+ LNET_UNLOCK();
+ RETURN (0);
+ }
+
+ cfs_waitlink_init(&wl);
+ cfs_set_current_state(CFS_TASK_INTERRUPTIBLE);
+ cfs_waitq_add(&the_lnet.ln_waitq, &wl);
+
+ LNET_UNLOCK();
+
+ if (timeout_ms < 0) {
+ cfs_waitq_wait (&wl, CFS_TASK_INTERRUPTIBLE);
+ } else {
+ struct timeval tv;
+
+ now = cfs_time_current();
+ cfs_waitq_timedwait(&wl, CFS_TASK_INTERRUPTIBLE,
+ cfs_time_seconds(timeout_ms)/1000);
+ cfs_duration_usec(cfs_time_sub(cfs_time_current(), now),
+ &tv);
+ timeout_ms -= (int)(tv.tv_sec * 1000 + tv.tv_usec / 1000);
+ if (timeout_ms < 0)
+ timeout_ms = 0;
+ }
+
+ LNET_LOCK();
+ cfs_waitq_del(&the_lnet.ln_waitq, &wl);
+#else
+ if (eqwaitni != NULL) {
+ /* I have a single NI that I have to call into, to get
+ * events queued, or to block. */
+ lnet_ni_addref_locked(eqwaitni);
+ LNET_UNLOCK();
+
+ if (timeout_ms <= 0) {
+ (eqwaitni->ni_lnd->lnd_wait)(eqwaitni, timeout_ms);
+ } else {
+ gettimeofday(&then, NULL);
+
+ (eqwaitni->ni_lnd->lnd_wait)(eqwaitni, timeout_ms);
- state_unlock (nal, &flags);
+ gettimeofday(&now, NULL);
+ timeout_ms -= (now.tv_sec - then.tv_sec) * 1000 +
+ (now.tv_usec - then.tv_usec) / 1000;
+ if (timeout_ms < 0)
+ timeout_ms = 0;
+ }
- return (ret->rc);
+ LNET_LOCK();
+ lnet_ni_decref_locked(eqwaitni);
+
+ /* don't call into eqwaitni again if timeout has
+ * expired */
+ if (timeout_ms == 0)
+ eqwaitni = NULL;
+
+ continue; /* go back and check for events */
+ }
+
+ if (timeout_ms == 0) {
+ LNET_UNLOCK();
+ RETURN (0);
+ }
+
+# ifndef HAVE_LIBPTHREAD
+ /* If I'm single-threaded, LNET fails at startup if it can't
+ * set the_lnet.ln_eqwaitni correctly. */
+ LBUG();
+# else
+ if (timeout_ms < 0) {
+ pthread_cond_wait(&the_lnet.ln_cond,
+ &the_lnet.ln_lock);
+ } else {
+ gettimeofday(&then, NULL);
+
+ ts.tv_sec = then.tv_sec + timeout_ms/1000;
+ ts.tv_nsec = then.tv_usec * 1000 +
+ (timeout_ms%1000) * 1000000;
+ if (ts.tv_nsec >= 1000000000) {
+ ts.tv_sec++;
+ ts.tv_nsec -= 1000000000;
+ }
+
+ pthread_cond_timedwait(&the_lnet.ln_cond,
+ &the_lnet.ln_lock, &ts);
+
+ gettimeofday(&now, NULL);
+ timeout_ms -= (now.tv_sec - then.tv_sec) * 1000 +
+ (now.tv_usec - then.tv_usec) / 1000;
+
+ if (timeout_ms < 0)
+ timeout_ms = 0;
+ }
+# endif
+#endif
+ }
}