ipxe/src/core/pending.c

/*
 * Copyright (C) 2012 Michael Brown <mbrown@fensystems.co.uk>.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or any later version.
 *
 * 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 for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 */

FILE_LICENCE ( GPL2_OR_LATER );

#include <errno.h>
#include <ipxe/process.h>
#include <ipxe/timer.h>
#include <ipxe/pending.h>

/** @file
 *
 * Pending operations
 *
 */

/** Total count of pending operations */
static int pending_total;

/**
 * Mark an operation as pending
 *
 * @v pending		Pending operation
 */
void pending_get ( struct pending_operation *pending ) {

	pending->count++;
	pending_total++;
	DBGC ( pending, "PENDING %p incremented to %d (total %d)\n",
	       pending, pending->count, pending_total );
}

/**
 * Mark an operation as no longer pending
 *
 * @v pending		Pending operation
 */
void pending_put ( struct pending_operation *pending ) {

	if ( pending->count ) {
		pending_total--;
		pending->count--;
		DBGC ( pending, "PENDING %p decremented to %d (total %d)\n",
		       pending, pending->count, pending_total );
	}
}

/**
 * Wait for pending operations to complete
 *
 * @v timeout		Timeout period, in ticks (0=indefinite)
 * @ret rc		Return status code
 */
int pending_wait ( unsigned long timeout ) {
	unsigned long start = currticks();

	do {
		if ( pending_total == 0 )
			return 0;
		step();
	} while ( ( timeout == 0 ) || ( ( currticks() - start ) < timeout ) );

	return -ETIMEDOUT;
}