osx_system_idle.c

/*
 * Copyright (c) 2013 Per Johansson
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <time.h>
#include <IOKit/IOKitLib.h>
#include <CoreFoundation/CoreFoundation.h>

int
osx_system_idle(struct timespec *dst)
{
	kern_return_t err;
	io_iterator_t it;
	io_registry_entry_t service;
	bool set = false;

	err = IOServiceGetMatchingServices(kIOMasterPortDefault, IOServiceMatching("IOHIDSystem"), &it);
	if (err)
		return -1;

	while ((service = IOIteratorNext(it)))
	{
		CFNumberRef value = IORegistryEntryCreateCFProperty(service, CFSTR("HIDIdleTime"), kCFAllocatorDefault, 0);
		long long n;
		struct timespec ts;

		if (!value)
			goto next;
		if (!CFNumberGetValue(value, kCFNumberLongLongType, &n))
			goto next;

		ts.tv_sec = n / 1000000000;
		ts.tv_nsec = n % 1000000000;

		if (!set || ts.tv_sec < dst->tv_sec || (ts.tv_sec == dst->tv_sec && ts.tv_nsec < dst->tv_nsec))
			*dst = ts;
		set = true;

next:
		if (value)
			CFRelease(value);
		IOObjectRelease(service);
	}
	IOObjectRelease(it);

	return set ? 0 : -1;
}