IOUSBWorkLoop.cpp   [plain text]

/*
 * Copyright (c) 2001-2002 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@ 
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This Original Code and all software distributed under the License are
 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*
 * Copyright (c) 1999 Apple Computer, Inc.  All rights reserved.
 *
 * HISTORY
 * 13 February 2001 wgulland created.
 *
 */

#define DEBUGGING_LEVEL 0	// 1 = low; 2 = high; 3 = extreme
#define DEBUGLOG IOLog

#include <IOKit/IOWorkLoop.h>
#include <IOKit/usb/IOUSBWorkLoop.h>

OSDefineMetaClassAndStructors( IOUSBWorkLoop, IOWorkLoop )

IOUSBWorkLoop * IOUSBWorkLoop::workLoop()
{
    IOUSBWorkLoop *loop;
    
    loop = new IOUSBWorkLoop;
    if(!loop)
        return loop;
    if(!loop->init()) 
    {
        loop->release();
        loop = NULL;
    }
    return loop;
}

void IOUSBWorkLoop::closeGate()
{
    IOWorkLoop::closeGate();
    if(fSleepToken) 
    {
        IOReturn res;
        do 
        {
            res = sleepGate(fSleepToken, THREAD_ABORTSAFE);
            if(res == kIOReturnSuccess)
                break;
            IOLog("sleepGate returned 0x%x\n", res);
        } while (true);
    }
}

bool IOUSBWorkLoop::tryCloseGate()
{
    bool ret;
    ret = IOWorkLoop::tryCloseGate();
    if(ret && fSleepToken) 
    {
        openGate();
        ret = false;
    }
    return ret;
}

IOReturn IOUSBWorkLoop::sleep(void *token)
{
    if(fSleepToken) 
    {
        DEBUGLOG("IOUSBWorkLoop::sleep: Already asleep: %p\n", token);
        return kIOReturnError;
    }
    fSleepToken = token;
    openGate();
    return kIOReturnSuccess;
}

IOReturn 
IOUSBWorkLoop::wake(void *token)
{
    if(fSleepToken != token) 
    {
        DEBUGLOG("IOUSBWorkLoop::wake: wrong token: %p<->%p\n", token, fSleepToken);
        return kIOReturnError;
    }
    IORecursiveLockLock(gateLock);
    fSleepToken = NULL;
    wakeupGate(token, false);
    return kIOReturnSuccess;
}

void  
IOUSBWorkLoop::CloseGate(void) 
{ 
    closeGate(); 
}

void  
IOUSBWorkLoop::OpenGate(void)  
{ 
    openGate(); 
}