IOKit设备添加/删除通知 - 只触发一次？ [英] IOKit device adding/removal notifications - only fire once?

问题描述

我一直在尝试在添加或删除特定USB设备时收到通知。我已经阅读从应用程序访问硬件文档，并有一个裸体演示应用程序，主要基于该文档中提供的代码。

I have been trying to get notified when a specific USB device is added or removed. I have read 'Accessing Hardware From Applications' document and have a bare-bones demo application, mainly based on the code provided in that document.

它第一次工作a设备被添加或删除，但之后，我的回调从未被调用。我不能解决为什么？任何人都可以找到我错误的地方？

It works the first time a device is added or removed, but after that my callbacks never get called. I cannot work out why? Can anyone spot where I am going wrong?

（xcode项目，如果你想测试）
http://monkeyfood.com/testIOKitNOtificaiton.zip

(xcode project if you would like to test) http://monkeyfood.com/testIOKitNOtificaiton.zip

感谢。

//
//  AppDelegate.m
//  testIOKitNotification
//
//  Created by Diggory Laycock on 23/07/2012.
//  Copyright (c) 2012 MonkeyFood.com. All rights reserved.
//

#import "AppDelegate.h"

@implementation AppDelegate


//          Arduino USB info
#define     matchVendorID           0x2341      
#define     matchProductID          0x0043


#pragma mark -
#pragma mark C Callback functions
#pragma mark -

void usbDeviceAppeared(void *refCon, io_iterator_t iterator){
    NSLog(@"Matching USB device appeared");
}
void usbDeviceDisappeared(void *refCon, io_iterator_t iterator){
    NSLog(@"Matching USB device disappeared");
}


@synthesize window = _window;


#pragma mark -
#pragma mark Application Methods
#pragma mark -



- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
    io_iterator_t newDevicesIterator;
    io_iterator_t lostDevicesIterator;

    newDevicesIterator = 0;
    lostDevicesIterator = 0;
    NSLog(@" ");

    NSMutableDictionary *matchingDict = (__bridge NSMutableDictionary *)IOServiceMatching(kIOUSBDeviceClassName);

    if (matchingDict == nil){
        NSLog(@"Could not create matching dictionary");
        return;
    }
    [matchingDict setObject:[NSNumber numberWithShort:matchVendorID] forKey:(NSString *)CFSTR(kUSBVendorID)];
    [matchingDict setObject:[NSNumber numberWithShort:matchProductID] forKey:(NSString *)CFSTR(kUSBProductID)];

    //  Add notification ports to runloop
    IONotificationPortRef notificationPort = IONotificationPortCreate(kIOMasterPortDefault);
    CFRunLoopSourceRef notificationRunLoopSource = IONotificationPortGetRunLoopSource(notificationPort);
    CFRunLoopAddSource([[NSRunLoop currentRunLoop] getCFRunLoop], notificationRunLoopSource, kCFRunLoopDefaultMode);

    kern_return_t err;
    err = IOServiceAddMatchingNotification(notificationPort, 
                                           kIOMatchedNotification, 
                                           (__bridge CFDictionaryRef)matchingDict, 
                                           usbDeviceAppeared, 
                                           (__bridge void *)self, 
                                           &newDevicesIterator);
    if (err)
    {
        NSLog(@"error adding publish notification");
    }
    [self matchingDevicesAdded: newDevicesIterator];


    NSMutableDictionary *matchingDictRemoved = (__bridge NSMutableDictionary *)IOServiceMatching(kIOUSBDeviceClassName);

    if (matchingDictRemoved == nil){
        NSLog(@"Could not create matching dictionary");
        return;
    }
    [matchingDictRemoved setObject:[NSNumber numberWithShort:matchVendorID] forKey:(NSString *)CFSTR(kUSBVendorID)];
    [matchingDictRemoved setObject:[NSNumber numberWithShort:matchProductID] forKey:(NSString *)CFSTR(kUSBProductID)];


    err = IOServiceAddMatchingNotification(notificationPort, 
                                           kIOTerminatedNotification, 
                                           (__bridge CFDictionaryRef)matchingDictRemoved, 
                                           usbDeviceDisappeared, 
                                           (__bridge void *)self, 
                                           &lostDevicesIterator);
    if (err)
    {
        NSLog(@"error adding removed notification");
    }
    [self matchingDevicesRemoved: lostDevicesIterator];


    //      CFRunLoopRun();
    //      [[NSRunLoop currentRunLoop] run];

}

#pragma mark -
#pragma mark ObjC Callback functions
#pragma mark -

- (void)matchingDevicesAdded:(io_iterator_t)devices
{
    io_object_t thisObject;
    while ( (thisObject = IOIteratorNext(devices))) {
        NSLog(@"new Matching device added ");
        IOObjectRelease(thisObject); 
    } 

}


- (void)matchingDevicesRemoved:(io_iterator_t)devices
{
    io_object_t thisObject;
    while ( (thisObject = IOIteratorNext(devices))) {
        NSLog(@"A matching device was removed ");
        IOObjectRelease(thisObject); 
    } 

}


@end

推荐答案

我已经弄清楚了什么是错的 - 我没有做任何事情在C Callback的迭代器。一个愚蠢的错误！

I've worked out what was wrong - I didn't do anything with the iterator in the C Callback. A stupid mistake!

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