[SOLVED] launchd.plist runs every 10 seconds instead of just once

launchd.plist runs every 10 seconds instead of just once

I have been setting up a launchd.plist XML that is run every time a specific USB device is mounted. I followed the instructions on the xpc_events(3) man page and it is running the application whenever the device is mounted.

The problem I'm having is that the application is run again and again every 10 seconds as long as the device is still mounted. How can I set it up so it only runs once when the device is inserted in the USB port?

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>Label</key>
    <string>com.myapp.agent</string>
    <key>Program</key>
    <string>/Applications/MyApp.app/Contents/MacOS/MyAgent</string>
    <key>LaunchEvents</key>
    <dict>
        <key>com.apple.iokit.matching</key>
        <dict>
            <key>com.apple.device-attach</key>
            <dict>
                <key>idVendor</key>
                <integer>2316</integer>
                <key>idProduct</key>
                <integer>4096</integer>
                <key>IOProviderClass</key>
                <string>IOUSBDevice</string>
                <key>IOMatchLaunchStream</key>
                <true/>
            </dict>
        </dict>
        <key>com.apple.notifyd.matching</key>
        <dict>
            <key>com.apple.interesting-notification</key>
            <dict>
                <key>Notification</key>
                <string>com.apple.interesting-notification</string>
            </dict>
        </dict>
    </dict>
</dict>
</plist>

Solution

AIUI your application must call xpc_set_event_stream_handler to remove the event from the queue. You might also have to add <key>KeepAlive</key><false/> to the .plist, but I'm not sure about that.