On May 24, 2013, at 3:03 PM, Sean McBride <s...@rogue-research.com> wrote:
> On Fri, 24 May 2013 11:22:13 -0600, Nathan Hjelm said: > >>> Is this hotplug API opt-in? libusbx won't start observing the comings >> and goings of all USB devices by default I hope? >> >> The hotplug API is opt-in but the internal event handlers are not. Here >> is a short summary of the changes within libusbx: >> - Devices are enumerated 1) when a context is created (by >> libusb_init()) or 2) when connected. Devices are no longer enumerated >> when you call libusb_get_device_list(). > > So once my process calls libusb_init(), libusbx code will run whenever any > kind of USB device is plugged in? The backend thread will wake up, run very briefly, and go back to sleep. > My app only communicates with one particular USB device, and I don't much > like the idea of my process running code whenever the user happens to plug in > a keyboard, mouse, USB key, or other unrelated thing. The code that is running is no different that what libudev or the os runs every time a device is plugged in. I doubt you would notice the < 1500 us time it takes to enumerate a device on darwin. Its much better than the nokia design which spawned an extra thread per context to handle device enumeration. That said, the design certainly can be tweaked if there is a real problem with libusb enumerating devices in the a backend thread. -Nathan ------------------------------------------------------------------------------ Try New Relic Now & We'll Send You this Cool Shirt New Relic is the only SaaS-based application performance monitoring service that delivers powerful full stack analytics. Optimize and monitor your browser, app, & servers with just a few lines of code. Try New Relic and get this awesome Nerd Life shirt! http://p.sf.net/sfu/newrelic_d2d_may _______________________________________________ libusbx-devel mailing list libusbx-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libusbx-devel
