Aleksander Morgado
71730509ee
We cannot in any way try to disconnect a GCancellable from within a
cancellation handler, or we'll deadlock.
Thread 1 (Thread 0x7fe98bf25700 (LWP 12079)):
#0 0x00007fe98a355f36 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#1 0x00007fe98a7f5ac0 in g_cond_wait () from /usr/lib/libglib-2.0.so.0
#2 0x00007fe98ad14650 in g_cancellable_disconnect () from /usr/lib/libgio-2.0.so.0
#3 0x000000000045be5d in port_probe_run_context_free ()
#4 0x00007fe98ad519ed in g_task_finalize () from /usr/lib/libgio-2.0.so.0
#5 0x00007fe98aaaa7b3 in g_object_unref () from /usr/lib/libgobject-2.0.so.0
#6 0x000000000045b5f8 in port_probe_task_return_error_if_cancelled ()
#7 0x000000000045c57d in serial_probe_at_parse_response ()
#8 0x00007fe98ad42ed2 in g_simple_async_result_complete () from /usr/lib/libgio-2.0.so.0
#9 0x0000000000485c7d in serial_command_ready ()
#10 0x00007fe98ad42ed2 in g_simple_async_result_complete () from /usr/lib/libgio-2.0.so.0
#11 0x0000000000482345 in command_context_complete_and_free ()
#12 0x0000000000482fa5 in port_serial_got_response ()
#13 0x00000000004830f5 in port_serial_response_wait_cancelled ()
#14 0x00007fe98aaa70c5 in g_closure_invoke () from /usr/lib/libgobject-2.0.so.0
#15 0x00007fe98aab47ce in signal_emit_unlocked_R () from /usr/lib/libgobject-2.0.so.0
#16 0x00007fe98aabb595 in g_signal_emit_valist () from /usr/lib/libgobject-2.0.so.0
#17 0x00007fe98aabb662 in g_signal_emit () from /usr/lib/libgobject-2.0.so.0
#18 0x00007fe98ad144c5 in g_cancellable_cancel () from /usr/lib/libgio-2.0.so.0
#19 0x00007fe98aaa70c5 in g_closure_invoke () from /usr/lib/libgobject-2.0.so.0
#20 0x00007fe98aab47ce in signal_emit_unlocked_R () from /usr/lib/libgobject-2.0.so.0
#21 0x00007fe98aabb595 in g_signal_emit_valist () from /usr/lib/libgobject-2.0.so.0
#22 0x00007fe98aabb662 in g_signal_emit () from /usr/lib/libgobject-2.0.so.0
#23 0x00007fe98ad144c5 in g_cancellable_cancel () from /usr/lib/libgio-2.0.so.0
#24 0x000000000042e9f6 in port_context_cancel ()
#25 0x00007fe989b99a4c in ffi_call_unix64 () at ../src/x86/unix64.S:75
#26 0x00007fe989b994b9 in ffi_call (cif=0x7fffc41dcdb0, fn=0x42ea40 <device_context_port_released>, rvalue=<optimized out>, avalue=0x7fffc41dccd0) at ../src/x86/ffi64.c:492
#27 0x00007fe98aaa7700 in g_cclosure_marshal_generic () from /usr/lib/libgobject-2.0.so.0
#28 0x00007fe98aaa70c5 in g_closure_invoke () from /usr/lib/libgobject-2.0.so.0
#29 0x00007fe98aab47ce in signal_emit_unlocked_R () from /usr/lib/libgobject-2.0.so.0
#30 0x00007fe98aabb595 in g_signal_emit_valist () from /usr/lib/libgobject-2.0.so.0
#31 0x00007fe98aabb662 in g_signal_emit () from /usr/lib/libgobject-2.0.so.0
#32 0x000000000042c8f0 in mm_device_release_port ()
#33 0x000000000042a6cb in device_removed ()
#34 0x000000000042af94 in handle_kernel_event ()
#35 0x000000000042b356 in report_kernel_event_auth_ready ()
#36 0x00007fe98ad51783 in g_task_return_now () from /usr/lib/libgio-2.0.so.0
#37 0x00007fe98ad517b9 in complete_in_idle_cb () from /usr/lib/libgio-2.0.so.0
#38 0x00007fe98a7bda5e in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#39 0x00007fe98a7bddb8 in g_main_context_iterate.isra () from /usr/lib/libglib-2.0.so.0
#40 0x00007fe98a7be042 in g_main_loop_run () from /usr/lib/libglib-2.0.so.0
#41 0x0000000000428dc4 in main ()
So, just clear the cancellation id before going on with the handler logic.
ModemManager. ModemManager provides a unified high level API for communicating with mobile broadband modems, regardless of the protocol used to communicate with the actual device (Generic AT, vendor-specific AT, QCDM, QMI, MBIM...). Using. ModemManager is a system daemon and is not meant to be used directly from the command line. However, since it provides a DBus API, it is possible to use 'dbus-send' commands or the new 'mmcli' command line interface to control it from the terminal. The devices are queried from udev and automatically updated based on hardware events, although a manual re-scan can also be requested to look for RS232 modems. Implementation. ModemManager is a DBus system bus activated service (meaning it's started automatically when a request arrives). It is written in C, using glib and gio. Several GInterfaces specify different features that the modems support, including the generic MMIfaceModem3gpp and MMIfaceModemCdma which provice basic operations for 3GPP (GSM, UMTS, LTE) or CDMA (CDMA1x, EV-DO) modems. If a given feature is not available in the modem, the specific interface will not be exported in DBus. Plugins. Plugins are loaded on startup, and must implement the MMPlugin interface. It consists of a couple of methods which tell the daemon whether the plugin supports a port and to create custom MMBroadbandModem implementations. It most likely makes sense to derive custom modem implementations from one of the generic classes and just add (or override) operations which are not standard. There are multiple fully working plugins in the plugins/ directory that can be used as an example for writing new plugins. Writing new plugins is highly encouraged! The plugin API is open for changes, so if you're writing a plugin and need to add or change some public method, feel free to suggest it! License. The ModemManager and mmcli binaries are both GPLv2+. The libmm-glib library is LGPLv2+.