Aleksander Morgado
891b1a41f9
If the DeviceContext is cancelled, we remove it from the list of
tracked DeviceContexts in the MMPluginManager, so that new port
additions happening at the same time don't end up being added to
it.
This should allow an early cancellation of the DeviceContext without
asserting on g_assert (!device_context->extra_probing_time_id) as
there is no chance that a new port addition has reseted the extra
probing time timeout.
0x00007c1154f16abf (libc.so.6 - pthread_kill.c: 44) __pthread_kill_implementation
0x00007c1154ecbf0c (libc.so.6 - raise.c: 26) raise
0x00007c1154eb74aa (libc.so.6 - abort.c: 79) abort
0x00007c11556c08a9 (libglib-2.0.so.0 - gtestutils.c: 3450) g_assertion_message
0x00007c11556c091d (libglib-2.0.so.0 - gtestutils.c: 3476) g_assertion_message_expr
0x00005897d1ed6e7b (ModemManager - mm-plugin-manager.c: 805) device_context_unref
0x00005897d1ed6ab9 (ModemManager - mm-plugin-manager.c: 163) common_async_context_free
0x00005897d1ed5dd6 (ModemManager - mm-plugin-manager.c: 1136) port_context_run_ready
0x00007c1155550e86 (libgio-2.0.so.0 - gtask.c: 1309) g_task_return_now
0x00007c115554fe50 (libgio-2.0.so.0 - gtask.c: 1378) g_task_return
0x00007c115555047b (libgio-2.0.so.0 - gtask.c: 2022) g_task_return_new_error
0x00005897d1ed581a (ModemManager - mm-plugin-manager.c: 296) port_context_complete
0x00005897d1ed6259 (ModemManager - mm-plugin-manager.c) plugin_supports_port_ready
0x00007c1155550e86 (libgio-2.0.so.0 - gtask.c: 1309) g_task_return_now
0x00007c1155550eb9 (libgio-2.0.so.0 - gtask.c: 1323) complete_in_idle_cb
0x00007c115569c91b (libglib-2.0.so.0 - gmain.c: 3460) g_main_dispatch
0x00007c115569c91b (libglib-2.0.so.0 - gmain.c: 4200) g_main_context_dispatch
0x00007c115569cc37 (libglib-2.0.so.0 - gmain.c: 4276) g_main_context_iterate
0x00007c115569ceb5 (libglib-2.0.so.0 - gmain.c: 4479) g_main_loop_run
0x00005897d1e715bf (ModemManager - main.c: 236) main
0x00007c1154eb7705 (libc.so.6 - libc_start_call_main.h: 58) __libc_start_call_main
0x00007c1154eb77c1 (libc.so.6 - libc-start.c: 360) __libc_start_main_impl
0x00005897d1e70f10 (ModemManager + 0x000b3f10) _start
0x00007ffd5acc5057
Manually reproducing this issue was challenging, so adding here the
steps taken, for reference. This is with ModemManager running with
--no-udev (i.e. port additions reported via mmcli). The key to
reproduce the problem is the different timing between the port
additions and removals of the three ttyACM ports.
COUNT=1
while ((COUNT < 10000)); do
echo "$COUNT..."
COUNT=$((COUNT + 1))
(
sudo mmcli --report-kernel-event="name=ttyACM0,subsystem=tty,action=add"
TIMEOUT="0.0$(((RANDOM % 10) + 1))"
sleep $TIMEOUT
sudo mmcli --report-kernel-event="name=ttyACM0,subsystem=tty,action=remove"
) &
(
sudo mmcli --report-kernel-event="name=ttyACM1,subsystem=tty,action=add"
TIMEOUT="0.0$(((RANDOM % 10) + 1))"
sleep $TIMEOUT
sudo mmcli --report-kernel-event="name=ttyACM1,subsystem=tty,action=remove"
) &
(
sudo mmcli --report-kernel-event="name=ttyACM2,subsystem=tty,action=add"
TIMEOUT="0.0$(((RANDOM % 10) + 1))"
sleep $TIMEOUT
sudo mmcli --report-kernel-event="name=ttyACM2,subsystem=tty,action=remove"
) &
TIMEOUT="0.0$(((RANDOM % 10) + 1))"
sleep $TIMEOUT
COUNT=$((COUNT + 1))
done
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...).
Getting Started
ModemManager uses the meson build system. Meson is likely available as a package from your Linux distrubtion, but if not please refer to the Meson project for installation instructions. Once you have Meson installed you'll probably want to install libmbim and libqmi which most modems require.
After dependencies are installed you can build ModemManager with:
$ meson setup build --prefix=/usr --buildtype=release
$ ninja -C build
And after a successful build, install with:
$ sudo ninja -C build install
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 provide 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+.
Code of Conduct
Please note that this project is released with a Contributor Code of Conduct. By participating in this project you agree to abide by its terms, which you can find in the following link: https://www.freedesktop.org/wiki/CodeOfConduct
CoC issues may be raised to the project maintainers at the following address: modemmanager-devel-owner@lists.freedesktop.org