Marc Hartmayer 2c3e4a0f6e node_device_udev: nodeStateShutdownPrepare: Disconnect the signals explicitly
The documentation of gobject signals reads:

"If you are connecting handlers to signals and using a GObject instance as your
signal handler user data, you should remember to pair calls to
g_signal_connect() with calls to g_signal_handler_disconnect() or
g_signal_handlers_disconnect_by_func(). While signal handlers are automatically
disconnected when the object emitting the signal is finalised..." [1]

This means that the signal handlers are automatically disconnected as soon as
the `priv->mdevCtlMonitors` are finalised/released by `udevEventDataDispose`.
But this also means that it's possible that new work is tried to be scheduled
for the workerpool by the `mdevctlEventHandleCallback` (main thread context)
even if the workerpool has already been stopped by `nodeStateShutdownWait`. To
fully understand this, it's important to know that the main loop of the main
thread is still running for some time even after `nodeStateShutdownPrepare` has
been called. Let's avoid this situation by explicitly disconnect the signals
during `nodeStateShutdownPrepare`, which is called in the main thread, so that
no new work is attempted to be scheduled for the worker pool.

[1] https://docs.gtk.org/gobject/signals.html#memory-management-of-signal-handlers

Reviewed-by: Jonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: Boris Fiuczynski <fiuczy@linux.ibm.com>
Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
2024-06-18 09:00:29 -05:00
2023-12-05 11:48:28 +01:00

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Libvirt API for virtualization

Libvirt provides a portable, long term stable C API for managing the virtualization technologies provided by many operating systems. It includes support for QEMU, KVM, Xen, LXC, bhyve, Virtuozzo, VMware vCenter and ESX, VMware Desktop, Hyper-V, VirtualBox and the POWER Hypervisor.

For some of these hypervisors, it provides a stateful management daemon which runs on the virtualization host allowing access to the API both by non-privileged local users and remote users.

Layered packages provide bindings of the libvirt C API into other languages including Python, Perl, PHP, Go, Java, OCaml, as well as mappings into object systems such as GObject, CIM and SNMP.

Further information about the libvirt project can be found on the website:

https://libvirt.org

License

The libvirt C API is distributed under the terms of GNU Lesser General Public License, version 2.1 (or later). Some parts of the code that are not part of the C library may have the more restrictive GNU General Public License, version 2.0 (or later). See the files COPYING.LESSER and COPYING for full license terms & conditions.

Installation

Instructions on building and installing libvirt can be found on the website:

https://libvirt.org/compiling.html

Contributing

The libvirt project welcomes contributions in many ways. For most components the best way to contribute is to send patches to the primary development mailing list. Further guidance on this can be found on the website:

https://libvirt.org/contribute.html

Contact

The libvirt project has two primary mailing lists:

Further details on contacting the project are available on the website:

https://libvirt.org/contact.html

Description
Libvirt provides a portable, long term stable C API for managing the virtualization technologies provided by many operating systems. It includes support for QEMU, KVM, Xen, LXC, bhyve, Virtuozzo, VMware vCenter and ESX, VMware Desktop, Hyper-V, VirtualBox and the POWER Hypervisor.
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