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31b5ad06e3
This is a partial revert of 87a43a907f0ad4897a28ad7c216bc70f37270b93 The change to use g_clear_pointer() in more places was accidentally applied to cases involving vir_g_source_unref(). In some cases, the ordering of g_source_destroy() and vir_g_source_unref() was reversed, which resulted in the source being marked as destroyed, after it is already unreferenced. This use-after-free case might work in many cases, but with versions of glib older than 2.64.0 it may defer unref to run within the main thread to avoid a race condition, which creates a large distance between the g_source_unref() and g_source_destroy(). In some cases, the call to vir_g_source_unref() was replaced with a second call to g_source_destroy(), leading to a memory leak or worse. In our experience, the symptoms were that use of libvirt-python became slower over time, with OpenStack nova-compute initially taking around one second to periodically query the host PCI devices, and within an hour it was taking over a minute to complete the same operation, until it is was eventually running this query back-to-back, resulting in the nova-compute process consuming 100% of one CPU thread, losing its RabbitMQ connection frequently, and showing up as down to the control plane. Signed-off-by: Mark Mielke <mark.mielke@gmail.com> Reviewed-by: Ján Tomko <jtomko@redhat.com> Signed-off-by: Ján Tomko <jtomko@redhat.com>