mirror of https://gitee.com/openkylin/libvirt.git
172 lines
6.4 KiB
ReStructuredText
172 lines
6.4 KiB
ReStructuredText
=========================
|
|
Advanced test suite usage
|
|
=========================
|
|
|
|
The basic requirement before submitting changes to libvirt is that
|
|
|
|
::
|
|
|
|
$ ninja test
|
|
|
|
succeed after each commit.
|
|
|
|
The libvirt test suite, however, support additional features: for
|
|
example, it's possible to look for memory leaks and similar issues
|
|
by running
|
|
|
|
::
|
|
|
|
$ meson test --setup valgrind
|
|
|
|
`Valgrind <https://valgrind.org/>`__ is a test that checks for
|
|
memory management issues, such as leaks or use of uninitialized
|
|
variables.
|
|
|
|
Some tests are skipped by default in a development environment,
|
|
based on the time they take in comparison to the likelihood
|
|
that those tests will turn up problems during incremental
|
|
builds. These tests default to being run when building from a
|
|
tarball or with the configure option -Dexpensive_tests=enabled.
|
|
|
|
If you encounter any failing tests, the VIR_TEST_DEBUG
|
|
environment variable may provide extra information to debug the
|
|
failures. Larger values of VIR_TEST_DEBUG may provide larger
|
|
amounts of information:
|
|
|
|
::
|
|
|
|
$ VIR_TEST_DEBUG=1 ninja test (or)
|
|
$ VIR_TEST_DEBUG=2 ninja test
|
|
|
|
When debugging failures during development, it is possible to
|
|
focus in on just the failing subtests by using VIR_TEST_RANGE.
|
|
I.e. to run all tests from 3 to 20 with the exception of tests
|
|
6 and 16, use:
|
|
|
|
::
|
|
|
|
$ VIR_TEST_DEBUG=1 VIR_TEST_RANGE=3-5,7-20,^16 ./run tests/qemuxml2argvtest
|
|
|
|
Also, individual tests can be run from inside the ``tests/``
|
|
directory, like:
|
|
|
|
::
|
|
|
|
$ ./qemuxml2xmltest
|
|
|
|
If you are adding new test cases, or making changes that alter
|
|
existing test output, you can use the environment variable
|
|
VIR_TEST_REGENERATE_OUTPUT to quickly update the saved test
|
|
data. Of course you still need to review the changes VERY
|
|
CAREFULLY to ensure they are correct.
|
|
|
|
::
|
|
|
|
$ VIR_TEST_REGENERATE_OUTPUT=1 ./qemuxml2argvtest
|
|
|
|
There is also a ``./run`` script at the top level, to make it
|
|
easier to run programs that have not yet been installed, as
|
|
well as to wrap invocations of various tests under gdb or
|
|
Valgrind.
|
|
|
|
When running our test suite it may happen that the test result
|
|
is nondeterministic because of the test suite relying on a
|
|
particular file in the system being accessible or having some
|
|
specific value. To catch this kind of errors, the test suite
|
|
has a module for that prints any path touched that fulfils
|
|
constraints described above into a file. To enable it just set
|
|
``VIR_TEST_FILE_ACCESS`` environment variable. Then
|
|
``VIR_TEST_FILE_ACCESS_OUTPUT`` environment variable can alter
|
|
location where the file is stored.
|
|
|
|
::
|
|
|
|
$ VIR_TEST_FILE_ACCESS=1 VIR_TEST_FILE_ACCESS_OUTPUT="/tmp/file_access.txt" ./qemuxml2argvtest
|
|
|
|
#. The Valgrind test should produce similar output to
|
|
``ninja test``. If the output has traces within libvirt API's,
|
|
then investigation is required in order to determine the cause
|
|
of the issue. Output such as the following indicates some sort
|
|
of leak:
|
|
|
|
::
|
|
|
|
==5414== 4 bytes in 1 blocks are definitely lost in loss record 3 of 89
|
|
==5414== at 0x4A0881C: malloc (vg_replace_malloc.c:270)
|
|
==5414== by 0x34DE0AAB85: xmlStrndup (in /usr/lib64/libxml2.so.2.7.8)
|
|
==5414== by 0x4CC97A6: virDomainVideoDefParseXML (domain_conf.c:7410)
|
|
==5414== by 0x4CD581D: virDomainDefParseXML (domain_conf.c:10188)
|
|
==5414== by 0x4CD8C73: virDomainDefParseNode (domain_conf.c:10640)
|
|
==5414== by 0x4CD8DDB: virDomainDefParse (domain_conf.c:10590)
|
|
==5414== by 0x41CB1D: testCompareXMLToArgvHelper (qemuxml2argvtest.c:100)
|
|
==5414== by 0x41E20F: virtTestRun (testutils.c:161)
|
|
==5414== by 0x41C7CB: mymain (qemuxml2argvtest.c:866)
|
|
==5414== by 0x41E84A: virtTestMain (testutils.c:723)
|
|
==5414== by 0x34D9021734: (below main) (in /usr/lib64/libc-2.15.so)
|
|
|
|
In this example, the ``virDomainDefParseXML()`` had an error
|
|
path where the ``virDomainVideoDefPtr video`` pointer was not
|
|
properly disposed. By simply adding a
|
|
``virDomainVideoDefFree(video);`` in the error path, the issue
|
|
was resolved.
|
|
|
|
Another common mistake is calling a printing function, such as
|
|
``VIR_DEBUG()`` without initializing a variable to be printed.
|
|
The following example involved a call which could return an
|
|
error, but not set variables passed by reference to the call.
|
|
The solution was to initialize the variables prior to the call.
|
|
|
|
::
|
|
|
|
==4749== Use of uninitialised value of size 8
|
|
==4749== at 0x34D904650B: _itoa_word (in /usr/lib64/libc-2.15.so)
|
|
==4749== by 0x34D9049118: vfprintf (in /usr/lib64/libc-2.15.so)
|
|
==4749== by 0x34D9108F60: __vasprintf_chk (in /usr/lib64/libc-2.15.so)
|
|
==4749== by 0x4CAEEF7: virVasprintf (stdio2.h:199)
|
|
==4749== by 0x4C8A55E: virLogVMessage (virlog.c:814)
|
|
==4749== by 0x4C8AA96: virLogMessage (virlog.c:751)
|
|
==4749== by 0x4DA0056: virNetTLSContextCheckCertKeyUsage (virnettlscontext.c:225)
|
|
==4749== by 0x4DA06DB: virNetTLSContextCheckCert (virnettlscontext.c:439)
|
|
==4749== by 0x4DA1620: virNetTLSContextNew (virnettlscontext.c:562)
|
|
==4749== by 0x4DA26FC: virNetTLSContextNewServer (virnettlscontext.c:927)
|
|
==4749== by 0x409C39: testTLSContextInit (virnettlscontexttest.c:467)
|
|
==4749== by 0x40AB8F: virtTestRun (testutils.c:161)
|
|
|
|
Valgrind will also find some false positives or code paths
|
|
which cannot be resolved by making changes to the libvirt code.
|
|
For these paths, it is possible to add a filter to avoid the
|
|
errors. For example:
|
|
|
|
::
|
|
|
|
==4643== 7 bytes in 1 blocks are possibly lost in loss record 4 of 20
|
|
==4643== at 0x4A0881C: malloc (vg_replace_malloc.c:270)
|
|
==4643== by 0x34D90853F1: strdup (in /usr/lib64/libc-2.15.so)
|
|
==4643== by 0x34EEC2C08A: ??? (in /usr/lib64/libnl.so.1.1)
|
|
==4643== by 0x34EEC15B81: ??? (in /usr/lib64/libnl.so.1.1)
|
|
==4643== by 0x34D8C0EE15: call_init.part.0 (in /usr/lib64/ld-2.15.so)
|
|
==4643== by 0x34D8C0EECF: _dl_init (in /usr/lib64/ld-2.15.so)
|
|
==4643== by 0x34D8C01569: ??? (in /usr/lib64/ld-2.15.so)
|
|
|
|
In this instance, it is acceptable to modify the
|
|
``tests/.valgrind.supp`` file in order to add a suppression
|
|
filter. The filter should be unique enough to not suppress real
|
|
leaks, but it should be generic enough to cover multiple code
|
|
paths. The format of the entry can be found in the
|
|
documentation found at the `Valgrind home
|
|
page <https://valgrind.org/>`__. The following trace was added
|
|
to ``tests/.valgrind.supp`` in order to suppress the warning:
|
|
|
|
::
|
|
|
|
{
|
|
dlInitMemoryLeak1
|
|
Memcheck:Leak
|
|
fun:?alloc
|
|
...
|
|
fun:call_init.part.0
|
|
fun:_dl_init
|
|
...
|
|
obj:*/lib*/ld-2.*so*
|
|
}
|