Re: [Qemu-devel] [PATCH v7 12/54] tests/tcg/multiarch: don't hard code paths/ports for linux-test

[Thomas Huth]

On 18.06.2018 13:08, Daniel P. Berrangé wrote:
> On Mon, Jun 18, 2018 at 11:56:08AM +0100, Alex Bennée wrote:
>>
>> Thomas Huth <address@hidden> writes:
>>
>>> On 15.06.2018 21:46, Alex Bennée wrote:
>>>> The fixed path and ports get in the way of running our tests and
>>>> builds in parallel. Instead of using TESTPATH we use mkdtemp() and
>>>> instead of a fixed port we allow the kernel to assign one and query it
>>>> afterwards.
>>>>
>>>> Signed-off-by: Alex Bennée <address@hidden>
>>>> ---
>>>>  tests/tcg/multiarch/linux-test.c | 37 ++++++++++++++++----------------
>>>>  1 file changed, 19 insertions(+), 18 deletions(-)
>>>>
>>>> diff --git a/tests/tcg/multiarch/linux-test.c 
>>>> b/tests/tcg/multiarch/linux-test.c
>>>> index 6f2c531474..3f73b96420 100644
>>>> --- a/tests/tcg/multiarch/linux-test.c
>>>> +++ b/tests/tcg/multiarch/linux-test.c
>>>> @@ -41,8 +41,6 @@
>>>>  #include <setjmp.h>
>>>>  #include <sys/shm.h>
>>>>
>>>> -#define TESTPATH "/tmp/linux-test.tmp"
>>>> -#define TESTPORT 7654
>>>>  #define STACK_SIZE 16384
>>>>
>>>>  static void error1(const char *filename, int line, const char *fmt, ...)
>>>> @@ -85,19 +83,15 @@ static void test_file(void)
>>>>      struct iovec vecs[2];
>>>>      DIR *dir;
>>>>      struct dirent *de;
>>>> +    char template[] = "/tmp/linux-test-XXXXXX";
>>>> +    char *tmpdir = mkdtemp(template);
>>>>
>>>> -    /* clean up, just in case */
>>>> -    unlink(TESTPATH "/file1");
>>>> -    unlink(TESTPATH "/file2");
>>>> -    unlink(TESTPATH "/file3");
>>>> -    rmdir(TESTPATH);
>>>> +    chk_error(strlen(tmpdir));
>>>
>>> That line looks wrong to me. According to my man-page of mkdtemp(), it
>>> returns either NULL or a pointer to the modified string.
>>> In case of NULL, strlen(tmpdir) will simply crash. And even if it would
>>> not crash, strlen() only returns values >= 0, so there is no way the
>>> chk_error could ever report an error here.
>>
>> As we only really want to check we did actually do a mkdtemp would:
>>
>>   chk_error(tmpdir)
>>
>> Be enough?
> 
> I feel like this is a common task across all our test cases, so we would
> be well served by defining a helper program to give better semantics.
> 
> I feel like we should be creating temporary files in the build dir too
> by default, rather than /tmp, since some of our test suites create quite
> large files and /tmp is a limited size RAMFS on many distros. THis leads
> to obscure errors when running many tests in parallel if space is exhausted.
> 
> So how about creating a shared function:
> 
>     char *qtest_tempdir(const char *basename) {

We're talking about a tcg test here, not a qtest.

 Thomas