[Spice-devel] [PATCH spice-streaming-agent 6/9] Add a unit test for the stream port

Frediano Ziglio fziglio at redhat.com
Wed May 16 09:43:52 UTC 2018


> On Tue, 2018-05-15 at 16:52 -0400, Frediano Ziglio wrote:
> > A bit more comments.
> > 
> > > 
> > > Signed-off-by: Lukáš Hrázký <lhrazky at redhat.com>
> > > ---
> > >  src/unittests/.gitignore           |  1 +
> > >  src/unittests/Makefile.am          |  9 ++++-
> > >  src/unittests/test-stream-port.cpp | 69
> > >  ++++++++++++++++++++++++++++++++++++++
> > >  3 files changed, 78 insertions(+), 1 deletion(-)
> > >  create mode 100644 src/unittests/test-stream-port.cpp
> > > 
> > > diff --git a/src/unittests/.gitignore b/src/unittests/.gitignore
> > > index 22f1335..ef9e31b 100644
> > > --- a/src/unittests/.gitignore
> > > +++ b/src/unittests/.gitignore
> > > @@ -2,4 +2,5 @@
> > >  /test-*.log
> > >  /test-*.trs
> > >  /test-mjpeg-fallback
> > > +/test-stream-port
> > >  /test-suite.log
> > > diff --git a/src/unittests/Makefile.am b/src/unittests/Makefile.am
> > > index 0fc6d50..67f9c42 100644
> > > --- a/src/unittests/Makefile.am
> > > +++ b/src/unittests/Makefile.am
> > > @@ -16,11 +16,12 @@ AM_CFLAGS = \
> > >  check_PROGRAMS = \
> > >  	hexdump \
> > >  	test-mjpeg-fallback \
> > > +	test-stream-port \
> > >  	$(NULL)
> > >  
> > >  TESTS = \
> > >  	test-hexdump.sh \
> > > -	test-mjpeg-fallback \
> > > +	test-stream-port \
> > >  	$(NULL)
> > >  
> > >  noinst_PROGRAMS = \
> > > @@ -46,6 +47,12 @@ test_mjpeg_fallback_LDADD = \
> > >  	$(JPEG_LIBS) \
> > >  	$(NULL)
> > >  
> > > +test_stream_port_SOURCES = \
> > > +	test-stream-port.cpp \
> > > +	../stream-port.cpp \
> > > +	../error.cpp \
> > > +	$(NULL)
> > > +
> > >  EXTRA_DIST = \
> > >  	test-hexdump.sh \
> > >  	hexdump1.in \
> > > diff --git a/src/unittests/test-stream-port.cpp
> > > b/src/unittests/test-stream-port.cpp
> > > new file mode 100644
> > > index 0000000..9added3
> > > --- /dev/null
> > > +++ b/src/unittests/test-stream-port.cpp
> > > @@ -0,0 +1,69 @@
> > > +#define CATCH_CONFIG_MAIN
> > > +#include <catch/catch.hpp>
> > > +#include <sys/socket.h>
> > > +
> > > +#include "stream-port.hpp"
> > > +
> > > +
> > > +namespace ssa = spice::streaming_agent;
> > > +
> > > +/*
> > > + * Note the semantics of a socketpair may be different from the virtio
> > > port
> > > + * that is actually used for the real interface.
> > > + */
> > > +SCENARIO("test basic IO on the stream port", "[port][io]") {
> > > +    GIVEN("An open port (socketpair)") {
> > > +        int fd[2];
> > > +        const char *src_buf = "brekeke";
> > > +        const size_t src_size = strlen(src_buf) + 1;
> > > +
> > > +        socketpair(AF_LOCAL, SOCK_STREAM, 0, fd);
> > > +
> > > +        WHEN("reading data in one go") {
> > > +            CHECK(write(fd[0], src_buf, src_size) == src_size);
> > > +            char buf[10];
> > > +            ssa::read_all(fd[1], buf, src_size);
> > > +            CHECK(std::string(buf) == src_buf);
> > > +        }
> > > +
> > > +        WHEN("reading data in two steps") {
> > > +            CHECK(write(fd[0], src_buf, src_size) == src_size);
> > > +            char buf[10];
> > > +            ssa::read_all(fd[1], buf, 3);
> > > +            CHECK(std::string(buf, 3) == "bre");
> > > +            ssa::read_all(fd[1], buf, 5);
> > 
> > The fact that src_buf contains a terminator is not helpful, in
> > this case is converting the string from C stripping the terminator
> > but the code read "keke\0" (5 bytes), here seems it read just "keke".
> 
> Not sure what you want to say here... The code is slightly confusing
> but correct, right? Would you suggest how to improve it?
> 
> The thing is the \0 gets written to the socket and then read from it
> too. So "keke\0" is terminated and you can construct the std::string
> with the line below. Can't do that with "bre".
> 

Is src_size is just strlen(src_buf), you can have

          ssa::read_all(fd[1], buf, 3);
          CHECK(std::string(buf, 3) == "bre");
          ssa::read_all(fd[1], buf, 4);
          CHECK(std::string(buf, 4) == "keke");

this will avoid confusion with the terminator.
Obviously requires some adjustment in other code.

> > > +            CHECK(std::string(buf) == "keke");
> > > +        }
> > > +
> > > +        WHEN("writing data") {
> > > +            ssa::write_all(fd[1], src_buf, src_size);
> > > +            char buf[10];
> > > +            CHECK(read(fd[0], buf, src_size) == src_size);
> > > +            CHECK(std::string(buf) == src_buf);
> > > +        }
> > > +
> > > +        WHEN("closing the remote end and trying to read") {
> > > +            CHECK(write(fd[0], src_buf, src_size) == src_size);
> > > +            char buf[10];
> > > +            ssa::read_all(fd[1], buf, 3);
> > > +            CHECK(std::string(buf, 3) == "bre");
> > > +            CHECK(close(fd[0]) == 0);
> > > +            ssa::read_all(fd[1], buf, 5);
> > > +            CHECK(std::string(buf) == "keke");
> > > +            // TODO loops infinitely, we should recognize the remote end
> > > is
> > > closed
> > 
> > This looks a bug to me.
> 
> Well, when thinking about it some days later after sending the patches
> I kinda think so too. But at the time we discussed it you didn't say
> you think it's a bug and just thought it's a bit weird (IIRC), so...
> 
> Shall we report a bug to qemu?
> 

Why does this loop forever, I don't remember ?
Always returning EAGAIN ?
I remember you told me was hanging, not looping.
For the test sake won't be better to put the entire test case on
the following patch?

> > > +            //ssa::read_all(fd[1], buf, 1);
> > > +        }
> > > +
> > > +        WHEN("closing the remote end and trying to write") {
> > > +            ssa::write_all(fd[1], src_buf, src_size);
> > > +            char buf[10];
> > > +            CHECK(close(fd[0]) == 0);
> > 
> > This file descriptor is not already closed? Does catch calls fork() ?
> 
> I don't think Catch (the unit test framework) calls fork. But no clue
> what you mean... I'm closing the fd here as part of the test case...
> 

Above you closed the socket so without fork() I expect i this test case to
have the file descriptor already closed, the fact that close still returns
0 is weird, unless there is a fork in the middle or another way.
Maybe the scenario is repeated every time for different cases?

> > > +            // TODO causes a SIGPIPE
> > > +            //ssa::write_all(fd[1], src_buf, src_size);
> > 
> > A signal(SIGPIPE, SIG_IGN) should fix this. The device does not raise a
> > signal apparently.
> 
> Got that in a later patch, where the test case is fixed... For a reason
> I forgot I couldn't make it work here I think...
> 

Yes, would more also this test case to the next patch.

> Thanks for the review!
> Lukas
> 
> > > +        }
> > > +
> > > +        // clean up the descriptors in case they are still open
> > > +        close(fd[0]);
> > > +        close(fd[1]);
> > > +    }
> > > +}
> > 
> > Frediano
> 


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