From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cyril Hrubis Date: Thu, 21 Mar 2019 16:51:11 +0100 Subject: [LTP] [PATCH v2 1/2] tst_test: Add test multiplex function In-Reply-To: <20190321155112.13449-1-chrubis@suse.cz> References: <20190321155112.13449-1-chrubis@suse.cz> Message-ID: <20190321155112.13449-2-chrubis@suse.cz> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ltp@lists.linux.it The test multiplex function is intended for running the test function in a loop for a different settings. The indended purpose is to run tests for both libc wrapper and raw syscall as well as for different syscall variants. The commit itself adds a test_multiplex() function into the tst_test structure, if set this function is called in a loop before each test iteration and is responsible for changing the test variant into next one. The iterations continue until the function returns zero. Signed-off-by: Cyril Hrubis Reviewed-by: Steve Muckle CC: Mark Salyzyn CC: Steve Muckle CC: Jan Stancek --- doc/test-writing-guidelines.txt | 80 +++++++++++++++++++++++++++++++++ include/tst_test.h | 14 ++++++ lib/tst_test.c | 11 ++++- 3 files changed, 103 insertions(+), 2 deletions(-) diff --git a/doc/test-writing-guidelines.txt b/doc/test-writing-guidelines.txt index c36b2a424..e5aa456e2 100644 --- a/doc/test-writing-guidelines.txt +++ b/doc/test-writing-guidelines.txt @@ -1603,6 +1603,86 @@ sturct tst_test test = { }; ------------------------------------------------------------------------------- +2.2.29 Testing similar syscalls in one test +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +In some cases kernel has several very similar syscalls that do either the same +or very similar job. This is most noticeable on i386 where we commonly have +two or three syscall versions because i386 was first platform that Linux was +developed on and because of that most mistakes in API happened there as well. +However this is not limited to i386 at all, it's quite common that version two +syscall has added missing flags parameters or so. + +In such cases it does not make much sense to copy&paste the test code over and +over, rather than that the test library provides mutiplexing support. The idea +behind multiplexing is simple, we run the test function several times each +time with different syscall variant. + +The implemenation consist of multiplex fuction that is called before each +iteration of the run function, this fuction is responsible for switching the +syscall variant and also controlls the number of iterations. The testrun is +done once the function returns zero. + +[source,c] +------------------------------------------------------------------------------- +#include "tst_test.h" + +static int mpx = -1; + +static int foo_mpx(void) +{ + switch (++mpx) { + case 0: + tst_res(TINFO, "Testing foo variant 1"); + break; + case 1: + tst_res(TINFO, "Testing foo variant 2"); + break; + case 2: + mpx = -1; + return 0; + } + + return 1; +} + +static int do_foo(void) +{ + switch (mpx) { + case 0: + return foo(); + case 1: + return syscall(__NR_foo); + } + + return -1; +} + +static void setup(void) +{ + ... +} + +static void run(void) +{ + ... + + TEST(do_foo); + + ... +} + + +sturct tst_test test = { + ... + .setup = setup, + .test_all = run, + .test_multiplex = foo_mpx, + ... +}; +------------------------------------------------------------------------------- + + 2.3 Writing a testcase in shell ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ diff --git a/include/tst_test.h b/include/tst_test.h index da41f776d..b747b24d5 100644 --- a/include/tst_test.h +++ b/include/tst_test.h @@ -146,6 +146,20 @@ struct tst_test { */ int all_filesystems:1; + /* + * If set this function is used to mutiplex between different test + * variants. + * + * Multiplexers are the way how to run the same test for different + * settings. The intended use is to test different syscall + * wrappers/variants but the API is generic and does not limit the + * usage in any way. + * + * Each time the function is called it switches to next test variant, + * returns zero if all variants has been iterated over. + */ + int (*test_multiplex)(void); + /* Minimal device size in megabytes */ unsigned int dev_min_size; diff --git a/lib/tst_test.c b/lib/tst_test.c index ba5eab011..aae7651c2 100644 --- a/lib/tst_test.c +++ b/lib/tst_test.c @@ -1009,8 +1009,15 @@ static void testrun(void) if (!cont) break; - run_tests(); - heartbeat(); + if (tst_test->test_multiplex) { + while (tst_test->test_multiplex()) { + run_tests(); + heartbeat(); + } + } else { + run_tests(); + heartbeat(); + } } do_test_cleanup(); -- 2.19.2