Re: [Qemu-devel] [PATCH 09/10] qht: add test program

["Alex Bennée" <alex.bennee@linaro.org>]

Emilio G. Cota <cota@braap.org> writes:

> Signed-off-by: Emilio G. Cota <cota@braap.org>
> ---
>  tests/.gitignore |   1 +
>  tests/Makefile   |   6 +++-
>  tests/test-qht.c | 100 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 106 insertions(+), 1 deletion(-)
>  create mode 100644 tests/test-qht.c
>
> diff --git a/tests/.gitignore b/tests/.gitignore
> index b7bf13e..d6d0700 100644
> --- a/tests/.gitignore
> +++ b/tests/.gitignore
> @@ -47,6 +47,7 @@ test-qapi-visit.[ch]
>  test-qdev-global-props
>  test-qemu-opts
>  test-qga
> +test-qht
>  test-qmp-commands
>  test-qmp-commands.h
>  test-qmp-event
> diff --git a/tests/Makefile b/tests/Makefile
> index 45b9048..b5a99d6 100644
> --- a/tests/Makefile
> +++ b/tests/Makefile
> @@ -68,6 +68,8 @@ check-unit-y += tests/rcutorture$(EXESUF)
>  gcov-files-rcutorture-y = util/rcu.c
>  check-unit-y += tests/test-rcu-list$(EXESUF)
>  gcov-files-test-rcu-list-y = util/rcu.c
> +check-unit-y += tests/test-qht$(EXESUF)
> +gcov-files-test-qht-y = util/qht.c
>  check-unit-y += tests/test-bitops$(EXESUF)
>  check-unit-$(CONFIG_HAS_GLIB_SUBPROCESS_TESTS) += tests/test-qdev-global-props$(EXESUF)
>  check-unit-y += tests/check-qom-interface$(EXESUF)
> @@ -387,7 +389,8 @@ test-obj-y = tests/check-qint.o tests/check-qstring.o tests/check-qdict.o \
>  	tests/test-qmp-commands.o tests/test-visitor-serialization.o \
>  	tests/test-x86-cpuid.o tests/test-mul64.o tests/test-int128.o \
>  	tests/test-opts-visitor.o tests/test-qmp-event.o \
> -	tests/rcutorture.o tests/test-rcu-list.o
> +	tests/rcutorture.o tests/test-rcu-list.o \
> +	tests/test-qht.o
>
>  $(test-obj-y): QEMU_INCLUDES += -Itests
>  QEMU_CFLAGS += -I$(SRC_PATH)/tests
> @@ -425,6 +428,7 @@ tests/test-cutils$(EXESUF): tests/test-cutils.o util/cutils.o
>  tests/test-int128$(EXESUF): tests/test-int128.o
>  tests/rcutorture$(EXESUF): tests/rcutorture.o $(test-util-obj-y)
>  tests/test-rcu-list$(EXESUF): tests/test-rcu-list.o $(test-util-obj-y)
> +tests/test-qht$(EXESUF): tests/test-qht.o $(test-util-obj-y)
>
>  tests/test-qdev-global-props$(EXESUF): tests/test-qdev-global-props.o \
>  	hw/core/qdev.o hw/core/qdev-properties.o hw/core/hotplug.o\
> diff --git a/tests/test-qht.c b/tests/test-qht.c
> new file mode 100644
> index 0000000..f553fbc
> --- /dev/null
> +++ b/tests/test-qht.c
> @@ -0,0 +1,100 @@
> +#include "qemu/osdep.h"
> +#include "qemu/xxhash.h"
> +#include "qemu/qht.h"
> +
> +#define N 5000
> +#define SEED 1
> +
> +static struct qht ht;
> +static int32_t arr[N];
> +
> +static bool is_equal(const void *obj, const void *userp)
> +{
> +    const int32_t *a = obj;
> +    const int32_t *b = userp;
> +
> +    return *a == *b;
> +}
> +
> +static void insert(int a, int b)
> +{
> +    int i;
> +
> +    for (i = a; i < b; i++) {
> +        uint32_t hash;
> +
> +        arr[i] = i;
> +        hash = qemu_xxh32((uint32_t *)&arr[i], 1, SEED);
> +
> +        qht_insert(&ht, &arr[i], hash);
> +    }
> +}
> +
> +static void rm(int init, int end)
> +{
> +    int i;
> +
> +    for (i = init; i < end; i++) {
> +        uint32_t hash;
> +
> +        hash = qemu_xxh32((uint32_t *)&arr[i], 1, SEED);
> +        assert(qht_remove(&ht, &arr[i], hash));
> +    }
> +}
> +
> +static void check(int a, int b, bool expected)
> +{
> +    int i;
> +
> +    for (i = a; i < b; i++) {
> +        void *p;
> +        uint32_t hash;
> +        int32_t val;
> +
> +        val = i;
> +        hash = qemu_xxh32((uint32_t *)&val, 1, SEED);
> +        p = qht_lookup(&ht, is_equal, &val, hash);
> +        assert(!!p == expected);
> +    }
> +}
> +
> +static void count_func(struct qht *ht, void *p, uint32_t hash, void *userp)
> +{
> +    unsigned int *curr = userp;
> +
> +    (*curr)++;
> +}
> +
> +static void iter_check(unsigned int count)
> +{
> +    unsigned int curr = 0;
> +
> +    qht_iter(&ht, count_func, &curr);
> +    assert(curr == count);
> +}
> +
> +static void qht_test(unsigned int mode)
> +{
> +    qht_init(&ht, 0, mode);
> +
> +    insert(0, N);
> +    check(0, N, true);
> +    check(-N, -1, false);
> +    iter_check(N);
> +    rm(1, 2);
> +    qht_reset_size(&ht, 0);
> +    check(0, N, false);
> +
> +    qht_destroy(&ht);
> +}
> +
> +int main(int argc, char *argv[])
> +{
> +    qht_test(0);
> +    qht_test(QHT_MODE_MRU_LOOKUP);
> +    qht_test(QHT_MODE_MRU_LOOKUP | QHT_MODE_MRU_INSERT);
> +    qht_test(QHT_MODE_MRU_LOOKUP | QHT_MODE_MRU_INSERT | QHT_MODE_AUTO_RESIZE);
> +    qht_test(QHT_MODE_AUTO_RESIZE | QHT_MODE_MRU_INSERT);
> +    qht_test(QHT_MODE_MRU_LOOKUP | QHT_MODE_MRU_INSERT);
> +    return 0;
> +}

A couple of notes:

  - these should use the gtester boiler plate for reporting results
  - AFAICT they are not exercising the multi-element hashing we actually
    use in the main code
  - it would be nice to add a check on the bucket/map distribution to
    defend against the algorithm being accidentally weakened with follow up patches

However tests are good :-)

--
Alex Bennée