From: Peter Krempa <pkrempa@redhat.com> The helper makes a dummy (file) FD to be used as FD in tests which want to handle a FD but don't really use it. It also optionally records the FD number along with a hint in a hash table which can be later used to fetch the hint and stabilize test outputs. Signed-off-by: Peter Krempa <pkrempa@redhat.com> --- tests/testutils.c | 113 ++++++++++++++++++++++++++++++++++++++++++++++ tests/testutils.h | 32 +++++++++++++ 2 files changed, 145 insertions(+) diff --git a/tests/testutils.c b/tests/testutils.c index 484852ecc2..5d6c918fd7 100644 --- a/tests/testutils.c +++ b/tests/testutils.c @@ -293,6 +293,119 @@ virTestLoadFileGetPath(const char *p, } +static virTestDummyFDContext *dummyFDContext; + +void +virTestDummyFDContextFree(virTestDummyFDContext *ctxt G_GNUC_UNUSED) +{ + g_clear_pointer(&dummyFDContext, g_hash_table_unref); +} + + +/** + * virTestDummyFDContextNew: + * + * Create a new context for marking dummy FDs so that they can be later + * cross-referenced and stripped from test output. Marked FDs are recorded + * in the returned GHashTable (virTestDummyFDContext type is a direct alias + * of GHashTable, allowing for registering custom autoptr cleanup function + * so that the context can be properly disposed), where keys are stringified + * FD numbers and the passed 'hint' strings are recorded as values. + * + * The context uses a global variable 'dummyFDContext' so that mocked functions + * which don't allow custom data can use this infrastructure. + * + * Note that in order to be able to track FDs across duplication via dup(), any + * test program must install a mock for dup() which calls virTestMakeDummyMarkDup. + * VIR_TEST_MAKE_DUMMY_FD_INSTALL_DUP_MOCK macro can be used to install one. + */ +virTestDummyFDContext * +virTestDummyFDContextNew(void) +{ + return dummyFDContext = virHashNew(g_free); +} + + +/** + * virTestDummyFDContextMarkFD: + * @fd: file descriptor to mark + * @hint: allocated buffer containing the name of @fd; the pointer is stolen and freed later + * + * Records @hint as a reference to @fd in the global 'dummyFDContext' table. + */ +void +virTestDummyFDContextMarkFD(int fd, + char *hint) +{ + if (!dummyFDContext) { + g_free(hint); + return; + } + + g_hash_table_insert(dummyFDContext, g_strdup_printf("%d", fd), hint); +} + + +/** + * virTestMakeDummyMarkDup: + * @newfd: new fd number + * @oldfd: old fd number + * + * Mark @newfd as a duplicate of @oldfd, e.g. when dup() is mocked. Transfers + * the hint from @oldfd to @newfd with a suffix marking that it's a dup'd fd. + */ +void +virTestMakeDummyMarkDup(int newfd, + int oldfd) +{ + const char *oldhint; + g_autofree char *oldlabel = NULL; + + if (!dummyFDContext) + return; + + oldlabel = g_strdup_printf("%d", oldfd); + + if (!(oldhint = g_hash_table_lookup(dummyFDContext, oldlabel))) + return; + + virTestDummyFDContextMarkFD(newfd, g_strdup_printf("%s-dup", oldhint)); +} + + +/** + * virTestMakeDummyFD: + * @hint: name for the FD to record into @hints + * + * Create a dummy file and return FD to it. The file is removed directly. This + * is useful for code where FDs are needed but will not be actually used. + * + * If 'virTestMakeDummyFDContextNew' was called @hint is recorded in the hash + * table corresponding to the contex. @hint is used as-is, caller must pass + * an allocated string which will be onwned by the context, or NULL. + */ +int +virTestMakeDummyFD(char *hint) +{ + int fd = -1; + char path[] = abs_builddir "dummyfd.XXXXXXXX"; + + if ((fd = g_mkstemp_full(path, O_RDWR | O_CLOEXEC, S_IRUSR | S_IWUSR)) < 0) { + VIR_TEST_VERBOSE("failed create dummy file/fd at '%s'", path); + abort(); + } + + if (unlink(path) < 0) { + VIR_TEST_VERBOSE("failed to unlink dummy file '%s' used for fd", path); + abort(); + } + + virTestDummyFDContextMarkFD(fd, hint); + + return fd; +} + + /** * virTestLoadFilePath: * @...: file name components terminated with a NULL diff --git a/tests/testutils.h b/tests/testutils.h index ce348f1287..84003ba0ac 100644 --- a/tests/testutils.h +++ b/tests/testutils.h @@ -106,6 +106,38 @@ const char *virTestCounterNext(void); char *virTestFakeRootDirInit(void); void virTestFakeRootDirCleanup(char *fakerootdir); + +typedef GHashTable virTestDummyFDContext; + +void virTestDummyFDContextFree(virTestDummyFDContext *ctxt); +G_DEFINE_AUTOPTR_CLEANUP_FUNC(virTestDummyFDContext, virTestDummyFDContextFree); + +virTestDummyFDContext *virTestDummyFDContextNew(void); + +void virTestDummyFDContextMarkFD(int fd, + char *hint); + +void virTestMakeDummyMarkDup(int newfd, + int oldfd); + +int virTestMakeDummyFD(char *hint); + +/* VIR_TEST_MAKE_DUMMY_FD_INSTALL_DUP_MOCK installs a mock for dup() that + * marks duplicated FDs via virTestMakeDummyFD */ +#define VIR_TEST_MAKE_DUMMY_FD_INSTALL_DUP_MOCK \ + static int (*real_dup)(int oldfd); \ + int \ + dup(int oldfd) \ + { \ + int newfd; \ + if (!real_dup) \ + VIR_MOCK_REAL_INIT(dup); \ + newfd = real_dup(oldfd); \ + virTestMakeDummyMarkDup(newfd, oldfd); \ + return newfd; \ + } + + /** * The @func shall return EXIT_FAILURE or EXIT_SUCCESS or * EXIT_AM_SKIP or EXIT_AM_HARDFAIL. -- 2.54.0