[PATCH v10 01/15] tools/libperf: avoid internal moving of fdarray fds

Alexey Budankov
2020-07-08T07:45:58Z

Avoid moving of fds by fdarray__filter() so fds indices returned
by fdarray__add() can be used for access and processing of
objects at struct pollfd *entries.

Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
---
tools/lib/api/fd/array.c | 11 +++++------
tools/perf/tests/fdarray.c | 20 ++------------------
2 files changed, 7 insertions(+), 24 deletions(-)

diff --git a/tools/lib/api/fd/array.c b/tools/lib/api/fd/array.c
index 58d44d5eee31..89f9a2193c2d 100644
--- a/tools/lib/api/fd/array.c
+++ b/tools/lib/api/fd/array.c
@@ -93,22 +93,21 @@ int fdarray__filter(struct fdarray *fda, short revents,
return 0;

for (fd = 0; fd < fda->nr; ++fd) {
+ if (!fda->entries[fd].events)
+ continue;
+
if (fda->entries[fd].revents & revents) {
if (entry_destructor)
entry_destructor(fda, fd, arg);

+ fda->entries[fd].revents = fda->entries[fd].events = 0;
continue;
}

- if (fd != nr) {
- fda->entries[nr] = fda->entries[fd];
- fda->priv[nr] = fda->priv[fd];
- }
-
++nr;
}

- return fda->nr = nr;
+ return nr;
}

int fdarray__poll(struct fdarray *fda, int timeout)
diff --git a/tools/perf/tests/fdarray.c b/tools/perf/tests/fdarray.c
index c7c81c4a5b2b..d0c8a05aab2f 100644
--- a/tools/perf/tests/fdarray.c
+++ b/tools/perf/tests/fdarray.c
@@ -12,6 +12,7 @@ static void fdarray__init_revents(struct fdarray *fda, short revents)

for (fd = 0; fd < fda->nr; ++fd) {
fda->entries[fd].fd = fda->nr - fd;
+ fda->entries[fd].events = revents;
fda->entries[fd].revents = revents;
}
}
@@ -29,7 +30,7 @@ static int fdarray__fprintf_prefix(struct fdarray *fda, const char *prefix, FILE

int test__fdarray__filter(struct test *test __maybe_unused, int subtest __maybe_unused)
{
- int nr_fds, expected_fd[2], fd, err = TEST_FAIL;
+ int nr_fds, err = TEST_FAIL;
struct fdarray *fda = fdarray__new(5, 5);

if (fda == NULL) {
@@ -55,7 +56,6 @@ int test__fdarray__filter(struct test *test __maybe_unused, int subtest __maybe_

fdarray__init_revents(fda, POLLHUP);
fda->entries[2].revents = POLLIN;
- expected_fd[0] = fda->entries[2].fd;

pr_debug("\nfiltering all but fda->entries[2]:");
fdarray__fprintf_prefix(fda, "before", stderr);
@@ -66,17 +66,9 @@ int test__fdarray__filter(struct test *test __maybe_unused, int subtest __maybe_
goto out_delete;
}

- if (fda->entries[0].fd != expected_fd[0]) {
- pr_debug("\nfda->entries[0].fd=%d != %d\n",
- fda->entries[0].fd, expected_fd[0]);
- goto out_delete;
- }
-
fdarray__init_revents(fda, POLLHUP);
fda->entries[0].revents = POLLIN;
- expected_fd[0] = fda->entries[0].fd;
fda->entries[3].revents = POLLIN;
- expected_fd[1] = fda->entries[3].fd;

pr_debug("\nfiltering all but (fda->entries[0], fda->entries[3]):");
fdarray__fprintf_prefix(fda, "before", stderr);
@@ -88,14 +80,6 @@ int test__fdarray__filter(struct test *test __maybe_unused, int subtest __maybe_
goto out_delete;
}

- for (fd = 0; fd < 2; ++fd) {
- if (fda->entries[fd].fd != expected_fd[fd]) {
- pr_debug("\nfda->entries[%d].fd=%d != %d\n", fd,
- fda->entries[fd].fd, expected_fd[fd]);
- goto out_delete;
- }
- }
-
pr_debug("\n");

err = 0;
--
2.24.1