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| author |   Adrian Hunter <adrian.hunter@intel.com> | 2022-05-20 18:56:04 +0300 |
|---|---|---|
| committer |   Arnaldo Carvalho de Melo <acme@redhat.com> | 2022-05-23 10:11:12 -0300 |
| commit | 618ee7838e409513635320ca9c4c8d52c44f2dd0 (patch) | |
| tree | e6d84ca947db644cbcd7816056989b0de8a8e35f /tools/lib/perf/lib.c | |
| parent | perf header: Add ability to keep feature sections (diff) | |
| download | wireguard-linux-618ee7838e409513635320ca9c4c8d52c44f2dd0.tar.xz wireguard-linux-618ee7838e409513635320ca9c4c8d52c44f2dd0.zip | |
libperf: Add preadn()
Add preadn() to provide pread() and readn() semantics.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/ab8918a4-7ac8-a37e-2e2c-28438c422d87@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/lib/perf/lib.c')
| -rw-r--r-- | tools/lib/perf/lib.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/tools/lib/perf/lib.c b/tools/lib/perf/lib.c index 18658931fc71..696fb0ea67c6 100644 --- a/tools/lib/perf/lib.c +++ b/tools/lib/perf/lib.c @@ -38,6 +38,26 @@ ssize_t readn(int fd, void *buf, size_t n) return ion(true, fd, buf, n); } +ssize_t preadn(int fd, void *buf, size_t n, off_t offs) +{ + size_t left = n; + + while (left) { + ssize_t ret = pread(fd, buf, left, offs); + + if (ret < 0 && errno == EINTR) + continue; + if (ret <= 0) + return ret; + + left -= ret; + buf += ret; + offs += ret; + } + + return n; +} + /* * Write exactly 'n' bytes or return an error. */ |