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| author | Christian Heimes <christian@python.org> | 2021-11-28 18:40:27 (GMT) |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2021-11-28 18:40:27 (GMT) |
| commit | f87ea0350286837e9e96de03f8bfa215176c2928 (patch) | |
| tree | 80950443b07bb7ff42bab26e29e4e5383d5041c8 /Python/pylifecycle.c | |
| parent | aaf42222cfd5774d23ca48ff304ace1f64426201 (diff) | |
| download | cpython-f87ea0350286837e9e96de03f8bfa215176c2928.zip cpython-f87ea0350286837e9e96de03f8bfa215176c2928.tar.gz cpython-f87ea0350286837e9e96de03f8bfa215176c2928.tar.bz2 | |
bpo-45915: use fcntl(fd, F_GETFD) in is_valid_fd() (GH-29821)
Diffstat (limited to 'Python/pylifecycle.c')
| -rw-r--r-- | Python/pylifecycle.c | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c index 7e6060e..74d269b 100644 --- a/Python/pylifecycle.c +++ b/Python/pylifecycle.c @@ -30,6 +30,10 @@ # include <langinfo.h> // nl_langinfo(CODESET) #endif +#ifdef HAVE_FCNTL_H +# include <fcntl.h> // F_GETFD +#endif + #ifdef MS_WINDOWS # undef BYTE # include "windows.h" @@ -2129,18 +2133,26 @@ is_valid_fd(int fd) startup. Problem: dup() doesn't check if the file descriptor is valid on some platforms. + fcntl(fd, F_GETFD) is even faster, because it only checks the process table. + bpo-30225: On macOS Tiger, when stdout is redirected to a pipe and the other side of the pipe is closed, dup(1) succeed, whereas fstat(1, &st) fails with EBADF. FreeBSD has similar issue (bpo-32849). Only use dup() on platforms where dup() is enough to detect invalid FD in - corner cases: on Linux and Windows (bpo-32849). */ -#if defined(__linux__) || defined(MS_WINDOWS) + corner cases: on Linux and Windows (bpo-32849). +*/ if (fd < 0) { return 0; } +#if defined(F_GETFD) && (defined(__linux__) || defined(__APPLE__) || defined(MS_WINDOWS)) + int res; + _Py_BEGIN_SUPPRESS_IPH + res = fcntl(fd, F_GETFD); + _Py_END_SUPPRESS_IPH + return res >= 0; +#elif defined(__linux__) || defined(MS_WINDOWS) int fd2; - _Py_BEGIN_SUPPRESS_IPH fd2 = dup(fd); if (fd2 >= 0) { |