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Improve system call wrappers

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This change improves copy_file_range(), sendfile(), splice(), openpty(),
closefrom(), close_range(), fadvise() and posix_fadvise() in addition to
writing tests that confirm things like errno and seeking behavior across
platforms. We now less aggressively polyfill behavior with some of these
functions when the platform support isn't available. Please see:

https://justine.lol/cosmopolitan/functions.html
This commit is contained in:
Justine Tunney 2022-09-19 15:01:48 -07:00
parent 224c12f54d
commit c7a8cd21e9
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GPG key ID: BE714B4575D6E328
89 changed files with 1151 additions and 414 deletions
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48
libc/calls/posix_fadvise.c
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@ -16,8 +16,52 @@
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/assert.h"
#include "libc/calls/calls.h"
#include "libc/calls/syscall-nt.internal.h"
#include "libc/calls/syscall-sysv.internal.h"
#include "libc/dce.h"
#include "libc/errno.h"
#include "libc/intrin/strace.internal.h"
#include "libc/str/str.h"
#include "libc/sysv/errfuns.h"
int(posix_fadvise)(int fd, uint64_t offset, uint64_t len, int advice) {
return fadvise(fd, offset, len, advice);
int sys_fadvise_netbsd(int, int, int64_t, int64_t, int) asm("sys_fadvise");
/**
* Drops hints to O/S about intended I/O behavior.
*
* It makes a huge difference. For example, when copying a large file,
* it can stop the system from persisting GBs of useless memory content.
*
* @param len 0 means until end of file
* @param advice can be POSIX_FADV_SEQUENTIAL, POSIX_FADV_RANDOM, etc.
* @return 0 on success, or errno on error
* @raise EBADF if `fd` isn't a valid file descriptor
* @raise EINVAL if `advice` is invalid or `len` is huge
* @raise ESPIPE if `fd` refers to a pipe
* @raise ENOSYS on XNU and OpenBSD
*/
errno_t posix_fadvise(int fd, uint64_t offset, uint64_t len, int advice) {
int rc, e = errno;
if (IsLinux()) {
rc = sys_fadvise(fd, offset, len, advice);
} else if (IsFreebsd()) {
rc = sys_fadvise(fd, offset, len, advice);
_unassert(rc >= 0);
} else if (IsNetbsd()) {
rc = sys_fadvise_netbsd(fd, offset, offset, len, advice);
_unassert(rc >= 0);
} else if (IsWindows()) {
rc = sys_fadvise_nt(fd, offset, len, advice);
} else {
rc = enosys();
}
if (rc == -1) {
rc = errno;
errno = e;
}
STRACE("posix_fadvise(%d, %'lu, %'lu, %d) → %s", fd, offset, len, advice,
!rc ? "0" : _strerrno(rc));
return rc;
}