Implement __zipos_dup (#972)

* Implement __zipos_dup

Makes ZiposHandle reference-counted by an `rc` field in a union with its
freelist `next` pointer. The functions `__zipos_free` and `__zipos_keep`
function as incref/decref for it. Adds `__zipos_postdup` to fix metadata
on file descriptors after dup-like operations, and adds zipos support to
`sys_dup_nt` + `sys_close_nt`.

* Remove noop __zipos_postdup

rc is never a zipos file because it is always a previously unused file
descriptor. fd is never a zipos file because that case has been handled
above by __zipos_fcntl.
This commit is contained in:
Jōshin 2023-12-01 03:08:30 -05:00 committed by GitHub
parent 6556dd2673
commit d1a745c17c
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GPG key ID: 4AEE18F83AFDEB23
11 changed files with 138 additions and 39 deletions

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@ -70,14 +70,17 @@ int dup3(int oldfd, int newfd, int flags) {
rc = einval(); // NetBSD doesn't do this
} else if (oldfd < 0 || newfd < 0) {
rc = ebadf();
} else if (__isfdkind(oldfd, kFdZip)) {
rc = enotsup();
} else if (!IsWindows()) {
rc = sys_dup3(oldfd, newfd, flags);
if (rc != -1 && __isfdkind(newfd, kFdZip) && !__vforked) {
_weaken(__zipos_free)(
(struct ZiposHandle *)(intptr_t)g_fds.p[newfd].handle);
bzero(g_fds.p + newfd, sizeof(*g_fds.p));
if (__isfdkind(oldfd, kFdZip) || __isfdkind(newfd, kFdZip)) {
if (__vforked) {
return enotsup();
}
rc = sys_dup3(oldfd, newfd, flags);
if (rc != -1) {
_weaken(__zipos_postdup)(oldfd, newfd);
}
} else {
rc = sys_dup3(oldfd, newfd, flags);
}
} else {
rc = sys_dup_nt(oldfd, newfd, flags, -1);