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

View file

@ -24,6 +24,7 @@
#include "libc/nt/enum/filetype.h"
#include "libc/nt/files.h"
#include "libc/nt/runtime.h"
#include "libc/runtime/zipos.internal.h"
#include "libc/sock/syscall_fd.internal.h"
#include "libc/sysv/consts/o.h"
#include "libc/sysv/errfuns.h"
@ -32,6 +33,8 @@ textwindows int sys_close_nt(int fd, int fildes) {
if (fd + 0u >= g_fds.n) return ebadf();
struct Fd *f = g_fds.p + fd;
switch (f->kind) {
case kFdZip:
return _weaken(__zipos_close)(fd);
case kFdEmpty:
return ebadf();
case kFdFile:

View file

@ -59,30 +59,34 @@ static textwindows int sys_dup_nt_impl(int oldfd, int newfd, int flags,
return -1;
}
if (g_fds.p[newfd].kind) {
if (g_fds.p[newfd].kind == kFdZip) {
_weaken(__zipos_close)(newfd);
} else {
sys_close_nt(newfd, newfd);
}
sys_close_nt(newfd, newfd);
}
}
if (DuplicateHandle(GetCurrentProcess(), g_fds.p[oldfd].handle,
GetCurrentProcess(), &handle, 0, true,
kNtDuplicateSameAccess)) {
g_fds.p[newfd] = g_fds.p[oldfd];
g_fds.p[newfd].handle = handle;
if (flags & _O_CLOEXEC) {
g_fds.p[newfd].flags |= _O_CLOEXEC;
} else {
g_fds.p[newfd].flags &= ~_O_CLOEXEC;
}
if (__isfdkind(oldfd, kFdZip)) {
handle = (intptr_t)_weaken(__zipos_keep)(
(struct ZiposHandle *)(intptr_t)g_fds.p[oldfd].handle);
rc = newfd;
} else {
__releasefd(newfd);
rc = __winerr();
if (DuplicateHandle(GetCurrentProcess(), g_fds.p[oldfd].handle,
GetCurrentProcess(), &handle, 0, true,
kNtDuplicateSameAccess)) {
rc = newfd;
} else {
rc = __winerr();
__releasefd(newfd);
__fds_unlock();
return rc;
}
}
g_fds.p[newfd] = g_fds.p[oldfd];
g_fds.p[newfd].handle = handle;
if (flags & _O_CLOEXEC) {
g_fds.p[newfd].flags |= _O_CLOEXEC;
} else {
g_fds.p[newfd].flags &= ~_O_CLOEXEC;
}
__fds_unlock();
return rc;
}

View file

@ -22,7 +22,9 @@
#include "libc/calls/syscall-sysv.internal.h"
#include "libc/dce.h"
#include "libc/intrin/strace.internal.h"
#include "libc/intrin/weaken.h"
#include "libc/sysv/errfuns.h"
#include "libc/runtime/zipos.internal.h"
/**
* Duplicates file descriptor.
@ -51,10 +53,11 @@
*/
int dup(int fd) {
int rc;
if (__isfdkind(fd, kFdZip)) {
rc = enotsup();
} else if (!IsWindows()) {
if (!IsWindows()) {
rc = sys_dup(fd);
if (rc != -1 && __isfdkind(fd, kFdZip)) {
_weaken(__zipos_postdup)(fd, rc);
}
} else {
rc = sys_dup_nt(fd, -1, 0, -1);
}

View file

@ -67,20 +67,24 @@ int dup2(int oldfd, int newfd) {
int rc;
// helps guarantee stderr log gets duplicated before user closes
if (_weaken(kloghandle)) _weaken(kloghandle)();
if (__isfdkind(oldfd, kFdZip)) {
rc = enotsup();
#ifdef __aarch64__
} else if (oldfd == newfd) {
if (oldfd == newfd) {
// linux aarch64 defines dup3() but not dup2(), which wasn't such a
// great decision, since the two syscalls don't behave the same way
if (!(rc = read(oldfd, 0, 0))) rc = oldfd;
} else
#endif
} else if (!IsWindows()) {
rc = sys_dup2(oldfd, newfd, 0);
if (rc != -1 && oldfd != newfd && __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 (!IsWindows()) {
if (__isfdkind(oldfd, kFdZip) || __isfdkind(newfd, kFdZip)) {
if (__vforked) {
return enotsup();
}
rc = sys_dup2(oldfd, newfd, 0);
if (rc != -1) {
_weaken(__zipos_postdup)(oldfd, newfd);
}
} else {
rc = sys_dup2(oldfd, newfd, 0);
}
} else if (newfd < 0) {
rc = ebadf();

View file

@ -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);