Rewrite majority of impl reusing libstd (#34)

* Rewrite FdEntry reusing as much libstd as possible

* Use the new FdEntry, FdObject, Descriptor struct in *nix impl

* Adapt Windows impl

* Remove unnecessary check in fd_read

Check `host_nread == 0` caused premature FdEntry closure and removal
which ultimately was resulting in an attempt at "double closing" of
the same file descriptor at the end of the Wasm program:
...
fd_close(fd=4)
    -> errno=WASI_ESUCCESS
fd_close(fd=4)
    -> errno=WASI_EBADF

* Use libstd vectored IO

* Use std:🧵:yield_now to implement sched_yield

* Add logging to integration tests

* Add preliminary support for host-specific errors

* Operate on std::fs::File in path_get on *nix

* Add cross-platform RawString type encapsulating OsStrExt

* Fix Windows build

* Update Travis and README to Rust v1.36

* Remove unused winx::handle::close helper

* Refactor Descriptor into raw handles/fds

* Strip readlinkat in prep for path_get host-independent

* Strip openat in prep for path_get host-independent

* Move ManuallyDrop up one level from Descriptor to FdObject

* Make (c)iovec host fns unsafe

* Swap unwraps/expects for Results in fdentry_impl on nix

* Rewrite fd_pread/write and implement for Win

* Use File::sync_all to impl fd_sync

* Use File::sync_data to impl fd_datasync

* Rewind file cursor after fd_p{read, write} on Windows

* Add fd_p{read, write} tests

* Handle errors instead of panicking in path_get

* Use File::set_len to impl fd_allocate

* Add test for fd_allocate

* Replace all panics with Results

* Document the point of RawString
This commit is contained in:
Jakub Konka
2019-07-16 00:34:28 +02:00
committed by Dan Gohman
parent 93e1657bae
commit 667f272edd
32 changed files with 977 additions and 1045 deletions

View File

@@ -1,51 +1,54 @@
#![allow(non_camel_case_types)]
#![allow(unused)]
use super::fdentry::{determine_type_rights, FdEntry};
use super::fs_helpers::*;
use super::host_impl;
use crate::ctx::WasiCtx;
use crate::fdentry::FdEntry;
use crate::host;
use crate::sys::errno_from_host;
use crate::sys::fdentry_impl::determine_type_rights;
use crate::sys::host_impl::{self, RawString};
use std::ffi::OsStr;
use std::os::windows::prelude::FromRawHandle;
use std::fs::File;
use std::io::{self, Seek, SeekFrom};
use std::os::windows::fs::FileExt;
use std::os::windows::prelude::{AsRawHandle, FromRawHandle};
pub(crate) fn fd_close(fd_entry: FdEntry) -> Result<(), host::__wasi_errno_t> {
winx::handle::close(fd_entry.fd_object.raw_handle).map_err(|e| host_impl::errno_from_win(e))
fn read_at(mut file: &File, buf: &mut [u8], offset: u64) -> io::Result<usize> {
// get current cursor position
let cur_pos = file.seek(SeekFrom::Current(0))?;
// perform a seek read by a specified offset
let nread = file.seek_read(buf, offset)?;
// rewind the cursor back to the original position
file.seek(SeekFrom::Start(cur_pos))?;
Ok(nread)
}
pub(crate) fn fd_datasync(fd_entry: &FdEntry) -> Result<(), host::__wasi_errno_t> {
unimplemented!("fd_datasync")
fn write_at(mut file: &File, buf: &[u8], offset: u64) -> io::Result<usize> {
// get current cursor position
let cur_pos = file.seek(SeekFrom::Current(0))?;
// perform a seek write by a specified offset
let nwritten = file.seek_write(buf, offset)?;
// rewind the cursor back to the original position
file.seek(SeekFrom::Start(cur_pos))?;
Ok(nwritten)
}
pub(crate) fn fd_pread(
fd_entry: &FdEntry,
file: &File,
buf: &mut [u8],
offset: host::__wasi_filesize_t,
) -> Result<usize, host::__wasi_errno_t> {
unimplemented!("fd_pread")
read_at(file, buf, offset)
.map_err(|err| err.raw_os_error().map_or(host::__WASI_EIO, errno_from_host))
}
pub(crate) fn fd_pwrite(
fd_entry: &FdEntry,
file: &File,
buf: &[u8],
offset: host::__wasi_filesize_t,
) -> Result<usize, host::__wasi_errno_t> {
unimplemented!("fd_pwrite")
}
pub(crate) fn fd_read(
fd_entry: &FdEntry,
iovs: &mut [host::__wasi_iovec_t],
) -> Result<usize, host::__wasi_errno_t> {
use winx::io::{readv, IoVecMut};
let mut iovs: Vec<IoVecMut> = iovs
.iter_mut()
.map(|iov| unsafe { host_impl::iovec_to_win_mut(iov) })
.collect();
readv(fd_entry.fd_object.raw_handle, &mut iovs).map_err(|e| host_impl::errno_from_win(e))
write_at(file, buf, offset)
.map_err(|err| err.raw_os_error().map_or(host::__WASI_EIO, errno_from_host))
}
pub(crate) fn fd_renumber(
@@ -72,9 +75,9 @@ pub(crate) fn fd_fdstat_get(
fd_entry: &FdEntry,
) -> Result<host::__wasi_fdflags_t, host::__wasi_errno_t> {
use winx::file::AccessRight;
match winx::file::get_file_access_rights(fd_entry.fd_object.raw_handle)
.map(AccessRight::from_bits_truncate)
{
let raw_handle = fd_entry.fd_object.descriptor.as_raw_handle();
match winx::file::get_file_access_rights(raw_handle).map(AccessRight::from_bits_truncate) {
Ok(rights) => Ok(host_impl::fdflags_from_win(rights)),
Err(e) => Err(host_impl::errno_from_win(e)),
}
@@ -87,24 +90,6 @@ pub(crate) fn fd_fdstat_set_flags(
unimplemented!("fd_fdstat_set_flags")
}
pub(crate) fn fd_sync(fd_entry: &FdEntry) -> Result<(), host::__wasi_errno_t> {
unimplemented!("fd_sync")
}
pub(crate) fn fd_write(
fd_entry: &FdEntry,
iovs: &[host::__wasi_iovec_t],
) -> Result<usize, host::__wasi_errno_t> {
use winx::io::{writev, IoVec};
let iovs: Vec<IoVec> = iovs
.iter()
.map(|iov| unsafe { host_impl::iovec_to_win(iov) })
.collect();
writev(fd_entry.fd_object.raw_handle, &iovs).map_err(|e| host_impl::errno_from_win(e))
}
pub(crate) fn fd_advise(
fd_entry: &FdEntry,
advice: host::__wasi_advice_t,
@@ -114,18 +99,10 @@ pub(crate) fn fd_advise(
unimplemented!("fd_advise")
}
pub(crate) fn fd_allocate(
fd_entry: &FdEntry,
offset: host::__wasi_filesize_t,
len: host::__wasi_filesize_t,
) -> Result<(), host::__wasi_errno_t> {
unimplemented!("fd_allocate")
}
pub(crate) fn path_create_directory(
ctx: &WasiCtx,
dirfd: host::__wasi_fd_t,
path: &OsStr,
path: &RawString,
) -> Result<(), host::__wasi_errno_t> {
unimplemented!("path_create_directory")
}
@@ -134,8 +111,8 @@ pub(crate) fn path_link(
ctx: &WasiCtx,
old_dirfd: host::__wasi_fd_t,
new_dirfd: host::__wasi_fd_t,
old_path: &OsStr,
new_path: &OsStr,
old_path: &RawString,
new_path: &RawString,
source_rights: host::__wasi_rights_t,
target_rights: host::__wasi_rights_t,
) -> Result<(), host::__wasi_errno_t> {
@@ -146,7 +123,7 @@ pub(crate) fn path_open(
ctx: &WasiCtx,
dirfd: host::__wasi_fd_t,
dirflags: host::__wasi_lookupflags_t,
path: &OsStr,
path: &RawString,
oflags: host::__wasi_oflags_t,
read: bool,
write: bool,
@@ -196,23 +173,23 @@ pub(crate) fn path_open(
Err(e) => return Err(e),
};
let new_handle =
match winx::file::openat(dir, &path, win_rights, win_create_disp, win_flags_attrs) {
Ok(handle) => handle,
Err(e) => return Err(host_impl::errno_from_win(e)),
};
let new_handle = match winx::file::openat(
dir.as_raw_handle(),
&path,
win_rights,
win_create_disp,
win_flags_attrs,
) {
Ok(handle) => handle,
Err(e) => return Err(host_impl::errno_from_win(e)),
};
// Determine the type of the new file descriptor and which rights contradict with this type
match unsafe { determine_type_rights(new_handle) } {
Err(e) => {
// if `close` fails, note it but do not override the underlying errno
winx::handle::close(new_handle).unwrap_or_else(|e| {
dbg!(e);
});
Err(e)
}
let file = unsafe { File::from_raw_handle(new_handle) };
match determine_type_rights(&file) {
Err(e) => Err(e),
Ok((_ty, max_base, max_inheriting)) => {
let mut fe = unsafe { FdEntry::from_raw_handle(new_handle) };
let mut fe = FdEntry::from(file)?;
fe.rights_base &= max_base;
fe.rights_inheriting &= max_inheriting;
Ok(fe)
@@ -231,7 +208,7 @@ pub(crate) fn fd_readdir(
pub(crate) fn path_readlink(
wasi_ctx: &WasiCtx,
dirfd: host::__wasi_fd_t,
path: &OsStr,
path: &RawString,
rights: host::__wasi_rights_t,
buf: &mut [u8],
) -> Result<usize, host::__wasi_errno_t> {
@@ -241,10 +218,10 @@ pub(crate) fn path_readlink(
pub(crate) fn path_rename(
wasi_ctx: &WasiCtx,
old_dirfd: host::__wasi_fd_t,
old_path: &OsStr,
old_path: &RawString,
old_rights: host::__wasi_rights_t,
new_dirfd: host::__wasi_fd_t,
new_path: &OsStr,
new_path: &RawString,
new_rights: host::__wasi_rights_t,
) -> Result<(), host::__wasi_errno_t> {
unimplemented!("path_rename")
@@ -276,7 +253,7 @@ pub(crate) fn path_filestat_get(
wasi_ctx: &WasiCtx,
dirfd: host::__wasi_fd_t,
dirflags: host::__wasi_lookupflags_t,
path: &OsStr,
path: &RawString,
) -> Result<host::__wasi_filestat_t, host::__wasi_errno_t> {
unimplemented!("path_filestat_get")
}
@@ -285,7 +262,7 @@ pub(crate) fn path_filestat_set_times(
wasi_ctx: &WasiCtx,
dirfd: host::__wasi_fd_t,
dirflags: host::__wasi_lookupflags_t,
path: &OsStr,
path: &RawString,
rights: host::__wasi_rights_t,
st_atim: host::__wasi_timestamp_t,
mut st_mtim: host::__wasi_timestamp_t,
@@ -298,8 +275,8 @@ pub(crate) fn path_symlink(
wasi_ctx: &WasiCtx,
dirfd: host::__wasi_fd_t,
rights: host::__wasi_rights_t,
old_path: &OsStr,
new_path: &OsStr,
old_path: &RawString,
new_path: &RawString,
) -> Result<(), host::__wasi_errno_t> {
unimplemented!("path_symlink")
}
@@ -307,7 +284,7 @@ pub(crate) fn path_symlink(
pub(crate) fn path_unlink_file(
wasi_ctx: &WasiCtx,
dirfd: host::__wasi_fd_t,
path: &OsStr,
path: &RawString,
rights: host::__wasi_rights_t,
) -> Result<(), host::__wasi_errno_t> {
unimplemented!("path_unlink_file")
@@ -316,7 +293,7 @@ pub(crate) fn path_unlink_file(
pub(crate) fn path_remove_directory(
wasi_ctx: &WasiCtx,
dirfd: host::__wasi_fd_t,
path: &OsStr,
path: &RawString,
rights: host::__wasi_rights_t,
) -> Result<(), host::__wasi_errno_t> {
unimplemented!("path_remove_directory")