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Remove wrapper functions from c.rs
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@ChrisDenton
ChrisDenton committed Jul 23, 2024
1 parent 7ae76f0 commit 642c69b
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Showing 3 changed files with 43 additions and 126 deletions.
108 changes: 12 additions & 96 deletions std/src/sys/pal/windows/c.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -9,7 +9,6 @@
use crate::ffi::CStr;
use crate::mem;
use crate::os::raw::{c_uint, c_ulong, c_ushort, c_void};
use crate::os::windows::io::{AsRawHandle, BorrowedHandle};
use crate::ptr;

pub(super) mod windows_targets;
Expand Down Expand Up @@ -114,89 +113,6 @@ if #[cfg(not(target_vendor = "uwp"))] {
}
}

pub unsafe extern "system" fn WriteFileEx(
hFile: BorrowedHandle<'_>,
lpBuffer: *mut ::core::ffi::c_void,
nNumberOfBytesToWrite: u32,
lpOverlapped: *mut OVERLAPPED,
lpCompletionRoutine: LPOVERLAPPED_COMPLETION_ROUTINE,
) -> BOOL {
windows_sys::WriteFileEx(
hFile.as_raw_handle(),
lpBuffer.cast::<u8>(),
nNumberOfBytesToWrite,
lpOverlapped,
lpCompletionRoutine,
)
}

pub unsafe extern "system" fn ReadFileEx(
hFile: BorrowedHandle<'_>,
lpBuffer: *mut ::core::ffi::c_void,
nNumberOfBytesToRead: u32,
lpOverlapped: *mut OVERLAPPED,
lpCompletionRoutine: LPOVERLAPPED_COMPLETION_ROUTINE,
) -> BOOL {
windows_sys::ReadFileEx(
hFile.as_raw_handle(),
lpBuffer.cast::<u8>(),
nNumberOfBytesToRead,
lpOverlapped,
lpCompletionRoutine,
)
}

cfg_if::cfg_if! {
if #[cfg(not(target_vendor = "uwp"))] {
pub unsafe fn NtReadFile(
filehandle: BorrowedHandle<'_>,
event: HANDLE,
apcroutine: PIO_APC_ROUTINE,
apccontext: *mut c_void,
iostatusblock: &mut IO_STATUS_BLOCK,
buffer: *mut crate::mem::MaybeUninit<u8>,
length: u32,
byteoffset: Option<&i64>,
key: Option<&u32>,
) -> NTSTATUS {
windows_sys::NtReadFile(
filehandle.as_raw_handle(),
event,
apcroutine,
apccontext,
iostatusblock,
buffer.cast::<c_void>(),
length,
byteoffset.map(|o| o as *const i64).unwrap_or(ptr::null()),
key.map(|k| k as *const u32).unwrap_or(ptr::null()),
)
}
pub unsafe fn NtWriteFile(
filehandle: BorrowedHandle<'_>,
event: HANDLE,
apcroutine: PIO_APC_ROUTINE,
apccontext: *mut c_void,
iostatusblock: &mut IO_STATUS_BLOCK,
buffer: *const u8,
length: u32,
byteoffset: Option<&i64>,
key: Option<&u32>,
) -> NTSTATUS {
windows_sys::NtWriteFile(
filehandle.as_raw_handle(),
event,
apcroutine,
apccontext,
iostatusblock,
buffer.cast::<c_void>(),
length,
byteoffset.map(|o| o as *const i64).unwrap_or(ptr::null()),
key.map(|k| k as *const u32).unwrap_or(ptr::null()),
)
}
}
}

// Use raw-dylib to import ProcessPrng as we can't rely on there being an import library.
cfg_if::cfg_if! {
if #[cfg(not(target_vendor = "win7"))] {
Expand Down Expand Up @@ -331,29 +247,29 @@ compat_fn_with_fallback! {
}
#[cfg(target_vendor = "uwp")]
pub fn NtReadFile(
filehandle: BorrowedHandle<'_>,
filehandle: HANDLE,
event: HANDLE,
apcroutine: PIO_APC_ROUTINE,
apccontext: *mut c_void,
iostatusblock: &mut IO_STATUS_BLOCK,
buffer: *mut crate::mem::MaybeUninit<u8>,
apccontext: *const core::ffi::c_void,
iostatusblock: *mut IO_STATUS_BLOCK,
buffer: *mut core::ffi::c_void,
length: u32,
byteoffset: Option<&i64>,
key: Option<&u32>
byteoffset: *const i64,
key: *const u32
) -> NTSTATUS {
STATUS_NOT_IMPLEMENTED
}
#[cfg(target_vendor = "uwp")]
pub fn NtWriteFile(
filehandle: BorrowedHandle<'_>,
filehandle: HANDLE,
event: HANDLE,
apcroutine: PIO_APC_ROUTINE,
apccontext: *mut c_void,
iostatusblock: &mut IO_STATUS_BLOCK,
buffer: *const u8,
apccontext: *const core::ffi::c_void,
iostatusblock: *mut IO_STATUS_BLOCK,
buffer: *const core::ffi::c_void,
length: u32,
byteoffset: Option<&i64>,
key: Option<&u32>
byteoffset: *const i64,
key: *const u32
) -> NTSTATUS {
STATUS_NOT_IMPLEMENTED
}
Expand Down
16 changes: 8 additions & 8 deletions std/src/sys/pal/windows/handle.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -243,15 +243,15 @@ impl Handle {
// the provided `len`.
let status = unsafe {
c::NtReadFile(
self.as_handle(),
self.as_raw_handle(),
ptr::null_mut(),
None,
ptr::null_mut(),
&mut io_status,
buf,
buf.cast::<core::ffi::c_void>(),
len,
offset.map(|n| n as _).as_ref(),
None,
offset.as_ref().map(|n| ptr::from_ref(n).cast::<i64>()).unwrap_or(ptr::null()),
ptr::null(),
)
};

Expand Down Expand Up @@ -293,15 +293,15 @@ impl Handle {
let len = cmp::min(buf.len(), u32::MAX as usize) as u32;
let status = unsafe {
c::NtWriteFile(
self.as_handle(),
self.as_raw_handle(),
ptr::null_mut(),
None,
ptr::null_mut(),
&mut io_status,
buf.as_ptr(),
buf.as_ptr().cast::<core::ffi::c_void>(),
len,
offset.map(|n| n as _).as_ref(),
None,
offset.as_ref().map(|n| ptr::from_ref(n).cast::<i64>()).unwrap_or(ptr::null()),
ptr::null(),
)
};
let status = if status == c::STATUS_PENDING {
Expand Down
45 changes: 23 additions & 22 deletions std/src/sys/pal/windows/pipe.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -221,15 +221,6 @@ fn random_number() -> usize {
}
}

// Abstracts over `ReadFileEx` and `WriteFileEx`
type AlertableIoFn = unsafe extern "system" fn(
BorrowedHandle<'_>,
*mut core::ffi::c_void,
u32,
*mut c::OVERLAPPED,
c::LPOVERLAPPED_COMPLETION_ROUTINE,
) -> c::BOOL;

impl AnonPipe {
pub fn handle(&self) -> &Handle {
&self.inner
Expand All @@ -244,7 +235,10 @@ impl AnonPipe {
pub fn read(&self, buf: &mut [u8]) -> io::Result<usize> {
let result = unsafe {
let len = crate::cmp::min(buf.len(), u32::MAX as usize) as u32;
self.alertable_io_internal(c::ReadFileEx, buf.as_mut_ptr() as _, len)
let ptr = buf.as_mut_ptr();
self.alertable_io_internal(|overlapped, callback| {
c::ReadFileEx(self.inner.as_raw_handle(), ptr, len, overlapped, callback)
})
};

match result {
Expand All @@ -260,7 +254,10 @@ impl AnonPipe {
pub fn read_buf(&self, mut buf: BorrowedCursor<'_>) -> io::Result<()> {
let result = unsafe {
let len = crate::cmp::min(buf.capacity(), u32::MAX as usize) as u32;
self.alertable_io_internal(c::ReadFileEx, buf.as_mut().as_mut_ptr() as _, len)
let ptr = buf.as_mut().as_mut_ptr().cast::<u8>();
self.alertable_io_internal(|overlapped, callback| {
c::ReadFileEx(self.inner.as_raw_handle(), ptr, len, overlapped, callback)
})
};

match result {
Expand Down Expand Up @@ -295,7 +292,9 @@ impl AnonPipe {
pub fn write(&self, buf: &[u8]) -> io::Result<usize> {
unsafe {
let len = crate::cmp::min(buf.len(), u32::MAX as usize) as u32;
self.alertable_io_internal(c::WriteFileEx, buf.as_ptr() as _, len)
self.alertable_io_internal(|overlapped, callback| {
c::WriteFileEx(self.inner.as_raw_handle(), buf.as_ptr(), len, overlapped, callback)
})
}
}

Expand Down Expand Up @@ -323,12 +322,9 @@ impl AnonPipe {
/// [`ReadFileEx`]: https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-readfileex
/// [`WriteFileEx`]: https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-writefileex
/// [Asynchronous Procedure Call]: https://docs.microsoft.com/en-us/windows/win32/sync/asynchronous-procedure-calls
#[allow(unsafe_op_in_unsafe_fn)]
unsafe fn alertable_io_internal(
&self,
io: AlertableIoFn,
buf: *mut core::ffi::c_void,
len: u32,
io: impl FnOnce(&mut c::OVERLAPPED, c::LPOVERLAPPED_COMPLETION_ROUTINE) -> c::BOOL,
) -> io::Result<usize> {
// Use "alertable I/O" to synchronize the pipe I/O.
// This has four steps.
Expand Down Expand Up @@ -366,20 +362,25 @@ impl AnonPipe {
lpOverlapped: *mut c::OVERLAPPED,
) {
// Set `async_result` using a pointer smuggled through `hEvent`.
let result =
AsyncResult { error: dwErrorCode, transferred: dwNumberOfBytesTransferred };
*(*lpOverlapped).hEvent.cast::<Option<AsyncResult>>() = Some(result);
// SAFETY:
// At this point, the OVERLAPPED struct will have been written to by the OS,
// except for our `hEvent` field which we set to a valid AsyncResult pointer (see below)
unsafe {
let result =
AsyncResult { error: dwErrorCode, transferred: dwNumberOfBytesTransferred };
*(*lpOverlapped).hEvent.cast::<Option<AsyncResult>>() = Some(result);
}
}

// STEP 1: Start the I/O operation.
let mut overlapped: c::OVERLAPPED = crate::mem::zeroed();
let mut overlapped: c::OVERLAPPED = unsafe { crate::mem::zeroed() };
// `hEvent` is unused by `ReadFileEx` and `WriteFileEx`.
// Therefore the documentation suggests using it to smuggle a pointer to the callback.
overlapped.hEvent = core::ptr::addr_of_mut!(async_result) as *mut _;

// Asynchronous read of the pipe.
// If successful, `callback` will be called once it completes.
let result = io(self.inner.as_handle(), buf, len, &mut overlapped, Some(callback));
let result = io(&mut overlapped, Some(callback));
if result == c::FALSE {
// We can return here because the call failed.
// After this we must not return until the I/O completes.
Expand All @@ -390,7 +391,7 @@ impl AnonPipe {
let result = loop {
// STEP 2: Enter an alertable state.
// The second parameter of `SleepEx` is used to make this sleep alertable.
c::SleepEx(c::INFINITE, c::TRUE);
unsafe { c::SleepEx(c::INFINITE, c::TRUE) };
if let Some(result) = async_result {
break result;
}
Expand Down

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