commit 4dd7fe90a2b541a44aafc3a9596445387a3aed49 (tree)
parent 3320e6a1ae453d40dd78ff3abf6c8543bec2555d
Author: Andrew Kelley <andrew@ziglang.org>
Date: Wed, 28 Jan 2026 21:02:43 -0800
std.Io.Threaded: compress ntReadFile logic
Just use the ntstatus field rather than an additional enum
Diffstat:
1 file changed, 61 insertions(+), 76 deletions(-)
diff --git a/lib/std/Io/Threaded.zig b/lib/std/Io/Threaded.zig
@@ -2695,7 +2695,10 @@ fn batchWaitWindows(t: *Threaded, b: *Io.Batch, timeout: Io.Timeout) Io.Batch.Wa
const op = ring[submit_head.index(len)];
const operation = &operations[op];
const metadata = &metadatas[op];
- metadata.* = .{ .iosb = undefined, .pending = false };
+ metadata.* = .{ .iosb = .{
+ .u = .{ .Status = .PENDING },
+ .Information = 0,
+ }, .pending = false };
switch (operation.*) {
.noop => |*o| {
_ = o.status.unstarted;
@@ -2704,15 +2707,13 @@ fn batchWaitWindows(t: *Threaded, b: *Io.Batch, timeout: Io.Timeout) Io.Batch.Wa
},
.file_read_streaming => |*o| {
_ = o.status.unstarted;
- switch (try ntReadFile(o.file.handle, o.data, &metadata.iosb)) {
- .status => {
- o.status = .{ .result = ntReadFileResult(&metadata.iosb) };
- submitComplete(ring, &complete_tail, op);
- },
- .pending => {
- o.status = .{ .pending = b };
- metadata.pending = true;
- },
+ try ntReadFile(o.file.handle, o.data, &metadata.iosb);
+ if (@atomicLoad(windows.NTSTATUS, &metadata.iosb.u.Status, .acquire) == .PENDING) {
+ o.status = .{ .pending = b };
+ metadata.pending = true;
+ } else {
+ o.status = .{ .result = ntReadFileResult(&metadata.iosb) };
+ submitComplete(ring, &complete_tail, op);
}
},
}
@@ -8680,44 +8681,36 @@ fn fileReadStreamingPosix(file: File, data: []const []u8) File.ReadStreamingErro
}
fn fileReadStreamingWindows(file: File, data: []const []u8) File.ReadStreamingError!usize {
- var io_status_block: windows.IO_STATUS_BLOCK = undefined;
- if (ntReadFile(file.handle, data, &io_status_block)) |result| switch (result) {
- .status => return ntReadFileResult(&io_status_block),
- .pending => {
- // Once we get here we received PENDING so we must not return from the
- // function until the operation completes.
- defer while (@atomicLoad(windows.NTSTATUS, &io_status_block.u.Status, .acquire) == .PENDING) {
- waitForApcOrAlert();
- };
-
- const alertable_syscall = AlertableSyscall.start() catch |err| switch (err) {
- error.Canceled => |e| {
- _ = windows.ntdll.NtCancelIoFile(file.handle, &io_status_block);
- return e;
- },
- };
- waitForApcOrAlert();
- while (@atomicLoad(windows.NTSTATUS, &io_status_block.u.Status, .acquire) == .PENDING) {
- alertable_syscall.checkCancel() catch |err| switch (err) {
- error.Canceled => |e| {
- _ = windows.ntdll.NtCancelIoFile(file.handle, &io_status_block);
- return e;
- },
- };
- waitForApcOrAlert();
- }
- alertable_syscall.finish();
- },
- } else |err| return err;
+ var io_status_block: windows.IO_STATUS_BLOCK = .{
+ .u = .{ .Status = .PENDING },
+ .Information = 0,
+ };
+ try ntReadFile(file.handle, data, &io_status_block);
+ while (@atomicLoad(windows.NTSTATUS, &io_status_block.u.Status, .acquire) == .PENDING) {
+ // Once we get here we must not return from the function until the
+ // operation completes, thereby releasing reference to io_status_block.
+ const alertable_syscall = AlertableSyscall.start() catch |err| switch (err) {
+ error.Canceled => |e| {
+ _ = windows.ntdll.NtCancelIoFile(file.handle, &io_status_block);
+ while (@atomicLoad(windows.NTSTATUS, &io_status_block.u.Status, .acquire) == .PENDING) {
+ waitForApcOrAlert();
+ }
+ return e;
+ },
+ };
+ waitForApcOrAlert();
+ alertable_syscall.finish();
+ }
return ntReadFileResult(&io_status_block);
}
-fn ntReadFileResult(io_status_block: *windows.IO_STATUS_BLOCK) !usize {
+fn ntReadFileResult(io_status_block: *const windows.IO_STATUS_BLOCK) !usize {
switch (io_status_block.u.Status) {
+ .PENDING => unreachable,
+ .CANCELLED => unreachable,
.SUCCESS => return io_status_block.Information,
.END_OF_FILE => return error.EndOfStream,
.PIPE_BROKEN => return error.EndOfStream,
- .PENDING => unreachable,
.INVALID_DEVICE_REQUEST => return error.IsDir,
.LOCK_NOT_GRANTED => return error.LockViolation,
.ACCESS_DENIED => return error.AccessDenied,
@@ -8725,50 +8718,42 @@ fn ntReadFileResult(io_status_block: *windows.IO_STATUS_BLOCK) !usize {
}
}
-fn ntReadFile(handle: windows.HANDLE, data: []const []u8, iosb: *windows.IO_STATUS_BLOCK) Io.Cancelable!enum { status, pending } {
+fn ntReadFile(handle: windows.HANDLE, data: []const []u8, iosb: *windows.IO_STATUS_BLOCK) Io.Cancelable!void {
var index: usize = 0;
while (index < data.len and data[index].len == 0) index += 1;
if (index == data.len) {
iosb.u.Status = .SUCCESS;
iosb.Information = 0;
- return .status;
+ return;
}
const buffer = data[index];
const syscall: Syscall = try .start();
- while (true) {
- iosb.u.Status = .PENDING;
- switch (windows.ntdll.NtReadFile(
- handle,
- null, // event
- noopApc, // apc callback
- null, // apc context
- iosb,
- buffer.ptr,
- @min(std.math.maxInt(u32), buffer.len),
- null, // byte offset
- null, // key
- )) {
- .PENDING => {
- syscall.finish();
- return .pending;
- },
- .SUCCESS => {
- syscall.finish();
- iosb.u.Status = .SUCCESS;
- return .status;
- },
- .CANCELLED => {
- try syscall.checkCancel();
- continue;
- },
- else => |status| {
- syscall.finish();
- iosb.u.Status = status;
- return .status;
- },
- }
- }
+ while (true) switch (windows.ntdll.NtReadFile(
+ handle,
+ null, // event
+ noopApc, // apc callback
+ null, // apc context
+ iosb,
+ buffer.ptr,
+ @min(std.math.maxInt(u32), buffer.len),
+ null, // byte offset
+ null, // key
+ )) {
+ .PENDING => {
+ syscall.finish();
+ return;
+ },
+ .CANCELLED => {
+ try syscall.checkCancel();
+ continue;
+ },
+ else => |status| {
+ syscall.finish();
+ iosb.u.Status = status;
+ return;
+ },
+ };
}
fn fileReadPositionalPosix(file: File, data: []const []u8, offset: u64) File.ReadPositionalError!usize {
