refactor: remove dependency on lazy_static

This was only used in `src/sys/windows/afd.rs` for a set of objects that
could instead be defined using constant expressions.

Cargo.toml

@@ -41,7 +41,6 @@ libc = "0.2.69"
 miow   = "0.3.3"
 winapi = { version = "0.3", features = ["winsock2", "mswsock"] }
 ntapi  = "0.3"
-lazy_static = "1.4.0"
 
 [dev-dependencies]
 env_logger = { version = "0.6.2", default-features = false }

src/sys/windows/afd.rs

@@ -1,55 +1,19 @@
-use lazy_static::lazy_static;
 use ntapi::ntioapi::{IO_STATUS_BLOCK_u, IO_STATUS_BLOCK};
 use ntapi::ntioapi::{NtCancelIoFileEx, NtDeviceIoControlFile};
 use ntapi::ntrtl::RtlNtStatusToDosError;
-use std::ffi::OsStr;
 use std::fmt;
 use std::fs::File;
 use std::io;
 use std::mem::size_of;
-use std::os::windows::ffi::OsStrExt;
 use std::os::windows::io::AsRawHandle;
 use std::ptr::null_mut;
 use winapi::shared::ntdef::{
-    HANDLE, LARGE_INTEGER, NTSTATUS, OBJECT_ATTRIBUTES, PVOID, ULONG, UNICODE_STRING,
+    HANDLE, LARGE_INTEGER, NTSTATUS, PVOID, ULONG,
 };
 use winapi::shared::ntstatus::{STATUS_NOT_FOUND, STATUS_PENDING, STATUS_SUCCESS};
 
 const IOCTL_AFD_POLL: ULONG = 0x00012024;
 
-lazy_static! {
-    static ref AFD_HELPER_NAME: Vec<u16> = {
-        OsStr::new("\\Device\\Afd\\Mio")
-            .encode_wide()
-            .collect::<Vec<_>>()
-    };
-}
-
-struct UnicodeString(UNICODE_STRING);
-unsafe impl Send for UnicodeString {}
-unsafe impl Sync for UnicodeString {}
-
-struct ObjectAttributes(OBJECT_ATTRIBUTES);
-unsafe impl Send for ObjectAttributes {}
-unsafe impl Sync for ObjectAttributes {}
-
-lazy_static! {
-    static ref AFD_OBJ_NAME: UnicodeString = UnicodeString(UNICODE_STRING {
-        // Lengths are calced in bytes
-        Length: (AFD_HELPER_NAME.len() * 2) as u16,
-        MaximumLength: (AFD_HELPER_NAME.len() * 2) as u16,
-        Buffer: AFD_HELPER_NAME.as_ptr() as *mut _,
-    });
-    static ref AFD_HELPER_ATTRIBUTES: ObjectAttributes = ObjectAttributes(OBJECT_ATTRIBUTES {
-        Length: size_of::<OBJECT_ATTRIBUTES>() as ULONG,
-        RootDirectory: null_mut() as HANDLE,
-        ObjectName: &AFD_OBJ_NAME.0 as *const _ as *mut _,
-        Attributes: 0 as ULONG,
-        SecurityDescriptor: null_mut() as PVOID,
-        SecurityQualityOfService: null_mut() as PVOID,
-    });
-}
-
 /// Winsock2 AFD driver instance.
 ///
 /// All operations are unsafe due to IO_STATUS_BLOCK parameter are being used by Afd driver during STATUS_PENDING before I/O Completion Port returns its result.
@@ -156,11 +120,45 @@ cfg_net! {
     use std::mem::zeroed;
     use std::os::windows::io::{FromRawHandle, RawHandle};
     use std::sync::atomic::{AtomicUsize, Ordering};
+    use winapi::shared::ntdef::{OBJECT_ATTRIBUTES, UNICODE_STRING, USHORT, WCHAR};
     use winapi::um::handleapi::INVALID_HANDLE_VALUE;
     use winapi::um::winbase::{SetFileCompletionNotificationModes, FILE_SKIP_SET_EVENT_ON_HANDLE};
     use winapi::um::winnt::SYNCHRONIZE;
     use winapi::um::winnt::{FILE_SHARE_READ, FILE_SHARE_WRITE};
 
+    const AFD_HELPER_ATTRIBUTES: OBJECT_ATTRIBUTES = OBJECT_ATTRIBUTES {
+        Length: size_of::<OBJECT_ATTRIBUTES>() as ULONG,
+        RootDirectory: null_mut(),
+        ObjectName: &AFD_OBJ_NAME as *const _ as *mut _,
+        Attributes: 0,
+        SecurityDescriptor: null_mut(),
+        SecurityQualityOfService: null_mut(),
+    };
+
+    const AFD_OBJ_NAME: UNICODE_STRING = UNICODE_STRING {
+        Length: (AFD_HELPER_NAME.len() * size_of::<WCHAR>()) as USHORT,
+        MaximumLength: (AFD_HELPER_NAME.len() * size_of::<WCHAR>()) as USHORT,
+        Buffer: AFD_HELPER_NAME.as_ptr() as *mut _,
+    };
+
+    const AFD_HELPER_NAME: &[WCHAR] = &[
+        '\\' as _,
+        'D' as _,
+        'e' as _,
+        'v' as _,
+        'i' as _,
+        'c' as _,
+        'e' as _,
+        '\\' as _,
+        'A' as _,
+        'f' as _,
+        'd' as _,
+        '\\' as _,
+        'M' as _,
+        'i' as _,
+        'o' as _
+    ];
+
     static NEXT_TOKEN: AtomicUsize = AtomicUsize::new(0);
 
     impl AfdPollInfo {
@@ -182,7 +180,7 @@ cfg_net! {
                 let status = NtCreateFile(
                     &mut afd_helper_handle as *mut _,
                     SYNCHRONIZE,
-                    &AFD_HELPER_ATTRIBUTES.0 as *const _ as *mut _,
+                    &AFD_HELPER_ATTRIBUTES as *const _ as *mut _,
                     &mut iosb,
                     null_mut(),
                     0 as ULONG,