Implemented flock for vxworks using ioctl

Author: Jesse Hoogervorst

src/lib.rs

@@ -19,6 +19,7 @@
 )]
 #![cfg_attr(libc_deny_warnings, deny(warnings))]
 // Attributes needed when building as part of the standard library
+#![allow(internal_features)]
 #![cfg_attr(feature = "rustc-dep-of-std", feature(link_cfg, no_core))]
 // Enable extra lints:
 #![cfg_attr(feature = "extra_traits", deny(missing_debug_implementations))]

src/vxworks/mod.rs

@@ -412,6 +412,15 @@ s! {
         pub mq_flags:   ::c_long,
         pub mq_curmsgs: ::c_long,
     }
+
+    pub struct FLock {
+        l_type: ::c_short,
+        l_whence: ::c_short,
+        l_start: ::c_long,
+        l_len: ::c_long,
+        l_pid: ::c_short,
+        l_xxx: ::c_short,
+    }
 }
 
 s_no_extra_traits! {
@@ -2013,6 +2022,44 @@ pub unsafe fn posix_memalign(
     }
 }
 
+pub const LOCK_SH: ::c_int = 1;
+pub const LOCK_EX: ::c_int = 2;
+pub const LOCK_NB: ::c_int = 4;
+pub const LOCK_UN: ::c_int = 8;
+
+pub const F_RDLCK: ::c_int = 1;
+pub const F_WRLCK: ::c_int = 2;
+pub const F_UNLCK: ::c_int = 3;
+
+pub unsafe fn flock(fd: ::c_int, operation: ::c_int) -> ::c_int {
+    let lock_type = match operation & !LOCK_NB {
+        LOCK_SH => F_RDLCK,
+        LOCK_EX => F_WRLCK,
+        LOCK_UN => F_UNLCK,
+        _ => {
+            errnoSet(EINVAL);
+            return ERROR;
+        }
+    };
+
+    let request = if operation & LOCK_NB != 0 {
+        F_SETLK
+    } else {
+        F_SETLKW
+    };
+
+    let mut argument = FLock {
+        l_type: lock_type as i16,
+        l_whence: SEEK_SET as i16,
+        l_start: 0,
+        l_len: 0,
+        l_pid: 0,
+        l_xxx: 0,
+    };
+
+    return ioctl(fd, request, core::ptr::addr_of_mut!(argument));
+}
+
 pub use ffi::c_void;
 
 cfg_if! {