Add mmap, shm_open and other mman relatives

Add various wrappers to make interacting with Rust a bit more pleasant
for memory management.

Additionally, provide ftruncate(2), which is useful when working with
shared memory.

Allow managing CPU affinity of a Rust Task living in a system thread.

1 files changed, 10 insertions, 2 deletions

diff --git a/src/unistd.rs b/src/unistd.rs
index e658816b..1c8ed6ab 100644
--- a/src/unistd.rs
+++ b/src/unistd.rs
@@ -1,6 +1,6 @@
 use std::{mem, ptr};
 use std::c_str::{CString, ToCStr};
-use libc::{c_char, c_void, c_int, size_t, pid_t};
+use libc::{c_char, c_void, c_int, size_t, pid_t, off_t};
 use fcntl::{fcntl, Fd, OFlag, O_NONBLOCK, O_CLOEXEC, FD_CLOEXEC, F_SETFD, F_SETFL};
 use errno::{SysResult, SysError, from_ffi};
 use core::raw::Slice as RawSlice;
@@ -11,7 +11,7 @@ pub use self::linux::*;
 mod ffi {
     use super::{IovecR,IovecW};
     use libc::{c_char, c_int, size_t, ssize_t};
-    pub use libc::{close, read, write, pipe};
+    pub use libc::{close, read, write, pipe, ftruncate};
     pub use libc::funcs::posix88::unistd::fork;
     use fcntl::Fd;
 
@@ -393,6 +393,14 @@ fn pipe2_setflags(fd1: Fd, fd2: Fd, flags: OFlag) -> SysResult<()> {
     }
 }
 
+pub fn ftruncate(fd: Fd, len: off_t) -> SysResult<()> {
+    if unsafe { ffi::ftruncate(fd, len) } < 0 {
+        Err(SysError::last())
+    } else {
+        Ok(())
+    }
+}
+
 #[cfg(target_os = "linux")]
 mod linux {
     use std::path::Path;