2 files changed, 48 insertions, 1 deletions
diff --git a/src/libstd/sys/windows/mutex.rs b/src/libstd/sys/windows/mutex.rs
index 0847f3b52bf..ca20858bb5b 100644
--- a/src/libstd/sys/windows/mutex.rs
+++ b/src/libstd/sys/windows/mutex.rs
@@ -12,6 +12,7 @@ use prelude::v1::*;
 
 use cell::UnsafeCell;
 use sys::sync as ffi;
+use mem;
 
 pub struct Mutex { inner: UnsafeCell<ffi::SRWLOCK> }
 
@@ -57,3 +58,33 @@ impl Mutex {
         // ...
     }
 }
+
+pub struct ReentrantMutex { inner: Box<UnsafeCell<ffi::CRITICAL_SECTION>> }
+
+unsafe impl Send for ReentrantMutex {}
+unsafe impl Sync for ReentrantMutex {}
+
+impl ReentrantMutex {
+    pub unsafe fn new() -> ReentrantMutex {
+        let mutex = ReentrantMutex { inner: box mem::uninitialized() };
+        ffi::InitializeCriticalSection(mutex.inner.get());
+        mutex
+    }
+
+    pub unsafe fn lock(&self) {
+        ffi::EnterCriticalSection(self.inner.get());
+    }
+
+    #[inline]
+    pub unsafe fn try_lock(&self) -> bool {
+        ffi::TryEnterCriticalSection(self.inner.get()) != 0
+    }
+
+    pub unsafe fn unlock(&self) {
+        ffi::LeaveCriticalSection(self.inner.get());
+    }
+
+    pub unsafe fn destroy(&self) {
+        ffi::DeleteCriticalSection(self.inner.get());
+    }
+}
diff --git a/src/libstd/sys/windows/sync.rs b/src/libstd/sys/windows/sync.rs
index 7614104c98b..5410259540e 100644
--- a/src/libstd/sys/windows/sync.rs
+++ b/src/libstd/sys/windows/sync.rs
@@ -8,17 +8,27 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use libc::{BOOL, DWORD, LPVOID, c_ulong};
+use libc::{BOOL, DWORD, LPVOID, LONG, HANDLE, c_ulong};
 use libc::types::os::arch::extra::BOOLEAN;
 
 pub type PCONDITION_VARIABLE = *mut CONDITION_VARIABLE;
 pub type PSRWLOCK = *mut SRWLOCK;
 pub type ULONG = c_ulong;
+pub type ULONG_PTR = c_ulong;
 
 #[repr(C)]
 pub struct CONDITION_VARIABLE { pub ptr: LPVOID }
 #[repr(C)]
 pub struct SRWLOCK { pub ptr: LPVOID }
+#[repr(C)]
+pub struct CRITICAL_SECTION {
+    CriticalSectionDebug: LPVOID,
+    LockCount: LONG,
+    RecursionCount: LONG,
+    OwningThread: HANDLE,
+    LockSemaphore: HANDLE,
+    SpinCount: ULONG_PTR
+}
 
 pub const CONDITION_VARIABLE_INIT: CONDITION_VARIABLE = CONDITION_VARIABLE {
     ptr: 0 as *mut _,
@@ -41,4 +51,10 @@ extern "system" {
     pub fn ReleaseSRWLockShared(SRWLock: PSRWLOCK);
     pub fn TryAcquireSRWLockExclusive(SRWLock: PSRWLOCK) -> BOOLEAN;
     pub fn TryAcquireSRWLockShared(SRWLock: PSRWLOCK) -> BOOLEAN;
+
+    pub fn InitializeCriticalSection(CriticalSection: *mut CRITICAL_SECTION);
+    pub fn EnterCriticalSection(CriticalSection: *mut CRITICAL_SECTION);
+    pub fn TryEnterCriticalSection(CriticalSection: *mut CRITICAL_SECTION) -> BOOLEAN;
+    pub fn LeaveCriticalSection(CriticalSection: *mut CRITICAL_SECTION);
+    pub fn DeleteCriticalSection(CriticalSection: *mut CRITICAL_SECTION);
 }