1 files changed, 77 insertions, 0 deletions
diff --git a/library/std/src/sys/hermit/mutex.rs b/library/std/src/sys/hermit/mutex.rs
new file mode 100644
index 00000000000..3d4813209cb
--- /dev/null
+++ b/library/std/src/sys/hermit/mutex.rs
@@ -0,0 +1,77 @@
+use crate::ffi::c_void;
+use crate::ptr;
+use crate::sys::hermit::abi;
+
+pub struct Mutex {
+    inner: *const c_void,
+}
+
+unsafe impl Send for Mutex {}
+unsafe impl Sync for Mutex {}
+
+impl Mutex {
+    pub const fn new() -> Mutex {
+        Mutex { inner: ptr::null() }
+    }
+
+    #[inline]
+    pub unsafe fn init(&mut self) {
+        let _ = abi::sem_init(&mut self.inner as *mut *const c_void, 1);
+    }
+
+    #[inline]
+    pub unsafe fn lock(&self) {
+        let _ = abi::sem_timedwait(self.inner, 0);
+    }
+
+    #[inline]
+    pub unsafe fn unlock(&self) {
+        let _ = abi::sem_post(self.inner);
+    }
+
+    #[inline]
+    pub unsafe fn try_lock(&self) -> bool {
+        let result = abi::sem_trywait(self.inner);
+        result == 0
+    }
+
+    #[inline]
+    pub unsafe fn destroy(&self) {
+        let _ = abi::sem_destroy(self.inner);
+    }
+}
+
+pub struct ReentrantMutex {
+    inner: *const c_void,
+}
+
+impl ReentrantMutex {
+    pub const unsafe fn uninitialized() -> ReentrantMutex {
+        ReentrantMutex { inner: ptr::null() }
+    }
+
+    #[inline]
+    pub unsafe fn init(&self) {
+        let _ = abi::recmutex_init(&self.inner as *const *const c_void as *mut _);
+    }
+
+    #[inline]
+    pub unsafe fn lock(&self) {
+        let _ = abi::recmutex_lock(self.inner);
+    }
+
+    #[inline]
+    pub unsafe fn try_lock(&self) -> bool {
+        true
+    }
+
+    #[inline]
+    pub unsafe fn unlock(&self) {
+        let _ = abi::recmutex_unlock(self.inner);
+    }
+
+    #[inline]
+    pub unsafe fn destroy(&self) {
+        let _ = abi::recmutex_destroy(self.inner);
+    }
+}