Add a Mutex implementation.

rust/lib/mammoth/src/syscall.rs

@@ -412,6 +412,36 @@ pub fn reply_port_recv(
     Ok((num_bytes, num_caps))
 }
 
+pub fn mutex_create() -> Result<Capability, ZError> {
+    let mut mutex_cap: z_cap_t = 0;
+    syscall(
+        zion::kZionMutexCreate,
+        &zion::ZMutexCreateReq {
+            mutex_cap: &mut mutex_cap,
+        },
+    )?;
+
+    Ok(Capability::take(mutex_cap))
+}
+
+pub fn mutex_lock(mutex_cap: &Capability) -> Result<(), ZError> {
+    syscall(
+        zion::kZionMutexLock,
+        &zion::ZMutexLockReq {
+            mutex_cap: mutex_cap.raw(),
+        },
+    )
+}
+
+pub fn mutex_release(mutex_cap: &Capability) -> Result<(), ZError> {
+    syscall(
+        zion::kZionMutexRelease,
+        &zion::ZMutexReleaseReq {
+            mutex_cap: mutex_cap.raw(),
+        },
+    )
+}
+
 pub fn semaphore_create() -> Result<Capability, ZError> {
     let mut sem_cap: z_cap_t = 0;
     syscall(