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diff --git a/common/scope_lock.h b/common/scope_lock.h
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+++ b/common/scope_lock.h
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+/*
+ *  nextpnr -- Next Generation Place and Route
+ *
+ *  Copyright (C) 2021 Symbiflow Authors.
+ *
+ *  Permission to use, copy, modify, and/or distribute this software for any
+ *  purpose with or without fee is hereby granted, provided that the above
+ *  copyright notice and this permission notice appear in all copies.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#ifndef SCOPE_LOCK_H
+#define SCOPE_LOCK_H
+
+namespace nextpnr {
+
+// Provides a simple RIAA locking object.  ScopeLock takes a lock when
+// constructed, and releases the lock on destruction or if "unlock_early" is
+// called.
+//
+// LockingObject must have a method "void lock(void)" and "void unlock(void)".
+template<typename LockingObject>
+class ScopeLock {
+public:
+    ScopeLock(LockingObject * obj) : obj_(obj), locked_(false) {
+        obj_->lock();
+        locked_ = true;
+    }
+    ScopeLock(const ScopeLock &other) = delete;
+    ScopeLock(const ScopeLock &&other) = delete;
+
+    ~ScopeLock() {
+        if(locked_) {
+            obj_->unlock();
+        }
+    }
+    void unlock_early() {
+        locked_ = false;
+        obj_->unlock();
+    }
+private:
+    LockingObject *obj_;
+    bool locked_;
+};
+
+};
+
+#endif /* SCOPE_LOCK_H */