1 files changed, 67 insertions, 0 deletions
diff --git a/common/kernel/scope_lock.h b/common/kernel/scope_lock.h
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+++ b/common/kernel/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
+
+#include <stdexcept>
+
+#include "nextpnr_namespaces.h"
+
+NEXTPNR_NAMESPACE_BEGIN
+
+// Provides a simple RAII 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()
+    {
+        if (!locked_) {
+            throw std::runtime_error("Lock already released?");
+        }
+        locked_ = false;
+        obj_->unlock();
+    }
+
+  private:
+    LockingObject *obj_;
+    bool locked_;
+};
+
+NEXTPNR_NAMESPACE_END
+
+#endif /* SCOPE_LOCK_H */