Abstract out mutex type. Make threads optional.

1 files changed, 61 insertions, 0 deletions

diff --git a/src/lib/utils/mutex.h b/src/lib/utils/mutex.h
new file mode 100644
index 000000000..0daea3148
--- /dev/null
+++ b/src/lib/utils/mutex.h
@@ -0,0 +1,61 @@
+/*
+* (C) 2016 Jack Lloyd
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#ifndef BOTAN_UTIL_MUTEX_H__
+#define BOTAN_UTIL_MUTEX_H__
+
+#include <botan/build.h>
+#include <botan/types.h>
+
+#if defined(BOTAN_TARGET_OS_HAS_THREADS)
+
+#include <mutex>
+
+namespace Botan {
+
+template<typename T> using lock_guard_type = std::lock_guard<T>;
+typedef std::mutex mutex_type;
+
+}
+
+#elif defined(BOTAN_TARGET_OS_TYPE_IS_UNIKERNEL)
+
+// No threads
+
+namespace Botan {
+
+template<typename Mutex>
+class lock_guard
+   {
+   public:
+      explicit lock_guard(Mutex& m) : m_mutex(m)
+         { m_mutex.lock(); }
+
+      ~lock_guard() { m_mutex.unlock(); }
+
+      lock_guard(const lock_guard& other) = delete;
+      lock_guard& operator=(const lock_guard& other) = delete;
+   private:
+      Mutex& m_mutex;
+   };
+
+class noop_mutex
+   {
+   public:
+      void lock() {}
+      void unlock() {}
+   };
+
+typedef noop_mutex mutex_type;
+template<typename T> using lock_guard_type = lock_guard<T>;
+
+}
+
+#else
+  #error "Threads unexpectedly disabled in non unikernel build"
+#endif
+
+#endif