progminer zano miner fork https://github.com/hyle-team/progminer

zano/libethash/managed.cpp

@@ -0,0 +1,100 @@
+// ethash: C/C++ implementation of Ethash, the Ethereum Proof of Work algorithm.
+// Copyright 2018 Pawel Bylica.
+// Licensed under the Apache License, Version 2.0. See the LICENSE file.
+
+#include "ethash-internal.hpp"
+
+#include <memory>
+#include <mutex>
+
+#if !defined(__has_cpp_attribute)
+#define __has_cpp_attribute(x) 0
+#endif
+
+#if __has_cpp_attribute(gnu::noinline)
+#define ATTRIBUTE_NOINLINE [[gnu::noinline]]
+#elif _MSC_VER
+#define ATTRIBUTE_NOINLINE __declspec(noinline)
+#else
+#define ATTRIBUTE_NOINLINE
+#endif
+
+namespace ethash
+{
+namespace
+{
+std::mutex shared_context_mutex;
+std::shared_ptr<epoch_context> shared_context;
+thread_local std::shared_ptr<epoch_context> thread_local_context;
+
+std::mutex shared_context_full_mutex;
+std::shared_ptr<epoch_context_full> shared_context_full;
+thread_local std::shared_ptr<epoch_context_full> thread_local_context_full;
+
+/// Update thread local epoch context.
+///
+/// This function is on the slow path. It's separated to allow inlining the fast
+/// path.
+///
+/// @todo: Redesign to guarantee deallocation before new allocation.
+ATTRIBUTE_NOINLINE
+void update_local_context(int epoch_number)
+{
+    // Release the shared pointer of the obsoleted context.
+    thread_local_context.reset();
+
+    // Local context invalid, check the shared context.
+    std::lock_guard<std::mutex> lock{shared_context_mutex};
+
+    if (!shared_context || shared_context->epoch_number != epoch_number)
+    {
+        // Release the shared pointer of the obsoleted context.
+        shared_context.reset();
+
+        // Build new context.
+        shared_context = create_epoch_context(epoch_number);
+    }
+
+    thread_local_context = shared_context;
+}
+
+ATTRIBUTE_NOINLINE
+void update_local_context_full(int epoch_number)
+{
+    // Release the shared pointer of the obsoleted context.
+    thread_local_context_full.reset();
+
+    // Local context invalid, check the shared context.
+    std::lock_guard<std::mutex> lock{shared_context_full_mutex};
+
+    if (!shared_context_full || shared_context_full->epoch_number != epoch_number)
+    {
+        // Release the shared pointer of the obsoleted context.
+        shared_context_full.reset();
+
+        // Build new context.
+        shared_context_full = create_epoch_context_full(epoch_number);
+    }
+
+    thread_local_context_full = shared_context_full;
+}
+}  // namespace
+
+const epoch_context& get_global_epoch_context(int epoch_number)
+{
+    // Check if local context matches epoch number.
+    if (!thread_local_context || thread_local_context->epoch_number != epoch_number)
+        update_local_context(epoch_number);
+
+    return *thread_local_context;
+}
+
+const epoch_context_full& get_global_epoch_context_full(int epoch_number)
+{
+    // Check if local context matches epoch number.
+    if (!thread_local_context_full || thread_local_context_full->epoch_number != epoch_number)
+        update_local_context_full(epoch_number);
+
+    return *thread_local_context_full;
+}
+}  // namespace ethash