refactor: add kernel/cs_main.*

Co-authored-by: Anthony Towns <aj@erisian.com.au>

2 files changed, 29 insertions, 0 deletions

diff --git a/src/kernel/cs_main.cpp b/src/kernel/cs_main.cpp
new file mode 100644
index 0000000000..c3a08c9695
--- /dev/null
+++ b/src/kernel/cs_main.cpp
@@ -0,0 +1,7 @@
+// Copyright (c) 2023 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <sync.h>
+
+RecursiveMutex cs_main;
diff --git a/src/kernel/cs_main.h b/src/kernel/cs_main.h
new file mode 100644
index 0000000000..8d03903b8e
--- /dev/null
+++ b/src/kernel/cs_main.h
@@ -0,0 +1,22 @@
+// Copyright (c) 2023 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_KERNEL_CS_MAIN_H
+#define BITCOIN_KERNEL_CS_MAIN_H
+
+#include <sync.h>
+
+/**
+ * Mutex to guard access to validation specific variables, such as reading
+ * or changing the chainstate.
+ *
+ * This may also need to be locked when updating the transaction pool, e.g. on
+ * AcceptToMemoryPool. See CTxMemPool::cs comment for details.
+ *
+ * The transaction pool has a separate lock to allow reading from it and the
+ * chainstate at the same time.
+ */
+extern RecursiveMutex cs_main;
+
+#endif // BITCOIN_KERNEL_CS_MAIN_H