1 files changed, 45 insertions, 0 deletions
diff --git a/cmake/dependencies/system/liburcu.cmake b/cmake/dependencies/system/liburcu.cmake
new file mode 100644
index 00000000..89a7ab12
--- /dev/null
+++ b/cmake/dependencies/system/liburcu.cmake
@@ -0,0 +1,45 @@
+# Userspace RCU (liburcu) - optional. Enables lock-free data-plane key
+# rotation; absent => per-flow rwlock fallback. The "bulletproof" flavour
+# (urcu-bp) auto-registers reader threads, so application threads need no
+# RCU lifecycle plumbing.
+if(PkgConfig_FOUND)
+  pkg_check_modules(URCU_PKG QUIET IMPORTED_TARGET liburcu-bp)
+  if(URCU_PKG_FOUND AND NOT TARGET Urcu::Urcu)
+    add_library(Urcu::Urcu ALIAS PkgConfig::URCU_PKG)
+  endif()
+endif()
+
+if(NOT URCU_PKG_FOUND)
+  find_library(URCU_BP_LIBRARY urcu-bp QUIET)
+  find_library(URCU_COMMON_LIBRARY urcu-common QUIET)
+  find_path(URCU_INCLUDE_DIR urcu-bp.h QUIET)
+  if(URCU_BP_LIBRARY AND URCU_COMMON_LIBRARY AND URCU_INCLUDE_DIR)
+    set(URCU_PKG_FOUND TRUE)
+    if(NOT TARGET Urcu::Urcu)
+      add_library(Urcu::Urcu INTERFACE IMPORTED)
+      set_target_properties(Urcu::Urcu PROPERTIES
+        INTERFACE_LINK_LIBRARIES "${URCU_BP_LIBRARY};${URCU_COMMON_LIBRARY}"
+        INTERFACE_INCLUDE_DIRECTORIES "${URCU_INCLUDE_DIR}")
+    endif()
+  endif()
+endif()
+
+if(URCU_PKG_FOUND)
+  set(DISABLE_LIBURCU FALSE CACHE BOOL "Disable liburcu (RCU) support")
+  if(NOT DISABLE_LIBURCU)
+    if(URCU_PKG_VERSION)
+      message(STATUS "liburcu (RCU) support enabled (version ${URCU_PKG_VERSION})")
+    else()
+      message(STATUS "liburcu (RCU) support enabled")
+    endif()
+    set(HAVE_LIBURCU TRUE CACHE INTERNAL "Userspace RCU (liburcu) available")
+  else()
+    message(STATUS "liburcu (RCU) support disabled by user")
+    unset(HAVE_LIBURCU CACHE)
+  endif()
+else()
+  message(STATUS "Install liburcu (urcu-bp) for lock-free data-plane re-keying")
+  unset(HAVE_LIBURCU CACHE)
+endif()
+
+mark_as_advanced(URCU_BP_LIBRARY URCU_COMMON_LIBRARY URCU_INCLUDE_DIR)