MDEV-13585: RocksDB plugin fails to build on macOS because of unknown type `timer_t` etc.

Rdb_io_watchdog can not be built on  OS X. Disable it.

storage/rocksdb/CMakeLists.txt

@@ -146,7 +146,10 @@ ADD_CONVENIENCE_LIBRARY(rocksdb_aux_lib
 ADD_DEPENDENCIES(rocksdb_aux_lib GenError)
 
 # MARIAROCKS-TODO: how to properly depend on -lrt ?
-TARGET_LINK_LIBRARIES(rocksdb_aux_lib rocksdblib ${ZLIB_LIBRARY} -lrt)
+TARGET_LINK_LIBRARIES(rocksdb_aux_lib rocksdblib ${ZLIB_LIBRARY})
+if (UNIX AND NOT APPLE)
+  TARGET_LINK_LIBRARIES(rocksdb_aux_lib -lrt)
+endif()
 
 TARGET_LINK_LIBRARIES(rocksdb rocksdb_aux_lib)
 
@@ -182,7 +185,9 @@ ENDIF()
 #  ADD_SUBDIRECTORY(unittest)
 #ENDIF()
 
-SET(rocksdb_static_libs ${rocksdb_static_libs} "-lrt")
+if (UNIX AND NOT APPLE)
+  SET(rocksdb_static_libs ${rocksdb_static_libs} "-lrt")
+endif()
 
 ADD_LIBRARY(rocksdb_tools STATIC
    rocksdb/tools/ldb_tool.cc

storage/rocksdb/ha_rocksdb.cc

@@ -173,7 +173,7 @@ Rdb_ddl_manager ddl_manager;
 const char *m_mysql_gtid;
 Rdb_binlog_manager binlog_manager;
 
-#ifndef _WIN32 
+#if !defined(_WIN32) && !defined(__APPLE__)
 Rdb_io_watchdog *io_watchdog = nullptr;
 #endif
 /**
@@ -554,7 +554,7 @@ static void rocksdb_set_io_write_timeout(
     void *const var_ptr MY_ATTRIBUTE((__unused__)), const void *const save) {
   DBUG_ASSERT(save != nullptr);
   DBUG_ASSERT(rdb != nullptr);
-#ifndef _WIN32
+#if !defined(_WIN32) && !defined(__APPLE__)
   DBUG_ASSERT(io_watchdog != nullptr);
 #endif
 
@@ -563,7 +563,7 @@ static void rocksdb_set_io_write_timeout(
   const uint32_t new_val = *static_cast<const uint32_t *>(save);
 
   rocksdb_io_write_timeout_secs = new_val;
-#ifndef _WIN32
+#if !defined(_WIN32) && !defined(__APPLE__)
   io_watchdog->reset_timeout(rocksdb_io_write_timeout_secs);
 #endif
   RDB_MUTEX_UNLOCK_CHECK(rdb_sysvars_mutex);
@@ -3984,7 +3984,7 @@ static int rocksdb_init_func(void *const p) {
     directories.push_back(myrocks::rocksdb_wal_dir);
   }
 
-#ifndef _WIN32
+#if !defined(_WIN32) && !defined(__APPLE__)
   io_watchdog = new Rdb_io_watchdog(directories);
   io_watchdog->reset_timeout(rocksdb_io_write_timeout_secs);
 #endif
@@ -4076,7 +4076,7 @@ static int rocksdb_done_func(void *const p) {
   delete commit_latency_stats;
   commit_latency_stats = nullptr;
 
-#ifndef _WIN32
+#if !defined(_WIN32) && !defined(__APPLE__)
   delete io_watchdog;
   io_watchdog = nullptr;
 #endif

storage/rocksdb/rdb_io_watchdog.cc

@@ -22,7 +22,7 @@
 #include <vector>
 
 /* Rdb_io_watchdog doesn't work on Windows [yet] */
-#ifndef _WIN32
+#if !defined(_WIN32) && !defined(__APPLE__)
 
 namespace myrocks {
 

storage/rocksdb/rdb_io_watchdog.h

@@ -35,7 +35,7 @@
 namespace myrocks {
 
 // Rdb_io_watchdog does not support Windows ATM.
-#ifndef _WIN32 
+#if !defined(_WIN32) && !defined(__APPLE__)
 
 class Rdb_io_watchdog {
   const int RDB_IO_WRITE_BUFFER_SIZE = 4096;