fix(learn) avoid learn use DEFAULT_POOL

FLAGS_max_copy_rate_megabytes_per_disk will use `sleep_for` function to
block THREAD_POOL_DEFAULT. It's cause replica server cannot deal `remote
command`. This modify is same as FLAGS_max_send_rate_megabytes_per_disk,
only use THREAD_POOL_BLOCK_SERVICE to sleep.

relate issue:#1969

src/block_service/block_service.h

@@ -43,8 +43,6 @@ namespace dsn {
 namespace dist {
 namespace block_service {
 
-DEFINE_THREAD_POOL_CODE(THREAD_POOL_BLOCK_SERVICE)
-
 class block_file;
 typedef dsn::ref_ptr<block_file> block_file_ptr;
 

src/nfs/nfs_code_definition.h

@@ -29,16 +29,16 @@
 namespace dsn {
 namespace service {
 // define RPC task code for service 'nfs'
-DEFINE_TASK_CODE_RPC(RPC_NFS_COPY, TASK_PRIORITY_COMMON, ::dsn::THREAD_POOL_DEFAULT)
-DEFINE_TASK_CODE_RPC(RPC_NFS_GET_FILE_SIZE, TASK_PRIORITY_COMMON, ::dsn::THREAD_POOL_DEFAULT)
+DEFINE_TASK_CODE_RPC(RPC_NFS_COPY, TASK_PRIORITY_COMMON, ::dsn::THREAD_POOL_BLOCK_SERVICE)
+DEFINE_TASK_CODE_RPC(RPC_NFS_GET_FILE_SIZE, TASK_PRIORITY_COMMON, ::dsn::THREAD_POOL_BLOCK_SERVICE)
 // test timer task code
 DEFINE_TASK_CODE(LPC_NFS_REQUEST_TIMER, TASK_PRIORITY_COMMON, ::dsn::THREAD_POOL_DEFAULT)
 
-DEFINE_TASK_CODE_AIO(LPC_NFS_READ, TASK_PRIORITY_COMMON, THREAD_POOL_DEFAULT)
-DEFINE_TASK_CODE(LPC_NFS_FILE_CLOSE_TIMER, TASK_PRIORITY_COMMON, THREAD_POOL_DEFAULT)
+DEFINE_TASK_CODE_AIO(LPC_NFS_READ, TASK_PRIORITY_COMMON, ::dsn::THREAD_POOL_BLOCK_SERVICE)
+DEFINE_TASK_CODE(LPC_NFS_FILE_CLOSE_TIMER, TASK_PRIORITY_COMMON, ::dsn::THREAD_POOL_DEFAULT)
 
-DEFINE_TASK_CODE_AIO(LPC_NFS_WRITE, TASK_PRIORITY_COMMON, THREAD_POOL_DEFAULT)
+DEFINE_TASK_CODE_AIO(LPC_NFS_WRITE, TASK_PRIORITY_COMMON, ::dsn::THREAD_POOL_BLOCK_SERVICE)
 
-DEFINE_TASK_CODE_AIO(LPC_NFS_COPY_FILE, TASK_PRIORITY_COMMON, THREAD_POOL_DEFAULT)
+DEFINE_TASK_CODE_AIO(LPC_NFS_COPY_FILE, TASK_PRIORITY_COMMON, ::dsn::THREAD_POOL_BLOCK_SERVICE)
 } // namespace service
 } // namespace dsn

src/utils/threadpool_code.h

@@ -66,6 +66,7 @@ class threadpool_code
 
 DEFINE_THREAD_POOL_CODE(THREAD_POOL_INVALID)
 DEFINE_THREAD_POOL_CODE(THREAD_POOL_DEFAULT)
+DEFINE_THREAD_POOL_CODE(THREAD_POOL_BLOCK_SERVICE)
 } // namespace dsn
 
 USER_DEFINED_STRUCTURE_FORMATTER(::dsn::threadpool_code);