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Diffstat (limited to 'ndb/src/ndbapi/NdbPoolImpl.hpp')
| -rw-r--r-- | ndb/src/ndbapi/NdbPoolImpl.hpp | 166 |
1 files changed, 0 insertions, 166 deletions
diff --git a/ndb/src/ndbapi/NdbPoolImpl.hpp b/ndb/src/ndbapi/NdbPoolImpl.hpp deleted file mode 100644 index cd36f30e90b..00000000000 --- a/ndb/src/ndbapi/NdbPoolImpl.hpp +++ /dev/null @@ -1,166 +0,0 @@ -/* Copyright (C) 2003 MySQL AB - - This program is free software; you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 2 of the License, or - (at your option) any later version. - - This program is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - GNU General Public License for more details. - - You should have received a copy of the GNU General Public License - along with this program; if not, write to the Free Software - Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ - -/** - @section ndbPool Pooling of NDB objects - This class implements pooling of NDB objects to support MySQL, ODBC and - any application with a great number of threads. - - The general idea is to let the NdbPool class administer all Ndb objects. - When a thread needs a Ndb object it request a Ndb object from the Pool. - This interface contains some hints to ensure that the proper Ndb object - is returned. - - The object contains an array of references to all Ndb objects together with - an indication of whether the object is free or not. - - The idea is that the thread should keep track of the Ndb object it used the - last time. If this object is still free it will simply get this object - back. If the number of threads do not exceed the number of Ndb objects this - will always be successful. In certain situations the number of threads will - be much greater than the number of Ndb objects. In this situation the Pool - will attempt to provide an object that is attached to the same schema - as the thread is connected to. If this is not possible it will attempt to - get any free Ndb object. If not even this is possible the Pool will wait - until an Ndb object becomes free. If an Ndb object becomes available in - time it will deliver this Ndb object. In the worst case the call will - time-out and return NULL to indicate no free Ndb object was found in time. - - The implementation uses an array of structs which contain a reference to a - Ndb object, whether it is in use currently and a number of references to - set up linked lists of - 1) Free objects on a schema - 2) Free objects in LIFO order - - Usage: - The class is a singleton. - The first step is to call create_instance(..). If successful this will - create the NdbPool object and return a reference to it. When completed - drop_instance is called to remove the NdbPool object and all memory and - other resources attached to it. - - After initialising the NdbPool object all threads can now start using the - NdbPool. There are two methods in normal usage mode. The first - get_ndb_object gets a Ndb object and the second return_ndb_object returns - an Ndb object. The user of the NdbPool must keep track of the identity - of the Ndb object. The idea is that this identity can also be used to - find the object quickly again unless another thread have taken it. If the - user wants any Ndb object it requests identity 0 which means any here. - - When constructing the NdbPool one can set the number of NdbConnection - objects which are allowed in all Ndb objects. For use in synchronous - applications such as the MySQL server 4 objects should be enough. When - using the NdbPool for asynchronous applications one should use 1024 to - enable a high level of parallelism. It is also possible to set the - maximum number of Ndb objects in the pool and the initial number of - Ndb objects allocated. -*/ - -#ifndef NdbPool_H -#define NdbPool_H - -#include <Ndb.hpp> -#include <NdbMutex.h> -#include <NdbCondition.h> -#include <NdbOut.hpp> - -class NdbPool { -#define NULL_POOL 0 -#define NULL_HASH 0xFF -#define POOL_HASH_TABLE_SIZE 32 -#define MAX_NDB_OBJECTS 240 - struct POOL_STRUCT { - Ndb* ndb_reference; - bool in_use; - bool free_entry; - Uint16 next_free_object; - Uint16 prev_free_object; - Uint16 next_db_object; - Uint16 prev_db_object; - }; - public: - static NdbPool* create_instance(Ndb_cluster_connection*, - Uint32 max_ndb_objects = 240, - Uint32 no_conn_obj = 4, - Uint32 init_no_ndb_objects = 8); - static void drop_instance(); - Ndb* get_ndb_object(Uint32 &hint_id, - const char* a_catalog_name, - const char* a_schema_name); - void return_ndb_object(Ndb* returned_object, Uint32 id); - private: - bool init(Uint32 initial_no_of_ndb_objects = 8); - void release_all(); - static bool initPoolMutex(); - NdbPool(Ndb_cluster_connection*, - Uint32 max_no_of_ndb_objects, Uint32 no_conn_objects); - ~NdbPool(); - /* - We have three lists: - 1) A list for entries not in use - 2) A list for free entries - 3) A hash table with schema name and database name as key - - These lists are all initialised in the init call. - The list for entries not in use is very simple since the current - implementation have not yet any handling of dropping Ndb objects - until all Ndb objects are dropped. - */ - void add_free_list(Uint32 id); - void remove_free_list(Uint32 id); - Ndb* get_free_list(Uint32 &id, Uint32 hash_entry); - - void add_db_hash(Uint32 id); - void remove_db_hash(Uint32 id, Uint32 hash_entry); - Ndb* get_db_hash(Uint32 &id, - Uint32 hash_entry, - const char* a_catalog_name, - const char* a_schema_name); - - bool allocate_ndb(Uint32 &id, - const char* a_catalog_name, - const char* a_schema_name); - Ndb* get_hint_ndb(Uint32 id, Uint32 hash_entry); - Ndb* wait_free_ndb(Uint32 &id); - Uint32 compute_hash(const char *a_schema_name); - void add_wait_list(Uint32 id); - void remove_wait_list(); - void switch_condition_queue(); - - static NdbMutex *pool_mutex; - struct NdbCondition *input_pool_cond; - struct NdbCondition *output_pool_cond; - - POOL_STRUCT *m_pool_reference; - Uint8 *m_hash_entry; - - bool m_inited; - Uint32 m_no_of_conn_objects; - - Uint16 m_no_of_objects; - Uint16 m_max_ndb_objects; - Uint16 m_first_free; - Uint16 m_last_free; - Uint16 m_first_not_in_use; - Uint16 m_waiting; - Uint16 m_first_wait; - Uint16 m_input_queue; - Uint16 m_output_queue; - Uint16 m_signal_count; - - Ndb_cluster_connection * m_cluster_connection; -}; -#endif |