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pool.h
1 /* TDSPool - Connection pooling for TDS based databases
2  * Copyright (C) 2001 Brian Bruns
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17  *
18  */
19 
20 #ifndef _pool_h_
21 #define _pool_h_
22 
23 #include <assert.h>
24 
25 #if HAVE_SYS_TYPES_H
26 #include <sys/types.h>
27 #endif
28 
29 #if HAVE_NETINET_IN_H
30 #include <netinet/in.h>
31 #endif
32 
33 /*
34  * POSIX says fd_set type may be defined in either sys/select.h or sys/time.h.
35  */
36 #if HAVE_SYS_TIME_H
37 #include <sys/time.h>
38 #endif
39 
40 #include <freetds/tds.h>
41 #include <freetds/dlist.h>
42 
43 /* defines */
44 #define PGSIZ 2048
45 #define BLOCKSIZ 512
46 #define MAX_POOL_USERS 1024
47 
48 /* enums and typedefs */
49 typedef enum
50 {
51  TDS_SRV_WAIT, /* if no members are free wait */
52  TDS_SRV_QUERY,
53 } TDS_USER_STATE;
54 
55 /* forward declaration */
56 typedef struct tds_pool_event TDS_POOL_EVENT;
57 typedef struct tds_pool_socket TDS_POOL_SOCKET;
58 typedef struct tds_pool_member TDS_POOL_MEMBER;
59 typedef struct tds_pool_user TDS_POOL_USER;
60 typedef struct tds_pool TDS_POOL;
61 typedef void (*TDS_POOL_EXECUTE)(TDS_POOL_EVENT *event);
62 
64 {
65  TDS_POOL_EVENT *next;
66  TDS_POOL_EXECUTE execute;
67 };
68 
70 {
71  TDSSOCKET *tds;
72  bool poll_recv;
73  bool poll_send;
74 };
75 
77 {
78  TDS_POOL_SOCKET sock;
79  DLIST_FIELDS(dlist_user_item);
80  TDSLOGIN *login;
81  TDS_USER_STATE user_state;
82  TDS_POOL_MEMBER *assigned_member;
83 };
84 
86 {
87  TDS_POOL_SOCKET sock;
88  DLIST_FIELDS(dlist_member_item);
89  bool doing_async;
90  time_t last_used_tm;
91  TDS_POOL_USER *current_user;
92 };
93 
94 #define DLIST_NAME(suffix) dlist_member_ ## suffix
95 #define DLIST_LIST_TYPE dlist_members
96 #define DLIST_TYPE TDS_POOL_MEMBER
97 #include <freetds/dlist.tmpl.h>
98 
99 #define DLIST_NAME(suffix) dlist_user_ ## suffix
100 #define DLIST_LIST_TYPE dlist_users
101 #define DLIST_TYPE TDS_POOL_USER
102 #include <freetds/dlist.tmpl.h>
103 
104 struct tds_pool
105 {
106  char *name;
107  char *user;
108  char *password;
109  char *server;
110  char *database;
111  int port;
112  int max_member_age; /* in seconds */
113  int min_open_conn;
114  int max_open_conn;
115  tds_mutex events_mtx;
116  TDS_SYS_SOCKET listen_fd;
117  TDS_SYS_SOCKET wakeup_fd;
118  TDS_SYS_SOCKET event_fd;
119  TDS_POOL_EVENT *events;
120 
121  int num_active_members;
122  dlist_members active_members;
123  dlist_members idle_members;
124 
126  dlist_users waiters;
127  int num_users;
128  dlist_users users;
129  TDSCONTEXT *ctx;
130 
131  unsigned long user_logins;
132  unsigned long member_logins;
133 };
134 
135 /* prototypes */
136 
137 /* member.c */
138 void pool_process_members(TDS_POOL * pool, fd_set * rfds, fd_set * wfds);
139 TDS_POOL_MEMBER *pool_assign_idle_member(TDS_POOL * pool, TDS_POOL_USER *user);
140 void pool_mbr_init(TDS_POOL * pool);
141 void pool_mbr_destroy(TDS_POOL * pool);
142 void pool_free_member(TDS_POOL *pool, TDS_POOL_MEMBER * pmbr);
143 void pool_assign_member(TDS_POOL *pool, TDS_POOL_MEMBER * pmbr, TDS_POOL_USER *puser);
144 void pool_deassign_member(TDS_POOL *pool, TDS_POOL_MEMBER * pmbr);
145 void pool_reset_member(TDS_POOL *pool, TDS_POOL_MEMBER * pmbr);
146 bool pool_packet_read(TDSSOCKET * tds);
147 
148 /* user.c */
149 void pool_process_users(TDS_POOL * pool, fd_set * rfds, fd_set * wfds);
150 void pool_user_init(TDS_POOL * pool);
151 void pool_user_destroy(TDS_POOL * pool);
152 TDS_POOL_USER *pool_user_create(TDS_POOL * pool, TDS_SYS_SOCKET s);
153 void pool_free_user(TDS_POOL * pool, TDS_POOL_USER * puser);
154 void pool_user_query(TDS_POOL * pool, TDS_POOL_USER * puser);
155 bool pool_user_send_login_ack(TDS_POOL * pool, TDS_POOL_USER * puser);
156 void pool_user_finish_login(TDS_POOL * pool, TDS_POOL_USER * puser);
157 
158 /* util.c */
159 void dump_login(TDSLOGIN * login);
160 void pool_event_add(TDS_POOL *pool, TDS_POOL_EVENT *ev, TDS_POOL_EXECUTE execute);
161 int pool_write(TDS_SYS_SOCKET sock, const void *buf, size_t len);
162 bool pool_write_data(TDS_POOL_SOCKET *from, TDS_POOL_SOCKET *to);
163 
164 /* config.c */
165 int pool_read_conf_file(const char *poolname, TDS_POOL * pool, char **err);
166 
167 
168 #endif
Information for a server connection.
Definition: tds.h:1168
Definition: pool.h:63
Definition: pool.h:76
Definition: pool.h:69
Definition: pool.h:104
Main include file for libtds.
Definition: tds.h:1058
Definition: tds.h:547
Definition: pool.h:85
dlist_users waiters
users in wait state
Definition: pool.h:126