FreeTDS API
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 #if HAVE_POLL_H
41 #include <poll.h>
42 #endif /* HAVE_POLL_H */
43 
44 #include <freetds/tds.h>
45 #include <freetds/utils/dlist.h>
46 #include <freetds/replacements.h>
47 
48 /* defines */
49 #define PGSIZ 2048
50 #define BLOCKSIZ 512
51 #define MAX_POOL_USERS 1024
52 
53 /* enums and typedefs */
54 typedef enum
55 {
56  TDS_SRV_WAIT, /* if no members are free wait */
57  TDS_SRV_QUERY,
58 } TDS_USER_STATE;
59 
60 /* forward declaration */
61 typedef struct tds_pool_event TDS_POOL_EVENT;
62 typedef struct tds_pool_socket TDS_POOL_SOCKET;
63 typedef struct tds_pool_member TDS_POOL_MEMBER;
64 typedef struct tds_pool_user TDS_POOL_USER;
65 typedef struct tds_pool TDS_POOL;
66 typedef void (*TDS_POOL_EXECUTE)(TDS_POOL_EVENT *event);
67 
69 {
70  TDS_POOL_EVENT *next;
71  TDS_POOL_EXECUTE execute;
72 };
73 
75 {
76  TDSSOCKET *tds;
77  uint32_t poll_index;
78  bool poll_recv;
79  bool poll_send;
80 };
81 
83 {
84  TDS_POOL_SOCKET sock;
85  DLIST_FIELDS(dlist_user_item);
86  TDSLOGIN *login;
87  TDS_USER_STATE user_state;
88  TDS_POOL_MEMBER *assigned_member;
89 };
90 
92 {
93  TDS_POOL_SOCKET sock;
94  DLIST_FIELDS(dlist_member_item);
95  bool doing_async;
96  time_t last_used_tm;
97  TDS_POOL_USER *current_user;
98 };
99 
100 #define DLIST_PREFIX dlist_member
101 #define DLIST_LIST_TYPE dlist_members
102 #define DLIST_ITEM_TYPE TDS_POOL_MEMBER
103 #include <freetds/utils/dlist.tmpl.h>
104 
105 #define DLIST_PREFIX dlist_user
106 #define DLIST_LIST_TYPE dlist_users
107 #define DLIST_ITEM_TYPE TDS_POOL_USER
108 #include <freetds/utils/dlist.tmpl.h>
109 
110 struct tds_pool
111 {
112  char *name;
113  char *user;
114  char *password;
115  char *server;
116  char *database;
117  char *server_user;
118  char *server_password;
119  int port;
120  int max_member_age; /* in seconds */
121  int min_open_conn;
122  int max_open_conn;
123  tds_mutex events_mtx;
124  TDS_SYS_SOCKET listen_fd;
125  TDS_SYS_SOCKET wakeup_fd;
126  TDS_SYS_SOCKET event_fd;
127  TDS_POOL_EVENT *events;
128 
129  int num_active_members;
130  dlist_members active_members;
131  dlist_members idle_members;
132 
134  dlist_users waiters;
135  int num_users;
136  dlist_users users;
137  TDSCONTEXT *ctx;
138 
139  unsigned long user_logins;
140  unsigned long member_logins;
141 };
142 
143 /* prototypes */
144 
145 /* member.c */
146 int pool_process_members(TDS_POOL * pool, struct pollfd *fds, unsigned num_fds);
147 TDS_POOL_MEMBER *pool_assign_idle_member(TDS_POOL * pool, TDS_POOL_USER *user);
148 void pool_mbr_init(TDS_POOL * pool);
149 void pool_mbr_destroy(TDS_POOL * pool);
150 void pool_free_member(TDS_POOL *pool, TDS_POOL_MEMBER * pmbr);
151 void pool_assign_member(TDS_POOL *pool, TDS_POOL_MEMBER * pmbr, TDS_POOL_USER *puser);
152 void pool_deassign_member(TDS_POOL *pool, TDS_POOL_MEMBER * pmbr);
153 void pool_reset_member(TDS_POOL *pool, TDS_POOL_MEMBER * pmbr);
154 bool pool_packet_read(TDSSOCKET * tds);
155 
156 /* user.c */
157 void pool_process_users(TDS_POOL * pool, struct pollfd *fds, unsigned num_fds);
158 void pool_user_init(TDS_POOL * pool);
159 void pool_user_destroy(TDS_POOL * pool);
160 TDS_POOL_USER *pool_user_create(TDS_POOL * pool, TDS_SYS_SOCKET s);
161 void pool_free_user(TDS_POOL * pool, TDS_POOL_USER * puser);
162 void pool_user_query(TDS_POOL * pool, TDS_POOL_USER * puser);
163 bool pool_user_send_login_ack(TDS_POOL * pool, TDS_POOL_USER * puser);
164 void pool_user_finish_login(TDS_POOL * pool, TDS_POOL_USER * puser);
165 
166 /* util.c */
167 void dump_login(TDSLOGIN * login);
168 void pool_event_add(TDS_POOL *pool, TDS_POOL_EVENT *ev, TDS_POOL_EXECUTE execute);
169 int pool_write(TDS_SYS_SOCKET sock, const void *buf, size_t len);
170 bool pool_write_data(TDS_POOL_SOCKET *from, TDS_POOL_SOCKET *to);
171 
172 /* config.c */
173 bool pool_read_conf_files(const char *path, const char *poolname, TDS_POOL * pool, char **err);
174 
175 
176 #endif
Definition: poll.h:52
Definition: pool.h:68
Provide poll call where missing.
Definition: tds.h:517
dlist_users waiters
users in wait state
Definition: pool.h:134
Definition: pool.h:82
Main include file for libtds.
Definition: tds.h:1032
Definition: pool.h:110
Definition: pool.h:74
Information for a server connection.
Definition: tds.h:1179
Definition: pool.h:91