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Commitd0c1682

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Improve libpq documentation
1 parent7fdcd47 commitd0c1682

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13 files changed

+94
-61
lines changed

13 files changed

+94
-61
lines changed

‎doc/src/sgml/libpq.sgml

Lines changed: 49 additions & 14 deletions
Original file line numberDiff line numberDiff line change
@@ -330,8 +330,8 @@ PostgresPollingStatusType PQconnectPoll(PGconn *conn);
330330
socket underlying the database connection.
331331
Loop thus: If <function>PQconnectPoll(conn)</function> last returned
332332
<symbol>PGRES_POLLING_READING</symbol>, wait until the socket is ready to
333-
read (as indicated by <function>select()</>, <function>poll()</>, or
334-
similar systemfunction).
333+
read (as indicated by <function>PQselect()</> or
334+
<function>PQselectExtended()</>).
335335
Then call <function>PQconnectPoll(conn)</function> again.
336336
Conversely, if <function>PQconnectPoll(conn)</function> last returned
337337
<symbol>PGRES_POLLING_WRITING</symbol>, wait until the socket is ready
@@ -1879,6 +1879,42 @@ int PQsocket(const PGconn *conn);
18791879
</listitem>
18801880
</varlistentry>
18811881

1882+
<varlistentry id="libpq-pqselect">
1883+
<term><function>PQselect</function><indexterm><primary>PQselect</></></term>
1884+
<listitem>
1885+
<para>
1886+
Uses select(2) to monitor multiple file descriptors, waiting until one or
1887+
more of the file descriptors become "ready" for some class of I/O
1888+
operation (e.g., input possible).
1889+
1890+
<synopsis>
1891+
int PQselect(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, struct timeval *timeout, int isRsocket);
1892+
</synopsis>
1893+
1894+
</para>
1895+
</listitem>
1896+
</varlistentry>
1897+
1898+
<varlistentry id="libpq-pqselectextended">
1899+
<term><function>PQselectExtended</function><indexterm><primary>PQselectExtended</></></term>
1900+
<listitem>
1901+
<para>
1902+
Uses select(2) or poll(2) to wait for input. The <literal>timeout</>
1903+
argument specifies the number of milliseconds that
1904+
<function>PQselectExtended</> should block waiting for a file descriptor
1905+
of the connection to become ready. Specifying a negative value
1906+
in <literal>timeout</> means an infinite timeout. Specifying a
1907+
<literal>timeout</> of zero causes <function>poll()</> to return
1908+
immediately.
1909+
1910+
<synopsis>
1911+
int PQselectExtended(const PGconn *conn, int timeout_ms);
1912+
</synopsis>
1913+
1914+
</para>
1915+
</listitem>
1916+
</varlistentry>
1917+
18821918
<varlistentry id="libpq-pqbackendpid">
18831919
<term><function>PQbackendPID</function><indexterm><primary>PQbackendPID</></></term>
18841920
<listitem>
@@ -4494,10 +4530,10 @@ int PQconsumeInput(PGconn *conn);
44944530
<function>PQconsumeInput</function> can be called even if the
44954531
application is not prepared to deal with a result or notification
44964532
just yet. The function will read available data and save it in
4497-
a buffer, thereby causing a <function>select()</function>
4533+
a buffer, thereby causing a <function>PQselect()</function>
44984534
read-ready indication to go away. The application can thus use
44994535
<function>PQconsumeInput</function> to clear the
4500-
<function>select()</function> condition immediately, and then
4536+
<function>PQselect()</function> condition immediately, and then
45014537
examine the results at leisure.
45024538
</para>
45034539
</listitem>
@@ -4534,10 +4570,10 @@ int PQisBusy(PGconn *conn);
45344570

45354571
<para>
45364572
A typical application using these functions will have a main loop that
4537-
uses <function>select()</function> or <function>poll()</> to wait for
4573+
uses <function>PQselect()</function> or <function>PQselectExtended()</> to wait for
45384574
all the conditions that it must respond to. One of the conditions
45394575
will be input available from the server, which in terms of
4540-
<function>select()</function> means readable data on the file
4576+
<function>PQselect()</function> means readable data on the file
45414577
descriptor identified by <function>PQsocket</function>. When the main
45424578
loop detects input ready, it should call
45434579
<function>PQconsumeInput</function> to read the input. It can then
@@ -5084,10 +5120,11 @@ typedef struct pgNotify
50845120
useful commands to execute is to call
50855121
<function>PQconsumeInput</function>, then check
50865122
<function>PQnotifies</function>. You can use
5087-
<function>select()</function> to wait for data to arrive from the
5123+
<function>PQselect()</function> or <function>PQselectExtended()</function>
5124+
to wait for data to arrive from the
50885125
server, thereby using no <acronym>CPU</acronym> power unless there is
50895126
something to do. (See <function>PQsocket</function> to obtain the file
5090-
descriptor number to use with <function>select()</function>.) Note that
5127+
descriptor number to use with <function>PQselect()</function>.) Note that
50915128
this will work OK whether you submit commands with
50925129
<function>PQsendQuery</function>/<function>PQgetResult</function> or
50935130
simply use <function>PQexec</function>. You should, however, remember
@@ -8347,12 +8384,10 @@ main(int argc, char **argv)
83478384
while (nnotifies < 4)
83488385
{
83498386
/*
8350-
* Sleep until something happens on the connection. We use select(2)
8351-
* to wait for input, but you could also use poll() or similar
8352-
* facilities.
8387+
* Sleep until something happens on the connection. We use
8388+
* PQselectExtended to wait for input.
83538389
*/
83548390
int sock;
8355-
fd_set input_mask;
83568391

83578392
sock = PQsocket(conn);
83588393

@@ -8362,9 +8397,9 @@ main(int argc, char **argv)
83628397
FD_ZERO(&input_mask);
83638398
FD_SET(sock, &input_mask);
83648399

8365-
if (select(sock + 1, &input_mask, NULL, NULL, NULL) < 0)
8400+
if (PQselectExtended(conn, -1) < 0)
83668401
{
8367-
fprintf(stderr, "select() failed: %s\n", strerror(errno));
8402+
fprintf(stderr, "PQselectExtended() failed: %s\n", strerror(errno));
83688403
exit_nicely(conn);
83698404
}
83708405

‎src/backend/postmaster/postmaster.c

Lines changed: 0 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -105,7 +105,6 @@
105105
#include"libpq/pqsignal.h"
106106
#include"miscadmin.h"
107107
#include"pg_getopt.h"
108-
#include"pg_socket.h"
109108
#include"pgstat.h"
110109
#include"postmaster/autovacuum.h"
111110
#include"postmaster/bgworker_internals.h"

‎src/backend/replication/walreceiver.c

Lines changed: 4 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -67,6 +67,10 @@
6767
#include"utils/resowner.h"
6868
#include"utils/timestamp.h"
6969

70+
#ifdefWITH_RSOCKET
71+
#include"pg_socket.h"
72+
#endif
73+
7074

7175
/* GUC variables */
7276
intwal_receiver_status_interval;

‎src/bin/pg_basebackup/pg_recvlogical.c

Lines changed: 0 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -17,7 +17,6 @@
1717
#include<unistd.h>
1818

1919
/* local includes */
20-
#include"pg_socket.h"
2120
#include"streamutil.h"
2221

2322
#include"access/xlog_internal.h"

‎src/bin/pg_basebackup/receivelog.c

Lines changed: 0 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -18,7 +18,6 @@
1818
#include<unistd.h>
1919

2020
/* local includes */
21-
#include"pg_socket.h"
2221
#include"receivelog.h"
2322
#include"streamutil.h"
2423

‎src/bin/pgbench/pgbench.c

Lines changed: 0 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -53,7 +53,6 @@
5353
#endif
5454

5555
#include"pgbench.h"
56-
#include"pg_socket.h"
5756

5857
#defineERRCODE_IN_FAILED_SQL_TRANSACTION "25P02"
5958
#defineERRCODE_T_R_SERIALIZATION_FAILURE "40001"

‎src/bin/scripts/vacuumdb.c

Lines changed: 0 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -15,7 +15,6 @@
1515
#include"common.h"
1616
#include"fe_utils/simple_list.h"
1717
#include"fe_utils/string_utils.h"
18-
#include"pg_socket.h"
1918

2019

2120
#defineERRCODE_UNDEFINED_TABLE "42P01"

‎src/include/pg_socket.h

Lines changed: 27 additions & 27 deletions
Original file line numberDiff line numberDiff line change
@@ -13,14 +13,9 @@
1313
#ifndefPG_SOCKET_H
1414
#definePG_SOCKET_H
1515

16-
#ifndefFRONTEND
17-
#include"postgres.h"
18-
#else
19-
#include"postgres_fe.h"
20-
#endif
21-
2216
#include"pg_config.h"
2317

18+
#ifndefWIN32
2419
#include<sys/socket.h>
2520
#include<sys/time.h>
2621
#include<sys/types.h>
@@ -35,46 +30,44 @@
3530
#ifdefHAVE_SYS_SELECT_H
3631
#include<sys/select.h>
3732
#endif
33+
#else/* WIN32 */
34+
#include"win32.h"
35+
#endif/* WIN32 */
3836

3937
#ifdefWITH_RSOCKET
4038

41-
#include"port.h"
42-
4339
/* Rsocket function pointers */
4440
typedefstructPgSocketCall
4541
{
46-
pgsocket(*socket) (intdomain,inttype,intprotocol);
47-
int(*bind) (pgsocketsocket,conststructsockaddr*addr,
42+
int(*socket) (intdomain,inttype,intprotocol);
43+
int(*bind) (intsocket,conststructsockaddr*addr,
4844
socklen_taddrlen);
49-
int(*listen) (pgsocketsocket,intbacklog);
50-
int(*accept) (pgsocketsocket,structsockaddr*addr,
45+
int(*listen) (intsocket,intbacklog);
46+
int(*accept) (intsocket,structsockaddr*addr,
5147
socklen_t*addrlen);
52-
int(*connect) (pgsocketsocket,conststructsockaddr*addr,
48+
int(*connect) (intsocket,conststructsockaddr*addr,
5349
socklen_taddrlen);
54-
int(*close) (pgsocketsocket);
50+
int(*close) (intsocket);
5551

56-
ssize_t(*recv) (pgsocketsocket,void*buf,size_tlen,intflags);
57-
ssize_t(*send) (pgsocketsocket,constvoid*buf,size_tlen,
52+
ssize_t(*recv) (intsocket,void*buf,size_tlen,intflags);
53+
ssize_t(*send) (intsocket,constvoid*buf,size_tlen,
5854
intflags);
59-
ssize_t(*sendmsg) (pgsocketsocket,conststructmsghdr*msg,
60-
intflags);
55+
ssize_t(*sendmsg) (intsocket,conststructmsghdr*msg,intflags);
6156

6257
#ifdefHAVE_POLL
6358
int(*poll) (structpollfd*fds,nfds_tnfds,inttimeout);
6459
#endif
65-
int(*select) (pgsocketnfds,fd_set*readfds,fd_set*writefds,
60+
int(*select) (intnfds,fd_set*readfds,fd_set*writefds,
6661
fd_set*exceptfds,structtimeval*timeout);
6762

68-
int(*getsockname) (pgsocketsocket,structsockaddr*addr,
63+
int(*getsockname) (intsocket,structsockaddr*addr,
6964
socklen_t*addrlen);
70-
int(*setsockopt) (pgsocketsocket,intlevel,intoptname,
65+
int(*setsockopt) (intsocket,intlevel,intoptname,
7166
constvoid*optval,socklen_toptlen);
72-
int(*getsockopt) (pgsocketsocket,intlevel,intoptname,
67+
int(*getsockopt) (intsocket,intlevel,intoptname,
7368
void*optval,socklen_t*optlen);
7469

75-
#if !defined(WIN32)
76-
int(*fcntl) (pgsocketsocket,intcmd, .../* arg */ );
77-
#endif
70+
int(*fcntl) (intsocket,intcmd, .../* arg */ );
7871
}PgSocketCall;
7972

8073
externPgSocketCall*rcalls;
@@ -109,7 +102,7 @@ extern PgSocketCall *rcalls;
109102

110103
#definepg_closesocket(socket,isRsocket) \
111104
((isRsocket) ? rcalls->close(socket) : \
112-
close(socket))
105+
closesocket(socket))
113106

114107
#definepg_recv(socket,buf,len,flags,isRsocket) \
115108
((isRsocket) ? rcalls->recv(socket, buf, len, flags) : \
@@ -145,10 +138,15 @@ extern PgSocketCall *rcalls;
145138
((isRsocket) ? rcalls->getsockopt(socket, level, optname, optval, optlen) : \
146139
getsockopt(socket, level, optname, optval, optlen))
147140

141+
/* port/pg_rsocket.c */
142+
externvoidinitialize_rsocket(void);
143+
148144
#else
149145

146+
#if !defined(WIN32)
150147
#definepg_fcntl(fd,flag,value,isRsocket) \
151148
fcntl(fd, flag, value)
149+
#endif
152150

153151
#definepg_socket(domain,type,protocol,isRsocket) \
154152
socket(domain, type, protocol)
@@ -166,16 +164,18 @@ extern PgSocketCall *rcalls;
166164
connect(socket, addr, addrlen)
167165

168166
#definepg_closesocket(socket,isRsocket) \
169-
close(socket)
167+
closesocket(socket)
170168

171169
#definepg_recv(socket,buf,len,flags,isRsocket) \
172170
recv(socket, buf, len, flags)
173171

174172
#definepg_send(socket,buf,len,flags,isRsocket) \
175173
send(socket, buf, len, flags)
176174

175+
#if !defined(WIN32)
177176
#definepg_sendmsg(socket,msg,flags,isRsocket) \
178177
sendmsg(socket, msg, flags)
178+
#endif
179179

180180
#ifdefHAVE_POLL
181181
#definepg_poll(fds,nfds,timeout,isRsocket) \

‎src/include/port.h

Lines changed: 0 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -489,7 +489,4 @@ extern char *escape_single_quotes_ascii(const char *src);
489489
/* port/wait_error.c */
490490
externchar*wait_result_to_str(intexit_status);
491491

492-
/* port/pg_rsocket.c */
493-
externvoidinitialize_rsocket(void);
494-
495492
#endif/* PG_PORT_H */

‎src/interfaces/libpq/fe-auth.c

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -42,6 +42,7 @@
4242
#include"fe-auth.h"
4343
#include"libpq/scram.h"
4444
#include"libpq/md5.h"
45+
#include"pg_socket.h"
4546

4647

4748
#ifdefENABLE_GSS

‎src/interfaces/libpq/fe-connect.c

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -6636,8 +6636,8 @@ PQselectExtended(const PGconn *conn, int timeout_ms)
66366636
ptr_timeout=&timeout;
66376637
}
66386638

6639-
ret=pg_select(PQsocket(conn)+1,&input_mask,
6640-
NULL,NULL,ptr_timeout,PQisRsocket(conn));
6639+
returnpg_select(PQsocket(conn)+1,&input_mask,
6640+
NULL,NULL,ptr_timeout,PQisRsocket(conn));
66416641
#endif/* HAVE_POLL */
66426642
}
66436643

‎src/interfaces/libpq/libpq-fe.h

Lines changed: 7 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -22,6 +22,12 @@ extern"C"
2222

2323
#include<stdio.h>
2424

25+
#ifndefWIN32
26+
#include<sys/time.h>
27+
#else
28+
#include<winsock2.h>
29+
#endif
30+
2531
/*
2632
* postgres_ext.h defines the backend's externally visible types,
2733
* such as Oid.
@@ -326,7 +332,7 @@ extern intPQserverVersion(const PGconn *conn);
326332
externchar*PQerrorMessage(constPGconn*conn);
327333
externintPQsocket(constPGconn*conn);
328334
externintPQisRsocket(constPGconn*conn);
329-
externintPQselect(pgsocketnfds,fd_set*readfds,fd_set*writefds,
335+
externintPQselect(intnfds,fd_set*readfds,fd_set*writefds,
330336
fd_set*exceptfds,structtimeval*timeout,intisRsocket);
331337
externintPQselectExtended(constPGconn*conn,inttimeout_ms);
332338
externintPQbackendPID(constPGconn*conn);

‎src/test/examples/testlibpq2.c

Lines changed: 4 additions & 9 deletions
Original file line numberDiff line numberDiff line change
@@ -99,24 +99,19 @@ main(int argc, char **argv)
9999
while (nnotifies<4)
100100
{
101101
/*
102-
* Sleep until something happens on the connection. We use select(2)
103-
* to wait for input, but you could also use poll() or similar
104-
* facilities.
102+
* Sleep until something happens on the connection. We use
103+
* PQselectExtended to wait for input.
105104
*/
106105
intsock;
107-
fd_setinput_mask;
108106

109107
sock=PQsocket(conn);
110108

111109
if (sock<0)
112110
break;/* shouldn't happen */
113111

114-
FD_ZERO(&input_mask);
115-
FD_SET(sock,&input_mask);
116-
117-
if (select(sock+1,&input_mask,NULL,NULL,NULL)<0)
112+
if (PQselectExtended(conn,-1)<0)
118113
{
119-
fprintf(stderr,"select() failed: %s\n",strerror(errno));
114+
fprintf(stderr,"PQselectExtended() failed: %s\n",strerror(errno));
120115
exit_nicely(conn);
121116
}
122117

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