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Plug several holes in backend's ability to cope with

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unexpected loss of connection to frontend.
This commit is contained in:
Tom Lane
1999-07-22 02:40:07 +00:00
parent 991b82ee13
commit 2aa64f79f5
3 changed files with 84 additions and 48 deletions
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36
src/backend/tcop/fastpath.c
View File

@@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/tcop/fastpath.c,v 1.29 1999/07/17 20:17:50 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/tcop/fastpath.c,v 1.30 1999/07/22 02:40:07 tgl Exp $
*
* NOTES
* This cruft is the server side of PQfn.
@@ -265,8 +265,11 @@ update_fp_info(Oid func_id, struct fp_info * fip)
* This corresponds to the libpq protocol symbol "F".
*
* RETURNS:
* nothing of significance.
* All errors result in elog(ERROR,...).
* 0 if successful completion, EOF if frontend connection lost.
*
* Note: All ordinary errors result in elog(ERROR,...). However,
* if we lose the frontend connection there is no one to elog to,
* and no use in proceeding...
*/
int
HandleFunctionRequest()
@@ -282,9 +285,11 @@ HandleFunctionRequest()
char *p;
struct fp_info *fip;
pq_getint(&tmp, 4); /* function oid */
if (pq_getint(&tmp, 4)) /* function oid */
return EOF;
fid = (Oid) tmp;
pq_getint(&nargs, 4); /* # of arguments */
if (pq_getint(&nargs, 4)) /* # of arguments */
return EOF;
/*
* This is where the one-back caching is done. If you want to save
@@ -294,6 +299,13 @@ HandleFunctionRequest()
if (!valid_fp_info(fid, fip))
update_fp_info(fid, fip);
/*
* XXX FIXME: elog() here means we lose sync with the frontend,
* since we have not swallowed all of its input message. What
* should happen is we absorb all of the input message per protocol
* syntax, and *then* do error checking and elog if appropriate.
*/
if (fip->nargs != nargs)
{
elog(ERROR, "HandleFunctionRequest: actual arguments (%d) != registered arguments (%d)",
@@ -311,13 +323,15 @@ HandleFunctionRequest()
arg[i] = (char *) NULL;
else
{
pq_getint(&argsize, 4);
if (pq_getint(&argsize, 4))
return EOF;
Assert(argsize > 0);
if (fip->argbyval[i])
{ /* by-value */
Assert(argsize <= 4);
pq_getint(&tmp, argsize);
if (pq_getint(&tmp, argsize))
return EOF;
arg[i] = (char *) tmp;
}
else
@@ -329,14 +343,16 @@ HandleFunctionRequest()
* 98 Jan 6 */
elog(ERROR, "HandleFunctionRequest: palloc failed");
VARSIZE(p) = argsize + VARHDRSZ;
pq_getbytes(VARDATA(p), argsize);
if (pq_getbytes(VARDATA(p), argsize))
return EOF;
}
else
{ /* ... fixed */
/* XXX cross our fingers and trust "argsize" */
if (!(p = palloc(argsize + 1)))
elog(ERROR, "HandleFunctionRequest: palloc failed");
pq_getbytes(p, argsize);
if (pq_getbytes(p, argsize))
return EOF;
}
palloced |= (1 << i);
arg[i] = p;
@@ -374,7 +390,5 @@ HandleFunctionRequest()
if (!fip->retbyval)
pfree(retval);
return 0;
}

56
src/backend/tcop/postgres.c
View File

@@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/tcop/postgres.c,v 1.126 1999/07/19 02:27:06 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/tcop/postgres.c,v 1.127 1999/07/22 02:40:07 tgl Exp $
*
* NOTES
* this is the "main" module of the postgres backend and
@@ -158,9 +158,9 @@ int _exec_repeat_ = 1;
* decls for routines only used in this file
* ----------------------------------------------------------------
*/
static char InteractiveBackend(char *inBuf);
static char SocketBackend(char *inBuf);
static char ReadCommand(char *inBuf);
static int InteractiveBackend(char *inBuf);
static int SocketBackend(char *inBuf);
static int ReadCommand(char *inBuf);
static void pg_exec_query(char *query_string);
@@ -172,10 +172,12 @@ static void pg_exec_query(char *query_string);
/* ----------------
* InteractiveBackend() is called for user interactive connections
* the string entered by the user is placed in its parameter inBuf.
*
* EOF is returned if end-of-file input is seen; time to shut down.
* ----------------
*/
static char
static int
InteractiveBackend(char *inBuf)
{
char *stuff = inBuf; /* current place in input buffer */
@@ -244,8 +246,7 @@ InteractiveBackend(char *inBuf)
{
if (Verbose)
puts("EOF");
IsEmptyQuery = true;
proc_exit(0);
return EOF;
}
/* ----------------
@@ -274,11 +275,13 @@ InteractiveBackend(char *inBuf)
*
* If the input is a fastpath function call (case 'F') then
* the function call is processed in HandleFunctionRequest().
* (now called from PostgresMain())
* (now called from PostgresMain()).
*
* EOF is returned if the connection is lost.
* ----------------
*/
static char
static int
SocketBackend(char *inBuf)
{
char qtype;
@@ -290,13 +293,7 @@ SocketBackend(char *inBuf)
*/
qtype = '?';
if (pq_getbytes(&qtype, 1) == EOF)
{
/* ------------
* when front-end applications quits/dies
* ------------
*/
proc_exit(0);
}
return EOF;
switch (qtype)
{
@@ -305,7 +302,8 @@ SocketBackend(char *inBuf)
* ----------------
*/
case 'Q':
pq_getstr(inBuf, MAX_PARSE_BUFFER);
if (pq_getstr(inBuf, MAX_PARSE_BUFFER))
return EOF;
result = 'Q';
break;
@@ -314,8 +312,8 @@ SocketBackend(char *inBuf)
* ----------------
*/
case 'F':
pq_getstr(inBuf, MAX_PARSE_BUFFER); /* ignore the rest of the
* line */
if (pq_getstr(inBuf, MAX_PARSE_BUFFER))
return EOF; /* ignore "string" at start of F message */
result = 'F';
break;
@@ -345,10 +343,10 @@ SocketBackend(char *inBuf)
* ReadCommand reads a command from either the frontend or
* standard input, places it in inBuf, and returns a char
* representing whether the string is a 'Q'uery or a 'F'astpath
* call.
* call. EOF is returned if end of file.
* ----------------
*/
static char
static int
ReadCommand(char *inBuf)
{
if (IsUnderPostmaster)
@@ -890,7 +888,7 @@ PostgresMain(int argc, char *argv[], int real_argc, char *real_argv[])
bool secure = true;
int errs = 0;
char firstchar;
int firstchar;
char parser_input[MAX_PARSE_BUFFER];
char *userName;
@@ -1494,7 +1492,7 @@ PostgresMain(int argc, char *argv[], int real_argc, char *real_argv[])
if (!IsUnderPostmaster)
{
puts("\nPOSTGRES backend interactive interface ");
puts("$Revision: 1.126 $ $Date: 1999/07/19 02:27:06 $\n");
puts("$Revision: 1.127 $ $Date: 1999/07/22 02:40:07 $\n");
}
/* ----------------
@@ -1581,7 +1579,12 @@ PostgresMain(int argc, char *argv[], int real_argc, char *real_argv[])
TPRINTF(TRACE_VERBOSE, "StartTransactionCommand");
StartTransactionCommand();
HandleFunctionRequest();
if (HandleFunctionRequest() == EOF)
{
/* lost frontend connection during F message input */
pq_close();
proc_exit(0);
}
break;
/* ----------------
@@ -1621,10 +1624,13 @@ PostgresMain(int argc, char *argv[], int real_argc, char *real_argv[])
break;
/* ----------------
* 'X' means that the frontend is closing down the socket
* 'X' means that the frontend is closing down the socket.
* EOF means unexpected loss of frontend connection.
* Either way, perform normal shutdown.
* ----------------
*/
case 'X':
case EOF:
pq_close();
proc_exit(0);
break;