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When closure of the backend connection is detected during pqFlush,

do the right thing: look for a NOTICE message from the backend before we
close our side of the socket.  6.4 libpq did not reliably print the backend's
hara-kiri message, 'The Postmaster has informed me ...', because it only
did the right thing if connection closure was detected during a read
attempt instead of a write attempt.
This commit is contained in:
Tom Lane
1999-05-28 01:54:53 +00:00
parent 615e77ede2
commit f0ae1e8d10
2 changed files with 70 additions and 20 deletions

View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-exec.c,v 1.80 1999/05/25 16:15:12 momjian Exp $
* $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-exec.c,v 1.81 1999/05/28 01:54:53 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -47,6 +47,7 @@ const char *const pgresStatus[] = {
static int addTuple(PGresult *res, PGresAttValue *tup);
static void parseInput(PGconn *conn);
static void handleSendFailure(PGconn *conn);
static int getRowDescriptions(PGconn *conn);
static int getAnotherTuple(PGconn *conn, int binary);
static int getNotify(PGconn *conn);
@ -433,18 +434,53 @@ PQsendQuery(PGconn *conn, const char *query)
/* send the query to the backend; */
/* the frontend-backend protocol uses 'Q' to designate queries */
if (pqPutnchar("Q", 1, conn))
return 0;
if (pqPuts(query, conn))
return 0;
if (pqFlush(conn))
if (pqPutnchar("Q", 1, conn) ||
pqPuts(query, conn) ||
pqFlush(conn))
{
handleSendFailure(conn);
return 0;
}
/* OK, it's launched! */
conn->asyncStatus = PGASYNC_BUSY;
return 1;
}
/*
* handleSendFailure: try to clean up after failure to send command.
*
* Primarily, what we want to accomplish here is to process an async
* NOTICE message that the backend might have sent just before it died.
*
* NOTE: this routine should only be called in PGASYNC_IDLE state.
*/
static void
handleSendFailure(PGconn *conn)
{
/* Preserve the error message emitted by the failing output routine */
char * svErrMsg = strdup(conn->errorMessage);
/*
* Accept any available input data, ignoring errors. Note that if
* pqReadData decides the backend has closed the channel, it will
* close our side of the socket --- that's just what we want here.
*/
while (pqReadData(conn) > 0)
/* loop until no more data readable */ ;
/*
* Parse any available input messages. Since we are in PGASYNC_IDLE
* state, only NOTICE and NOTIFY messages will be eaten.
*/
parseInput(conn);
/* Restore error message generated by output routine, if any. */
if (*svErrMsg != '\0')
strcpy(conn->errorMessage, svErrMsg);
free(svErrMsg);
}
/*
* Consume any available input from the backend
@ -1399,31 +1435,44 @@ PQfn(PGconn *conn,
/* clear the error string */
conn->errorMessage[0] = '\0';
if (pqPuts("F ", conn)) /* function */
return NULL;
if (pqPutInt(fnid, 4, conn))/* function id */
return NULL;
if (pqPutInt(nargs, 4, conn)) /* # of args */
if (pqPuts("F ", conn) || /* function */
pqPutInt(fnid, 4, conn) || /* function id */
pqPutInt(nargs, 4, conn)) /* # of args */
{
handleSendFailure(conn);
return NULL;
}
for (i = 0; i < nargs; ++i)
{ /* len.int4 + contents */
if (pqPutInt(args[i].len, 4, conn))
{
handleSendFailure(conn);
return NULL;
}
if (args[i].isint)
{
if (pqPutInt(args[i].u.integer, 4, conn))
{
handleSendFailure(conn);
return NULL;
}
}
else
{
if (pqPutnchar((char *) args[i].u.ptr, args[i].len, conn))
{
handleSendFailure(conn);
return NULL;
}
}
}
if (pqFlush(conn))
{
handleSendFailure(conn);
return NULL;
}
for (;;)
{