1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
|
/*-------------------------------------------------------------------------
*
* execAsync.c
* Support routines for asynchronous execution
*
* Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* src/backend/executor/execAsync.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "executor/execAsync.h"
#include "executor/nodeAppend.h"
#include "executor/nodeForeignscan.h"
/*
* Asynchronously request a tuple from a designed async-capable node.
*/
void
ExecAsyncRequest(AsyncRequest *areq)
{
switch (nodeTag(areq->requestee))
{
case T_ForeignScanState:
ExecAsyncForeignScanRequest(areq);
break;
default:
/* If the node doesn't support async, caller messed up. */
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(areq->requestee));
}
ExecAsyncResponse(areq);
}
/*
* Give the asynchronous node a chance to configure the file descriptor event
* for which it wishes to wait. We expect the node-type specific callback to
* make a single call of the following form:
*
* AddWaitEventToSet(set, WL_SOCKET_READABLE, fd, NULL, areq);
*/
void
ExecAsyncConfigureWait(AsyncRequest *areq)
{
switch (nodeTag(areq->requestee))
{
case T_ForeignScanState:
ExecAsyncForeignScanConfigureWait(areq);
break;
default:
/* If the node doesn't support async, caller messed up. */
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(areq->requestee));
}
}
/*
* Call the asynchronous node back when a relevant event has occurred.
*/
void
ExecAsyncNotify(AsyncRequest *areq)
{
switch (nodeTag(areq->requestee))
{
case T_ForeignScanState:
ExecAsyncForeignScanNotify(areq);
break;
default:
/* If the node doesn't support async, caller messed up. */
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(areq->requestee));
}
ExecAsyncResponse(areq);
}
/*
* Call the requestor back when an asynchronous node has produced a result.
*/
void
ExecAsyncResponse(AsyncRequest *areq)
{
switch (nodeTag(areq->requestor))
{
case T_AppendState:
ExecAsyncAppendResponse(areq);
break;
default:
/* If the node doesn't support async, caller messed up. */
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(areq->requestor));
}
}
/*
* A requestee node should call this function to deliver the tuple to its
* requestor node. The requestee node can call this from its ExecAsyncRequest
* or ExecAsyncNotify callback.
*/
void
ExecAsyncRequestDone(AsyncRequest *areq, TupleTableSlot *result)
{
areq->request_complete = true;
areq->result = result;
}
/*
* A requestee node should call this function to indicate that it is pending
* for a callback. The requestee node can call this from its ExecAsyncRequest
* or ExecAsyncNotify callback.
*/
void
ExecAsyncRequestPending(AsyncRequest *areq)
{
areq->callback_pending = true;
areq->request_complete = false;
areq->result = NULL;
}
|
