/src/postgres/src/backend/executor/execAsync.c
Line | Count | Source |
1 | | /*------------------------------------------------------------------------- |
2 | | * |
3 | | * execAsync.c |
4 | | * Support routines for asynchronous execution |
5 | | * |
6 | | * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group |
7 | | * Portions Copyright (c) 1994, Regents of the University of California |
8 | | * |
9 | | * IDENTIFICATION |
10 | | * src/backend/executor/execAsync.c |
11 | | * |
12 | | *------------------------------------------------------------------------- |
13 | | */ |
14 | | |
15 | | #include "postgres.h" |
16 | | |
17 | | #include "executor/execAsync.h" |
18 | | #include "executor/executor.h" |
19 | | #include "executor/instrument.h" |
20 | | #include "executor/nodeAppend.h" |
21 | | #include "executor/nodeForeignscan.h" |
22 | | |
23 | | /* |
24 | | * Asynchronously request a tuple from a designed async-capable node. |
25 | | */ |
26 | | void |
27 | | ExecAsyncRequest(AsyncRequest *areq) |
28 | 0 | { |
29 | 0 | if (areq->requestee->chgParam != NULL) /* something changed? */ |
30 | 0 | ExecReScan(areq->requestee); /* let ReScan handle this */ |
31 | | |
32 | | /* must provide our own instrumentation support */ |
33 | 0 | if (areq->requestee->instrument) |
34 | 0 | InstrStartNode(areq->requestee->instrument); |
35 | |
|
36 | 0 | switch (nodeTag(areq->requestee)) |
37 | 0 | { |
38 | 0 | case T_ForeignScanState: |
39 | 0 | ExecAsyncForeignScanRequest(areq); |
40 | 0 | break; |
41 | 0 | default: |
42 | | /* If the node doesn't support async, caller messed up. */ |
43 | 0 | elog(ERROR, "unrecognized node type: %d", |
44 | 0 | (int) nodeTag(areq->requestee)); |
45 | 0 | } |
46 | | |
47 | 0 | ExecAsyncResponse(areq); |
48 | | |
49 | | /* must provide our own instrumentation support */ |
50 | 0 | if (areq->requestee->instrument) |
51 | 0 | InstrStopNode(areq->requestee->instrument, |
52 | 0 | TupIsNull(areq->result) ? 0.0 : 1.0); |
53 | 0 | } |
54 | | |
55 | | /* |
56 | | * Give the asynchronous node a chance to configure the file descriptor event |
57 | | * for which it wishes to wait. We expect the node-type specific callback to |
58 | | * make a single call of the following form: |
59 | | * |
60 | | * AddWaitEventToSet(set, WL_SOCKET_READABLE, fd, NULL, areq); |
61 | | */ |
62 | | void |
63 | | ExecAsyncConfigureWait(AsyncRequest *areq) |
64 | 0 | { |
65 | | /* must provide our own instrumentation support */ |
66 | 0 | if (areq->requestee->instrument) |
67 | 0 | InstrStartNode(areq->requestee->instrument); |
68 | |
|
69 | 0 | switch (nodeTag(areq->requestee)) |
70 | 0 | { |
71 | 0 | case T_ForeignScanState: |
72 | 0 | ExecAsyncForeignScanConfigureWait(areq); |
73 | 0 | break; |
74 | 0 | default: |
75 | | /* If the node doesn't support async, caller messed up. */ |
76 | 0 | elog(ERROR, "unrecognized node type: %d", |
77 | 0 | (int) nodeTag(areq->requestee)); |
78 | 0 | } |
79 | | |
80 | | /* must provide our own instrumentation support */ |
81 | 0 | if (areq->requestee->instrument) |
82 | 0 | InstrStopNode(areq->requestee->instrument, 0.0); |
83 | 0 | } |
84 | | |
85 | | /* |
86 | | * Call the asynchronous node back when a relevant event has occurred. |
87 | | */ |
88 | | void |
89 | | ExecAsyncNotify(AsyncRequest *areq) |
90 | 0 | { |
91 | | /* must provide our own instrumentation support */ |
92 | 0 | if (areq->requestee->instrument) |
93 | 0 | InstrStartNode(areq->requestee->instrument); |
94 | |
|
95 | 0 | switch (nodeTag(areq->requestee)) |
96 | 0 | { |
97 | 0 | case T_ForeignScanState: |
98 | 0 | ExecAsyncForeignScanNotify(areq); |
99 | 0 | break; |
100 | 0 | default: |
101 | | /* If the node doesn't support async, caller messed up. */ |
102 | 0 | elog(ERROR, "unrecognized node type: %d", |
103 | 0 | (int) nodeTag(areq->requestee)); |
104 | 0 | } |
105 | | |
106 | 0 | ExecAsyncResponse(areq); |
107 | | |
108 | | /* must provide our own instrumentation support */ |
109 | 0 | if (areq->requestee->instrument) |
110 | 0 | InstrStopNode(areq->requestee->instrument, |
111 | 0 | TupIsNull(areq->result) ? 0.0 : 1.0); |
112 | 0 | } |
113 | | |
114 | | /* |
115 | | * Call the requestor back when an asynchronous node has produced a result. |
116 | | */ |
117 | | void |
118 | | ExecAsyncResponse(AsyncRequest *areq) |
119 | 0 | { |
120 | 0 | switch (nodeTag(areq->requestor)) |
121 | 0 | { |
122 | 0 | case T_AppendState: |
123 | 0 | ExecAsyncAppendResponse(areq); |
124 | 0 | break; |
125 | 0 | default: |
126 | | /* If the node doesn't support async, caller messed up. */ |
127 | 0 | elog(ERROR, "unrecognized node type: %d", |
128 | 0 | (int) nodeTag(areq->requestor)); |
129 | 0 | } |
130 | 0 | } |
131 | | |
132 | | /* |
133 | | * A requestee node should call this function to deliver the tuple to its |
134 | | * requestor node. The requestee node can call this from its ExecAsyncRequest |
135 | | * or ExecAsyncNotify callback. |
136 | | */ |
137 | | void |
138 | | ExecAsyncRequestDone(AsyncRequest *areq, TupleTableSlot *result) |
139 | 0 | { |
140 | 0 | areq->request_complete = true; |
141 | 0 | areq->result = result; |
142 | 0 | } |
143 | | |
144 | | /* |
145 | | * A requestee node should call this function to indicate that it is pending |
146 | | * for a callback. The requestee node can call this from its ExecAsyncRequest |
147 | | * or ExecAsyncNotify callback. |
148 | | */ |
149 | | void |
150 | | ExecAsyncRequestPending(AsyncRequest *areq) |
151 | 0 | { |
152 | 0 | areq->callback_pending = true; |
153 | 0 | areq->request_complete = false; |
154 | | areq->result = NULL; |
155 | 0 | } |