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-rw-r--r--src/backend/executor/spi.c82
1 files changed, 53 insertions, 29 deletions
diff --git a/src/backend/executor/spi.c b/src/backend/executor/spi.c
index 00aa78ea539..b8bd05e8942 100644
--- a/src/backend/executor/spi.c
+++ b/src/backend/executor/spi.c
@@ -66,7 +66,7 @@ static void _SPI_prepare_oneshot_plan(const char *src, SPIPlanPtr plan);
static int _SPI_execute_plan(SPIPlanPtr plan, ParamListInfo paramLI,
Snapshot snapshot, Snapshot crosscheck_snapshot,
- bool read_only, bool no_snapshots,
+ bool read_only, bool allow_nonatomic,
bool fire_triggers, uint64 tcount,
DestReceiver *caller_dest,
ResourceOwner plan_owner);
@@ -260,12 +260,8 @@ _SPI_commit(bool chain)
/* Start the actual commit */
_SPI_current->internal_xact = true;
- /*
- * Before committing, pop all active snapshots to avoid error about
- * "snapshot %p still active".
- */
- while (ActiveSnapshotSet())
- PopActiveSnapshot();
+ /* Release snapshots associated with portals */
+ ForgetPortalSnapshots();
if (chain)
SaveTransactionCharacteristics();
@@ -322,6 +318,9 @@ _SPI_rollback(bool chain)
/* Start the actual rollback */
_SPI_current->internal_xact = true;
+ /* Release snapshots associated with portals */
+ ForgetPortalSnapshots();
+
if (chain)
SaveTransactionCharacteristics();
@@ -567,7 +566,7 @@ SPI_execute_extended(const char *src,
res = _SPI_execute_plan(&plan, options->params,
InvalidSnapshot, InvalidSnapshot,
- options->read_only, options->no_snapshots,
+ options->read_only, options->allow_nonatomic,
true, options->tcount,
options->dest, options->owner);
@@ -627,7 +626,7 @@ SPI_execute_plan_extended(SPIPlanPtr plan,
res = _SPI_execute_plan(plan, options->params,
InvalidSnapshot, InvalidSnapshot,
- options->read_only, options->no_snapshots,
+ options->read_only, options->allow_nonatomic,
true, options->tcount,
options->dest, options->owner);
@@ -2264,7 +2263,7 @@ _SPI_prepare_oneshot_plan(const char *src, SPIPlanPtr plan)
* behavior of taking a new snapshot for each query.
* crosscheck_snapshot: for RI use, all others pass InvalidSnapshot
* read_only: true for read-only execution (no CommandCounterIncrement)
- * no_snapshots: true to skip snapshot management
+ * allow_nonatomic: true to allow nonatomic CALL/DO execution
* fire_triggers: true to fire AFTER triggers at end of query (normal case);
* false means any AFTER triggers are postponed to end of outer query
* tcount: execution tuple-count limit, or 0 for none
@@ -2275,7 +2274,7 @@ _SPI_prepare_oneshot_plan(const char *src, SPIPlanPtr plan)
static int
_SPI_execute_plan(SPIPlanPtr plan, ParamListInfo paramLI,
Snapshot snapshot, Snapshot crosscheck_snapshot,
- bool read_only, bool no_snapshots,
+ bool read_only, bool allow_nonatomic,
bool fire_triggers, uint64 tcount,
DestReceiver *caller_dest, ResourceOwner plan_owner)
{
@@ -2318,11 +2317,12 @@ _SPI_execute_plan(SPIPlanPtr plan, ParamListInfo paramLI,
* In the first two cases, we can just push the snap onto the stack once
* for the whole plan list.
*
- * But if no_snapshots is true, then don't manage snapshots at all here.
- * The caller must then take care of that.
+ * Note that snapshot != InvalidSnapshot implies an atomic execution
+ * context.
*/
- if (snapshot != InvalidSnapshot && !no_snapshots)
+ if (snapshot != InvalidSnapshot)
{
+ Assert(!allow_nonatomic);
if (read_only)
{
PushActiveSnapshot(snapshot);
@@ -2408,15 +2408,39 @@ _SPI_execute_plan(SPIPlanPtr plan, ParamListInfo paramLI,
stmt_list = cplan->stmt_list;
/*
- * In the default non-read-only case, get a new snapshot, replacing
- * any that we pushed in a previous cycle.
+ * If we weren't given a specific snapshot to use, and the statement
+ * list requires a snapshot, set that up.
*/
- if (snapshot == InvalidSnapshot && !read_only && !no_snapshots)
+ if (snapshot == InvalidSnapshot &&
+ (list_length(stmt_list) > 1 ||
+ (list_length(stmt_list) == 1 &&
+ PlannedStmtRequiresSnapshot(linitial_node(PlannedStmt,
+ stmt_list)))))
{
- if (pushed_active_snap)
- PopActiveSnapshot();
- PushActiveSnapshot(GetTransactionSnapshot());
- pushed_active_snap = true;
+ /*
+ * First, ensure there's a Portal-level snapshot. This back-fills
+ * the snapshot stack in case the previous operation was a COMMIT
+ * or ROLLBACK inside a procedure or DO block. (We can't put back
+ * the Portal snapshot any sooner, or we'd break cases like doing
+ * SET or LOCK just after COMMIT.) It's enough to check once per
+ * statement list, since COMMIT/ROLLBACK/CALL/DO can't appear
+ * within a multi-statement list.
+ */
+ EnsurePortalSnapshotExists();
+
+ /*
+ * In the default non-read-only case, get a new per-statement-list
+ * snapshot, replacing any that we pushed in a previous cycle.
+ * Skip it when doing non-atomic execution, though (we rely
+ * entirely on the Portal snapshot in that case).
+ */
+ if (!read_only && !allow_nonatomic)
+ {
+ if (pushed_active_snap)
+ PopActiveSnapshot();
+ PushActiveSnapshot(GetTransactionSnapshot());
+ pushed_active_snap = true;
+ }
}
foreach(lc2, stmt_list)
@@ -2434,6 +2458,7 @@ _SPI_execute_plan(SPIPlanPtr plan, ParamListInfo paramLI,
_SPI_current->processed = 0;
_SPI_current->tuptable = NULL;
+ /* Check for unsupported cases. */
if (stmt->utilityStmt)
{
if (IsA(stmt->utilityStmt, CopyStmt))
@@ -2462,9 +2487,10 @@ _SPI_execute_plan(SPIPlanPtr plan, ParamListInfo paramLI,
/*
* If not read-only mode, advance the command counter before each
- * command and update the snapshot.
+ * command and update the snapshot. (But skip it if the snapshot
+ * isn't under our control.)
*/
- if (!read_only && !no_snapshots)
+ if (!read_only && pushed_active_snap)
{
CommandCounterIncrement();
UpdateActiveSnapshotCommandId();
@@ -2507,13 +2533,11 @@ _SPI_execute_plan(SPIPlanPtr plan, ParamListInfo paramLI,
QueryCompletion qc;
/*
- * If the SPI context is atomic, or we are asked to manage
- * snapshots, then we are in an atomic execution context.
- * Conversely, to propagate a nonatomic execution context, the
- * caller must be in a nonatomic SPI context and manage
- * snapshots itself.
+ * If the SPI context is atomic, or we were not told to allow
+ * nonatomic operations, tell ProcessUtility this is an atomic
+ * execution context.
*/
- if (_SPI_current->atomic || !no_snapshots)
+ if (_SPI_current->atomic || !allow_nonatomic)
context = PROCESS_UTILITY_QUERY;
else
context = PROCESS_UTILITY_QUERY_NONATOMIC;
generated by cgit v1.2.3 (git 2.25.1) at 2025-05-31 06:36:11 +0000