From 293f5c5f496cd8ce87c65b393613da675fc0bb8d Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Wed, 22 Jun 2022 12:12:00 -0400 Subject: [PATCH] Fix SPI's handling of errors during transaction commit. SPI_commit previously left it up to the caller to recover from any error occurring during commit. Since that's complicated and requires use of low-level xact.c facilities, it's not too surprising that no caller got it right. Let's move the responsibility for cleanup into spi.c. Doing that requires redefining SPI_commit as starting a new transaction, so that it becomes equivalent to SPI_commit_and_chain except that you get default transaction characteristics instead of preserving the prior transaction's characteristics. We can make this pretty transparent API-wise by redefining SPI_start_transaction() as a no-op. Callers that expect to do something in between might be surprised, but available evidence is that no callers do so. Having made that API redefinition, we can fix this mess by having SPI_commit[_and_chain] trap errors and start a new, clean transaction before re-throwing the error. Likewise for SPI_rollback[_and_chain]. Some cleanup is also needed in AtEOXact_SPI, which was nowhere near smart enough to deal with SPI contexts nested inside a committing context. While plperl and pltcl need no changes beyond removing their now-useless SPI_start_transaction() calls, plpython needs some more work because it hadn't gotten the memo about catching commit/rollback errors in the first place. Such an error resulted in longjmp'ing out of the Python interpreter, which leaks Python stack entries at present and is reported to crash Python 3.11 altogether. Add the missing logic to catch such errors and convert them into Python exceptions. This is a back-patch of commit 2e517818f. That's now aged long enough to reduce the concerns about whether it will break something, and we do need to ensure that supported branches will work with Python 3.11. Peter Eisentraut and Tom Lane Discussion: https://postgr.es/m/3375ffd8-d71c-2565-e348-a597d6e739e3@enterprisedb.com Discussion: https://postgr.es/m/17416-ed8fe5d7213d6c25@postgresql.org --- doc/src/sgml/spi.sgml | 51 ++-- src/backend/executor/spi.c | 225 +++++++++++++----- src/backend/tcop/postgres.c | 2 - src/backend/utils/mmgr/portalmem.c | 2 +- src/include/executor/spi.h | 1 - src/pl/plperl/expected/plperl_transaction.out | 48 ++++ src/pl/plperl/plperl.c | 2 - src/pl/plperl/sql/plperl_transaction.sql | 32 +++ src/pl/plpgsql/src/pl_exec.c | 6 - .../expected/plpython_transaction.out | 67 +++++- src/pl/plpython/plpy_plpymodule.c | 30 --- src/pl/plpython/plpy_spi.c | 94 ++++++++ src/pl/plpython/plpy_spi.h | 3 + src/pl/plpython/sql/plpython_transaction.sql | 30 +++ src/pl/tcl/expected/pltcl_transaction.out | 49 ++++ src/pl/tcl/pltcl.c | 2 - src/pl/tcl/sql/pltcl_transaction.sql | 37 +++ 17 files changed, 537 insertions(+), 144 deletions(-) diff --git a/doc/src/sgml/spi.sgml b/doc/src/sgml/spi.sgml index b2d330f17c..e52a57dc26 100644 --- a/doc/src/sgml/spi.sgml +++ b/doc/src/sgml/spi.sgml @@ -99,10 +99,9 @@ int SPI_connect_ext(int options) Sets the SPI connection to be nonatomic, which - means that transaction control calls SPI_commit, - SPI_rollback, and - SPI_start_transaction are allowed. Otherwise, - calling these functions will result in an immediate error. + means that transaction control calls (SPI_commit, + SPI_rollback) are allowed. Otherwise, + calling those functions will result in an immediate error. @@ -4405,15 +4404,17 @@ void SPI_commit_and_chain(void) SPI_commit commits the current transaction. It is approximately equivalent to running the SQL - command COMMIT. After a transaction is committed, a new - transaction has to be started - using SPI_start_transaction before further database - actions can be executed. + command COMMIT. After the transaction is committed, a + new transaction is automatically started using default transaction + characteristics, so that the caller can continue using SPI facilities. + If there is a failure during commit, the current transaction is instead + rolled back and a new transaction is started, after which the error is + thrown in the usual way. - SPI_commit_and_chain is the same, but a new - transaction is immediately started with the same transaction + SPI_commit_and_chain is the same, but the new + transaction is started with the same transaction characteristics as the just finished one, like with the SQL command COMMIT AND CHAIN. @@ -4458,14 +4459,13 @@ void SPI_rollback_and_chain(void) SPI_rollback rolls back the current transaction. It is approximately equivalent to running the SQL - command ROLLBACK. After a transaction is rolled back, a - new transaction has to be started - using SPI_start_transaction before further database - actions can be executed. + command ROLLBACK. After the transaction is rolled back, + a new transaction is automatically started using default transaction + characteristics, so that the caller can continue using SPI facilities. - SPI_rollback_and_chain is the same, but a new - transaction is immediately started with the same transaction + SPI_rollback_and_chain is the same, but the new + transaction is started with the same transaction characteristics as the just finished one, like with the SQL command ROLLBACK AND CHAIN. @@ -4489,7 +4489,7 @@ void SPI_rollback_and_chain(void) SPI_start_transaction - start a new transaction + obsolete function @@ -4502,17 +4502,12 @@ void SPI_start_transaction(void) Description - SPI_start_transaction starts a new transaction. It - can only be called after SPI_commit - or SPI_rollback, as there is no transaction active at - that point. Normally, when an SPI-using procedure is called, there is already a - transaction active, so attempting to start another one before closing out - the current one will result in an error. - - - - This function can only be executed if the SPI connection has been set as - nonatomic in the call to SPI_connect_ext. + SPI_start_transaction does nothing, and exists + only for code compatibility with + earlier PostgreSQL releases. It used to + be required after calling SPI_commit + or SPI_rollback, but now those functions start + a new transaction automatically. diff --git a/src/backend/executor/spi.c b/src/backend/executor/spi.c index 27849a927c..308e74fc0b 100644 --- a/src/backend/executor/spi.c +++ b/src/backend/executor/spi.c @@ -150,7 +150,8 @@ SPI_connect_ext(int options) * XXX It could be better to use PortalContext as the parent context in * all cases, but we may not be inside a portal (consider deferred-trigger * execution). Perhaps CurTransactionContext could be an option? For now - * it doesn't matter because we clean up explicitly in AtEOSubXact_SPI(). + * it doesn't matter because we clean up explicitly in AtEOSubXact_SPI(); + * but see also AtEOXact_SPI(). */ _SPI_current->procCxt = AllocSetContextCreate(_SPI_current->atomic ? TopTransactionContext : PortalContext, "SPI Proc", @@ -208,13 +209,13 @@ SPI_finish(void) return SPI_OK_FINISH; } +/* + * SPI_start_transaction is a no-op, kept for backwards compatibility. + * SPI callers are *always* inside a transaction. + */ void SPI_start_transaction(void) { - MemoryContext oldcontext = CurrentMemoryContext; - - StartTransactionCommand(); - MemoryContextSwitchTo(oldcontext); } static void @@ -222,6 +223,12 @@ _SPI_commit(bool chain) { MemoryContext oldcontext = CurrentMemoryContext; + /* + * Complain if we are in a context that doesn't permit transaction + * termination. (Note: here and _SPI_rollback should be the only places + * that throw ERRCODE_INVALID_TRANSACTION_TERMINATION, so that callers can + * test for that with security that they know what happened.) + */ if (_SPI_current->atomic) ereport(ERROR, (errcode(ERRCODE_INVALID_TRANSACTION_TERMINATION), @@ -234,40 +241,74 @@ _SPI_commit(bool chain) * top-level transaction in such a block violates that idea. A future PL * implementation might have different ideas about this, in which case * this restriction would have to be refined or the check possibly be - * moved out of SPI into the PLs. + * moved out of SPI into the PLs. Note however that the code below relies + * on not being within a subtransaction. */ if (IsSubTransaction()) ereport(ERROR, (errcode(ERRCODE_INVALID_TRANSACTION_TERMINATION), errmsg("cannot commit while a subtransaction is active"))); - /* - * Hold any pinned portals that any PLs might be using. We have to do - * this before changing transaction state, since this will run - * user-defined code that might throw an error. - */ - HoldPinnedPortals(); - - /* Start the actual commit */ - _SPI_current->internal_xact = true; - - /* Release snapshots associated with portals */ - ForgetPortalSnapshots(); - + /* XXX this ain't re-entrant enough for my taste */ if (chain) SaveTransactionCharacteristics(); - CommitTransactionCommand(); - - if (chain) + /* Catch any error occurring during the COMMIT */ + PG_TRY(); { + /* Protect current SPI stack entry against deletion */ + _SPI_current->internal_xact = true; + + /* + * Hold any pinned portals that any PLs might be using. We have to do + * this before changing transaction state, since this will run + * user-defined code that might throw an error. + */ + HoldPinnedPortals(); + + /* Release snapshots associated with portals */ + ForgetPortalSnapshots(); + + /* Do the deed */ + CommitTransactionCommand(); + + /* Immediately start a new transaction */ StartTransactionCommand(); - RestoreTransactionCharacteristics(); + if (chain) + RestoreTransactionCharacteristics(); + + MemoryContextSwitchTo(oldcontext); + + _SPI_current->internal_xact = false; } + PG_CATCH(); + { + ErrorData *edata; - MemoryContextSwitchTo(oldcontext); + /* Save error info in caller's context */ + MemoryContextSwitchTo(oldcontext); + edata = CopyErrorData(); + FlushErrorState(); - _SPI_current->internal_xact = false; + /* + * Abort the failed transaction. If this fails too, we'll just + * propagate the error out ... there's not that much we can do. + */ + AbortCurrentTransaction(); + + /* ... and start a new one */ + StartTransactionCommand(); + if (chain) + RestoreTransactionCharacteristics(); + + MemoryContextSwitchTo(oldcontext); + + _SPI_current->internal_xact = false; + + /* Now that we've cleaned up the transaction, re-throw the error */ + ReThrowError(edata); + } + PG_END_TRY(); } void @@ -287,6 +328,7 @@ _SPI_rollback(bool chain) { MemoryContext oldcontext = CurrentMemoryContext; + /* see under SPI_commit() */ if (_SPI_current->atomic) ereport(ERROR, (errcode(ERRCODE_INVALID_TRANSACTION_TERMINATION), @@ -298,34 +340,68 @@ _SPI_rollback(bool chain) (errcode(ERRCODE_INVALID_TRANSACTION_TERMINATION), errmsg("cannot roll back while a subtransaction is active"))); - /* - * Hold any pinned portals that any PLs might be using. We have to do - * this before changing transaction state, since this will run - * user-defined code that might throw an error, and in any case couldn't - * be run in an already-aborted transaction. - */ - HoldPinnedPortals(); - - /* Start the actual rollback */ - _SPI_current->internal_xact = true; - - /* Release snapshots associated with portals */ - ForgetPortalSnapshots(); - + /* XXX this ain't re-entrant enough for my taste */ if (chain) SaveTransactionCharacteristics(); - AbortCurrentTransaction(); - - if (chain) + /* Catch any error occurring during the ROLLBACK */ + PG_TRY(); { + /* Protect current SPI stack entry against deletion */ + _SPI_current->internal_xact = true; + + /* + * Hold any pinned portals that any PLs might be using. We have to do + * this before changing transaction state, since this will run + * user-defined code that might throw an error, and in any case + * couldn't be run in an already-aborted transaction. + */ + HoldPinnedPortals(); + + /* Release snapshots associated with portals */ + ForgetPortalSnapshots(); + + /* Do the deed */ + AbortCurrentTransaction(); + + /* Immediately start a new transaction */ StartTransactionCommand(); - RestoreTransactionCharacteristics(); + if (chain) + RestoreTransactionCharacteristics(); + + MemoryContextSwitchTo(oldcontext); + + _SPI_current->internal_xact = false; } + PG_CATCH(); + { + ErrorData *edata; - MemoryContextSwitchTo(oldcontext); + /* Save error info in caller's context */ + MemoryContextSwitchTo(oldcontext); + edata = CopyErrorData(); + FlushErrorState(); - _SPI_current->internal_xact = false; + /* + * Try again to abort the failed transaction. If this fails too, + * we'll just propagate the error out ... there's not that much we can + * do. + */ + AbortCurrentTransaction(); + + /* ... and start a new one */ + StartTransactionCommand(); + if (chain) + RestoreTransactionCharacteristics(); + + MemoryContextSwitchTo(oldcontext); + + _SPI_current->internal_xact = false; + + /* Now that we've cleaned up the transaction, re-throw the error */ + ReThrowError(edata); + } + PG_END_TRY(); } void @@ -340,38 +416,55 @@ SPI_rollback_and_chain(void) _SPI_rollback(true); } -/* - * Clean up SPI state. Called on transaction end (of non-SPI-internal - * transactions) and when returning to the main loop on error. - */ -void -SPICleanup(void) -{ - _SPI_current = NULL; - _SPI_connected = -1; - /* Reset API global variables, too */ - SPI_processed = 0; - SPI_tuptable = NULL; - SPI_result = 0; -} - /* * Clean up SPI state at transaction commit or abort. */ void AtEOXact_SPI(bool isCommit) { - /* Do nothing if the transaction end was initiated by SPI. */ - if (_SPI_current && _SPI_current->internal_xact) - return; + bool found = false; - if (isCommit && _SPI_connected != -1) + /* + * Pop stack entries, stopping if we find one marked internal_xact (that + * one belongs to the caller of SPI_commit or SPI_abort). + */ + while (_SPI_connected >= 0) + { + _SPI_connection *connection = &(_SPI_stack[_SPI_connected]); + + if (connection->internal_xact) + break; + + found = true; + + /* + * We need not release the procedure's memory contexts explicitly, as + * they'll go away automatically when their parent context does; see + * notes in SPI_connect_ext. + */ + + /* + * Restore outer global variables and pop the stack entry. Unlike + * SPI_finish(), we don't risk switching to memory contexts that might + * be already gone. + */ + SPI_processed = connection->outer_processed; + SPI_tuptable = connection->outer_tuptable; + SPI_result = connection->outer_result; + + _SPI_connected--; + if (_SPI_connected < 0) + _SPI_current = NULL; + else + _SPI_current = &(_SPI_stack[_SPI_connected]); + } + + /* We should only find entries to pop during an ABORT. */ + if (found && isCommit) ereport(WARNING, (errcode(ERRCODE_WARNING), errmsg("transaction left non-empty SPI stack"), errhint("Check for missing \"SPI_finish\" calls."))); - - SPICleanup(); } /* diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c index 1928cdd3c0..01891a9774 100644 --- a/src/backend/tcop/postgres.c +++ b/src/backend/tcop/postgres.c @@ -42,7 +42,6 @@ #include "catalog/pg_type.h" #include "commands/async.h" #include "commands/prepare.h" -#include "executor/spi.h" #include "jit/jit.h" #include "libpq/libpq.h" #include "libpq/pqformat.h" @@ -4057,7 +4056,6 @@ PostgresMain(int argc, char *argv[], WalSndErrorCleanup(); PortalErrorCleanup(); - SPICleanup(); /* * We can't release replication slots inside AbortTransaction() as we diff --git a/src/backend/utils/mmgr/portalmem.c b/src/backend/utils/mmgr/portalmem.c index b7de468773..1ab5592712 100644 --- a/src/backend/utils/mmgr/portalmem.c +++ b/src/backend/utils/mmgr/portalmem.c @@ -1274,7 +1274,7 @@ HoldPinnedPortals(void) */ if (portal->strategy != PORTAL_ONE_SELECT) ereport(ERROR, - (errcode(ERRCODE_INVALID_TRANSACTION_TERMINATION), + (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("cannot perform transaction commands inside a cursor loop that is not read-only"))); /* Verify it's in a suitable state to be held */ diff --git a/src/include/executor/spi.h b/src/include/executor/spi.h index 7bf361874d..7741dfbca8 100644 --- a/src/include/executor/spi.h +++ b/src/include/executor/spi.h @@ -164,7 +164,6 @@ extern void SPI_commit_and_chain(void); extern void SPI_rollback(void); extern void SPI_rollback_and_chain(void); -extern void SPICleanup(void); extern void AtEOXact_SPI(bool isCommit); extern void AtEOSubXact_SPI(bool isCommit, SubTransactionId mySubid); extern bool SPI_inside_nonatomic_context(void); diff --git a/src/pl/plperl/expected/plperl_transaction.out b/src/pl/plperl/expected/plperl_transaction.out index 7ca0ef35fb..da4283cbce 100644 --- a/src/pl/plperl/expected/plperl_transaction.out +++ b/src/pl/plperl/expected/plperl_transaction.out @@ -192,5 +192,53 @@ SELECT * FROM pg_cursors; ------+-----------+-------------+-----------+---------------+--------------- (0 rows) +-- check handling of an error during COMMIT +CREATE TABLE testpk (id int PRIMARY KEY); +CREATE TABLE testfk(f1 int REFERENCES testpk DEFERRABLE INITIALLY DEFERRED); +DO LANGUAGE plperl $$ +# this insert will fail during commit: +spi_exec_query("INSERT INTO testfk VALUES (0)"); +spi_commit(); +elog(WARNING, 'should not get here'); +$$; +ERROR: insert or update on table "testfk" violates foreign key constraint "testfk_f1_fkey" at line 4. +CONTEXT: PL/Perl anonymous code block +SELECT * FROM testpk; + id +---- +(0 rows) + +SELECT * FROM testfk; + f1 +---- +(0 rows) + +DO LANGUAGE plperl $$ +# this insert will fail during commit: +spi_exec_query("INSERT INTO testfk VALUES (0)"); +eval { + spi_commit(); +}; +if ($@) { + elog(INFO, $@); +} +# these inserts should work: +spi_exec_query("INSERT INTO testpk VALUES (1)"); +spi_exec_query("INSERT INTO testfk VALUES (1)"); +$$; +INFO: insert or update on table "testfk" violates foreign key constraint "testfk_f1_fkey" at line 5. + +SELECT * FROM testpk; + id +---- + 1 +(1 row) + +SELECT * FROM testfk; + f1 +---- + 1 +(1 row) + DROP TABLE test1; DROP TABLE test2; diff --git a/src/pl/plperl/plperl.c b/src/pl/plperl/plperl.c index 8c4e65936e..850bd53130 100644 --- a/src/pl/plperl/plperl.c +++ b/src/pl/plperl/plperl.c @@ -4010,7 +4010,6 @@ plperl_spi_commit(void) PG_TRY(); { SPI_commit(); - SPI_start_transaction(); } PG_CATCH(); { @@ -4037,7 +4036,6 @@ plperl_spi_rollback(void) PG_TRY(); { SPI_rollback(); - SPI_start_transaction(); } PG_CATCH(); { diff --git a/src/pl/plperl/sql/plperl_transaction.sql b/src/pl/plperl/sql/plperl_transaction.sql index 0a60799805..d10c8bee89 100644 --- a/src/pl/plperl/sql/plperl_transaction.sql +++ b/src/pl/plperl/sql/plperl_transaction.sql @@ -159,5 +159,37 @@ SELECT * FROM test1; SELECT * FROM pg_cursors; +-- check handling of an error during COMMIT +CREATE TABLE testpk (id int PRIMARY KEY); +CREATE TABLE testfk(f1 int REFERENCES testpk DEFERRABLE INITIALLY DEFERRED); + +DO LANGUAGE plperl $$ +# this insert will fail during commit: +spi_exec_query("INSERT INTO testfk VALUES (0)"); +spi_commit(); +elog(WARNING, 'should not get here'); +$$; + +SELECT * FROM testpk; +SELECT * FROM testfk; + +DO LANGUAGE plperl $$ +# this insert will fail during commit: +spi_exec_query("INSERT INTO testfk VALUES (0)"); +eval { + spi_commit(); +}; +if ($@) { + elog(INFO, $@); +} +# these inserts should work: +spi_exec_query("INSERT INTO testpk VALUES (1)"); +spi_exec_query("INSERT INTO testfk VALUES (1)"); +$$; + +SELECT * FROM testpk; +SELECT * FROM testfk; + + DROP TABLE test1; DROP TABLE test2; diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c index 3358f830f8..fe3f9fdf27 100644 --- a/src/pl/plpgsql/src/pl_exec.c +++ b/src/pl/plpgsql/src/pl_exec.c @@ -4876,10 +4876,7 @@ exec_stmt_commit(PLpgSQL_execstate *estate, PLpgSQL_stmt_commit *stmt) if (stmt->chain) SPI_commit_and_chain(); else - { SPI_commit(); - SPI_start_transaction(); - } /* * We need to build new simple-expression infrastructure, since the old @@ -4902,10 +4899,7 @@ exec_stmt_rollback(PLpgSQL_execstate *estate, PLpgSQL_stmt_rollback *stmt) if (stmt->chain) SPI_rollback_and_chain(); else - { SPI_rollback(); - SPI_start_transaction(); - } /* * We need to build new simple-expression infrastructure, since the old diff --git a/src/pl/plpython/expected/plpython_transaction.out b/src/pl/plpython/expected/plpython_transaction.out index 14152993c7..72d1e45a76 100644 --- a/src/pl/plpython/expected/plpython_transaction.out +++ b/src/pl/plpython/expected/plpython_transaction.out @@ -55,8 +55,11 @@ for i in range(0, 10): return 1 $$; SELECT transaction_test2(); -ERROR: invalid transaction termination -CONTEXT: PL/Python function "transaction_test2" +ERROR: spiexceptions.InvalidTransactionTermination: invalid transaction termination +CONTEXT: Traceback (most recent call last): + PL/Python function "transaction_test2", line 5, in + plpy.commit() +PL/Python function "transaction_test2" SELECT * FROM test1; a | b ---+--- @@ -70,7 +73,7 @@ plpy.execute("CALL transaction_test1()") return 1 $$; SELECT transaction_test3(); -ERROR: spiexceptions.InvalidTransactionTermination: invalid transaction termination +ERROR: spiexceptions.InvalidTransactionTermination: spiexceptions.InvalidTransactionTermination: invalid transaction termination CONTEXT: Traceback (most recent call last): PL/Python function "transaction_test3", line 2, in plpy.execute("CALL transaction_test1()") @@ -88,7 +91,7 @@ plpy.execute("DO LANGUAGE plpythonu $x$ plpy.commit() $x$") return 1 $$; SELECT transaction_test4(); -ERROR: spiexceptions.InvalidTransactionTermination: invalid transaction termination +ERROR: spiexceptions.InvalidTransactionTermination: spiexceptions.InvalidTransactionTermination: invalid transaction termination CONTEXT: Traceback (most recent call last): PL/Python function "transaction_test4", line 2, in plpy.execute("DO LANGUAGE plpythonu $x$ plpy.commit() $x$") @@ -100,8 +103,11 @@ s.enter() plpy.commit() $$; WARNING: forcibly aborting a subtransaction that has not been exited -ERROR: cannot commit while a subtransaction is active -CONTEXT: PL/Python anonymous code block +ERROR: spiexceptions.InvalidTransactionTermination: cannot commit while a subtransaction is active +CONTEXT: Traceback (most recent call last): + PL/Python anonymous code block, line 4, in + plpy.commit() +PL/Python anonymous code block -- commit inside cursor loop CREATE TABLE test2 (x int); INSERT INTO test2 VALUES (0), (1), (2), (3), (4); @@ -191,5 +197,54 @@ SELECT * FROM pg_cursors; ------+-----------+-------------+-----------+---------------+--------------- (0 rows) +-- check handling of an error during COMMIT +CREATE TABLE testpk (id int PRIMARY KEY); +CREATE TABLE testfk(f1 int REFERENCES testpk DEFERRABLE INITIALLY DEFERRED); +DO LANGUAGE plpythonu $$ +# this insert will fail during commit: +plpy.execute("INSERT INTO testfk VALUES (0)") +plpy.commit() +plpy.warning('should not get here') +$$; +ERROR: spiexceptions.ForeignKeyViolation: insert or update on table "testfk" violates foreign key constraint "testfk_f1_fkey" +DETAIL: Key (f1)=(0) is not present in table "testpk". +CONTEXT: Traceback (most recent call last): + PL/Python anonymous code block, line 4, in + plpy.commit() +PL/Python anonymous code block +SELECT * FROM testpk; + id +---- +(0 rows) + +SELECT * FROM testfk; + f1 +---- +(0 rows) + +DO LANGUAGE plpythonu $$ +# this insert will fail during commit: +plpy.execute("INSERT INTO testfk VALUES (0)") +try: + plpy.commit() +except Exception as e: + plpy.info('sqlstate: %s' % (e.sqlstate)) +# these inserts should work: +plpy.execute("INSERT INTO testpk VALUES (1)") +plpy.execute("INSERT INTO testfk VALUES (1)") +$$; +INFO: sqlstate: 23503 +SELECT * FROM testpk; + id +---- + 1 +(1 row) + +SELECT * FROM testfk; + f1 +---- + 1 +(1 row) + DROP TABLE test1; DROP TABLE test2; diff --git a/src/pl/plpython/plpy_plpymodule.c b/src/pl/plpython/plpy_plpymodule.c index c80b35040b..a1575c046f 100644 --- a/src/pl/plpython/plpy_plpymodule.c +++ b/src/pl/plpython/plpy_plpymodule.c @@ -44,8 +44,6 @@ static PyObject *PLy_fatal(PyObject *self, PyObject *args, PyObject *kw); static PyObject *PLy_quote_literal(PyObject *self, PyObject *args); static PyObject *PLy_quote_nullable(PyObject *self, PyObject *args); static PyObject *PLy_quote_ident(PyObject *self, PyObject *args); -static PyObject *PLy_commit(PyObject *self, PyObject *args); -static PyObject *PLy_rollback(PyObject *self, PyObject *args); /* A list of all known exceptions, generated from backend/utils/errcodes.txt */ @@ -582,31 +580,3 @@ PLy_output(volatile int level, PyObject *self, PyObject *args, PyObject *kw) */ Py_RETURN_NONE; } - -static PyObject * -PLy_commit(PyObject *self, PyObject *args) -{ - PLyExecutionContext *exec_ctx = PLy_current_execution_context(); - - SPI_commit(); - SPI_start_transaction(); - - /* was cleared at transaction end, reset pointer */ - exec_ctx->scratch_ctx = NULL; - - Py_RETURN_NONE; -} - -static PyObject * -PLy_rollback(PyObject *self, PyObject *args) -{ - PLyExecutionContext *exec_ctx = PLy_current_execution_context(); - - SPI_rollback(); - SPI_start_transaction(); - - /* was cleared at transaction end, reset pointer */ - exec_ctx->scratch_ctx = NULL; - - Py_RETURN_NONE; -} diff --git a/src/pl/plpython/plpy_spi.c b/src/pl/plpython/plpy_spi.c index 2fe435d42b..586dfa8163 100644 --- a/src/pl/plpython/plpy_spi.c +++ b/src/pl/plpython/plpy_spi.c @@ -462,6 +462,100 @@ PLy_spi_execute_fetch_result(SPITupleTable *tuptable, uint64 rows, int status) return (PyObject *) result; } +PyObject * +PLy_commit(PyObject *self, PyObject *args) +{ + MemoryContext oldcontext = CurrentMemoryContext; + PLyExecutionContext *exec_ctx = PLy_current_execution_context(); + + PG_TRY(); + { + SPI_commit(); + + /* was cleared at transaction end, reset pointer */ + exec_ctx->scratch_ctx = NULL; + } + PG_CATCH(); + { + ErrorData *edata; + PLyExceptionEntry *entry; + PyObject *exc; + + /* Save error info */ + MemoryContextSwitchTo(oldcontext); + edata = CopyErrorData(); + FlushErrorState(); + + /* was cleared at transaction end, reset pointer */ + exec_ctx->scratch_ctx = NULL; + + /* Look up the correct exception */ + entry = hash_search(PLy_spi_exceptions, &(edata->sqlerrcode), + HASH_FIND, NULL); + + /* + * This could be a custom error code, if that's the case fallback to + * SPIError + */ + exc = entry ? entry->exc : PLy_exc_spi_error; + /* Make Python raise the exception */ + PLy_spi_exception_set(exc, edata); + FreeErrorData(edata); + + return NULL; + } + PG_END_TRY(); + + Py_RETURN_NONE; +} + +PyObject * +PLy_rollback(PyObject *self, PyObject *args) +{ + MemoryContext oldcontext = CurrentMemoryContext; + PLyExecutionContext *exec_ctx = PLy_current_execution_context(); + + PG_TRY(); + { + SPI_rollback(); + + /* was cleared at transaction end, reset pointer */ + exec_ctx->scratch_ctx = NULL; + } + PG_CATCH(); + { + ErrorData *edata; + PLyExceptionEntry *entry; + PyObject *exc; + + /* Save error info */ + MemoryContextSwitchTo(oldcontext); + edata = CopyErrorData(); + FlushErrorState(); + + /* was cleared at transaction end, reset pointer */ + exec_ctx->scratch_ctx = NULL; + + /* Look up the correct exception */ + entry = hash_search(PLy_spi_exceptions, &(edata->sqlerrcode), + HASH_FIND, NULL); + + /* + * This could be a custom error code, if that's the case fallback to + * SPIError + */ + exc = entry ? entry->exc : PLy_exc_spi_error; + /* Make Python raise the exception */ + PLy_spi_exception_set(exc, edata); + FreeErrorData(edata); + + return NULL; + } + PG_END_TRY(); + + Py_RETURN_NONE; +} + /* * Utilities for running SPI functions in subtransactions. * diff --git a/src/pl/plpython/plpy_spi.h b/src/pl/plpython/plpy_spi.h index ec7b689359..2aaff7455e 100644 --- a/src/pl/plpython/plpy_spi.h +++ b/src/pl/plpython/plpy_spi.h @@ -13,6 +13,9 @@ extern PyObject *PLy_spi_prepare(PyObject *self, PyObject *args); extern PyObject *PLy_spi_execute(PyObject *self, PyObject *args); extern PyObject *PLy_spi_execute_plan(PyObject *ob, PyObject *list, long limit); +extern PyObject *PLy_commit(PyObject *self, PyObject *args); +extern PyObject *PLy_rollback(PyObject *self, PyObject *args); + typedef struct PLyExceptionEntry { int sqlstate; /* hash key, must be first */ diff --git a/src/pl/plpython/sql/plpython_transaction.sql b/src/pl/plpython/sql/plpython_transaction.sql index 33b37e5b7f..68588d9fb0 100644 --- a/src/pl/plpython/sql/plpython_transaction.sql +++ b/src/pl/plpython/sql/plpython_transaction.sql @@ -148,5 +148,35 @@ SELECT * FROM test1; SELECT * FROM pg_cursors; +-- check handling of an error during COMMIT +CREATE TABLE testpk (id int PRIMARY KEY); +CREATE TABLE testfk(f1 int REFERENCES testpk DEFERRABLE INITIALLY DEFERRED); + +DO LANGUAGE plpythonu $$ +# this insert will fail during commit: +plpy.execute("INSERT INTO testfk VALUES (0)") +plpy.commit() +plpy.warning('should not get here') +$$; + +SELECT * FROM testpk; +SELECT * FROM testfk; + +DO LANGUAGE plpythonu $$ +# this insert will fail during commit: +plpy.execute("INSERT INTO testfk VALUES (0)") +try: + plpy.commit() +except Exception as e: + plpy.info('sqlstate: %s' % (e.sqlstate)) +# these inserts should work: +plpy.execute("INSERT INTO testpk VALUES (1)") +plpy.execute("INSERT INTO testfk VALUES (1)") +$$; + +SELECT * FROM testpk; +SELECT * FROM testfk; + + DROP TABLE test1; DROP TABLE test2; diff --git a/src/pl/tcl/expected/pltcl_transaction.out b/src/pl/tcl/expected/pltcl_transaction.out index 007204b99a..f557b79138 100644 --- a/src/pl/tcl/expected/pltcl_transaction.out +++ b/src/pl/tcl/expected/pltcl_transaction.out @@ -96,5 +96,54 @@ SELECT * FROM test1; ---+--- (0 rows) +-- check handling of an error during COMMIT +CREATE TABLE testpk (id int PRIMARY KEY); +CREATE TABLE testfk(f1 int REFERENCES testpk DEFERRABLE INITIALLY DEFERRED); +CREATE PROCEDURE transaction_testfk() +LANGUAGE pltcl +AS $$ +# this insert will fail during commit: +spi_exec "INSERT INTO testfk VALUES (0)" +commit +elog WARNING "should not get here" +$$; +CALL transaction_testfk(); +ERROR: insert or update on table "testfk" violates foreign key constraint "testfk_f1_fkey" +SELECT * FROM testpk; + id +---- +(0 rows) + +SELECT * FROM testfk; + f1 +---- +(0 rows) + +CREATE OR REPLACE PROCEDURE transaction_testfk() +LANGUAGE pltcl +AS $$ +# this insert will fail during commit: +spi_exec "INSERT INTO testfk VALUES (0)" +if [catch {commit} msg] { + elog INFO $msg +} +# these inserts should work: +spi_exec "INSERT INTO testpk VALUES (1)" +spi_exec "INSERT INTO testfk VALUES (1)" +$$; +CALL transaction_testfk(); +INFO: insert or update on table "testfk" violates foreign key constraint "testfk_f1_fkey" +SELECT * FROM testpk; + id +---- + 1 +(1 row) + +SELECT * FROM testfk; + f1 +---- + 1 +(1 row) + DROP TABLE test1; DROP TABLE test2; diff --git a/src/pl/tcl/pltcl.c b/src/pl/tcl/pltcl.c index eecd2032d8..58fd348870 100644 --- a/src/pl/tcl/pltcl.c +++ b/src/pl/tcl/pltcl.c @@ -2939,7 +2939,6 @@ pltcl_commit(ClientData cdata, Tcl_Interp *interp, PG_TRY(); { SPI_commit(); - SPI_start_transaction(); } PG_CATCH(); { @@ -2979,7 +2978,6 @@ pltcl_rollback(ClientData cdata, Tcl_Interp *interp, PG_TRY(); { SPI_rollback(); - SPI_start_transaction(); } PG_CATCH(); { diff --git a/src/pl/tcl/sql/pltcl_transaction.sql b/src/pl/tcl/sql/pltcl_transaction.sql index c752faf665..bd759850a7 100644 --- a/src/pl/tcl/sql/pltcl_transaction.sql +++ b/src/pl/tcl/sql/pltcl_transaction.sql @@ -94,5 +94,42 @@ CALL transaction_test4b(); SELECT * FROM test1; +-- check handling of an error during COMMIT +CREATE TABLE testpk (id int PRIMARY KEY); +CREATE TABLE testfk(f1 int REFERENCES testpk DEFERRABLE INITIALLY DEFERRED); + +CREATE PROCEDURE transaction_testfk() +LANGUAGE pltcl +AS $$ +# this insert will fail during commit: +spi_exec "INSERT INTO testfk VALUES (0)" +commit +elog WARNING "should not get here" +$$; + +CALL transaction_testfk(); + +SELECT * FROM testpk; +SELECT * FROM testfk; + +CREATE OR REPLACE PROCEDURE transaction_testfk() +LANGUAGE pltcl +AS $$ +# this insert will fail during commit: +spi_exec "INSERT INTO testfk VALUES (0)" +if [catch {commit} msg] { + elog INFO $msg +} +# these inserts should work: +spi_exec "INSERT INTO testpk VALUES (1)" +spi_exec "INSERT INTO testfk VALUES (1)" +$$; + +CALL transaction_testfk(); + +SELECT * FROM testpk; +SELECT * FROM testfk; + + DROP TABLE test1; DROP TABLE test2;