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postgresql/src/include/utils/resowner.h

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Invent ResourceOwner mechanism as per my recent proposal, and use it to keep track of portal-related resources separately from transaction-related resources. This allows cursors to work in a somewhat sane fashion with nested transactions. For now, cursor behavior is non-subtransactional, that is a cursor's state does not roll back if you abort a subtransaction that fetched from the cursor. We might want to change that later.
2004-07-17 05:32:14 +02:00
/*-------------------------------------------------------------------------
*
* resowner.h
* POSTGRES resource owner definitions.
*
* Query-lifespan resources are tracked by associating them with
* ResourceOwner objects. This provides a simple mechanism for ensuring
* that such resources are freed at the right time.
* See utils/resowner/README for more info.
*
*
Update copyright for 2019 Backpatch-through: certain files through 9.4
2019-01-02 18:44:25 +01:00
* Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
Invent ResourceOwner mechanism as per my recent proposal, and use it to keep track of portal-related resources separately from transaction-related resources. This allows cursors to work in a somewhat sane fashion with nested transactions. For now, cursor behavior is non-subtransactional, that is a cursor's state does not roll back if you abort a subtransaction that fetched from the cursor. We might want to change that later.
2004-07-17 05:32:14 +02:00
* Portions Copyright (c) 1994, Regents of the University of California
*
Remove cvs keywords from all files.
2010-09-20 22:08:53 +02:00
* src/include/utils/resowner.h
Invent ResourceOwner mechanism as per my recent proposal, and use it to keep track of portal-related resources separately from transaction-related resources. This allows cursors to work in a somewhat sane fashion with nested transactions. For now, cursor behavior is non-subtransactional, that is a cursor's state does not roll back if you abort a subtransaction that fetched from the cursor. We might want to change that later.
2004-07-17 05:32:14 +02:00
*
*-------------------------------------------------------------------------
*/
#ifndef RESOWNER_H
#define RESOWNER_H
/*
* ResourceOwner objects are an opaque data structure known only within
* resowner.c.
*/
typedef struct ResourceOwnerData *ResourceOwner;
/*
* Globally known ResourceOwners
*/
Rename DLLIMPORT macro to PGDLLIMPORT to avoid conflict with third party includes (like tcl) that define DLLIMPORT.
2007-07-25 14:22:54 +02:00
extern PGDLLIMPORT ResourceOwner CurrentResourceOwner;
extern PGDLLIMPORT ResourceOwner CurTransactionResourceOwner;
extern PGDLLIMPORT ResourceOwner TopTransactionResourceOwner;
Use a ResourceOwner to track buffer pins in all cases. Historically, we've allowed auxiliary processes to take buffer pins without tracking them in a ResourceOwner. However, that creates problems for error recovery. In particular, we've seen multiple reports of assertion crashes in the startup process when it gets an error while holding a buffer pin, as for example if it gets ENOSPC during a write. In a non-assert build, the process would simply exit without releasing the pin at all. We've gotten away with that so far just because a failure exit of the startup process translates to a database crash anyhow; but any similar behavior in other aux processes could result in stuck pins and subsequent problems in vacuum. To improve this, institute a policy that we must *always* have a resowner backing any attempt to pin a buffer, which we can enforce just by removing the previous special-case code in resowner.c. Add infrastructure to make it easy to create a process-lifespan AuxProcessResourceOwner and clear out its contents at appropriate times. Replace existing ad-hoc resowner management in bgwriter.c and other aux processes with that. (Thus, while the startup process gains a resowner where it had none at all before, some other aux process types are replacing an ad-hoc resowner with this code.) Also use the AuxProcessResourceOwner to manage buffer pins taken during StartupXLOG and ShutdownXLOG, even when those are being run in a bootstrap process or a standalone backend rather than a true auxiliary process. In passing, remove some other ad-hoc resource owner creations that had gotten cargo-culted into various other places. As far as I can tell that was all unnecessary, and if it had been necessary it was incomplete, due to lacking any provision for clearing those resowners later. (Also worth noting in this connection is that a process that hasn't called InitBufferPoolBackend has no business accessing buffers; so there's more to do than just add the resowner if we want to touch buffers in processes not covered by this patch.) Although this fixes a very old bug, no back-patch, because there's no evidence of any significant problem in non-assert builds. Patch by me, pursuant to a report from Justin Pryzby. Thanks to Robert Haas and Kyotaro Horiguchi for reviews. Discussion: https://postgr.es/m/20180627233939.GA10276@telsasoft.com
2018-07-18 18:15:16 +02:00
extern PGDLLIMPORT ResourceOwner AuxProcessResourceOwner;
Invent ResourceOwner mechanism as per my recent proposal, and use it to keep track of portal-related resources separately from transaction-related resources. This allows cursors to work in a somewhat sane fashion with nested transactions. For now, cursor behavior is non-subtransactional, that is a cursor's state does not roll back if you abort a subtransaction that fetched from the cursor. We might want to change that later.
2004-07-17 05:32:14 +02:00
/*
* Resource releasing is done in three phases: pre-locks, locks, and
pgindent run for 9.4 This includes removing tabs after periods in C comments, which was applied to back branches, so this change should not effect backpatching.
2014-05-06 18:12:18 +02:00
* post-locks. The pre-lock phase must release any resources that are
Invent ResourceOwner mechanism as per my recent proposal, and use it to keep track of portal-related resources separately from transaction-related resources. This allows cursors to work in a somewhat sane fashion with nested transactions. For now, cursor behavior is non-subtransactional, that is a cursor's state does not roll back if you abort a subtransaction that fetched from the cursor. We might want to change that later.
2004-07-17 05:32:14 +02:00
* visible to other backends (such as pinned buffers); this ensures that
* when we release a lock that another backend may be waiting on, it will
* see us as being fully out of our transaction. The post-lock phase
* should be used for backend-internal cleanup.
*/
typedef enum
{
RESOURCE_RELEASE_BEFORE_LOCKS,
RESOURCE_RELEASE_LOCKS,
RESOURCE_RELEASE_AFTER_LOCKS
} ResourceReleasePhase;
/*
* Dynamically loaded modules can get control during ResourceOwnerRelease
* by providing a callback of this form.
*/
typedef void (*ResourceReleaseCallback) (ResourceReleasePhase phase,
Initial pgindent run with pg_bsd_indent version 2.0. The new indent version includes numerous fixes thanks to Piotr Stefaniak. The main changes visible in this commit are: * Nicer formatting of function-pointer declarations. * No longer unexpectedly removes spaces in expressions using casts, sizeof, or offsetof. * No longer wants to add a space in "struct structname *varname", as well as some similar cases for const- or volatile-qualified pointers. * Declarations using PG_USED_FOR_ASSERTS_ONLY are formatted more nicely. * Fixes bug where comments following declarations were sometimes placed with no space separating them from the code. * Fixes some odd decisions for comments following case labels. * Fixes some cases where comments following code were indented to less than the expected column 33. On the less good side, it now tends to put more whitespace around typedef names that are not listed in typedefs.list. This might encourage us to put more effort into typedef name collection; it's not really a bug in indent itself. There are more changes coming after this round, having to do with comment indentation and alignment of lines appearing within parentheses. I wanted to limit the size of the diffs to something that could be reviewed without one's eyes completely glazing over, so it seemed better to split up the changes as much as practical. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
2017-06-21 20:39:04 +02:00
bool isCommit,
bool isTopLevel,
void *arg);
Invent ResourceOwner mechanism as per my recent proposal, and use it to keep track of portal-related resources separately from transaction-related resources. This allows cursors to work in a somewhat sane fashion with nested transactions. For now, cursor behavior is non-subtransactional, that is a cursor's state does not roll back if you abort a subtransaction that fetched from the cursor. We might want to change that later.
2004-07-17 05:32:14 +02:00
/*
* Functions in resowner.c
*/
/* generic routines */
extern ResourceOwner ResourceOwnerCreate(ResourceOwner parent,
Phase 2 pgindent run for v12. Switch to 2.1 version of pg_bsd_indent. This formats multiline function declarations "correctly", that is with additional lines of parameter declarations indented to match where the first line's left parenthesis is. Discussion: https://postgr.es/m/CAEepm=0P3FeTXRcU5B2W3jv3PgRVZ-kGUXLGfd42FFhUROO3ug@mail.gmail.com
2019-05-22 19:04:48 +02:00
const char *name);
Invent ResourceOwner mechanism as per my recent proposal, and use it to keep track of portal-related resources separately from transaction-related resources. This allows cursors to work in a somewhat sane fashion with nested transactions. For now, cursor behavior is non-subtransactional, that is a cursor's state does not roll back if you abort a subtransaction that fetched from the cursor. We might want to change that later.
2004-07-17 05:32:14 +02:00
extern void ResourceOwnerRelease(ResourceOwner owner,
Phase 2 pgindent run for v12. Switch to 2.1 version of pg_bsd_indent. This formats multiline function declarations "correctly", that is with additional lines of parameter declarations indented to match where the first line's left parenthesis is. Discussion: https://postgr.es/m/CAEepm=0P3FeTXRcU5B2W3jv3PgRVZ-kGUXLGfd42FFhUROO3ug@mail.gmail.com
2019-05-22 19:04:48 +02:00
ResourceReleasePhase phase,
bool isCommit,
bool isTopLevel);
Invent ResourceOwner mechanism as per my recent proposal, and use it to keep track of portal-related resources separately from transaction-related resources. This allows cursors to work in a somewhat sane fashion with nested transactions. For now, cursor behavior is non-subtransactional, that is a cursor's state does not roll back if you abort a subtransaction that fetched from the cursor. We might want to change that later.
2004-07-17 05:32:14 +02:00
extern void ResourceOwnerDelete(ResourceOwner owner);
Introduce local hash table for lock state, as per recent proposal. PROCLOCK structs in shared memory now have only a bitmask for held locks, rather than counts (making them 40 bytes smaller, which is a good thing). Multiple locks within a transaction are counted in the local hash table instead, and we have provision for tracking which ResourceOwner each count belongs to. Solves recently reported problem with memory leakage within long transactions.
2004-08-27 19:07:42 +02:00
extern ResourceOwner ResourceOwnerGetParent(ResourceOwner owner);
Invent ResourceOwner mechanism as per my recent proposal, and use it to keep track of portal-related resources separately from transaction-related resources. This allows cursors to work in a somewhat sane fashion with nested transactions. For now, cursor behavior is non-subtransactional, that is a cursor's state does not roll back if you abort a subtransaction that fetched from the cursor. We might want to change that later.
2004-07-17 05:32:14 +02:00
extern void ResourceOwnerNewParent(ResourceOwner owner,
Phase 2 pgindent run for v12. Switch to 2.1 version of pg_bsd_indent. This formats multiline function declarations "correctly", that is with additional lines of parameter declarations indented to match where the first line's left parenthesis is. Discussion: https://postgr.es/m/CAEepm=0P3FeTXRcU5B2W3jv3PgRVZ-kGUXLGfd42FFhUROO3ug@mail.gmail.com
2019-05-22 19:04:48 +02:00
ResourceOwner newparent);
Invent ResourceOwner mechanism as per my recent proposal, and use it to keep track of portal-related resources separately from transaction-related resources. This allows cursors to work in a somewhat sane fashion with nested transactions. For now, cursor behavior is non-subtransactional, that is a cursor's state does not roll back if you abort a subtransaction that fetched from the cursor. We might want to change that later.
2004-07-17 05:32:14 +02:00
extern void RegisterResourceReleaseCallback(ResourceReleaseCallback callback,
Phase 2 pgindent run for v12. Switch to 2.1 version of pg_bsd_indent. This formats multiline function declarations "correctly", that is with additional lines of parameter declarations indented to match where the first line's left parenthesis is. Discussion: https://postgr.es/m/CAEepm=0P3FeTXRcU5B2W3jv3PgRVZ-kGUXLGfd42FFhUROO3ug@mail.gmail.com
2019-05-22 19:04:48 +02:00
void *arg);
Invent ResourceOwner mechanism as per my recent proposal, and use it to keep track of portal-related resources separately from transaction-related resources. This allows cursors to work in a somewhat sane fashion with nested transactions. For now, cursor behavior is non-subtransactional, that is a cursor's state does not roll back if you abort a subtransaction that fetched from the cursor. We might want to change that later.
2004-07-17 05:32:14 +02:00
extern void UnregisterResourceReleaseCallback(ResourceReleaseCallback callback,
Phase 2 pgindent run for v12. Switch to 2.1 version of pg_bsd_indent. This formats multiline function declarations "correctly", that is with additional lines of parameter declarations indented to match where the first line's left parenthesis is. Discussion: https://postgr.es/m/CAEepm=0P3FeTXRcU5B2W3jv3PgRVZ-kGUXLGfd42FFhUROO3ug@mail.gmail.com
2019-05-22 19:04:48 +02:00
void *arg);
Use a ResourceOwner to track buffer pins in all cases. Historically, we've allowed auxiliary processes to take buffer pins without tracking them in a ResourceOwner. However, that creates problems for error recovery. In particular, we've seen multiple reports of assertion crashes in the startup process when it gets an error while holding a buffer pin, as for example if it gets ENOSPC during a write. In a non-assert build, the process would simply exit without releasing the pin at all. We've gotten away with that so far just because a failure exit of the startup process translates to a database crash anyhow; but any similar behavior in other aux processes could result in stuck pins and subsequent problems in vacuum. To improve this, institute a policy that we must *always* have a resowner backing any attempt to pin a buffer, which we can enforce just by removing the previous special-case code in resowner.c. Add infrastructure to make it easy to create a process-lifespan AuxProcessResourceOwner and clear out its contents at appropriate times. Replace existing ad-hoc resowner management in bgwriter.c and other aux processes with that. (Thus, while the startup process gains a resowner where it had none at all before, some other aux process types are replacing an ad-hoc resowner with this code.) Also use the AuxProcessResourceOwner to manage buffer pins taken during StartupXLOG and ShutdownXLOG, even when those are being run in a bootstrap process or a standalone backend rather than a true auxiliary process. In passing, remove some other ad-hoc resource owner creations that had gotten cargo-culted into various other places. As far as I can tell that was all unnecessary, and if it had been necessary it was incomplete, due to lacking any provision for clearing those resowners later. (Also worth noting in this connection is that a process that hasn't called InitBufferPoolBackend has no business accessing buffers; so there's more to do than just add the resowner if we want to touch buffers in processes not covered by this patch.) Although this fixes a very old bug, no back-patch, because there's no evidence of any significant problem in non-assert builds. Patch by me, pursuant to a report from Justin Pryzby. Thanks to Robert Haas and Kyotaro Horiguchi for reviews. Discussion: https://postgr.es/m/20180627233939.GA10276@telsasoft.com
2018-07-18 18:15:16 +02:00
extern void CreateAuxProcessResourceOwner(void);
extern void ReleaseAuxProcessResources(bool isCommit);
Invent ResourceOwner mechanism as per my recent proposal, and use it to keep track of portal-related resources separately from transaction-related resources. This allows cursors to work in a somewhat sane fashion with nested transactions. For now, cursor behavior is non-subtransactional, that is a cursor's state does not roll back if you abort a subtransaction that fetched from the cursor. We might want to change that later.
2004-07-17 05:32:14 +02:00
Phase 2 of pgindent updates. Change pg_bsd_indent to follow upstream rules for placement of comments to the right of code, and remove pgindent hack that caused comments following #endif to not obey the general rule. Commit e3860ffa4dd0dad0dd9eea4be9cc1412373a8c89 wasn't actually using the published version of pg_bsd_indent, but a hacked-up version that tried to minimize the amount of movement of comments to the right of code. The situation of interest is where such a comment has to be moved to the right of its default placement at column 33 because there's code there. BSD indent has always moved right in units of tab stops in such cases --- but in the previous incarnation, indent was working in 8-space tab stops, while now it knows we use 4-space tabs. So the net result is that in about half the cases, such comments are placed one tab stop left of before. This is better all around: it leaves more room on the line for comment text, and it means that in such cases the comment uniformly starts at the next 4-space tab stop after the code, rather than sometimes one and sometimes two tabs after. Also, ensure that comments following #endif are indented the same as comments following other preprocessor commands such as #else. That inconsistency turns out to have been self-inflicted damage from a poorly-thought-through post-indent "fixup" in pgindent. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
2017-06-21 21:18:54 +02:00
#endif /* RESOWNER_H */