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path: root/src/backend/postmaster/launch_backend.c
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2024-10-27Remove unused #include's from backend .c filesPeter Eisentraut
as determined by IWYU These are mostly issues that are new since commit dbbca2cf299. Discussion: https://www.postgresql.org/message-id/flat/0df1d5b1-8ca8-4f84-93be-121081bde049%40eisentraut.org
2024-07-30Remove useless member of BackendParameters.Thomas Munro
Oversight in e2562667, which stopped using SpinlockSemaArray but forgot to remove it from the array. Reported-by: Heikki Linnakangas <hlinnaka@iki.fi> Discussion: https://postgr.es/m/310f4005-91d7-42b2-ac70-92624260dd28%40iki.fi
2024-07-30Remove --disable-spinlocks.Thomas Munro
A later change will require atomic support, so it wouldn't make sense for a hypothetical new system not to be able to implement spinlocks. Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> (concept, not the patch) Reviewed-by: Andres Freund <andres@anarazel.de> (concept, not the patch) Discussion: https://postgr.es/m/3351991.1697728588%40sss.pgh.pa.us
2024-07-29Detach syslogger from shared memoryHeikki Linnakangas
Commit aafc05de1b removed the calls to detach from shared memory from syslogger startup. That was not intentional, so put them back. Author: Rui Zhao Reviewed-by: Aleksander Alekseev Backpatch-through: 17 Discussion: https://www.postgresql.org/message-id/11505016-8cf3-4691-b996-7faed99b7877.xiyuan.zr@alibaba-inc.com
2024-07-29Move cancel key generation to after forking the backendHeikki Linnakangas
Move responsibility of generating the cancel key to the backend process. The cancel key is now generated after forking, and the backend advertises it in the ProcSignal array. When a cancel request arrives, the backend handling it scans the ProcSignal array to find the target pid and cancel key. This is similar to how this previously worked in the EXEC_BACKEND case with the ShmemBackendArray, just reusing the ProcSignal array. One notable change is that we no longer generate cancellation keys for non-backend processes. We generated them before just to prevent a malicious user from canceling them; the keys for non-backend processes were never actually given to anyone. There is now an explicit flag indicating whether a process has a valid key or not. I wrote this originally in preparation for supporting longer cancel keys, but it's a nice cleanup on its own. Reviewed-by: Jelte Fennema-Nio Discussion: https://www.postgresql.org/message-id/508d0505-8b7a-4864-a681-e7e5edfe32aa@iki.fi
2024-07-26Fix using injection points at backend startup in EXEC_BACKEND modeHeikki Linnakangas
Commit 86db52a506 changed the locking of injection points to use only atomic ops and spinlocks, to make it possible to define injection points in processes that don't have a PGPROC entry (yet). However, it didn't work in EXEC_BACKEND mode, because the pointer to shared memory area was not initialized until the process "attaches" to all the shared memory structs. To fix, pass the pointer to the child process along with other global variables that need to be set up early. Backpatch-through: 17
2024-07-23Move extern declarations for EXEC_BACKEND to header filesPeter Eisentraut
This fixes warnings from -Wmissing-variable-declarations (not yet part of the standard warning options) under EXEC_BACKEND. The NON_EXEC_STATIC variables need a suitable declaration in a header file under EXEC_BACKEND. Also fix the inconsistent application of the volatile qualifier for PMSignalState, which was revealed by this change. Reviewed-by: Andres Freund <andres@anarazel.de> Discussion: https://www.postgresql.org/message-id/flat/e0a62134-83da-4ba4-8cdb-ceb0111c95ce@eisentraut.org
2024-07-03Avoid 0-length memcpy to NULL with EXEC_BACKENDHeikki Linnakangas
memcpy(NULL, src, 0) is forbidden by POSIX, even though every production version of libc allows it. Let's be tidy. Per report from Thomas Munro, running UBSan with EXEC_BACKEND. Backpatch to v17, where this code was added. Discussion: https://www.postgresql.org/message-id/CA%2BhUKG%2Be-dV7YWBzfBZXsgovgRuX5VmvmOT%2Bv0aXiZJ-EKbXcw@mail.gmail.com
2024-07-02Improve some global variable declarationsPeter Eisentraut
We have in launch_backend.c: /* * The following need to be available to the save/restore_backend_variables * functions. They are marked NON_EXEC_STATIC in their home modules. */ extern slock_t *ShmemLock; extern slock_t *ProcStructLock; extern PGPROC *AuxiliaryProcs; extern PMSignalData *PMSignalState; extern pg_time_t first_syslogger_file_time; extern struct bkend *ShmemBackendArray; extern bool redirection_done; That comment is not completely true: ShmemLock, ShmemBackendArray, and redirection_done are not in fact NON_EXEC_STATIC. ShmemLock once was, but was then needed elsewhere. ShmemBackendArray was static inside postmaster.c before launch_backend.c was created. redirection_done was never static. This patch moves the declaration of ShmemLock and redirection_done to a header file. ShmemBackendArray gets a NON_EXEC_STATIC. This doesn't make a difference, since it only exists if EXEC_BACKEND anyway, but it makes it consistent. After that, the comment is now correct. Reviewed-by: Andres Freund <andres@anarazel.de> Discussion: https://www.postgresql.org/message-id/flat/e0a62134-83da-4ba4-8cdb-ceb0111c95ce@eisentraut.org
2024-07-02Convert some extern variables to staticPeter Eisentraut
These probably should have been static all along, it was only forgotten out of sloppiness. Reviewed-by: Andres Freund <andres@anarazel.de> Discussion: https://www.postgresql.org/message-id/flat/e0a62134-83da-4ba4-8cdb-ceb0111c95ce@eisentraut.org
2024-05-15Fix incorrect year in some copyright notices added this yearDavid Rowley
A few patches that were written <= 2023 and committed in 2024 still contained 2023 copyright year. Fix that. Discussion: https://postgr.es/m/CAApHDvr5egyW3FmHbAg-Uq2p_Aizwco1Zjs6Vbq18KqN64-hRA@mail.gmail.com
2024-04-18Fix typos and duplicate wordsDaniel Gustafsson
This fixes various typos, duplicated words, and tiny bits of whitespace mainly in code comments but also in docs. Author: Daniel Gustafsson <daniel@yesql.se> Author: Heikki Linnakangas <hlinnaka@iki.fi> Author: Alexander Lakhin <exclusion@gmail.com> Author: David Rowley <dgrowleyml@gmail.com> Author: Nazir Bilal Yavuz <byavuz81@gmail.com> Discussion: https://postgr.es/m/3F577953-A29E-4722-98AD-2DA9EFF2CBB8@yesql.se
2024-03-20Remove assertions that some compiler say are tautologicalHeikki Linnakangas
To avoid the compiler warnings: launch_backend.c:211:39: warning: comparison of constant 16 with expression of type 'BackendType' (aka 'enum BackendType') is always true [-Wtautological-constant-out-of-range-compare] launch_backend.c:233:39: warning: comparison of constant 16 with expression of type 'BackendType' (aka 'enum BackendType') is always true [-Wtautological-constant-out-of-range-compare] The point of the assertions was to fail more explicitly if someone adds a new BackendType to the end of the enum, but forgets to add it to the child_process_kinds array. It was a pretty weak assertion to begin with, because it wouldn't catch if you added a new BackendType in the middle of the enum. So let's just remove it. Per buildfarm member ayu and a few others, spotted by Tom Lane. Discussion: https://www.postgresql.org/message-id/4119680.1710913067@sss.pgh.pa.us
2024-03-18Move code for backend startup to separate fileHeikki Linnakangas
This is code that runs in the backend process after forking, rather than postmaster. Move it out of postmaster.c for clarity. Reviewed-by: Tristan Partin, Andres Freund Discussion: https://www.postgresql.org/message-id/7a59b073-5b5b-151e-7ed3-8b01ff7ce9ef@iki.fi
2024-03-18Refactor postmaster child process launchingHeikki Linnakangas
Introduce new postmaster_child_launch() function that deals with the differences in EXEC_BACKEND mode. Refactor the mechanism of passing information from the parent to child process. Instead of using different command-line arguments when launching the child process in EXEC_BACKEND mode, pass a variable-length blob of startup data along with all the global variables. The contents of that blob depend on the kind of child process being launched. In !EXEC_BACKEND mode, we use the same blob, but it's simply inherited from the parent to child process. Reviewed-by: Tristan Partin, Andres Freund Discussion: https://www.postgresql.org/message-id/7a59b073-5b5b-151e-7ed3-8b01ff7ce9ef@iki.fi
2024-03-18Move some functions from postmaster.c to a new source fileHeikki Linnakangas
This just moves the functions, with no other changes, to make the next commits smaller and easier to review. The moved functions are related to launching postmaster child processes in EXEC_BACKEND mode. Reviewed-by: Tristan Partin, Andres Freund Discussion: https://www.postgresql.org/message-id/7a59b073-5b5b-151e-7ed3-8b01ff7ce9ef@iki.fi