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fb844b9f06
Due to concerns raised about the approach, and memory leaks found in sensitive contexts the functionality is reverted. This reverts commits45e7e8ca9,f8c115a6c,d2a1ed172,55ef7abf8and042a66291for v18 with an intent to revisit this patch for v19. Discussion: https://postgr.es/m/594293.1747708165@sss.pgh.pa.us
94 lines
3.2 KiB
C
94 lines
3.2 KiB
C
/*-------------------------------------------------------------------------
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*
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* procsignal.h
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* Routines for interprocess signaling
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*
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*
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* Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* src/include/storage/procsignal.h
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*
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*-------------------------------------------------------------------------
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*/
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#ifndef PROCSIGNAL_H
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#define PROCSIGNAL_H
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#include "storage/procnumber.h"
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/*
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* Reasons for signaling a Postgres child process (a backend or an auxiliary
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* process, like checkpointer). We can cope with concurrent signals for different
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* reasons. However, if the same reason is signaled multiple times in quick
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* succession, the process is likely to observe only one notification of it.
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* This is okay for the present uses.
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*
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* Also, because of race conditions, it's important that all the signals be
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* defined so that no harm is done if a process mistakenly receives one.
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*/
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typedef enum
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{
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PROCSIG_CATCHUP_INTERRUPT, /* sinval catchup interrupt */
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PROCSIG_NOTIFY_INTERRUPT, /* listen/notify interrupt */
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PROCSIG_PARALLEL_MESSAGE, /* message from cooperating parallel backend */
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PROCSIG_WALSND_INIT_STOPPING, /* ask walsenders to prepare for shutdown */
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PROCSIG_BARRIER, /* global barrier interrupt */
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PROCSIG_LOG_MEMORY_CONTEXT, /* ask backend to log the memory contexts */
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PROCSIG_PARALLEL_APPLY_MESSAGE, /* Message from parallel apply workers */
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/* Recovery conflict reasons */
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PROCSIG_RECOVERY_CONFLICT_FIRST,
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PROCSIG_RECOVERY_CONFLICT_DATABASE = PROCSIG_RECOVERY_CONFLICT_FIRST,
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PROCSIG_RECOVERY_CONFLICT_TABLESPACE,
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PROCSIG_RECOVERY_CONFLICT_LOCK,
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PROCSIG_RECOVERY_CONFLICT_SNAPSHOT,
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PROCSIG_RECOVERY_CONFLICT_LOGICALSLOT,
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PROCSIG_RECOVERY_CONFLICT_BUFFERPIN,
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PROCSIG_RECOVERY_CONFLICT_STARTUP_DEADLOCK,
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PROCSIG_RECOVERY_CONFLICT_LAST = PROCSIG_RECOVERY_CONFLICT_STARTUP_DEADLOCK,
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} ProcSignalReason;
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#define NUM_PROCSIGNALS (PROCSIG_RECOVERY_CONFLICT_LAST + 1)
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typedef enum
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{
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PROCSIGNAL_BARRIER_SMGRRELEASE, /* ask smgr to close files */
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} ProcSignalBarrierType;
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/*
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* Length of query cancel keys generated.
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*
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* Note that the protocol allows for longer keys, or shorter, but this is the
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* length we actually generate. Client code, and the server code that handles
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* incoming cancellation packets from clients, mustn't use this hardcoded
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* length.
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*/
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#define MAX_CANCEL_KEY_LENGTH 32
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/*
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* prototypes for functions in procsignal.c
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*/
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extern Size ProcSignalShmemSize(void);
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extern void ProcSignalShmemInit(void);
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extern void ProcSignalInit(const uint8 *cancel_key, int cancel_key_len);
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extern int SendProcSignal(pid_t pid, ProcSignalReason reason,
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ProcNumber procNumber);
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extern void SendCancelRequest(int backendPID, const uint8 *cancel_key, int cancel_key_len);
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extern uint64 EmitProcSignalBarrier(ProcSignalBarrierType type);
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extern void WaitForProcSignalBarrier(uint64 generation);
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extern void ProcessProcSignalBarrier(void);
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extern void procsignal_sigusr1_handler(SIGNAL_ARGS);
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/* ProcSignalHeader is an opaque struct, details known only within procsignal.c */
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typedef struct ProcSignalHeader ProcSignalHeader;
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#ifdef EXEC_BACKEND
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extern PGDLLIMPORT ProcSignalHeader *ProcSignal;
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#endif
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#endif /* PROCSIGNAL_H */
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