From 4234a083913d93b27cd6763f41c092adc8d4cf6c Mon Sep 17 00:00:00 2001 From: Mike Palmiotto Date: Mon, 9 Mar 2020 22:12:10 +0000 Subject: [PATCH v2 01/12] Add subprocess infrastructure This commit introduces a new infrastructure for postmaster subprocesses initialization, forking, exec'ing and main function control. The intent is to have all subprocess control information live in the process_types struct, defined in subprocess.h. As more processes are added to the struct, the fields will be expanded to differentiate actions. There are several advantages to such an infrastructure: 1) Centralized definition of subprocess information 2) Standardized function arguments/naming schemes 3) Code minimization and removal of duplicate code --- src/backend/bootstrap/bootstrap.c | 74 +++++++-------------------- src/backend/postmaster/Makefile | 1 + src/backend/postmaster/bgwriter.c | 2 +- src/backend/postmaster/checkpointer.c | 2 +- src/backend/postmaster/startup.c | 3 +- src/backend/postmaster/subprocess.c | 62 ++++++++++++++++++++++ src/backend/postmaster/walwriter.c | 2 +- src/backend/replication/walreceiver.c | 2 +- src/include/bootstrap/bootstrap.h | 3 +- src/include/postmaster/bgwriter.h | 4 +- src/include/postmaster/startup.h | 5 +- src/include/postmaster/subprocess.h | 44 ++++++++++++++++ src/include/postmaster/walwriter.h | 2 +- src/include/replication/walreceiver.h | 2 +- 14 files changed, 140 insertions(+), 68 deletions(-) create mode 100644 src/backend/postmaster/subprocess.c create mode 100644 src/include/postmaster/subprocess.h diff --git a/src/backend/bootstrap/bootstrap.c b/src/backend/bootstrap/bootstrap.c index 5480a024e0..9d41567467 100644 --- a/src/backend/bootstrap/bootstrap.c +++ b/src/backend/bootstrap/bootstrap.c @@ -35,6 +35,7 @@ #include "pgstat.h" #include "postmaster/bgwriter.h" #include "postmaster/startup.h" +#include "postmaster/subprocess.h" #include "postmaster/walwriter.h" #include "replication/walreceiver.h" #include "storage/bufmgr.h" @@ -56,8 +57,6 @@ uint32 bootstrap_data_checksum_version = 0; /* No checksum */ #define ALLOC(t, c) \ ((t *) MemoryContextAllocZero(TopMemoryContext, (unsigned)(c) * sizeof(t))) -static void CheckerModeMain(void); -static void BootstrapModeMain(void); static void bootstrap_signals(void); static void ShutdownAuxiliaryProcess(int code, Datum arg); static Form_pg_attribute AllocateAttribute(void); @@ -334,6 +333,12 @@ AuxiliaryProcessMain(int argc, char *argv[]) default: MyBackendType = B_INVALID; } + + /* + * We've read the arguments and know what backend type we are. + */ + InitMySubprocess((SubprocessType)MyAuxProcType); + if (IsUnderPostmaster) init_ps_display(NULL); @@ -418,56 +423,10 @@ AuxiliaryProcessMain(int argc, char *argv[]) */ SetProcessingMode(NormalProcessing); - switch (MyAuxProcType) - { - case CheckerProcess: - /* don't set signals, they're useless here */ - CheckerModeMain(); - proc_exit(1); /* should never return */ - - case BootstrapProcess: - - /* - * There was a brief instant during which mode was Normal; this is - * okay. We need to be in bootstrap mode during BootStrapXLOG for - * the sake of multixact initialization. - */ - SetProcessingMode(BootstrapProcessing); - bootstrap_signals(); - BootStrapXLOG(); - BootstrapModeMain(); - proc_exit(1); /* should never return */ - - case StartupProcess: - /* don't set signals, startup process has its own agenda */ - StartupProcessMain(); - proc_exit(1); /* should never return */ - - case BgWriterProcess: - /* don't set signals, bgwriter has its own agenda */ - BackgroundWriterMain(); - proc_exit(1); /* should never return */ - - case CheckpointerProcess: - /* don't set signals, checkpointer has its own agenda */ - CheckpointerMain(); - proc_exit(1); /* should never return */ - - case WalWriterProcess: - /* don't set signals, walwriter has its own agenda */ - InitXLOGAccess(); - WalWriterMain(); - proc_exit(1); /* should never return */ - - case WalReceiverProcess: - /* don't set signals, walreceiver has its own agenda */ - WalReceiverMain(); - proc_exit(1); /* should never return */ + /* Now jump into the subprocess main function and never look back! */ + MySubprocess->entrypoint(argc, argv); - default: - elog(PANIC, "unrecognized process type: %d", (int) MyAuxProcType); - proc_exit(1); - } + proc_exit(1); /* should never return */ } /* @@ -476,8 +435,8 @@ AuxiliaryProcessMain(int argc, char *argv[]) * settings). Since, in fact, that was already done by BaseInit(), * we have nothing more to do here. */ -static void -CheckerModeMain(void) +void +CheckerModeMain(int argc, char *argv[]) { proc_exit(0); } @@ -489,11 +448,15 @@ CheckerModeMain(void) * The bootstrap backend doesn't speak SQL, but instead expects * commands in a special bootstrap language. */ -static void -BootstrapModeMain(void) +void +BootstrapModeMain(int argc, char *argv[]) { int i; + SetProcessingMode(BootstrapProcessing); + bootstrap_signals(); + BootStrapXLOG(); + Assert(!IsUnderPostmaster); Assert(IsBootstrapProcessingMode()); @@ -508,7 +471,6 @@ BootstrapModeMain(void) * Do backend-like initialization for bootstrap mode */ InitProcess(); - InitPostgres(NULL, InvalidOid, NULL, InvalidOid, NULL, false); /* Initialize stuff for bootstrap-file processing */ diff --git a/src/backend/postmaster/Makefile b/src/backend/postmaster/Makefile index bfdf6a833d..52b4c2142c 100644 --- a/src/backend/postmaster/Makefile +++ b/src/backend/postmaster/Makefile @@ -23,6 +23,7 @@ OBJS = \ pgstat.o \ postmaster.o \ startup.o \ + subprocess.o \ syslogger.o \ walwriter.o diff --git a/src/backend/postmaster/bgwriter.c b/src/backend/postmaster/bgwriter.c index 069e27e427..b2170938f3 100644 --- a/src/backend/postmaster/bgwriter.c +++ b/src/backend/postmaster/bgwriter.c @@ -91,7 +91,7 @@ static XLogRecPtr last_snapshot_lsn = InvalidXLogRecPtr; * basic execution environment, but not enabled signals yet. */ void -BackgroundWriterMain(void) +BackgroundWriterMain(int argc, char *argv[]) { sigjmp_buf local_sigjmp_buf; MemoryContext bgwriter_context; diff --git a/src/backend/postmaster/checkpointer.c b/src/backend/postmaster/checkpointer.c index e354a78725..83f7be1b1e 100644 --- a/src/backend/postmaster/checkpointer.c +++ b/src/backend/postmaster/checkpointer.c @@ -180,7 +180,7 @@ static void ReqCheckpointHandler(SIGNAL_ARGS); * basic execution environment, but not enabled signals yet. */ void -CheckpointerMain(void) +CheckpointerMain(int argc, char *argv[]) { sigjmp_buf local_sigjmp_buf; MemoryContext checkpointer_context; diff --git a/src/backend/postmaster/startup.c b/src/backend/postmaster/startup.c index c2250d7d4e..e29649a6a1 100644 --- a/src/backend/postmaster/startup.c +++ b/src/backend/postmaster/startup.c @@ -127,13 +127,12 @@ HandleStartupProcInterrupts(void) ProcessProcSignalBarrier(); } - /* ---------------------------------- * Startup Process main entry point * ---------------------------------- */ void -StartupProcessMain(void) +StartupProcessMain(int argc, char *argv[]) { /* * Properly accept or ignore signals the postmaster might send us. diff --git a/src/backend/postmaster/subprocess.c b/src/backend/postmaster/subprocess.c new file mode 100644 index 0000000000..3e7a45bf10 --- /dev/null +++ b/src/backend/postmaster/subprocess.c @@ -0,0 +1,62 @@ +/*------------------------------------------------------------------------- + * + * subprocess.c + * + * Copyright (c) 2004-2020, PostgreSQL Global Development Group + * + * + * IDENTIFICATION + * src/backend/postmaster/syslogger.c + * + *------------------------------------------------------------------------- + */ +#include "postgres.h" +#include "bootstrap/bootstrap.h" +#include "postmaster/bgwriter.h" +#include "postmaster/postmaster.h" +#include "postmaster/startup.h" +#include "postmaster/subprocess.h" +#include "postmaster/walwriter.h" +#include "replication/walreceiver.h" + +SubprocessType MySubprocessType; +PgSubprocess *MySubprocess; + +static PgSubprocess process_types[] = { + { + .desc = "checker", + .entrypoint = CheckerModeMain + }, + { + .desc = "bootstrap", + .entrypoint = BootstrapModeMain + }, + { + .desc = "startup", + .entrypoint = StartupProcessMain + }, + { + .desc = "background writer", + .entrypoint = BackgroundWriterMain + }, + { + .desc = "checkpointer", + .entrypoint = CheckpointerMain + }, + { + .desc = "wal writer", + .entrypoint = WalWriterMain + }, + { + .desc = "wal receiver", + .entrypoint = WalReceiverMain + } +}; + +void +InitMySubprocess(SubprocessType type) +{ + MySubprocessType = type; + MySubprocess = &process_types[type]; + MySubprocess->desc = gettext(MySubprocess->desc); +} diff --git a/src/backend/postmaster/walwriter.c b/src/backend/postmaster/walwriter.c index 45a2757969..3a0cec3371 100644 --- a/src/backend/postmaster/walwriter.c +++ b/src/backend/postmaster/walwriter.c @@ -85,7 +85,7 @@ int WalWriterFlushAfter = 128; * basic execution environment, but not enabled signals yet. */ void -WalWriterMain(void) +WalWriterMain(int argc, char *argv[]) { sigjmp_buf local_sigjmp_buf; MemoryContext walwriter_context; diff --git a/src/backend/replication/walreceiver.c b/src/backend/replication/walreceiver.c index 25e0333c9e..cd39a8c982 100644 --- a/src/backend/replication/walreceiver.c +++ b/src/backend/replication/walreceiver.c @@ -165,7 +165,7 @@ ProcessWalRcvInterrupts(void) /* Main entry point for walreceiver process */ void -WalReceiverMain(void) +WalReceiverMain(int argc, char *argv[]) { char conninfo[MAXCONNINFO]; char *tmp_conninfo; diff --git a/src/include/bootstrap/bootstrap.h b/src/include/bootstrap/bootstrap.h index b67fa9acc1..f85cfb5202 100644 --- a/src/include/bootstrap/bootstrap.h +++ b/src/include/bootstrap/bootstrap.h @@ -16,7 +16,6 @@ #include "nodes/execnodes.h" - /* * MAXATTR is the maximum number of attributes in a relation supported * at bootstrap time (i.e., the max possible in a system table). @@ -31,6 +30,8 @@ extern Relation boot_reldesc; extern Form_pg_attribute attrtypes[MAXATTR]; extern int numattr; +extern void CheckerModeMain(int argc, char *argv[]); +extern void BootstrapModeMain(int argc, char *argv[]); extern void AuxiliaryProcessMain(int argc, char *argv[]) pg_attribute_noreturn(); diff --git a/src/include/postmaster/bgwriter.h b/src/include/postmaster/bgwriter.h index 0a5708b32e..6fb1ee1d6d 100644 --- a/src/include/postmaster/bgwriter.h +++ b/src/include/postmaster/bgwriter.h @@ -27,8 +27,8 @@ extern int CheckPointTimeout; extern int CheckPointWarning; extern double CheckPointCompletionTarget; -extern void BackgroundWriterMain(void) pg_attribute_noreturn(); -extern void CheckpointerMain(void) pg_attribute_noreturn(); +extern void BackgroundWriterMain(int argc, char *argv[]) pg_attribute_noreturn(); +extern void CheckpointerMain(int argc, char *argv[]) pg_attribute_noreturn(); extern void RequestCheckpoint(int flags); extern void CheckpointWriteDelay(int flags, double progress); diff --git a/src/include/postmaster/startup.h b/src/include/postmaster/startup.h index 9f59c1ffa3..6a8108dfe0 100644 --- a/src/include/postmaster/startup.h +++ b/src/include/postmaster/startup.h @@ -13,10 +13,13 @@ #define _STARTUP_H extern void HandleStartupProcInterrupts(void); -extern void StartupProcessMain(void) pg_attribute_noreturn(); extern void PreRestoreCommand(void); extern void PostRestoreCommand(void); extern bool IsPromoteTriggered(void); extern void ResetPromoteTriggered(void); +/* Startup subprocess functions */ +extern void StartupProcessMain(int argc, char *argv[]) pg_attribute_noreturn(); +extern bool StartupCleanup(int child_errno); + #endif /* _STARTUP_H */ diff --git a/src/include/postmaster/subprocess.h b/src/include/postmaster/subprocess.h new file mode 100644 index 0000000000..56e8edf2d8 --- /dev/null +++ b/src/include/postmaster/subprocess.h @@ -0,0 +1,44 @@ +/*------------------------------------------------------------------------- + * + * subprocess.h + * + * Copyright (c) 1996-2020, PostgreSQL Global Development Group + * + * src/include/postmaster/subprocess.h + * + *------------------------------------------------------------------------- + */ +#ifndef SUBPROCESS_H +#define SUBPROCESS_H + +#include "postmaster.h" + +typedef enum +{ + NoProcessType = -1, + CheckerType = 0, + BootstrapType, + StartupType, + BgWriterType, + CheckpointerType, + WalWriterType, + WalReceiverType, /* end of Auxiliary Process Forks */ + + NUMSUBPROCESSTYPES /* Must be last! */ +} SubprocessType; + +typedef void (*SubprocessEntryPoint) (int argc, char *argv[]); + +/* Current subprocess initializer */ +extern void InitMySubprocess(SubprocessType type); + +typedef struct PgSubprocess +{ + const char *desc; + SubprocessEntryPoint entrypoint; +} PgSubprocess; + +extern SubprocessType MySubprocessType; +extern PGDLLIMPORT PgSubprocess *MySubprocess; + +#endif /* SUBPROCESS_H */ diff --git a/src/include/postmaster/walwriter.h b/src/include/postmaster/walwriter.h index 011dc26a6e..596c437c54 100644 --- a/src/include/postmaster/walwriter.h +++ b/src/include/postmaster/walwriter.h @@ -16,6 +16,6 @@ extern int WalWriterDelay; extern int WalWriterFlushAfter; -extern void WalWriterMain(void) pg_attribute_noreturn(); +extern void WalWriterMain(int argc, char *argv[]) pg_attribute_noreturn(); #endif /* _WALWRITER_H */ diff --git a/src/include/replication/walreceiver.h b/src/include/replication/walreceiver.h index e08afc6548..2025f19ab3 100644 --- a/src/include/replication/walreceiver.h +++ b/src/include/replication/walreceiver.h @@ -311,7 +311,7 @@ walrcv_clear_result(WalRcvExecResult *walres) } /* prototypes for functions in walreceiver.c */ -extern void WalReceiverMain(void) pg_attribute_noreturn(); +extern void WalReceiverMain(int argc, char *argv[]); extern void ProcessWalRcvInterrupts(void); /* prototypes for functions in walreceiverfuncs.c */ -- 2.17.0