From b863a63613c56036eecdf03f7aebe5e5fb45d8df Mon Sep 17 00:00:00 2001 From: Andres Freund Date: Wed, 8 Sep 2021 12:19:50 -0700 Subject: [PATCH v2 3/3] process startup: Split single user code out of PostgresMain(). Author: Andres Freund Discussion: https://postgr.es/m/20210802164124.ufo5buo4apl6yuvs@alap3.anarazel.de --- src/include/tcop/tcopprot.h | 5 +- src/backend/main/main.c | 5 +- src/backend/postmaster/postmaster.c | 8 +- src/backend/tcop/postgres.c | 148 +++++++++++++++------------- 4 files changed, 88 insertions(+), 78 deletions(-) diff --git a/src/include/tcop/tcopprot.h b/src/include/tcop/tcopprot.h index 968345404e5..5c77075aedd 100644 --- a/src/include/tcop/tcopprot.h +++ b/src/include/tcop/tcopprot.h @@ -75,8 +75,9 @@ extern void ProcessClientWriteInterrupt(bool blocked); extern void process_postgres_switches(int argc, char *argv[], GucContext ctx, const char **dbname); -extern void PostgresMain(int argc, char *argv[], - const char *dbname, +extern void PostgresSingleUserMain(int argc, char *argv[], + const char *username) pg_attribute_noreturn(); +extern void PostgresMain(const char *dbname, const char *username) pg_attribute_noreturn(); extern long get_stack_depth_rlimit(void); extern void ResetUsage(void); diff --git a/src/backend/main/main.c b/src/backend/main/main.c index 3a2a0d598cd..ad84a45e28c 100644 --- a/src/backend/main/main.c +++ b/src/backend/main/main.c @@ -192,9 +192,8 @@ main(int argc, char *argv[]) else if (argc > 1 && strcmp(argv[1], "--describe-config") == 0) GucInfoMain(); else if (argc > 1 && strcmp(argv[1], "--single") == 0) - PostgresMain(argc, argv, - NULL, /* no dbname */ - strdup(get_user_name_or_exit(progname))); + PostgresSingleUserMain(argc, argv, + strdup(get_user_name_or_exit(progname))); else PostmasterMain(argc, argv); /* the functions above should not return */ diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c index 96e94a55f27..cc3e245562a 100644 --- a/src/backend/postmaster/postmaster.c +++ b/src/backend/postmaster/postmaster.c @@ -4515,19 +4515,13 @@ BackendInitialize(Port *port) static void BackendRun(Port *port) { - char *av[2]; - const int ac = 1; - - av[0] = "postgres"; - av[1] = NULL; - /* * Make sure we aren't in PostmasterContext anymore. (We can't delete it * just yet, though, because InitPostgres will need the HBA data.) */ MemoryContextSwitchTo(TopMemoryContext); - PostgresMain(ac, av, port->database_name, port->user_name); + PostgresMain(port->database_name, port->user_name); } diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c index 1dd5800d6b3..8d003ea9ce7 100644 --- a/src/backend/tcop/postgres.c +++ b/src/backend/tcop/postgres.c @@ -3915,40 +3915,30 @@ process_postgres_switches(int argc, char *argv[], GucContext ctx, } -/* ---------------------------------------------------------------- - * PostgresMain - * postgres main loop -- all backends, interactive or otherwise start here +/* + * PostgresSingleUserMain + * Entry point for single user mode. argc/argv are the command line + * arguments to be used. * - * argc/argv are the command line arguments to be used. (When being forked - * by the postmaster, these are not the original argv array of the process.) - * dbname is the name of the database to connect to, or NULL if the database - * name should be extracted from the command line arguments or defaulted. - * username is the PostgreSQL user name to be used for the session. - * ---------------------------------------------------------------- + * Performs single user specific setup then calls PostgresMain() to actually + * process queries. Single user mode specific setup should go here, rather + * than PostgresMain() or InitPostgres() when reasonably possible. */ void -PostgresMain(int argc, char *argv[], - const char *dbname, - const char *username) +PostgresSingleUserMain(int argc, char *argv[], + const char *username) { - int firstchar; - StringInfoData input_message; - sigjmp_buf local_sigjmp_buf; - volatile bool send_ready_for_query = true; - bool idle_in_transaction_timeout_enabled = false; - bool idle_session_timeout_enabled = false; + const char *dbname = NULL; - /* Initialize startup process environment if necessary. */ - if (!IsUnderPostmaster) - InitStandaloneProcess(argv[0]); + Assert(!IsUnderPostmaster); - SetProcessingMode(InitProcessing); + /* Initialize startup process environment. */ + InitStandaloneProcess(argv[0]); /* * Set default values for command-line options. */ - if (!IsUnderPostmaster) - InitializeGUCOptions(); + InitializeGUCOptions(); /* * Parse command-line options. @@ -3966,12 +3956,74 @@ PostgresMain(int argc, char *argv[], progname))); } - /* Acquire configuration parameters, unless inherited from postmaster */ - if (!IsUnderPostmaster) - { - if (!SelectConfigFiles(userDoption, progname)) - proc_exit(1); - } + /* Acquire configuration parameters */ + if (!SelectConfigFiles(userDoption, progname)) + proc_exit(1); + + /* + * Validate we have been given a reasonable-looking DataDir and change + * into it. + */ + checkDataDir(); + ChangeToDataDir(); + + /* + * Create lockfile for data directory. + */ + CreateDataDirLockFile(false); + + /* read control file (error checking and contains config ) */ + LocalProcessControlFile(false); + + /* Initialize MaxBackends */ + InitializeMaxBackends(); + + CreateSharedMemoryAndSemaphores(); + + /* + * Remember stand-alone backend startup time + */ + PgStartTime = GetCurrentTimestamp(); + + /* + * Create a per-backend PGPROC struct in shared memory. We must do this + * before we can use LWLocks. + */ + InitProcess(); + + /* + * Now that sufficient infrastructure has been initialized, PostgresMain() + * can do the rest. + */ + PostgresMain(dbname, username); +} + + +/* ---------------------------------------------------------------- + * PostgresMain + * postgres main loop -- all backends, interactive or otherwise loop here + * + * dbname is the name of the database to connect to, username is the + * PostgreSQL user name to be used for the session. + * + * NB: Single user mode specific setup should go to PostgresSingleUserMain() + * if reasonably possible. + * ---------------------------------------------------------------- + */ +void +PostgresMain(const char *dbname, const char *username) +{ + int firstchar; + StringInfoData input_message; + sigjmp_buf local_sigjmp_buf; + volatile bool send_ready_for_query = true; + bool idle_in_transaction_timeout_enabled = false; + bool idle_session_timeout_enabled = false; + + AssertArg(dbname != NULL); + AssertArg(username != NULL); + + SetProcessingMode(InitProcessing); /* * Set up signal handlers. (InitPostmasterChild or InitStandaloneProcess @@ -4029,42 +4081,6 @@ PostgresMain(int argc, char *argv[], * platforms */ } - if (!IsUnderPostmaster) - { - /* - * Validate we have been given a reasonable-looking DataDir (if under - * postmaster, assume postmaster did this already). - */ - checkDataDir(); - - /* Change into DataDir (if under postmaster, was done already) */ - ChangeToDataDir(); - - /* - * Create lockfile for data directory. - */ - CreateDataDirLockFile(false); - - /* read control file (error checking and contains config ) */ - LocalProcessControlFile(false); - - /* Initialize MaxBackends (if under postmaster, was done already) */ - InitializeMaxBackends(); - - CreateSharedMemoryAndSemaphores(); - - /* - * Remember stand-alone backend startup time - */ - PgStartTime = GetCurrentTimestamp(); - - /* - * Create a per-backend PGPROC struct in shared memory. We must do - * this before we can use LWLocks. - */ - InitProcess(); - } - /* Early initialization */ BaseInit(); -- 2.32.0.rc2