From 088f7911d2e300bad23e5afe66370340a96275e4 Mon Sep 17 00:00:00 2001 From: Heikki Linnakangas Date: Thu, 1 Aug 2024 22:58:17 +0300 Subject: [PATCH v4 7/8] Pass MyPMChildSlot as an explicit argument to child process All the other global variables passed from postmaster to child are have the same value in all the processes, while MyPMChildSlot is more like a parameter to each child process. --- src/backend/postmaster/launch_backend.c | 32 ++++++++++++++++--------- src/backend/postmaster/pmchild.c | 3 --- src/backend/postmaster/postmaster.c | 16 ++++++------- src/backend/postmaster/syslogger.c | 8 ++++--- src/include/postmaster/postmaster.h | 1 + src/include/postmaster/syslogger.h | 2 +- 6 files changed, 35 insertions(+), 27 deletions(-) diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index b0b91dc97f..4e93bd1d94 100644 --- a/src/backend/postmaster/launch_backend.c +++ b/src/backend/postmaster/launch_backend.c @@ -96,7 +96,6 @@ typedef int InheritableSocket; typedef struct { char DataDir[MAXPGPATH]; - int MyPMChildSlot; #ifndef WIN32 unsigned long UsedShmemSegID; #else @@ -137,6 +136,8 @@ typedef struct char my_exec_path[MAXPGPATH]; char pkglib_path[MAXPGPATH]; + int MyPMChildSlot; + /* * These are only used by backend processes, but are here because passing * a socket needs some special handling on Windows. 'client_sock' is an @@ -158,13 +159,16 @@ typedef struct static void read_backend_variables(char *id, char **startup_data, size_t *startup_data_len); static void restore_backend_variables(BackendParameters *param); -static bool save_backend_variables(BackendParameters *param, ClientSocket *client_sock, +static bool save_backend_variables(BackendParameters *param, int child_slot, + ClientSocket *client_sock, #ifdef WIN32 HANDLE childProcess, pid_t childPid, #endif char *startup_data, size_t startup_data_len); -static pid_t internal_forkexec(const char *child_kind, char *startup_data, size_t startup_data_len, ClientSocket *client_sock); +static pid_t internal_forkexec(const char *child_kind, int child_slot, + char *startup_data, size_t startup_data_len, + ClientSocket *client_sock); #endif /* EXEC_BACKEND */ @@ -226,7 +230,7 @@ PostmasterChildName(BackendType child_type) * the child process. */ pid_t -postmaster_child_launch(BackendType child_type, +postmaster_child_launch(BackendType child_type, int child_slot, char *startup_data, size_t startup_data_len, ClientSocket *client_sock) { @@ -235,7 +239,7 @@ postmaster_child_launch(BackendType child_type, Assert(IsPostmasterEnvironment && !IsUnderPostmaster); #ifdef EXEC_BACKEND - pid = internal_forkexec(child_process_kinds[child_type].name, + pid = internal_forkexec(child_process_kinds[child_type].name, child_slot, startup_data, startup_data_len, client_sock); /* the child process will arrive in SubPostmasterMain */ #else /* !EXEC_BACKEND */ @@ -263,6 +267,7 @@ postmaster_child_launch(BackendType child_type, */ MemoryContextSwitchTo(TopMemoryContext); + MyPMChildSlot = child_slot; if (client_sock) { MyClientSocket = palloc(sizeof(ClientSocket)); @@ -289,7 +294,8 @@ postmaster_child_launch(BackendType child_type, * - fork():s, and then exec():s the child process */ static pid_t -internal_forkexec(const char *child_kind, char *startup_data, size_t startup_data_len, ClientSocket *client_sock) +internal_forkexec(const char *child_kind, int child_slot, + char *startup_data, size_t startup_data_len, ClientSocket *client_sock) { static unsigned long tmpBackendFileNum = 0; pid_t pid; @@ -309,7 +315,7 @@ internal_forkexec(const char *child_kind, char *startup_data, size_t startup_dat */ paramsz = SizeOfBackendParameters(startup_data_len); param = palloc0(paramsz); - if (!save_backend_variables(param, client_sock, startup_data, startup_data_len)) + if (!save_backend_variables(param, child_slot, client_sock, startup_data, startup_data_len)) { pfree(param); return -1; /* log made by save_backend_variables */ @@ -398,7 +404,8 @@ internal_forkexec(const char *child_kind, char *startup_data, size_t startup_dat * file is complete. */ static pid_t -internal_forkexec(const char *child_kind, char *startup_data, size_t startup_data_len, ClientSocket *client_sock) +internal_forkexec(const char *child_kind, int child_slot, + char *startup_data, size_t startup_data_len, ClientSocket *client_sock) { int retry_count = 0; STARTUPINFO si; @@ -479,7 +486,9 @@ retry: return -1; } - if (!save_backend_variables(param, client_sock, pi.hProcess, pi.dwProcessId, startup_data, startup_data_len)) + if (!save_backend_variables(param, child_slot, client_sock, + pi.hProcess, pi.dwProcessId, + startup_data, startup_data_len)) { /* * log made by save_backend_variables, but we have to clean up the @@ -691,7 +700,8 @@ static void read_inheritable_socket(SOCKET *dest, InheritableSocket *src); /* Save critical backend variables into the BackendParameters struct */ static bool -save_backend_variables(BackendParameters *param, ClientSocket *client_sock, +save_backend_variables(BackendParameters *param, + int child_slot, ClientSocket *client_sock, #ifdef WIN32 HANDLE childProcess, pid_t childPid, #endif @@ -708,7 +718,7 @@ save_backend_variables(BackendParameters *param, ClientSocket *client_sock, strlcpy(param->DataDir, DataDir, MAXPGPATH); - param->MyPMChildSlot = MyPMChildSlot; + param->MyPMChildSlot = child_slot; #ifdef WIN32 param->ShmemProtectiveRegion = ShmemProtectiveRegion; diff --git a/src/backend/postmaster/pmchild.c b/src/backend/postmaster/pmchild.c index 735c66f8e7..ac8776bd95 100644 --- a/src/backend/postmaster/pmchild.c +++ b/src/backend/postmaster/pmchild.c @@ -209,9 +209,6 @@ AssignPostmasterChildSlot(BackendType btype) ReservePostmasterChildSlot(pmchild->child_slot); - /* FIXME: find a more elegant way to pass this */ - MyPMChildSlot = pmchild->child_slot; - elog(DEBUG2, "assigned pm child slot %d for %s", pmchild->child_slot, PostmasterChildName(btype)); return pmchild; diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c index a029e28786..798cd330f3 100644 --- a/src/backend/postmaster/postmaster.c +++ b/src/backend/postmaster/postmaster.c @@ -983,7 +983,7 @@ PostmasterMain(int argc, char *argv[]) SysLoggerPMChild = AssignPostmasterChildSlot(B_LOGGER); if (!SysLoggerPMChild) elog(ERROR, "no postmaster child slot available for syslogger"); - SysLoggerPMChild->pid = SysLogger_Start(); + SysLoggerPMChild->pid = SysLogger_Start(SysLoggerPMChild->child_slot); if (SysLoggerPMChild->pid == 0) { FreePostmasterChildSlot(SysLoggerPMChild); @@ -2413,7 +2413,7 @@ process_pm_child_exit(void) if (SysLoggerPMChild && pid == SysLoggerPMChild->pid) { /* for safety's sake, launch new logger *first* */ - SysLoggerPMChild->pid = SysLogger_Start(); + SysLoggerPMChild->pid = SysLogger_Start(SysLoggerPMChild->child_slot); if (SysLoggerPMChild->pid == 0) { FreePostmasterChildSlot(SysLoggerPMChild); @@ -3054,7 +3054,7 @@ LaunchMissingBackgroundProcesses(void) elog(LOG, "no postmaster child slot available for syslogger"); else { - SysLoggerPMChild->pid = SysLogger_Start(); + SysLoggerPMChild->pid = SysLogger_Start(SysLoggerPMChild->child_slot); if (SysLoggerPMChild->pid == 0) { FreePostmasterChildSlot(SysLoggerPMChild); @@ -3325,8 +3325,7 @@ BackendStartup(ClientSocket *client_sock) /* Hasn't asked to be notified about any bgworkers yet */ bn->bgworker_notify = false; - MyPMChildSlot = bn->child_slot; - pid = postmaster_child_launch(bn->bkend_type, + pid = postmaster_child_launch(bn->bkend_type, bn->child_slot, (char *) &startup_data, sizeof(startup_data), client_sock); if (pid < 0) @@ -3650,8 +3649,7 @@ StartChildProcess(BackendType type) return NULL; } - MyPMChildSlot = pmchild->child_slot; - pid = postmaster_child_launch(type, NULL, 0, NULL); + pid = postmaster_child_launch(type, pmchild->child_slot, NULL, 0, NULL); if (pid < 0) { /* in parent, fork failed */ @@ -3806,8 +3804,8 @@ do_start_bgworker(RegisteredBgWorker *rw) (errmsg_internal("starting background worker process \"%s\"", rw->rw_worker.bgw_name))); - MyPMChildSlot = bn->child_slot; - worker_pid = postmaster_child_launch(B_BG_WORKER, (char *) &rw->rw_worker, sizeof(BackgroundWorker), NULL); + worker_pid = postmaster_child_launch(B_BG_WORKER, bn->child_slot, + (char *) &rw->rw_worker, sizeof(BackgroundWorker), NULL); if (worker_pid == -1) { /* in postmaster, fork failed ... */ diff --git a/src/backend/postmaster/syslogger.c b/src/backend/postmaster/syslogger.c index 7951599fa8..d68853d429 100644 --- a/src/backend/postmaster/syslogger.c +++ b/src/backend/postmaster/syslogger.c @@ -590,7 +590,7 @@ SysLoggerMain(char *startup_data, size_t startup_data_len) * Postmaster subroutine to start a syslogger subprocess. */ int -SysLogger_Start(void) +SysLogger_Start(int child_slot) { pid_t sysloggerPid; char *filename; @@ -699,9 +699,11 @@ SysLogger_Start(void) startup_data.syslogFile = syslogger_fdget(syslogFile); startup_data.csvlogFile = syslogger_fdget(csvlogFile); startup_data.jsonlogFile = syslogger_fdget(jsonlogFile); - sysloggerPid = postmaster_child_launch(B_LOGGER, (char *) &startup_data, sizeof(startup_data), NULL); + sysloggerPid = postmaster_child_launch(B_LOGGER, child_slot, + (char *) &startup_data, sizeof(startup_data), NULL); #else - sysloggerPid = postmaster_child_launch(B_LOGGER, NULL, 0, NULL); + sysloggerPid = postmaster_child_launch(B_LOGGER, child_slot, + NULL, 0, NULL); #endif /* EXEC_BACKEND */ if (sysloggerPid == -1) diff --git a/src/include/postmaster/postmaster.h b/src/include/postmaster/postmaster.h index deca2e8370..81a3520021 100644 --- a/src/include/postmaster/postmaster.h +++ b/src/include/postmaster/postmaster.h @@ -103,6 +103,7 @@ extern PGDLLIMPORT struct ClientSocket *MyClientSocket; /* prototypes for functions in launch_backend.c */ extern pid_t postmaster_child_launch(BackendType child_type, + int child_slot, char *startup_data, size_t startup_data_len, struct ClientSocket *client_sock); diff --git a/src/include/postmaster/syslogger.h b/src/include/postmaster/syslogger.h index b5fc239ba9..d72b978b0a 100644 --- a/src/include/postmaster/syslogger.h +++ b/src/include/postmaster/syslogger.h @@ -86,7 +86,7 @@ extern PGDLLIMPORT HANDLE syslogPipe[2]; #endif -extern int SysLogger_Start(void); +extern int SysLogger_Start(int child_slot); extern void write_syslogger_file(const char *buffer, int count, int destination); -- 2.39.2