From 935a3708fae9bc721ea23ebb5955705252ab4b37 Mon Sep 17 00:00:00 2001 From: Heikki Linnakangas Date: Wed, 9 Oct 2024 22:15:41 +0300 Subject: [PATCH 4/4] Pass MyPMChildSlot as an explicit argument to child process All the other global variables passed from postmaster to child have the same value in all the processes, while MyPMChildSlot is more like a parameter to each child process. Reviewed-by: Andres Freund Discussion: https://www.postgresql.org/message-id/a102f15f-eac4-4ff2-af02-f9ff209ec66f@iki.fi --- src/backend/postmaster/launch_backend.c | 32 ++++++++++++++++--------- src/backend/postmaster/postmaster.c | 10 ++++---- src/backend/postmaster/syslogger.c | 7 +++--- src/include/postmaster/postmaster.h | 1 + 4 files changed, 30 insertions(+), 20 deletions(-) diff --git a/src/backend/postmaster/launch_backend.c b/src/backend/postmaster/launch_backend.c index 02755b6448..20c8d1e038 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 @@ -138,6 +137,8 @@ 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 @@ -159,13 +160,16 @@ 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 */ @@ -227,7 +231,7 @@ 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) { @@ -236,7 +240,7 @@ 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 */ @@ -264,6 +268,7 @@ postmaster_child_launch(BackendType child_type, */ MemoryContextSwitchTo(TopMemoryContext); + MyPMChildSlot = child_slot; if (client_sock) { MyClientSocket = palloc(sizeof(ClientSocket)); @@ -290,7 +295,8 @@ 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; @@ -310,7 +316,7 @@ 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 */ @@ -399,7 +405,8 @@ 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; @@ -480,7 +487,9 @@ 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 @@ -692,7 +701,8 @@ 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 @@ -709,7 +719,7 @@ 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/postmaster.c b/src/backend/postmaster/postmaster.c index 97a1b7ae1a..6eab012dc2 100644 --- a/src/backend/postmaster/postmaster.c +++ b/src/backend/postmaster/postmaster.c @@ -3376,8 +3376,7 @@ 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) @@ -3702,8 +3701,7 @@ 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 */ @@ -3875,8 +3873,8 @@ 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 7ca24c6663..f12639056f 100644 --- a/src/backend/postmaster/syslogger.c +++ b/src/backend/postmaster/syslogger.c @@ -694,14 +694,15 @@ SysLogger_Start(int child_slot) pfree(filename); } - MyPMChildSlot = child_slot; #ifdef EXEC_BACKEND 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 5a40aee3ce..df18e6cfc5 100644 --- a/src/include/postmaster/postmaster.h +++ b/src/include/postmaster/postmaster.h @@ -108,6 +108,7 @@ 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); -- 2.39.5