/*-------------------------------------------------------------------- * Symbols referenced in this file: * - ClientAuthInProgress *-------------------------------------------------------------------- */ /*------------------------------------------------------------------------- * * postmaster.c * This program acts as a clearing house for requests to the * POSTGRES system. Frontend programs send a startup message * to the Postmaster and the postmaster uses the info in the * message to setup a backend process. * * The postmaster also manages system-wide operations such as * startup and shutdown. The postmaster itself doesn't do those * operations, mind you --- it just forks off a subprocess to do them * at the right times. It also takes care of resetting the system * if a backend crashes. * * The postmaster process creates the shared memory and semaphore * pools during startup, but as a rule does not touch them itself. * In particular, it is not a member of the PGPROC array of backends * and so it cannot participate in lock-manager operations. Keeping * the postmaster away from shared memory operations makes it simpler * and more reliable. The postmaster is almost always able to recover * from crashes of individual backends by resetting shared memory; * if it did much with shared memory then it would be prone to crashing * along with the backends. * * When a request message is received, we now fork() immediately. * The child process performs authentication of the request, and * then becomes a backend if successful. This allows the auth code * to be written in a simple single-threaded style (as opposed to the * crufty "poor man's multitasking" code that used to be needed). * More importantly, it ensures that blockages in non-multithreaded * libraries like SSL or PAM cannot cause denial of service to other * clients. * * * Portions Copyright (c) 1996-2015, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * * IDENTIFICATION * src/backend/postmaster/postmaster.c * * NOTES * * Initialization: * The Postmaster sets up shared memory data structures * for the backends. * * Synchronization: * The Postmaster shares memory with the backends but should avoid * touching shared memory, so as not to become stuck if a crashing * backend screws up locks or shared memory. Likewise, the Postmaster * should never block on messages from frontend clients. * * Garbage Collection: * The Postmaster cleans up after backends if they have an emergency * exit and/or core dump. * * Error Reporting: * Use write_stderr() only for reporting "interactive" errors * (essentially, bogus arguments on the command line). Once the * postmaster is launched, use ereport(). * *------------------------------------------------------------------------- */ #include "postgres.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef HAVE_SYS_SELECT_H #include #endif #ifdef USE_BONJOUR #include #endif #ifdef HAVE_PTHREAD_IS_THREADED_NP #include #endif #include "access/transam.h" #include "access/xlog.h" #include "bootstrap/bootstrap.h" #include "catalog/pg_control.h" #include "lib/ilist.h" #include "libpq/auth.h" #include "libpq/ip.h" #include "libpq/libpq.h" #include "libpq/pqsignal.h" #include "miscadmin.h" #include "pg_getopt.h" #include "pgstat.h" #include "postmaster/autovacuum.h" #include "postmaster/bgworker_internals.h" #include "postmaster/fork_process.h" #include "postmaster/pgarch.h" #include "postmaster/postmaster.h" #include "postmaster/syslogger.h" #include "replication/walsender.h" #include "storage/fd.h" #include "storage/ipc.h" #include "storage/pg_shmem.h" #include "storage/pmsignal.h" #include "storage/proc.h" #include "tcop/tcopprot.h" #include "utils/builtins.h" #include "utils/datetime.h" #include "utils/dynamic_loader.h" #include "utils/memutils.h" #include "utils/ps_status.h" #include "utils/timeout.h" #ifdef EXEC_BACKEND #include "storage/spin.h" #endif /* * Possible types of a backend. Beyond being the possible bkend_type values in * struct bkend, these are OR-able request flag bits for SignalSomeChildren() * and CountChildren(). */ #define BACKEND_TYPE_NORMAL 0x0001 /* normal backend */ #define BACKEND_TYPE_AUTOVAC 0x0002 /* autovacuum worker process */ #define BACKEND_TYPE_WALSND 0x0004 /* walsender process */ #define BACKEND_TYPE_BGWORKER 0x0008 /* bgworker process */ #define BACKEND_TYPE_ALL 0x000F /* OR of all the above */ #define BACKEND_TYPE_WORKER (BACKEND_TYPE_AUTOVAC | BACKEND_TYPE_BGWORKER) /* * List of active backends (or child processes anyway; we don't actually * know whether a given child has become a backend or is still in the * authorization phase). This is used mainly to keep track of how many * children we have and send them appropriate signals when necessary. * * "Special" children such as the startup, bgwriter and autovacuum launcher * tasks are not in this list. Autovacuum worker and walsender are in it. * Also, "dead_end" children are in it: these are children launched just for * the purpose of sending a friendly rejection message to a would-be client. * We must track them because they are attached to shared memory, but we know * they will never become live backends. dead_end children are not assigned a * PMChildSlot. * * Background workers are in this list, too. */ typedef struct bkend { pid_t pid; /* process id of backend */ long cancel_key; /* cancel key for cancels for this backend */ int child_slot; /* PMChildSlot for this backend, if any */ /* * Flavor of backend or auxiliary process. Note that BACKEND_TYPE_WALSND * backends initially announce themselves as BACKEND_TYPE_NORMAL, so if * bkend_type is normal, you should check for a recent transition. */ int bkend_type; bool dead_end; /* is it going to send an error and quit? */ bool bgworker_notify; /* gets bgworker start/stop notifications */ dlist_node elem; /* list link in BackendList */ } Backend; #ifdef EXEC_BACKEND static Backend *ShmemBackendArray; #endif /* The socket number we are listening for connections on */ /* The directory names for Unix socket(s) */ /* The TCP listen address(es) */ /* * ReservedBackends is the number of backends reserved for superuser use. * This number is taken out of the pool size given by MaxBackends so * number of backend slots available to non-superusers is * (MaxBackends - ReservedBackends). Note what this really means is * "if there are <= ReservedBackends connections available, only superusers * can make new connections" --- pre-existing superuser connections don't * count against the limit. */ /* The socket(s) we're listening to. */ #define MAXLISTEN 64 /* * Set by the -o option */ /* * These globals control the behavior of the postmaster in case some * backend dumps core. Normally, it kills all peers of the dead backend * and reinitializes shared memory. By specifying -s or -n, we can have * the postmaster stop (rather than kill) peers and not reinitialize * shared data structures. (Reinit is currently dead code, though.) */ /* still more option variables */ /* for ps display and logging */ /* PIDs of special child processes; 0 when not running */ /* Startup process's status */ typedef enum { STARTUP_NOT_RUNNING, STARTUP_RUNNING, STARTUP_SIGNALED, /* we sent it a SIGQUIT or SIGKILL */ STARTUP_CRASHED } StartupStatusEnum; /* Startup/shutdown state */ #define NoShutdown 0 #define SmartShutdown 1 #define FastShutdown 2 #define ImmediateShutdown 3 /* T if recovering from backend crash */ /* * We use a simple state machine to control startup, shutdown, and * crash recovery (which is rather like shutdown followed by startup). * * After doing all the postmaster initialization work, we enter PM_STARTUP * state and the startup process is launched. The startup process begins by * reading the control file and other preliminary initialization steps. * In a normal startup, or after crash recovery, the startup process exits * with exit code 0 and we switch to PM_RUN state. However, archive recovery * is handled specially since it takes much longer and we would like to support * hot standby during archive recovery. * * When the startup process is ready to start archive recovery, it signals the * postmaster, and we switch to PM_RECOVERY state. The background writer and * checkpointer are launched, while the startup process continues applying WAL. * If Hot Standby is enabled, then, after reaching a consistent point in WAL * redo, startup process signals us again, and we switch to PM_HOT_STANDBY * state and begin accepting connections to perform read-only queries. When * archive recovery is finished, the startup process exits with exit code 0 * and we switch to PM_RUN state. * * Normal child backends can only be launched when we are in PM_RUN or * PM_HOT_STANDBY state. (We also allow launch of normal * child backends in PM_WAIT_BACKUP state, but only for superusers.) * In other states we handle connection requests by launching "dead_end" * child processes, which will simply send the client an error message and * quit. (We track these in the BackendList so that we can know when they * are all gone; this is important because they're still connected to shared * memory, and would interfere with an attempt to destroy the shmem segment, * possibly leading to SHMALL failure when we try to make a new one.) * In PM_WAIT_DEAD_END state we are waiting for all the dead_end children * to drain out of the system, and therefore stop accepting connection * requests at all until the last existing child has quit (which hopefully * will not be very long). * * Notice that this state variable does not distinguish *why* we entered * states later than PM_RUN --- Shutdown and FatalError must be consulted * to find that out. FatalError is never true in PM_RECOVERY_* or PM_RUN * states, nor in PM_SHUTDOWN states (because we don't enter those states * when trying to recover from a crash). It can be true in PM_STARTUP state, * because we don't clear it until we've successfully started WAL redo. */ typedef enum { PM_INIT, /* postmaster starting */ PM_STARTUP, /* waiting for startup subprocess */ PM_RECOVERY, /* in archive recovery mode */ PM_HOT_STANDBY, /* in hot standby mode */ PM_RUN, /* normal "database is alive" state */ PM_WAIT_BACKUP, /* waiting for online backup mode to end */ PM_WAIT_READONLY, /* waiting for read only backends to exit */ PM_WAIT_BACKENDS, /* waiting for live backends to exit */ PM_SHUTDOWN, /* waiting for checkpointer to do shutdown * ckpt */ PM_SHUTDOWN_2, /* waiting for archiver and walsenders to * finish */ PM_WAIT_DEAD_END, /* waiting for dead_end children to exit */ PM_NO_CHILDREN /* all important children have exited */ } PMState; /* Start time of SIGKILL timeout during immediate shutdown or child crash */ /* Zero means timeout is not running */ /* Length of said timeout */ #define SIGKILL_CHILDREN_AFTER_SECS 5 /* T if we've reached PM_RUN */ __thread bool ClientAuthInProgress = false; /* T during new-client * authentication */ /* stderr redirected for syslogger? */ /* received START_AUTOVAC_LAUNCHER signal */ /* the launcher needs to be signalled to communicate some condition */ /* set when there's a worker that needs to be started up */ /* * State for assigning random salts and cancel keys. * Also, the global MyCancelKey passes the cancel key assigned to a given * backend from the postmaster to that backend (via fork). */ #ifdef USE_BONJOUR static DNSServiceRef bonjour_sdref = NULL; #endif /* * postmaster.c - function prototypes */ static void CloseServerPorts(int status, Datum arg); static void unlink_external_pid_file(int status, Datum arg); static void getInstallationPaths(const char *argv0); static void checkDataDir(void); static Port *ConnCreate(int serverFd); static void ConnFree(Port *port); static void reset_shared(int port); static void SIGHUP_handler(SIGNAL_ARGS); static void pmdie(SIGNAL_ARGS); static void reaper(SIGNAL_ARGS); static void sigusr1_handler(SIGNAL_ARGS); static void startup_die(SIGNAL_ARGS); static void dummy_handler(SIGNAL_ARGS); static void StartupPacketTimeoutHandler(void); static void CleanupBackend(int pid, int exitstatus); static bool CleanupBackgroundWorker(int pid, int exitstatus); static void HandleChildCrash(int pid, int exitstatus, const char *procname); static void LogChildExit(int lev, const char *procname, int pid, int exitstatus); static void PostmasterStateMachine(void); static void BackendInitialize(Port *port); static void BackendRun(Port *port) pg_attribute_noreturn(); static void ExitPostmaster(int status) pg_attribute_noreturn(); static int ServerLoop(void); static int BackendStartup(Port *port); static int ProcessStartupPacket(Port *port, bool SSLdone); static void processCancelRequest(Port *port, void *pkt); static int initMasks(fd_set *rmask); static void report_fork_failure_to_client(Port *port, int errnum); static CAC_state canAcceptConnections(void); static long PostmasterRandom(void); static void RandomSalt(char *md5Salt); static void signal_child(pid_t pid, int signal); static bool SignalSomeChildren(int signal, int targets); static void TerminateChildren(int signal); #define SignalChildren(sig) SignalSomeChildren(sig, BACKEND_TYPE_ALL) static int CountChildren(int target); static void maybe_start_bgworker(void); static bool CreateOptsFile(int argc, char *argv[], char *fullprogname); static pid_t StartChildProcess(AuxProcType type); static void StartAutovacuumWorker(void); static void InitPostmasterDeathWatchHandle(void); /* * Archiver is allowed to start up at the current postmaster state? * * If WAL archiving is enabled always, we are allowed to start archiver * even during recovery. */ #define PgArchStartupAllowed() \ ((XLogArchivingActive() && pmState == PM_RUN) || \ (XLogArchivingAlways() && \ (pmState == PM_RECOVERY || pmState == PM_HOT_STANDBY))) #ifdef EXEC_BACKEND #ifdef WIN32 #define WNOHANG 0 /* ignored, so any integer value will do */ static pid_t waitpid(pid_t pid, int *exitstatus, int options); static void WINAPI pgwin32_deadchild_callback(PVOID lpParameter, BOOLEAN TimerOrWaitFired); static HANDLE win32ChildQueue; typedef struct { HANDLE waitHandle; HANDLE procHandle; DWORD procId; } win32_deadchild_waitinfo; #endif /* WIN32 */ static pid_t backend_forkexec(Port *port); static pid_t internal_forkexec(int argc, char *argv[], Port *port); /* Type for a socket that can be inherited to a client process */ #ifdef WIN32 typedef struct { SOCKET origsocket; /* Original socket value, or PGINVALID_SOCKET * if not a socket */ WSAPROTOCOL_INFO wsainfo; } InheritableSocket; #else typedef int InheritableSocket; #endif /* * Structure contains all variables passed to exec:ed backends */ typedef struct { Port port; InheritableSocket portsocket; char DataDir[MAXPGPATH]; pgsocket ListenSocket[MAXLISTEN]; long MyCancelKey; int MyPMChildSlot; #ifndef WIN32 unsigned long UsedShmemSegID; #else HANDLE UsedShmemSegID; #endif void *UsedShmemSegAddr; slock_t *ShmemLock; VariableCache ShmemVariableCache; Backend *ShmemBackendArray; #ifndef HAVE_SPINLOCKS PGSemaphore SpinlockSemaArray; #endif LWLockPadded *MainLWLockArray; slock_t *ProcStructLock; PROC_HDR *ProcGlobal; PGPROC *AuxiliaryProcs; PGPROC *PreparedXactProcs; PMSignalData *PMSignalState; InheritableSocket pgStatSock; pid_t PostmasterPid; TimestampTz PgStartTime; TimestampTz PgReloadTime; pg_time_t first_syslogger_file_time; bool redirection_done; bool IsBinaryUpgrade; int max_safe_fds; int MaxBackends; #ifdef WIN32 HANDLE PostmasterHandle; HANDLE initial_signal_pipe; HANDLE syslogPipe[2]; #else int postmaster_alive_fds[2]; int syslogPipe[2]; #endif char my_exec_path[MAXPGPATH]; char pkglib_path[MAXPGPATH]; char ExtraOptions[MAXPGPATH]; } BackendParameters; static void read_backend_variables(char *id, Port *port); static void restore_backend_variables(BackendParameters *param, Port *port); #ifndef WIN32 static bool save_backend_variables(BackendParameters *param, Port *port); #else static bool save_backend_variables(BackendParameters *param, Port *port, HANDLE childProcess, pid_t childPid); #endif static void ShmemBackendArrayAdd(Backend *bn); static void ShmemBackendArrayRemove(Backend *bn); #endif /* EXEC_BACKEND */ #define StartupDataBase() StartChildProcess(StartupProcess) #define StartBackgroundWriter() StartChildProcess(BgWriterProcess) #define StartCheckpointer() StartChildProcess(CheckpointerProcess) #define StartWalWriter() StartChildProcess(WalWriterProcess) #define StartWalReceiver() StartChildProcess(WalReceiverProcess) /* Macros to check exit status of a child process */ #define EXIT_STATUS_0(st) ((st) == 0) #define EXIT_STATUS_1(st) (WIFEXITED(st) && WEXITSTATUS(st) == 1) #define EXIT_STATUS_3(st) (WIFEXITED(st) && WEXITSTATUS(st) == 3) #ifndef WIN32 /* * File descriptors for pipe used to monitor if postmaster is alive. * First is POSTMASTER_FD_WATCH, second is POSTMASTER_FD_OWN. */ #else /* Process handle of postmaster used for the same purpose on Windows */ HANDLE PostmasterHandle; #endif /* * Postmaster main entry point */ #ifdef SIGXFSZ #endif #ifdef HAVE_INT_OPTRESET #endif #ifdef USE_SSL #endif #ifdef USE_BONJOUR #endif #ifdef HAVE_UNIX_SOCKETS #endif #ifdef WIN32 #endif #ifdef EXEC_BACKEND #endif #ifdef HAVE_PTHREAD_IS_THREADED_NP #endif /* * on_proc_exit callback to close server's listen sockets */ /* * on_proc_exit callback to delete external_pid_file */ /* * Compute and check the directory paths to files that are part of the * installation (as deduced from the postgres executable's own location) */ #ifdef EXEC_BACKEND #endif /* * Validate the proposed data directory */ #if !defined(WIN32) && !defined(__CYGWIN__) #endif #if !defined(WIN32) && !defined(__CYGWIN__) #endif /* * Determine how long should we let ServerLoop sleep. * * In normal conditions we wait at most one minute, to ensure that the other * background tasks handled by ServerLoop get done even when no requests are * arriving. However, if there are background workers waiting to be started, * we don't actually sleep so that they are quickly serviced. Other exception * cases are as shown in the code. */ /* * Main idle loop of postmaster * * NB: Needs to be called with signals blocked */ #ifdef HAVE_PTHREAD_IS_THREADED_NP #endif /* * Initialise the masks for select() for the ports we are listening on. * Return the number of sockets to listen on. */ /* * Read a client's startup packet and do something according to it. * * Returns STATUS_OK or STATUS_ERROR, or might call ereport(FATAL) and * not return at all. * * (Note that ereport(FATAL) stuff is sent to the client, so only use it * if that's what you want. Return STATUS_ERROR if you don't want to * send anything to the client, which would typically be appropriate * if we detect a communications failure.) */ #ifdef USE_SSL #else #endif #ifdef USE_SSL #endif /* * The client has sent a cancel request packet, not a normal * start-a-new-connection packet. Perform the necessary processing. * Nothing is sent back to the client. */ #ifndef EXEC_BACKEND #else #endif #ifndef EXEC_BACKEND #else #endif /* * canAcceptConnections --- check to see if database state allows connections. */ /* * ConnCreate -- create a local connection data structure * * Returns NULL on failure, other than out-of-memory which is fatal. */ #ifndef EXEC_BACKEND #if defined(ENABLE_GSS) || defined(ENABLE_SSPI) #endif #endif /* * ConnFree -- free a local connection data structure */ #ifdef USE_SSL #endif /* * ClosePostmasterPorts -- close all the postmaster's open sockets * * This is called during child process startup to release file descriptors * that are not needed by that child process. The postmaster still has * them open, of course. * * Note: we pass am_syslogger as a boolean because we don't want to set * the global variable yet when this is called. */ #ifndef WIN32 #endif #ifndef WIN32 #else #endif #ifdef USE_BONJOUR #endif /* * reset_shared -- reset shared memory and semaphores */ /* * SIGHUP -- reread config files, and tell children to do same */ #ifdef EXEC_BACKEND #endif /* * pmdie -- signal handler for processing various postmaster signals. */ /* * Reaper -- signal handler to cleanup after a child process dies. */ /* * Scan the bgworkers list and see if the given PID (which has just stopped * or crashed) is in it. Handle its shutdown if so, and return true. If not a * bgworker, return false. * * This is heavily based on CleanupBackend. One important difference is that * we don't know yet that the dying process is a bgworker, so we must be silent * until we're sure it is. */ #ifdef WIN32 #endif #ifdef EXEC_BACKEND #endif /* * CleanupBackend -- cleanup after terminated backend. * * Remove all local state associated with backend. * * If you change this, see also CleanupBackgroundWorker. */ #ifdef WIN32 #endif #ifdef EXEC_BACKEND #endif /* * HandleChildCrash -- cleanup after failed backend, bgwriter, checkpointer, * walwriter, autovacuum, or background worker. * * The objectives here are to clean up our local state about the child * process, and to signal all other remaining children to quickdie. */ #ifdef EXEC_BACKEND #endif #ifdef EXEC_BACKEND #endif /* * Log the death of a child process. */ #if defined(WIN32) #else #endif /* * Advance the postmaster's state machine and take actions as appropriate * * This is common code for pmdie(), reaper() and sigusr1_handler(), which * receive the signals that might mean we need to change state. */ /* * Send a signal to a postmaster child process * * On systems that have setsid(), each child process sets itself up as a * process group leader. For signals that are generally interpreted in the * appropriate fashion, we signal the entire process group not just the * direct child process. This allows us to, for example, SIGQUIT a blocked * archive_recovery script, or SIGINT a script being run by a backend via * system(). * * There is a race condition for recently-forked children: they might not * have executed setsid() yet. So we signal the child directly as well as * the group. We assume such a child will handle the signal before trying * to spawn any grandchild processes. We also assume that signaling the * child twice will not cause any problems. */ #ifdef HAVE_SETSID #endif /* * Send a signal to the targeted children (but NOT special children; * dead_end children are never signaled, either). */ /* * Send a termination signal to children. This considers all of our children * processes, except syslogger and dead_end backends. */ /* * BackendStartup -- start backend process * * returns: STATUS_ERROR if the fork failed, STATUS_OK otherwise. * * Note: if you change this code, also consider StartAutovacuumWorker. */ #ifdef EXEC_BACKEND #else /* !EXEC_BACKEND */ #endif /* EXEC_BACKEND */ #ifdef EXEC_BACKEND #endif /* * Try to report backend fork() failure to client before we close the * connection. Since we do not care to risk blocking the postmaster on * this connection, we set the connection to non-blocking and try only once. * * This is grungy special-purpose code; we cannot use backend libpq since * it's not up and running. */ /* * BackendInitialize -- initialize an interactive (postmaster-child) * backend process, and collect the client's startup packet. * * returns: nothing. Will not return at all if there's any failure. * * Note: this code does not depend on having any access to shared memory. * In the EXEC_BACKEND case, we are physically attached to shared memory * but have not yet set up most of our local pointers to shmem structures. */ /* * BackendRun -- set up the backend's argument list and invoke PostgresMain() * * returns: * Shouldn't return at all. * If PostgresMain() fails, return status. */ #ifdef EXEC_BACKEND /* * postmaster_forkexec -- fork and exec a postmaster subprocess * * The caller must have set up the argv array already, except for argv[2] * which will be filled with the name of the temp variable file. * * Returns the child process PID, or -1 on fork failure (a suitable error * message has been logged on failure). * * All uses of this routine will dispatch to SubPostmasterMain in the * child process. */ pid_t postmaster_forkexec(int argc, char *argv[]) { Port port; /* This entry point passes dummy values for the Port variables */ memset(&port, 0, sizeof(port)); return internal_forkexec(argc, argv, &port); } /* * backend_forkexec -- fork/exec off a backend process * * Some operating systems (WIN32) don't have fork() so we have to simulate * it by storing parameters that need to be passed to the child and * then create a new child process. * * returns the pid of the fork/exec'd process, or -1 on failure */ static pid_t backend_forkexec(Port *port) { char *av[4]; int ac = 0; av[ac++] = "postgres"; av[ac++] = "--forkbackend"; av[ac++] = NULL; /* filled in by internal_forkexec */ av[ac] = NULL; Assert(ac < lengthof(av)); return internal_forkexec(ac, av, port); } #ifndef WIN32 /* * internal_forkexec non-win32 implementation * * - writes out backend variables to the parameter file * - fork():s, and then exec():s the child process */ static pid_t internal_forkexec(int argc, char *argv[], Port *port) { static unsigned long tmpBackendFileNum = 0; pid_t pid; char tmpfilename[MAXPGPATH]; BackendParameters param; FILE *fp; if (!save_backend_variables(¶m, port)) return -1; /* log made by save_backend_variables */ /* Calculate name for temp file */ snprintf(tmpfilename, MAXPGPATH, "%s/%s.backend_var.%d.%lu", PG_TEMP_FILES_DIR, PG_TEMP_FILE_PREFIX, MyProcPid, ++tmpBackendFileNum); /* Open file */ fp = AllocateFile(tmpfilename, PG_BINARY_W); if (!fp) { /* * As in OpenTemporaryFileInTablespace, try to make the temp-file * directory */ mkdir(PG_TEMP_FILES_DIR, S_IRWXU); fp = AllocateFile(tmpfilename, PG_BINARY_W); if (!fp) { ereport(LOG, (errcode_for_file_access(), errmsg("could not create file \"%s\": %m", tmpfilename))); return -1; } } if (fwrite(¶m, sizeof(param), 1, fp) != 1) { ereport(LOG, (errcode_for_file_access(), errmsg("could not write to file \"%s\": %m", tmpfilename))); FreeFile(fp); return -1; } /* Release file */ if (FreeFile(fp)) { ereport(LOG, (errcode_for_file_access(), errmsg("could not write to file \"%s\": %m", tmpfilename))); return -1; } /* Make sure caller set up argv properly */ Assert(argc >= 3); Assert(argv[argc] == NULL); Assert(strncmp(argv[1], "--fork", 6) == 0); Assert(argv[2] == NULL); /* Insert temp file name after --fork argument */ argv[2] = tmpfilename; /* Fire off execv in child */ if ((pid = fork_process()) == 0) { if (execv(postgres_exec_path, argv) < 0) { ereport(LOG, (errmsg("could not execute server process \"%s\": %m", postgres_exec_path))); /* We're already in the child process here, can't return */ exit(1); } } return pid; /* Parent returns pid, or -1 on fork failure */ } #else /* WIN32 */ /* * internal_forkexec win32 implementation * * - starts backend using CreateProcess(), in suspended state * - writes out backend variables to the parameter file * - during this, duplicates handles and sockets required for * inheritance into the new process * - resumes execution of the new process once the backend parameter * file is complete. */ static pid_t internal_forkexec(int argc, char *argv[], Port *port) { STARTUPINFO si; PROCESS_INFORMATION pi; int i; int j; char cmdLine[MAXPGPATH * 2]; HANDLE paramHandle; BackendParameters *param; SECURITY_ATTRIBUTES sa; char paramHandleStr[32]; win32_deadchild_waitinfo *childinfo; /* Make sure caller set up argv properly */ Assert(argc >= 3); Assert(argv[argc] == NULL); Assert(strncmp(argv[1], "--fork", 6) == 0); Assert(argv[2] == NULL); /* Set up shared memory for parameter passing */ ZeroMemory(&sa, sizeof(sa)); sa.nLength = sizeof(sa); sa.bInheritHandle = TRUE; paramHandle = CreateFileMapping(INVALID_HANDLE_VALUE, &sa, PAGE_READWRITE, 0, sizeof(BackendParameters), NULL); if (paramHandle == INVALID_HANDLE_VALUE) { elog(LOG, "could not create backend parameter file mapping: error code %lu", GetLastError()); return -1; } param = MapViewOfFile(paramHandle, FILE_MAP_WRITE, 0, 0, sizeof(BackendParameters)); if (!param) { elog(LOG, "could not map backend parameter memory: error code %lu", GetLastError()); CloseHandle(paramHandle); return -1; } /* Insert temp file name after --fork argument */ #ifdef _WIN64 sprintf(paramHandleStr, "%llu", (LONG_PTR) paramHandle); #else sprintf(paramHandleStr, "%lu", (DWORD) paramHandle); #endif argv[2] = paramHandleStr; /* Format the cmd line */ cmdLine[sizeof(cmdLine) - 1] = '\0'; cmdLine[sizeof(cmdLine) - 2] = '\0'; snprintf(cmdLine, sizeof(cmdLine) - 1, "\"%s\"", postgres_exec_path); i = 0; while (argv[++i] != NULL) { j = strlen(cmdLine); snprintf(cmdLine + j, sizeof(cmdLine) - 1 - j, " \"%s\"", argv[i]); } if (cmdLine[sizeof(cmdLine) - 2] != '\0') { elog(LOG, "subprocess command line too long"); return -1; } memset(&pi, 0, sizeof(pi)); memset(&si, 0, sizeof(si)); si.cb = sizeof(si); /* * Create the subprocess in a suspended state. This will be resumed later, * once we have written out the parameter file. */ if (!CreateProcess(NULL, cmdLine, NULL, NULL, TRUE, CREATE_SUSPENDED, NULL, NULL, &si, &pi)) { elog(LOG, "CreateProcess call failed: %m (error code %lu)", GetLastError()); return -1; } if (!save_backend_variables(param, port, pi.hProcess, pi.dwProcessId)) { /* * log made by save_backend_variables, but we have to clean up the * mess with the half-started process */ if (!TerminateProcess(pi.hProcess, 255)) ereport(LOG, (errmsg_internal("could not terminate unstarted process: error code %lu", GetLastError()))); CloseHandle(pi.hProcess); CloseHandle(pi.hThread); return -1; /* log made by save_backend_variables */ } /* Drop the parameter shared memory that is now inherited to the backend */ if (!UnmapViewOfFile(param)) elog(LOG, "could not unmap view of backend parameter file: error code %lu", GetLastError()); if (!CloseHandle(paramHandle)) elog(LOG, "could not close handle to backend parameter file: error code %lu", GetLastError()); /* * Reserve the memory region used by our main shared memory segment before * we resume the child process. */ if (!pgwin32_ReserveSharedMemoryRegion(pi.hProcess)) { /* * Failed to reserve the memory, so terminate the newly created * process and give up. */ if (!TerminateProcess(pi.hProcess, 255)) ereport(LOG, (errmsg_internal("could not terminate process that failed to reserve memory: error code %lu", GetLastError()))); CloseHandle(pi.hProcess); CloseHandle(pi.hThread); return -1; /* logging done made by * pgwin32_ReserveSharedMemoryRegion() */ } /* * Now that the backend variables are written out, we start the child * thread so it can start initializing while we set up the rest of the * parent state. */ if (ResumeThread(pi.hThread) == -1) { if (!TerminateProcess(pi.hProcess, 255)) { ereport(LOG, (errmsg_internal("could not terminate unstartable process: error code %lu", GetLastError()))); CloseHandle(pi.hProcess); CloseHandle(pi.hThread); return -1; } CloseHandle(pi.hProcess); CloseHandle(pi.hThread); ereport(LOG, (errmsg_internal("could not resume thread of unstarted process: error code %lu", GetLastError()))); return -1; } /* * Queue a waiter for to signal when this child dies. The wait will be * handled automatically by an operating system thread pool. * * Note: use malloc instead of palloc, since it needs to be thread-safe. * Struct will be free():d from the callback function that runs on a * different thread. */ childinfo = malloc(sizeof(win32_deadchild_waitinfo)); if (!childinfo) ereport(FATAL, (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of memory"))); childinfo->procHandle = pi.hProcess; childinfo->procId = pi.dwProcessId; if (!RegisterWaitForSingleObject(&childinfo->waitHandle, pi.hProcess, pgwin32_deadchild_callback, childinfo, INFINITE, WT_EXECUTEONLYONCE | WT_EXECUTEINWAITTHREAD)) ereport(FATAL, (errmsg_internal("could not register process for wait: error code %lu", GetLastError()))); /* Don't close pi.hProcess here - the wait thread needs access to it */ CloseHandle(pi.hThread); return pi.dwProcessId; } #endif /* WIN32 */ /* * SubPostmasterMain -- Get the fork/exec'd process into a state equivalent * to what it would be if we'd simply forked on Unix, and then * dispatch to the appropriate place. * * The first two command line arguments are expected to be "--forkFOO" * (where FOO indicates which postmaster child we are to become), and * the name of a variables file that we can read to load data that would * have been inherited by fork() on Unix. Remaining arguments go to the * subprocess FooMain() routine. */ void SubPostmasterMain(int argc, char *argv[]) { Port port; /* In EXEC_BACKEND case we will not have inherited these settings */ IsPostmasterEnvironment = true; whereToSendOutput = DestNone; /* Setup as postmaster child */ InitPostmasterChild(); /* Setup essential subsystems (to ensure elog() behaves sanely) */ InitializeGUCOptions(); /* Read in the variables file */ memset(&port, 0, sizeof(Port)); read_backend_variables(argv[2], &port); /* * Set reference point for stack-depth checking */ set_stack_base(); /* * Set up memory area for GSS information. Mirrors the code in ConnCreate * for the non-exec case. */ #if defined(ENABLE_GSS) || defined(ENABLE_SSPI) port.gss = (pg_gssinfo *) calloc(1, sizeof(pg_gssinfo)); if (!port.gss) ereport(FATAL, (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of memory"))); #endif /* Check we got appropriate args */ if (argc < 3) elog(FATAL, "invalid subpostmaster invocation"); /* * If appropriate, physically re-attach to shared memory segment. We want * to do this before going any further to ensure that we can attach at the * same address the postmaster used. On the other hand, if we choose not * to re-attach, we may have other cleanup to do. */ if (strcmp(argv[1], "--forkbackend") == 0 || strcmp(argv[1], "--forkavlauncher") == 0 || strcmp(argv[1], "--forkavworker") == 0 || strcmp(argv[1], "--forkboot") == 0 || strncmp(argv[1], "--forkbgworker=", 15) == 0) PGSharedMemoryReAttach(); else PGSharedMemoryNoReAttach(); /* autovacuum needs this set before calling InitProcess */ if (strcmp(argv[1], "--forkavlauncher") == 0) AutovacuumLauncherIAm(); if (strcmp(argv[1], "--forkavworker") == 0) AutovacuumWorkerIAm(); /* * Start our win32 signal implementation. This has to be done after we * read the backend variables, because we need to pick up the signal pipe * from the parent process. */ #ifdef WIN32 pgwin32_signal_initialize(); #endif /* In EXEC_BACKEND case we will not have inherited these settings */ pqinitmask(); PG_SETMASK(&BlockSig); /* Read in remaining GUC variables */ read_nondefault_variables(); /* * Reload any libraries that were preloaded by the postmaster. Since we * exec'd this process, those libraries didn't come along with us; but we * should load them into all child processes to be consistent with the * non-EXEC_BACKEND behavior. */ process_shared_preload_libraries(); /* Run backend or appropriate child */ if (strcmp(argv[1], "--forkbackend") == 0) { Assert(argc == 3); /* shouldn't be any more args */ /* Close the postmaster's sockets */ ClosePostmasterPorts(false); /* * Need to reinitialize the SSL library in the backend, since the * context structures contain function pointers and cannot be passed * through the parameter file. * * XXX should we do this in all child processes? For the moment it's * enough to do it in backend children. */ #ifdef USE_SSL if (EnableSSL) secure_initialize(); #endif /* * Perform additional initialization and collect startup packet. * * We want to do this before InitProcess() for a couple of reasons: 1. * so that we aren't eating up a PGPROC slot while waiting on the * client. 2. so that if InitProcess() fails due to being out of * PGPROC slots, we have already initialized libpq and are able to * report the error to the client. */ BackendInitialize(&port); /* Restore basic shared memory pointers */ InitShmemAccess(UsedShmemSegAddr); /* Need a PGPROC to run CreateSharedMemoryAndSemaphores */ InitProcess(); /* * Attach process to shared data structures. If testing EXEC_BACKEND * on Linux, you must run this as root before starting the postmaster: * * echo 0 >/proc/sys/kernel/randomize_va_space * * This prevents a randomized stack base address that causes child * shared memory to be at a different address than the parent, making * it impossible to attached to shared memory. Return the value to * '1' when finished. */ CreateSharedMemoryAndSemaphores(false, 0); /* And run the backend */ BackendRun(&port); /* does not return */ } if (strcmp(argv[1], "--forkboot") == 0) { /* Close the postmaster's sockets */ ClosePostmasterPorts(false); /* Restore basic shared memory pointers */ InitShmemAccess(UsedShmemSegAddr); /* Need a PGPROC to run CreateSharedMemoryAndSemaphores */ InitAuxiliaryProcess(); /* Attach process to shared data structures */ CreateSharedMemoryAndSemaphores(false, 0); AuxiliaryProcessMain(argc - 2, argv + 2); /* does not return */ } if (strcmp(argv[1], "--forkavlauncher") == 0) { /* Close the postmaster's sockets */ ClosePostmasterPorts(false); /* Restore basic shared memory pointers */ InitShmemAccess(UsedShmemSegAddr); /* Need a PGPROC to run CreateSharedMemoryAndSemaphores */ InitProcess(); /* Attach process to shared data structures */ CreateSharedMemoryAndSemaphores(false, 0); AutoVacLauncherMain(argc - 2, argv + 2); /* does not return */ } if (strcmp(argv[1], "--forkavworker") == 0) { /* Close the postmaster's sockets */ ClosePostmasterPorts(false); /* Restore basic shared memory pointers */ InitShmemAccess(UsedShmemSegAddr); /* Need a PGPROC to run CreateSharedMemoryAndSemaphores */ InitProcess(); /* Attach process to shared data structures */ CreateSharedMemoryAndSemaphores(false, 0); AutoVacWorkerMain(argc - 2, argv + 2); /* does not return */ } if (strncmp(argv[1], "--forkbgworker=", 15) == 0) { int shmem_slot; /* do this as early as possible; in particular, before InitProcess() */ IsBackgroundWorker = true; InitPostmasterChild(); /* Close the postmaster's sockets */ ClosePostmasterPorts(false); /* Restore basic shared memory pointers */ InitShmemAccess(UsedShmemSegAddr); /* Need a PGPROC to run CreateSharedMemoryAndSemaphores */ InitProcess(); /* Attach process to shared data structures */ CreateSharedMemoryAndSemaphores(false, 0); shmem_slot = atoi(argv[1] + 15); MyBgworkerEntry = BackgroundWorkerEntry(shmem_slot); StartBackgroundWorker(); } if (strcmp(argv[1], "--forkarch") == 0) { /* Close the postmaster's sockets */ ClosePostmasterPorts(false); /* Do not want to attach to shared memory */ PgArchiverMain(argc, argv); /* does not return */ } if (strcmp(argv[1], "--forkcol") == 0) { /* Close the postmaster's sockets */ ClosePostmasterPorts(false); /* Do not want to attach to shared memory */ PgstatCollectorMain(argc, argv); /* does not return */ } if (strcmp(argv[1], "--forklog") == 0) { /* Close the postmaster's sockets */ ClosePostmasterPorts(true); /* Do not want to attach to shared memory */ SysLoggerMain(argc, argv); /* does not return */ } abort(); /* shouldn't get here */ } #endif /* EXEC_BACKEND */ /* * ExitPostmaster -- cleanup * * Do NOT call exit() directly --- always go through here! */ #ifdef HAVE_PTHREAD_IS_THREADED_NP #endif /* * sigusr1_handler - handle signal conditions from child processes */ /* * SIGTERM or SIGQUIT while processing startup packet. * Clean up and exit(1). * * XXX: possible future improvement: try to send a message indicating * why we are disconnecting. Problem is to be sure we don't block while * doing so, nor mess up SSL initialization. In practice, if the client * has wedged here, it probably couldn't do anything with the message anyway. */ /* * Dummy signal handler * * We use this for signals that we don't actually use in the postmaster, * but we do use in backends. If we were to SIG_IGN such signals in the * postmaster, then a newly started backend might drop a signal that arrives * before it's able to reconfigure its signal processing. (See notes in * tcop/postgres.c.) */ /* * Timeout while processing startup packet. * As for startup_die(), we clean up and exit(1). */ /* * RandomSalt */ /* * PostmasterRandom */ /* * Count up number of child processes of specified types (dead_end chidren * are always excluded). */ /* * StartChildProcess -- start an auxiliary process for the postmaster * * xlop determines what kind of child will be started. All child types * initially go to AuxiliaryProcessMain, which will handle common setup. * * Return value of StartChildProcess is subprocess' PID, or 0 if failed * to start subprocess. */ #ifdef EXEC_BACKEND #endif #ifdef EXEC_BACKEND #else /* !EXEC_BACKEND */ #endif /* EXEC_BACKEND */ /* * StartAutovacuumWorker * Start an autovac worker process. * * This function is here because it enters the resulting PID into the * postmaster's private backends list. * * NB -- this code very roughly matches BackendStartup. */ #ifdef EXEC_BACKEND #endif /* * Create the opts file */ #define OPTS_FILE "postmaster.opts" /* * MaxLivePostmasterChildren * * This reports the number of entries needed in per-child-process arrays * (the PMChildFlags array, and if EXEC_BACKEND the ShmemBackendArray). * These arrays include regular backends, autovac workers, walsenders * and background workers, but not special children nor dead_end children. * This allows the arrays to have a fixed maximum size, to wit the same * too-many-children limit enforced by canAcceptConnections(). The exact value * isn't too critical as long as it's more than MaxBackends. */ /* * Connect background worker to a database. */ /* * Connect background worker to a database using OIDs. */ /* * Block/unblock signals in a background worker */ #ifdef EXEC_BACKEND static pid_t bgworker_forkexec(int shmem_slot) { char *av[10]; int ac = 0; char forkav[MAXPGPATH]; snprintf(forkav, MAXPGPATH, "--forkbgworker=%d", shmem_slot); av[ac++] = "postgres"; av[ac++] = forkav; av[ac++] = NULL; /* filled in by postmaster_forkexec */ av[ac] = NULL; Assert(ac < lengthof(av)); return postmaster_forkexec(ac, av); } #endif /* * Start a new bgworker. * Starting time conditions must have been checked already. * * This code is heavily based on autovacuum.c, q.v. */ #ifdef EXEC_BACKEND #else #endif #ifndef EXEC_BACKEND #endif /* * Does the current postmaster state require starting a worker with the * specified start_time? */ /* * Allocate the Backend struct for a connected background worker, but don't * add it to the list of backends just yet. * * Some info from the Backend is copied into the passed rw. */ /* * If the time is right, start one background worker. * * As a side effect, the bgworker control variables are set or reset whenever * there are more workers to start after this one, and whenever the overall * system state requires it. */ #ifdef EXEC_BACKEND #endif /* * When a backend asks to be notified about worker state changes, we * set a flag in its backend entry. The background worker machinery needs * to know when such backends exit. */ #ifdef EXEC_BACKEND /* * The following need to be available to the save/restore_backend_variables * functions. They are marked NON_EXEC_STATIC in their home modules. */ extern slock_t *ShmemLock; extern slock_t *ProcStructLock; extern PGPROC *AuxiliaryProcs; extern PMSignalData *PMSignalState; extern pgsocket pgStatSock; extern pg_time_t first_syslogger_file_time; #ifndef WIN32 #define write_inheritable_socket(dest, src, childpid) ((*(dest) = (src)), true) #define read_inheritable_socket(dest, src) (*(dest) = *(src)) #else static bool write_duplicated_handle(HANDLE *dest, HANDLE src, HANDLE child); static bool write_inheritable_socket(InheritableSocket *dest, SOCKET src, pid_t childPid); static void read_inheritable_socket(SOCKET *dest, InheritableSocket *src); #endif /* Save critical backend variables into the BackendParameters struct */ #ifndef WIN32 static bool save_backend_variables(BackendParameters *param, Port *port) #else static bool save_backend_variables(BackendParameters *param, Port *port, HANDLE childProcess, pid_t childPid) #endif { memcpy(¶m->port, port, sizeof(Port)); if (!write_inheritable_socket(¶m->portsocket, port->sock, childPid)) return false; strlcpy(param->DataDir, DataDir, MAXPGPATH); memcpy(¶m->ListenSocket, &ListenSocket, sizeof(ListenSocket)); param->MyCancelKey = MyCancelKey; param->MyPMChildSlot = MyPMChildSlot; param->UsedShmemSegID = UsedShmemSegID; param->UsedShmemSegAddr = UsedShmemSegAddr; param->ShmemLock = ShmemLock; param->ShmemVariableCache = ShmemVariableCache; param->ShmemBackendArray = ShmemBackendArray; #ifndef HAVE_SPINLOCKS param->SpinlockSemaArray = SpinlockSemaArray; #endif param->MainLWLockArray = MainLWLockArray; param->ProcStructLock = ProcStructLock; param->ProcGlobal = ProcGlobal; param->AuxiliaryProcs = AuxiliaryProcs; param->PreparedXactProcs = PreparedXactProcs; param->PMSignalState = PMSignalState; if (!write_inheritable_socket(¶m->pgStatSock, pgStatSock, childPid)) return false; param->PostmasterPid = PostmasterPid; param->PgStartTime = PgStartTime; param->PgReloadTime = PgReloadTime; param->first_syslogger_file_time = first_syslogger_file_time; param->redirection_done = redirection_done; param->IsBinaryUpgrade = IsBinaryUpgrade; param->max_safe_fds = max_safe_fds; param->MaxBackends = MaxBackends; #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, pgwin32_create_signal_listener(childPid), childProcess)) return false; #else memcpy(¶m->postmaster_alive_fds, &postmaster_alive_fds, sizeof(postmaster_alive_fds)); #endif memcpy(¶m->syslogPipe, &syslogPipe, sizeof(syslogPipe)); strlcpy(param->my_exec_path, my_exec_path, MAXPGPATH); strlcpy(param->pkglib_path, pkglib_path, MAXPGPATH); strlcpy(param->ExtraOptions, ExtraOptions, MAXPGPATH); return true; } #ifdef WIN32 /* * Duplicate a handle for usage in a child process, and write the child * process instance of the handle to the parameter file. */ static bool write_duplicated_handle(HANDLE *dest, HANDLE src, HANDLE childProcess) { HANDLE hChild = INVALID_HANDLE_VALUE; if (!DuplicateHandle(GetCurrentProcess(), src, childProcess, &hChild, 0, TRUE, DUPLICATE_CLOSE_SOURCE | DUPLICATE_SAME_ACCESS)) { ereport(LOG, (errmsg_internal("could not duplicate handle to be written to backend parameter file: error code %lu", GetLastError()))); return false; } *dest = hChild; return true; } /* * Duplicate a socket for usage in a child process, and write the resulting * structure to the parameter file. * This is required because a number of LSPs (Layered Service Providers) very * common on Windows (antivirus, firewalls, download managers etc) break * straight socket inheritance. */ static bool write_inheritable_socket(InheritableSocket *dest, SOCKET src, pid_t childpid) { dest->origsocket = src; if (src != 0 && src != PGINVALID_SOCKET) { /* Actual socket */ if (WSADuplicateSocket(src, childpid, &dest->wsainfo) != 0) { ereport(LOG, (errmsg("could not duplicate socket %d for use in backend: error code %d", (int) src, WSAGetLastError()))); return false; } } return true; } /* * Read a duplicate socket structure back, and get the socket descriptor. */ static void read_inheritable_socket(SOCKET *dest, InheritableSocket *src) { SOCKET s; if (src->origsocket == PGINVALID_SOCKET || src->origsocket == 0) { /* Not a real socket! */ *dest = src->origsocket; } else { /* Actual socket, so create from structure */ s = WSASocket(FROM_PROTOCOL_INFO, FROM_PROTOCOL_INFO, FROM_PROTOCOL_INFO, &src->wsainfo, 0, 0); if (s == INVALID_SOCKET) { write_stderr("could not create inherited socket: error code %d\n", WSAGetLastError()); exit(1); } *dest = s; /* * To make sure we don't get two references to the same socket, close * the original one. (This would happen when inheritance actually * works.. */ closesocket(src->origsocket); } } #endif static void read_backend_variables(char *id, Port *port) { BackendParameters param; #ifndef WIN32 /* Non-win32 implementation reads from file */ FILE *fp; /* Open file */ fp = AllocateFile(id, PG_BINARY_R); if (!fp) { write_stderr("could not open backend variables file \"%s\": %s\n", id, strerror(errno)); exit(1); } if (fread(¶m, sizeof(param), 1, fp) != 1) { write_stderr("could not read from backend variables file \"%s\": %s\n", id, strerror(errno)); exit(1); } /* Release file */ FreeFile(fp); if (unlink(id) != 0) { write_stderr("could not remove file \"%s\": %s\n", id, strerror(errno)); exit(1); } #else /* Win32 version uses mapped file */ HANDLE paramHandle; BackendParameters *paramp; #ifdef _WIN64 paramHandle = (HANDLE) _atoi64(id); #else paramHandle = (HANDLE) atol(id); #endif paramp = MapViewOfFile(paramHandle, FILE_MAP_READ, 0, 0, 0); if (!paramp) { write_stderr("could not map view of backend variables: error code %lu\n", GetLastError()); exit(1); } memcpy(¶m, paramp, sizeof(BackendParameters)); if (!UnmapViewOfFile(paramp)) { write_stderr("could not unmap view of backend variables: error code %lu\n", GetLastError()); exit(1); } if (!CloseHandle(paramHandle)) { write_stderr("could not close handle to backend parameter variables: error code %lu\n", GetLastError()); exit(1); } #endif restore_backend_variables(¶m, port); } /* Restore critical backend variables from the BackendParameters struct */ static void restore_backend_variables(BackendParameters *param, Port *port) { memcpy(port, ¶m->port, sizeof(Port)); read_inheritable_socket(&port->sock, ¶m->portsocket); SetDataDir(param->DataDir); memcpy(&ListenSocket, ¶m->ListenSocket, sizeof(ListenSocket)); MyCancelKey = param->MyCancelKey; MyPMChildSlot = param->MyPMChildSlot; UsedShmemSegID = param->UsedShmemSegID; UsedShmemSegAddr = param->UsedShmemSegAddr; ShmemLock = param->ShmemLock; ShmemVariableCache = param->ShmemVariableCache; ShmemBackendArray = param->ShmemBackendArray; #ifndef HAVE_SPINLOCKS SpinlockSemaArray = param->SpinlockSemaArray; #endif MainLWLockArray = param->MainLWLockArray; ProcStructLock = param->ProcStructLock; ProcGlobal = param->ProcGlobal; AuxiliaryProcs = param->AuxiliaryProcs; PreparedXactProcs = param->PreparedXactProcs; PMSignalState = param->PMSignalState; read_inheritable_socket(&pgStatSock, ¶m->pgStatSock); PostmasterPid = param->PostmasterPid; PgStartTime = param->PgStartTime; PgReloadTime = param->PgReloadTime; first_syslogger_file_time = param->first_syslogger_file_time; redirection_done = param->redirection_done; IsBinaryUpgrade = param->IsBinaryUpgrade; max_safe_fds = param->max_safe_fds; MaxBackends = param->MaxBackends; #ifdef WIN32 PostmasterHandle = param->PostmasterHandle; pgwin32_initial_signal_pipe = param->initial_signal_pipe; #else memcpy(&postmaster_alive_fds, ¶m->postmaster_alive_fds, sizeof(postmaster_alive_fds)); #endif memcpy(&syslogPipe, ¶m->syslogPipe, sizeof(syslogPipe)); strlcpy(my_exec_path, param->my_exec_path, MAXPGPATH); strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH); strlcpy(ExtraOptions, param->ExtraOptions, MAXPGPATH); } Size ShmemBackendArraySize(void) { return mul_size(MaxLivePostmasterChildren(), sizeof(Backend)); } void ShmemBackendArrayAllocation(void) { Size size = ShmemBackendArraySize(); ShmemBackendArray = (Backend *) ShmemAlloc(size); /* Mark all slots as empty */ memset(ShmemBackendArray, 0, size); } static void ShmemBackendArrayAdd(Backend *bn) { /* The array slot corresponding to my PMChildSlot should be free */ int i = bn->child_slot - 1; Assert(ShmemBackendArray[i].pid == 0); ShmemBackendArray[i] = *bn; } static void ShmemBackendArrayRemove(Backend *bn) { int i = bn->child_slot - 1; Assert(ShmemBackendArray[i].pid == bn->pid); /* Mark the slot as empty */ ShmemBackendArray[i].pid = 0; } #endif /* EXEC_BACKEND */ #ifdef WIN32 /* * Subset implementation of waitpid() for Windows. We assume pid is -1 * (that is, check all child processes) and options is WNOHANG (don't wait). */ static pid_t waitpid(pid_t pid, int *exitstatus, int options) { DWORD dwd; ULONG_PTR key; OVERLAPPED *ovl; /* * Check if there are any dead children. If there are, return the pid of * the first one that died. */ if (GetQueuedCompletionStatus(win32ChildQueue, &dwd, &key, &ovl, 0)) { *exitstatus = (int) key; return dwd; } return -1; } /* * Note! Code below executes on a thread pool! All operations must * be thread safe! Note that elog() and friends must *not* be used. */ static void WINAPI pgwin32_deadchild_callback(PVOID lpParameter, BOOLEAN TimerOrWaitFired) { win32_deadchild_waitinfo *childinfo = (win32_deadchild_waitinfo *) lpParameter; DWORD exitcode; if (TimerOrWaitFired) return; /* timeout. Should never happen, since we use * INFINITE as timeout value. */ /* * Remove handle from wait - required even though it's set to wait only * once */ UnregisterWaitEx(childinfo->waitHandle, NULL); if (!GetExitCodeProcess(childinfo->procHandle, &exitcode)) { /* * Should never happen. Inform user and set a fixed exitcode. */ write_stderr("could not read exit code for process\n"); exitcode = 255; } if (!PostQueuedCompletionStatus(win32ChildQueue, childinfo->procId, (ULONG_PTR) exitcode, NULL)) write_stderr("could not post child completion status\n"); /* * Handle is per-process, so we close it here instead of in the * originating thread */ CloseHandle(childinfo->procHandle); /* * Free struct that was allocated before the call to * RegisterWaitForSingleObject() */ free(childinfo); /* Queue SIGCHLD signal */ pg_queue_signal(SIGCHLD); } #endif /* WIN32 */ /* * Initialize one and only handle for monitoring postmaster death. * * Called once in the postmaster, so that child processes can subsequently * monitor if their parent is dead. */ #ifndef WIN32 #else #endif /* WIN32 */