diff options
| -rw-r--r-- | src/backend/libpq/pqcomm.c | 54 | ||||
| -rw-r--r-- | src/backend/postmaster/postmaster.c | 47 | ||||
| -rw-r--r-- | src/backend/utils/init/miscinit.c | 6 | ||||
| -rw-r--r-- | src/include/libpq/libpq.h | 1 |
4 files changed, 78 insertions, 30 deletions
diff --git a/src/backend/libpq/pqcomm.c b/src/backend/libpq/pqcomm.c index b27ac952173..63673b16dfb 100644 --- a/src/backend/libpq/pqcomm.c +++ b/src/backend/libpq/pqcomm.c @@ -174,12 +174,15 @@ PQcommMethods *PqCommMethods = &PqCommSocketMethods; void pq_init(void) { + /* initialize state variables */ PqSendBufferSize = PQ_SEND_BUFFER_SIZE; PqSendBuffer = MemoryContextAlloc(TopMemoryContext, PqSendBufferSize); PqSendPointer = PqSendStart = PqRecvPointer = PqRecvLength = 0; PqCommBusy = false; PqCommReadingMsg = false; DoingCopyOut = false; + + /* set up process-exit hook to close the socket */ on_proc_exit(socket_close, 0); /* @@ -285,28 +288,6 @@ socket_close(int code, Datum arg) */ -/* StreamDoUnlink() - * Shutdown routine for backend connection - * If any Unix sockets are used for communication, explicitly close them. - */ -#ifdef HAVE_UNIX_SOCKETS -static void -StreamDoUnlink(int code, Datum arg) -{ - ListCell *l; - - /* Loop through all created sockets... */ - foreach(l, sock_paths) - { - char *sock_path = (char *) lfirst(l); - - unlink(sock_path); - } - /* Since we're about to exit, no need to reclaim storage */ - sock_paths = NIL; -} -#endif /* HAVE_UNIX_SOCKETS */ - /* * StreamServerPort -- open a "listening" port to accept connections. * @@ -588,16 +569,11 @@ Lock_AF_UNIX(char *unixSocketDir, char *unixSocketPath) * Once we have the interlock, we can safely delete any pre-existing * socket file to avoid failure at bind() time. */ - unlink(unixSocketPath); + (void) unlink(unixSocketPath); /* - * Arrange to unlink the socket file(s) at proc_exit. If this is the - * first one, set up the on_proc_exit function to do it; then add this - * socket file to the list of files to unlink. + * Remember socket file pathnames for later maintenance. */ - if (sock_paths == NIL) - on_proc_exit(StreamDoUnlink, 0); - sock_paths = lappend(sock_paths, pstrdup(unixSocketPath)); return STATUS_OK; @@ -858,6 +834,26 @@ TouchSocketFiles(void) } } +/* + * RemoveSocketFiles -- unlink socket files at postmaster shutdown + */ +void +RemoveSocketFiles(void) +{ + ListCell *l; + + /* Loop through all created sockets... */ + foreach(l, sock_paths) + { + char *sock_path = (char *) lfirst(l); + + /* Ignore any error. */ + (void) unlink(sock_path); + } + /* Since we're about to exit, no need to reclaim storage */ + sock_paths = NIL; +} + /* -------------------------------- * Low-level I/O routines begin here. diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c index 1bb3138a03a..000524dcb94 100644 --- a/src/backend/postmaster/postmaster.c +++ b/src/backend/postmaster/postmaster.c @@ -370,6 +370,7 @@ static DNSServiceRef bonjour_sdref = NULL; /* * 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); @@ -900,6 +901,11 @@ PostmasterMain(int argc, char *argv[]) * interlock (thanks to whoever decided to put socket files in /tmp :-(). * For the same reason, it's best to grab the TCP socket(s) before the * Unix socket(s). + * + * Also note that this internally sets up the on_proc_exit function that + * is responsible for removing both data directory and socket lockfiles; + * so it must happen before opening sockets so that at exit, the socket + * lockfiles go away after CloseServerPorts runs. */ CreateDataDirLockFile(true); @@ -924,10 +930,15 @@ PostmasterMain(int argc, char *argv[]) /* * Establish input sockets. + * + * First, mark them all closed, and set up an on_proc_exit function that's + * charged with closing the sockets again at postmaster shutdown. */ for (i = 0; i < MAXLISTEN; i++) ListenSocket[i] = PGINVALID_SOCKET; + on_proc_exit(CloseServerPorts, 0); + if (ListenAddresses) { char *rawstring; @@ -1272,6 +1283,42 @@ PostmasterMain(int argc, char *argv[]) /* + * on_proc_exit callback to close server's listen sockets + */ +static void +CloseServerPorts(int status, Datum arg) +{ + int i; + + /* + * First, explicitly close all the socket FDs. We used to just let this + * happen implicitly at postmaster exit, but it's better to close them + * before we remove the postmaster.pid lockfile; otherwise there's a race + * condition if a new postmaster wants to re-use the TCP port number. + */ + for (i = 0; i < MAXLISTEN; i++) + { + if (ListenSocket[i] != PGINVALID_SOCKET) + { + StreamClose(ListenSocket[i]); + ListenSocket[i] = PGINVALID_SOCKET; + } + } + + /* + * Next, remove any filesystem entries for Unix sockets. To avoid race + * conditions against incoming postmasters, this must happen after closing + * the sockets and before removing lock files. + */ + RemoveSocketFiles(); + + /* + * We don't do anything about socket lock files here; those will be + * removed in a later on_proc_exit callback. + */ +} + +/* * on_proc_exit callback to delete external_pid_file */ static void diff --git a/src/backend/utils/init/miscinit.c b/src/backend/utils/init/miscinit.c index ac3e764e8b8..5bf595c9e5f 100644 --- a/src/backend/utils/init/miscinit.c +++ b/src/backend/utils/init/miscinit.c @@ -1018,7 +1018,11 @@ CreateLockFile(const char *filename, bool amPostmaster, if (lock_files == NIL) on_proc_exit(UnlinkLockFiles, 0); - lock_files = lappend(lock_files, pstrdup(filename)); + /* + * Use lcons so that the lock files are unlinked in reverse order of + * creation; this is critical! + */ + lock_files = lcons(pstrdup(filename), lock_files); } /* diff --git a/src/include/libpq/libpq.h b/src/include/libpq/libpq.h index c408e5b5517..efb2dacbba3 100644 --- a/src/include/libpq/libpq.h +++ b/src/include/libpq/libpq.h @@ -59,6 +59,7 @@ extern int StreamServerPort(int family, char *hostName, extern int StreamConnection(pgsocket server_fd, Port *port); extern void StreamClose(pgsocket sock); extern void TouchSocketFiles(void); +extern void RemoveSocketFiles(void); extern void pq_init(void); extern int pq_getbytes(char *s, size_t len); extern int pq_getstring(StringInfo s); |