diff options
| -rw-r--r-- | ChangeLog | 10 | ||||
| -rw-r--r-- | nscd/Makefile | 44 | ||||
| -rw-r--r-- | nscd/connections.c | 245 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/Makefile | 4 |
4 files changed, 212 insertions, 91 deletions
@@ -1,5 +1,15 @@ +2004-10-03 Ulrich Drepper <drepper@redhat.com> + + * nscd/connections.c: Implement alternative loop for main thread + which uses epoll. + * sysdeps/unix/sysv/linux/Makefile [subdir=nscd] + (CFLAGS-connections.c): Add -DHAVE_EPOLL. + 2004-10-02 Ulrich Drepper <drepper@redhat.com> + * nscd/Makefile (CFLAGS-initgrcache.c): Add to CFLAGS-* variables, + don't replace old content. + * nscd/connections.c: Rewrite handling of incoming connections. All are handled by one thread which then hands of the descriptors for the real work to the worker threads. diff --git a/nscd/Makefile b/nscd/Makefile index 95fd1ea..4ccb0c2 100644 --- a/nscd/Makefile +++ b/nscd/Makefile @@ -70,28 +70,28 @@ CFLAGS-nscd_getai.c = -fexceptions CFLAGS-nscd_initgroups.c = -fexceptions ifeq (yesyes,$(have-fpie)$(build-shared)) -CFLAGS-nscd.c = -fpie -CFLAGS-connections.c = -fpie -CFLAGS-pwdcache.c = -fpie -CFLAGS-getpwnam_r.c = -fpie -CFLAGS-getpwuid_r.c = -fpie -CFLAGS-grpcache.c = -fpie -CFLAGS-getgrnam_r.c = -fpie -CFLAGS-getgrgid_r.c = -fpie -CFLAGS-hstcache.c = -fpie -CFLAGS-gethstbyad_r.c = -fpie -CFLAGS-gethstbynm2_r.c = -fpie -CFLAGS-dbg_log.c = -fpie -CFLAGS-nscd_conf.c = -fpie -CFLAGS-nscd_stat.c = -fpie -CFLAGS-cache.c = -fpie -CFLAGS-xmalloc.c = -fpie -CFLAGS-xstrdup.c = -fpie -CFLAGS-mem.c = -fpie -CFLAGS-nscd_setup_thread.c = -fpie -CFLAGS-aicache.c = -fpie -CFLAGS-selinux.c = -fpie -CFLAGS-initgrcache.c = -fpie +CFLAGS-nscd.c += -fpie +CFLAGS-connections.c += -fpie +CFLAGS-pwdcache.c += -fpie +CFLAGS-getpwnam_r.c += -fpie +CFLAGS-getpwuid_r.c += -fpie +CFLAGS-grpcache.c += -fpie +CFLAGS-getgrnam_r.c += -fpie +CFLAGS-getgrgid_r.c += -fpie +CFLAGS-hstcache.c += -fpie +CFLAGS-gethstbyad_r.c += -fpie +CFLAGS-gethstbynm2_r.c += -fpie +CFLAGS-dbg_log.c += -fpie +CFLAGS-nscd_conf.c += -fpie +CFLAGS-nscd_stat.c += -fpie +CFLAGS-cache.c += -fpie +CFLAGS-xmalloc.c += -fpie +CFLAGS-xstrdup.c += -fpie +CFLAGS-mem.c += -fpie +CFLAGS-nscd_setup_thread.c += -fpie +CFLAGS-aicache.c += -fpie +CFLAGS-selinux.c += -fpie +CFLAGS-initgrcache.c += -fpie $(objpfx)nscd: $(addprefix $(objpfx),$(nscd-modules:=.o)) $(LINK.o) -pie -Wl,-O1 \ diff --git a/nscd/connections.c b/nscd/connections.c index b658fddb..8b167aa 100644 --- a/nscd/connections.c +++ b/nscd/connections.c @@ -32,6 +32,9 @@ #include <stdlib.h> #include <unistd.h> #include <arpa/inet.h> +#ifdef HAVE_EPOLL +# include <sys/epoll.h> +#endif #include <sys/mman.h> #include <sys/param.h> #include <sys/poll.h> @@ -1017,34 +1020,56 @@ handle_request: request received (Version = %d)"), req.version); } +static unsigned int nconns; + static void -__attribute__ ((__noreturn__)) -main_loop (void) +fd_ready (int fd) { - /* Determine how much room for descriptors we should initially - allocate. This might need to change later if we cap the number - with MAXCONN. */ - const long int nfds = sysconf (_SC_OPEN_MAX); - unsigned int nconns; -#define MINCONN 32 -#define MAXCONN 16384 - if (nfds == -1 || nfds > MAXCONN) - nconns = MAXCONN; - else if (nfds < MINCONN) - nconns = MINCONN; + pthread_mutex_lock (&readylist_lock); + + /* Find an empty entry in FDLIST. */ + size_t inner; + for (inner = 0; inner < nconns; ++inner) + if (fdlist[inner].next == NULL) + break; + assert (inner < nconns); + + fdlist[inner].fd = fd; + + if (readylist == NULL) + readylist = fdlist[inner].next = &fdlist[inner]; else - nconns = nfds; + { + fdlist[inner].next = readylist->next; + readylist = readylist->next = &fdlist[inner]; + } + + bool do_signal = true; + if (__builtin_expect (nready == 0, 0)) + { + ++client_queued; + do_signal = false; + } + + pthread_mutex_unlock (&readylist_lock); + + /* Tell one of the worker threads there is work to do. */ + if (do_signal) + pthread_cond_signal (&readylist_cond); +} + +/* Time a connection was accepted. */ +static time_t *starttime; + + +static void +__attribute__ ((__noreturn__)) +main_loop_poll (void) +{ struct pollfd *conns = (struct pollfd *) xmalloc (nconns * sizeof (conns[0])); - /* We need two mirroring arrays filled with the times the connection - was accepted and a place to pass descriptors on to the worker - threads. We cannot put this in the same data structure as the - CONNS data since CONNS is passed as an array to poll(). */ - time_t *starttime = (time_t *) xmalloc (nconns * sizeof (starttime[0])); - fdlist = (struct fdlist *) xcalloc (nconns, sizeof (fdlist[0])); - conns[0].fd = sock; conns[0].events = POLLRDNORM; size_t nused = 1; @@ -1074,17 +1099,9 @@ main_loop (void) /* We have a new incoming connection. Accept the connection. */ int fd = TEMP_FAILURE_RETRY (accept (sock, NULL, NULL)); - if (fd >= 0) + /* use the descriptor if we have not reached the limit. */ + if (fd >= 0 && firstfree < nconns) { - /* We have a new file descriptor. Keep it around - and wait until data becomes available. */ - if (firstfree == nconns) - { - // XXX Maybe extend array. For now, reject - close (fd); - goto reject_out; - } - conns[firstfree].fd = fd; conns[firstfree].events = POLLRDNORM; starttime[firstfree] = now; @@ -1096,44 +1113,13 @@ main_loop (void) while (firstfree < nused && conns[firstfree].fd != -1); } - reject_out: --n; } for (size_t cnt = 1; cnt < nused && n > 0; ++cnt) if (conns[cnt].revents != 0) { - pthread_mutex_lock (&readylist_lock); - - /* Find an empty entry in FDLIST. */ - size_t inner; - for (inner = 0; inner < nconns; ++inner) - if (fdlist[inner].next == NULL) - break; - assert (inner < nconns); - - fdlist[inner].fd = conns[cnt].fd; - - if (readylist == NULL) - readylist = fdlist[inner].next = &fdlist[inner]; - else - { - fdlist[inner].next = readylist->next; - readylist = readylist->next = &fdlist[inner]; - } - - bool do_signal = true; - if (__builtin_expect (nready == 0, 0)) - { - ++client_queued; - do_signal = false; - } - - pthread_mutex_unlock (&readylist_lock); - - /* Tell one of the worker threads there is work to do. */ - if (do_signal) - pthread_cond_signal (&readylist_cond); + fd_ready (conns[cnt].fd); /* Clean up the CONNS array. */ conns[cnt].fd = -1; @@ -1150,15 +1136,16 @@ main_loop (void) /* Now find entries which have timed out. */ assert (nused > 0); - for (size_t cnt = nused - 1; cnt > 0; --cnt) - { - /* We make the timeout length depend on the number of file - descriptors currently used. */ + + /* We make the timeout length depend on the number of file + descriptors currently used. */ #define ACCEPT_TIMEOUT \ (MAX_ACCEPT_TIMEOUT \ - ((MAX_ACCEPT_TIMEOUT - MIN_ACCEPT_TIMEOUT) * nused) / nconns) + time_t laststart = now - ACCEPT_TIMEOUT; - time_t laststart = now - ACCEPT_TIMEOUT; + for (size_t cnt = nused - 1; cnt > 0; --cnt) + { if (conns[cnt].fd != -1 && starttime[cnt] < laststart) { /* Remove the entry, it timed out. */ @@ -1177,6 +1164,99 @@ main_loop (void) } +#ifdef HAVE_EPOLL +static void +main_loop_epoll (int efd) +{ + struct epoll_event ev = { 0, }; + int nused = 1; + size_t highest = 0; + + /* Add the socket. */ + ev.events = EPOLLRDNORM; + ev.data.fd = sock; + if (epoll_ctl (efd, EPOLL_CTL_ADD, sock, &ev) == -1) + /* We cannot use epoll. */ + return; + + while (1) + { + struct epoll_event revs[100]; +# define nrevs (sizeof (revs) / sizeof (revs[0])) + + int n = epoll_wait (efd, revs, nrevs, MAIN_THREAD_TIMEOUT); + + time_t now = time (NULL); + + for (int cnt = 0; cnt < n; ++cnt) + if (revs[cnt].data.fd == sock) + { + /* A new connection. */ + int fd = TEMP_FAILURE_RETRY (accept (sock, NULL, NULL)); + + if (fd >= 0) + { + /* Try to add the new descriptor. */ + ev.data.fd = fd; + if (fd >= nconns + || epoll_ctl (efd, EPOLL_CTL_ADD, fd, &ev) == -1) + /* The descriptor is too large or something went + wrong. Close the descriptor. */ + close (fd); + else + { + /* Remember when we accepted the connection. */ + starttime[fd] = now; + + if (fd > highest) + highest = fd; + + ++nused; + } + } + } + else + { + /* Remove the descriptor from the epoll descriptor. */ + struct epoll_event ev = { 0, }; + (void) epoll_ctl (efd, EPOLL_CTL_DEL, revs[cnt].data.fd, &ev); + + /* Get a worked to handle the request. */ + fd_ready (revs[cnt].data.fd); + + /* Reset the time. */ + starttime[revs[cnt].data.fd] = 0; + if (revs[cnt].data.fd == highest) + do + --highest; + while (highest > 0 && starttime[highest] == 0); + + --nused; + } + + /* Now look for descriptors for accepted connections which have + no reply in too long of a time. */ + time_t laststart = now - ACCEPT_TIMEOUT; + for (int cnt = highest; cnt > STDERR_FILENO; --cnt) + if (cnt != sock && starttime[cnt] != 0 && starttime[cnt] < laststart) + { + /* We are waiting for this one for too long. Close it. */ + struct epoll_event ev = {0, }; + (void) epoll_ctl (efd, EPOLL_CTL_DEL, cnt, &ev); + + (void) close (cnt); + + starttime[cnt] = 0; + if (cnt == highest) + --highest; + } + else if (cnt != sock && starttime[cnt] == 0 && cnt == highest) + --highest; + } +} +#endif + + /* Start all the threads we want. The initial process is thread no. 1. */ void start_threads (void) @@ -1216,9 +1296,36 @@ start_threads (void) pthread_attr_destroy (&attr); + /* Determine how much room for descriptors we should initially + allocate. This might need to change later if we cap the number + with MAXCONN. */ + const long int nfds = sysconf (_SC_OPEN_MAX); +#define MINCONN 32 +#define MAXCONN 16384 + if (nfds == -1 || nfds > MAXCONN) + nconns = MAXCONN; + else if (nfds < MINCONN) + nconns = MINCONN; + else + nconns = nfds; + + /* We need memory to pass descriptors on to the worker threads. */ + fdlist = (struct fdlist *) xcalloc (nconns, sizeof (fdlist[0])); + /* Array to keep track when connection was accepted. */ + starttime = (time_t *) xcalloc (nconns, sizeof (starttime[0])); + /* In the main thread we execute the loop which handles incoming connections. */ - main_loop (); +#ifdef HAVE_EPOLL + int efd = epoll_create (100); + if (efd != -1) + { + main_loop_epoll (efd); + close (efd); + } +#endif + + main_loop_poll (); } diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile index f834637..fd089dd 100644 --- a/sysdeps/unix/sysv/linux/Makefile +++ b/sysdeps/unix/sysv/linux/Makefile @@ -150,3 +150,7 @@ ifeq ($(subdir),rt) CFLAGS-mq_send.c += -fexceptions CFLAGS-mq_receive.c += -fexceptions endif + +ifeq ($(subdir),nscd) +CFLAGS-connections.c += -DHAVE_EPOLL +endif |