/* * $Id: pconn.c,v 1.25 1999/01/14 23:15:43 wessels Exp $ * * DEBUG: section 48 Persistent Connections * AUTHOR: Duane Wessels * * SQUID Internet Object Cache http://squid.nlanr.net/Squid/ * ---------------------------------------------------------- * * Squid is the result of efforts by numerous individuals from the * Internet community. Development is led by Duane Wessels of the * National Laboratory for Applied Network Research and funded by the * National Science Foundation. Squid is Copyrighted (C) 1998 by * Duane Wessels and the University of California San Diego. Please * see the COPYRIGHT file for full details. Squid incorporates * software developed and/or copyrighted by other sources. Please see * the CREDITS file for full details. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA. * */ #include "squid.h" struct _pconn { char *key; struct _pconn *next; int *fds; int nfds_alloc; int nfds; }; #define PCONN_HIST_SZ (1<<16) int client_pconn_hist[PCONN_HIST_SZ]; int server_pconn_hist[PCONN_HIST_SZ]; static PF pconnRead; static PF pconnTimeout; static const char *pconnKey(const char *host, u_short port); static hash_table *table = NULL; static struct _pconn *pconnNew(const char *key); static void pconnDelete(struct _pconn *p); static void pconnRemoveFD(struct _pconn *p, int fd); static OBJH pconnHistDump; static const char * pconnKey(const char *host, u_short port) { LOCAL_ARRAY(char, buf, SQUIDHOSTNAMELEN + 10); snprintf(buf, SQUIDHOSTNAMELEN + 10, "%s.%d", host, (int) port); return buf; } static struct _pconn * pconnNew(const char *key) { struct _pconn *p = xcalloc(1, sizeof(struct _pconn)); p->key = xstrdup(key); p->nfds_alloc = 2; p->fds = xcalloc(p->nfds_alloc, sizeof(int)); debug(48, 3) ("pconnNew: adding %s\n", p->key); hash_join(table, (hash_link *) p); return p; } static void pconnDelete(struct _pconn *p) { debug(48, 3) ("pconnDelete: deleting %s\n", p->key); hash_remove_link(table, (hash_link *) p); xfree(p->fds); xfree(p->key); xfree(p); } static void pconnRemoveFD(struct _pconn *p, int fd) { int i; for (i = 0; i < p->nfds; i++) { if (p->fds[i] == fd) break; } assert(i < p->nfds); debug(48, 3) ("pconnRemoveFD: found FD %d at index %d\n", fd, i); for (; i < p->nfds - 1; i++) p->fds[i] = p->fds[i + 1]; if (--p->nfds == 0) pconnDelete(p); } static void pconnTimeout(int fd, void *data) { struct _pconn *p = data; assert(table != NULL); debug(48, 3) ("pconnTimeout: FD %d %s\n", fd, p->key); pconnRemoveFD(p, fd); comm_close(fd); } static void pconnRead(int fd, void *data) { LOCAL_ARRAY(char, buf, 256); struct _pconn *p = data; int n; assert(table != NULL); Counter.syscalls.sock.reads++; n = read(fd, buf, 256); debug(48, 3) ("pconnRead: %d bytes from FD %d, %s\n", n, fd, p->key); pconnRemoveFD(p, fd); comm_close(fd); } static void pconnHistDump(StoreEntry * e) { int i; storeAppendPrintf(e, "Client-side persistent connection counts:\n" "\n" "\treq/\n" "\tconn count\n" "\t---- ---------\n"); for (i = 0; i < PCONN_HIST_SZ; i++) { if (client_pconn_hist[i] == 0) continue; storeAppendPrintf(e, "\t%4d %9d\n", i, client_pconn_hist[i]); } storeAppendPrintf(e, "\n" "Server-side persistent connection counts:\n" "\n" "\treq/\n" "\tconn count\n" "\t---- ---------\n"); for (i = 0; i < PCONN_HIST_SZ; i++) { if (server_pconn_hist[i] == 0) continue; storeAppendPrintf(e, "\t%4d %9d\n", i, server_pconn_hist[i]); } } /* ========== PUBLIC FUNCTIONS ============================================ */ void pconnInit(void) { int i; assert(table == NULL); table = hash_create((HASHCMP *) strcmp, 229, hash_string); for (i = 0; i < PCONN_HIST_SZ; i++) { client_pconn_hist[i] = 0; server_pconn_hist[i] = 0; } cachemgrRegister("pconn", "Persistent Connection Utilization Histograms", pconnHistDump, 0, 1); debug(48, 3) ("persistent connection module initialized\n"); } void pconnPush(int fd, const char *host, u_short port) { struct _pconn *p; int *old; LOCAL_ARRAY(char, key, SQUIDHOSTNAMELEN + 10); LOCAL_ARRAY(char, desc, FD_DESC_SZ); if (fdNFree() < (RESERVED_FD << 1)) { debug(48, 3) ("pconnPush: Not many unused FDs\n"); comm_close(fd); return; } else if (shutting_down) { comm_close(fd); return; } assert(table != NULL); strcpy(key, pconnKey(host, port)); p = (struct _pconn *) hash_lookup(table, key); if (p == NULL) p = pconnNew(key); if (p->nfds == p->nfds_alloc) { debug(48, 3) ("pconnPush: growing FD array\n"); p->nfds_alloc <<= 1; old = p->fds; p->fds = xmalloc(p->nfds_alloc * sizeof(int)); xmemcpy(p->fds, old, p->nfds * sizeof(int)); xfree(old); } p->fds[p->nfds++] = fd; commSetSelect(fd, COMM_SELECT_READ, pconnRead, p, 0); commSetTimeout(fd, Config.Timeout.pconn, pconnTimeout, p); snprintf(desc, FD_DESC_SZ, "%s idle connection", host); fd_note(fd, desc); debug(48, 3) ("pconnPush: pushed FD %d for %s\n", fd, key); } int pconnPop(const char *host, u_short port) { struct _pconn *p; hash_link *hptr; int fd = -1; LOCAL_ARRAY(char, key, SQUIDHOSTNAMELEN + 10); assert(table != NULL); strcpy(key, pconnKey(host, port)); hptr = hash_lookup(table, key); if (hptr != NULL) { p = (struct _pconn *) hptr; assert(p->nfds > 0); fd = p->fds[0]; pconnRemoveFD(p, fd); commSetSelect(fd, COMM_SELECT_READ, NULL, NULL, 0); commSetTimeout(fd, -1, NULL, NULL); } return fd; } void pconnHistCount(int what, int i) { if (i >= PCONN_HIST_SZ) i = PCONN_HIST_SZ - 1; /* what == 0 for client, 1 for server */ if (what == 0) client_pconn_hist[i]++; else if (what == 1) server_pconn_hist[i]++; else assert(0); }