/* map_shared.c -- memory-mapping routines. * $Id: map_shared.c,v 1.21 2003/10/22 18:50:12 rjs3 Exp $ * * Copyright (c) 1998-2003 Carnegie Mellon University. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. The name "Carnegie Mellon University" must not be used to * endorse or promote products derived from this software without * prior written permission. For permission or any other legal * details, please contact * Office of Technology Transfer * Carnegie Mellon University * 5000 Forbes Avenue * Pittsburgh, PA 15213-3890 * (412) 268-4387, fax: (412) 268-7395 * tech-transfer@andrew.cmu.edu * * 4. Redistributions of any form whatsoever must retain the following * acknowledgment: * "This product includes software developed by Computing Services * at Carnegie Mellon University (http://www.cmu.edu/computing/)." * * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. * */ #include <config.h> #include <stdio.h> #include <sys/types.h> #include <sys/mman.h> #include <sys/stat.h> #include <syslog.h> #include "map.h" #include "exitcodes.h" #include "xmalloc.h" #define SLOP (8*1024) const char *map_method_desc = "shared"; /* * Create/refresh mapping of file */ void map_refresh(fd, onceonly, base, len, newlen, name, mboxname) int fd; int onceonly; const char **base; unsigned long *len; unsigned long newlen; const char *name; const char *mboxname; { struct stat sbuf; char buf[80]; if (newlen == MAP_UNKNOWN_LEN) { if (fstat(fd, &sbuf) == -1) { syslog(LOG_ERR, "IOERROR: fstating %s file%s%s: %m", name, mboxname ? " for " : "", mboxname ? mboxname : ""); snprintf(buf, sizeof(buf), "failed to fstat %s file", name); fatal(buf, EC_IOERR); } newlen = sbuf.st_size; } /* Already mapped in */ if (*len >= newlen) return; if (*len) munmap((char *)*base, *len); if (!onceonly) { newlen = (newlen + 2*SLOP - 1) & ~(SLOP-1); } *base = (char *)mmap((caddr_t)0, newlen, PROT_READ, MAP_SHARED #ifdef MAP_FILE | MAP_FILE #endif #ifdef MAP_VARIABLE | MAP_VARIABLE #endif , fd, 0L); if (*base == (char *)-1) { syslog(LOG_ERR, "IOERROR: mapping %s file%s%s: %m", name, mboxname ? " for " : "", mboxname ? mboxname : ""); snprintf(buf, sizeof(buf), "failed to mmap %s file", name); fatal(buf, EC_IOERR); } *len = newlen; } /* * Destroy mapping of file */ void map_free(base, len) const char **base; unsigned long *len; { if (*len) munmap((char *)*base, *len); *base = 0; *len = 0; }