1*0Sstevel@tonic-gate /*- 2*0Sstevel@tonic-gate * See the file LICENSE for redistribution information. 3*0Sstevel@tonic-gate * 4*0Sstevel@tonic-gate * Copyright (c) 1996, 1997, 1998 5*0Sstevel@tonic-gate * Sleepycat Software. All rights reserved. 6*0Sstevel@tonic-gate */ 7*0Sstevel@tonic-gate 8*0Sstevel@tonic-gate #include "config.h" 9*0Sstevel@tonic-gate 10*0Sstevel@tonic-gate #ifndef lint 11*0Sstevel@tonic-gate static const char sccsid[] = "@(#)os_map.c 10.24 (Sleepycat) 10/12/98"; 12*0Sstevel@tonic-gate #endif /* not lint */ 13*0Sstevel@tonic-gate 14*0Sstevel@tonic-gate #ifndef NO_SYSTEM_INCLUDES 15*0Sstevel@tonic-gate #include <sys/types.h> 16*0Sstevel@tonic-gate #ifdef HAVE_MMAP 17*0Sstevel@tonic-gate #include <sys/mman.h> 18*0Sstevel@tonic-gate #endif 19*0Sstevel@tonic-gate 20*0Sstevel@tonic-gate #ifdef HAVE_SHMGET 21*0Sstevel@tonic-gate #include <sys/ipc.h> 22*0Sstevel@tonic-gate #include <sys/shm.h> 23*0Sstevel@tonic-gate #endif 24*0Sstevel@tonic-gate 25*0Sstevel@tonic-gate #include <errno.h> 26*0Sstevel@tonic-gate #include <string.h> 27*0Sstevel@tonic-gate #endif 28*0Sstevel@tonic-gate 29*0Sstevel@tonic-gate #include "db_int.h" 30*0Sstevel@tonic-gate #include "os_jump.h" 31*0Sstevel@tonic-gate #include "common_ext.h" 32*0Sstevel@tonic-gate 33*0Sstevel@tonic-gate #ifdef HAVE_MMAP 34*0Sstevel@tonic-gate static int __os_map __P((char *, int, size_t, int, int, int, void **)); 35*0Sstevel@tonic-gate #endif 36*0Sstevel@tonic-gate #ifdef HAVE_SHMGET 37*0Sstevel@tonic-gate static int __os_shmget __P((REGINFO *)); 38*0Sstevel@tonic-gate #endif 39*0Sstevel@tonic-gate 40*0Sstevel@tonic-gate /* 41*0Sstevel@tonic-gate * __db_mapanon_ok -- 42*0Sstevel@tonic-gate * Return if this OS can support anonymous memory regions. 43*0Sstevel@tonic-gate * 44*0Sstevel@tonic-gate * PUBLIC: int __db_mapanon_ok __P((int)); 45*0Sstevel@tonic-gate */ 46*0Sstevel@tonic-gate int 47*0Sstevel@tonic-gate __db_mapanon_ok(need_names) 48*0Sstevel@tonic-gate int need_names; 49*0Sstevel@tonic-gate { 50*0Sstevel@tonic-gate int ret; 51*0Sstevel@tonic-gate 52*0Sstevel@tonic-gate ret = EINVAL; 53*0Sstevel@tonic-gate 54*0Sstevel@tonic-gate /* 55*0Sstevel@tonic-gate * If we don't have spinlocks, we have to have a file descriptor 56*0Sstevel@tonic-gate * for fcntl(2) locking, which implies using mmap(2) to map in a 57*0Sstevel@tonic-gate * regular file. Theoretically, we could probably find ways to 58*0Sstevel@tonic-gate * get a file descriptor to lock other types of shared regions, 59*0Sstevel@tonic-gate * but I don't see any reason to do so. 60*0Sstevel@tonic-gate * 61*0Sstevel@tonic-gate * If need_names is set, the application wants to share anonymous 62*0Sstevel@tonic-gate * memory among multiple processes, so we have to have a way to 63*0Sstevel@tonic-gate * name it. This requires shmget(2), on UNIX systems. 64*0Sstevel@tonic-gate */ 65*0Sstevel@tonic-gate #ifdef HAVE_SPINLOCKS 66*0Sstevel@tonic-gate #ifdef HAVE_SHMGET 67*0Sstevel@tonic-gate ret = 0; 68*0Sstevel@tonic-gate #endif 69*0Sstevel@tonic-gate #ifdef HAVE_MMAP 70*0Sstevel@tonic-gate #ifdef MAP_ANON 71*0Sstevel@tonic-gate if (!need_names) 72*0Sstevel@tonic-gate ret = 0; 73*0Sstevel@tonic-gate #endif 74*0Sstevel@tonic-gate #ifdef MAP_ANONYMOUS 75*0Sstevel@tonic-gate if (!need_names) 76*0Sstevel@tonic-gate ret = 0; 77*0Sstevel@tonic-gate #endif 78*0Sstevel@tonic-gate #else 79*0Sstevel@tonic-gate COMPQUIET(need_names, 0); 80*0Sstevel@tonic-gate #endif /* HAVE_MMAP */ 81*0Sstevel@tonic-gate #endif /* HAVE_SPINLOCKS */ 82*0Sstevel@tonic-gate 83*0Sstevel@tonic-gate return (ret); 84*0Sstevel@tonic-gate } 85*0Sstevel@tonic-gate 86*0Sstevel@tonic-gate /* 87*0Sstevel@tonic-gate * __db_mapinit -- 88*0Sstevel@tonic-gate * Return if shared regions need to be initialized. 89*0Sstevel@tonic-gate * 90*0Sstevel@tonic-gate * PUBLIC: int __db_mapinit __P((void)); 91*0Sstevel@tonic-gate */ 92*0Sstevel@tonic-gate int 93*0Sstevel@tonic-gate __db_mapinit() 94*0Sstevel@tonic-gate { 95*0Sstevel@tonic-gate /* 96*0Sstevel@tonic-gate * Historically, some systems required that all of the bytes of the 97*0Sstevel@tonic-gate * region be written before it could be mmapped and accessed randomly. 98*0Sstevel@tonic-gate * We have the option of setting REGION_INIT_NEEDED at configuration 99*0Sstevel@tonic-gate * time if we're running on one of those systems. 100*0Sstevel@tonic-gate */ 101*0Sstevel@tonic-gate #ifdef REGION_INIT_NEEDED 102*0Sstevel@tonic-gate return (1); 103*0Sstevel@tonic-gate #else 104*0Sstevel@tonic-gate return (0); 105*0Sstevel@tonic-gate #endif 106*0Sstevel@tonic-gate } 107*0Sstevel@tonic-gate 108*0Sstevel@tonic-gate /* 109*0Sstevel@tonic-gate * __db_mapregion -- 110*0Sstevel@tonic-gate * Attach to a shared memory region. 111*0Sstevel@tonic-gate * 112*0Sstevel@tonic-gate * PUBLIC: int __db_mapregion __P((char *, REGINFO *)); 113*0Sstevel@tonic-gate */ 114*0Sstevel@tonic-gate int 115*0Sstevel@tonic-gate __db_mapregion(path, infop) 116*0Sstevel@tonic-gate char *path; 117*0Sstevel@tonic-gate REGINFO *infop; 118*0Sstevel@tonic-gate { 119*0Sstevel@tonic-gate int called, ret; 120*0Sstevel@tonic-gate 121*0Sstevel@tonic-gate called = 0; 122*0Sstevel@tonic-gate ret = EINVAL; 123*0Sstevel@tonic-gate 124*0Sstevel@tonic-gate /* If the user replaces the map call, call through their interface. */ 125*0Sstevel@tonic-gate if (__db_jump.j_map != NULL) { 126*0Sstevel@tonic-gate F_SET(infop, REGION_HOLDINGSYS); 127*0Sstevel@tonic-gate return (__db_jump.j_map(path, infop->fd, infop->size, 128*0Sstevel@tonic-gate 1, F_ISSET(infop, REGION_ANONYMOUS), 0, &infop->addr)); 129*0Sstevel@tonic-gate } 130*0Sstevel@tonic-gate 131*0Sstevel@tonic-gate if (F_ISSET(infop, REGION_ANONYMOUS)) { 132*0Sstevel@tonic-gate /* 133*0Sstevel@tonic-gate * !!! 134*0Sstevel@tonic-gate * If we're creating anonymous regions: 135*0Sstevel@tonic-gate * 136*0Sstevel@tonic-gate * If it's private, we use mmap(2). The problem with using 137*0Sstevel@tonic-gate * shmget(2) is that we may be creating a region of which the 138*0Sstevel@tonic-gate * application isn't aware, and if the application crashes 139*0Sstevel@tonic-gate * we'll have no way to remove the system resources for the 140*0Sstevel@tonic-gate * region. 141*0Sstevel@tonic-gate * 142*0Sstevel@tonic-gate * If it's not private, we use the shmget(2) interface if it's 143*0Sstevel@tonic-gate * available, because it allows us to name anonymous memory. 144*0Sstevel@tonic-gate * If shmget(2) isn't available, use the mmap(2) calls. 145*0Sstevel@tonic-gate * 146*0Sstevel@tonic-gate * In the case of anonymous memory, using mmap(2) means the 147*0Sstevel@tonic-gate * memory isn't named and only the single process and its 148*0Sstevel@tonic-gate * threads can access the region. 149*0Sstevel@tonic-gate */ 150*0Sstevel@tonic-gate #ifdef HAVE_MMAP 151*0Sstevel@tonic-gate #ifdef MAP_ANON 152*0Sstevel@tonic-gate #define HAVE_MMAP_ANONYMOUS 1 153*0Sstevel@tonic-gate #else 154*0Sstevel@tonic-gate #ifdef MAP_ANONYMOUS 155*0Sstevel@tonic-gate #define HAVE_MMAP_ANONYMOUS 1 156*0Sstevel@tonic-gate #endif 157*0Sstevel@tonic-gate #endif 158*0Sstevel@tonic-gate #endif 159*0Sstevel@tonic-gate #ifdef HAVE_MMAP_ANONYMOUS 160*0Sstevel@tonic-gate if (!called && F_ISSET(infop, REGION_PRIVATE)) { 161*0Sstevel@tonic-gate called = 1; 162*0Sstevel@tonic-gate ret = __os_map(path, 163*0Sstevel@tonic-gate infop->fd, infop->size, 1, 1, 0, &infop->addr); 164*0Sstevel@tonic-gate } 165*0Sstevel@tonic-gate #endif 166*0Sstevel@tonic-gate #ifdef HAVE_SHMGET 167*0Sstevel@tonic-gate if (!called) { 168*0Sstevel@tonic-gate called = 1; 169*0Sstevel@tonic-gate ret = __os_shmget(infop); 170*0Sstevel@tonic-gate } 171*0Sstevel@tonic-gate #endif 172*0Sstevel@tonic-gate #ifdef HAVE_MMAP 173*0Sstevel@tonic-gate /* 174*0Sstevel@tonic-gate * If we're trying to join an unnamed anonymous region, fail -- 175*0Sstevel@tonic-gate * that's not possible. 176*0Sstevel@tonic-gate */ 177*0Sstevel@tonic-gate if (!called) { 178*0Sstevel@tonic-gate called = 1; 179*0Sstevel@tonic-gate 180*0Sstevel@tonic-gate if (!F_ISSET(infop, REGION_CREATED)) { 181*0Sstevel@tonic-gate __db_err(infop->dbenv, 182*0Sstevel@tonic-gate "cannot join region in unnamed anonymous memory"); 183*0Sstevel@tonic-gate return (EINVAL); 184*0Sstevel@tonic-gate } 185*0Sstevel@tonic-gate 186*0Sstevel@tonic-gate ret = __os_map(path, 187*0Sstevel@tonic-gate infop->fd, infop->size, 1, 1, 0, &infop->addr); 188*0Sstevel@tonic-gate } 189*0Sstevel@tonic-gate #endif 190*0Sstevel@tonic-gate } else { 191*0Sstevel@tonic-gate /* 192*0Sstevel@tonic-gate * !!! 193*0Sstevel@tonic-gate * If we're creating normal regions, we use the mmap(2) 194*0Sstevel@tonic-gate * interface if it's available because it's POSIX 1003.1 195*0Sstevel@tonic-gate * standard and we trust it more than we do shmget(2). 196*0Sstevel@tonic-gate */ 197*0Sstevel@tonic-gate #ifdef HAVE_MMAP 198*0Sstevel@tonic-gate if (!called) { 199*0Sstevel@tonic-gate called = 1; 200*0Sstevel@tonic-gate 201*0Sstevel@tonic-gate /* Mmap(2) regions that aren't anonymous can grow. */ 202*0Sstevel@tonic-gate F_SET(infop, REGION_CANGROW); 203*0Sstevel@tonic-gate 204*0Sstevel@tonic-gate ret = __os_map(path, 205*0Sstevel@tonic-gate infop->fd, infop->size, 1, 0, 0, &infop->addr); 206*0Sstevel@tonic-gate } 207*0Sstevel@tonic-gate #endif 208*0Sstevel@tonic-gate #ifdef HAVE_SHMGET 209*0Sstevel@tonic-gate if (!called) { 210*0Sstevel@tonic-gate called = 1; 211*0Sstevel@tonic-gate ret = __os_shmget(infop); 212*0Sstevel@tonic-gate } 213*0Sstevel@tonic-gate #endif 214*0Sstevel@tonic-gate } 215*0Sstevel@tonic-gate return (ret); 216*0Sstevel@tonic-gate } 217*0Sstevel@tonic-gate 218*0Sstevel@tonic-gate /* 219*0Sstevel@tonic-gate * __db_unmapregion -- 220*0Sstevel@tonic-gate * Detach from the shared memory region. 221*0Sstevel@tonic-gate * 222*0Sstevel@tonic-gate * PUBLIC: int __db_unmapregion __P((REGINFO *)); 223*0Sstevel@tonic-gate */ 224*0Sstevel@tonic-gate int 225*0Sstevel@tonic-gate __db_unmapregion(infop) 226*0Sstevel@tonic-gate REGINFO *infop; 227*0Sstevel@tonic-gate { 228*0Sstevel@tonic-gate int called, ret; 229*0Sstevel@tonic-gate 230*0Sstevel@tonic-gate called = 0; 231*0Sstevel@tonic-gate ret = EINVAL; 232*0Sstevel@tonic-gate 233*0Sstevel@tonic-gate if (__db_jump.j_unmap != NULL) 234*0Sstevel@tonic-gate return (__db_jump.j_unmap(infop->addr, infop->size)); 235*0Sstevel@tonic-gate 236*0Sstevel@tonic-gate #ifdef HAVE_SHMGET 237*0Sstevel@tonic-gate if (infop->segid != INVALID_SEGID) { 238*0Sstevel@tonic-gate called = 1; 239*0Sstevel@tonic-gate ret = shmdt(infop->addr) ? errno : 0; 240*0Sstevel@tonic-gate } 241*0Sstevel@tonic-gate #endif 242*0Sstevel@tonic-gate #ifdef HAVE_MMAP 243*0Sstevel@tonic-gate if (!called) { 244*0Sstevel@tonic-gate called = 1; 245*0Sstevel@tonic-gate ret = munmap(infop->addr, infop->size) ? errno : 0; 246*0Sstevel@tonic-gate } 247*0Sstevel@tonic-gate #endif 248*0Sstevel@tonic-gate return (ret); 249*0Sstevel@tonic-gate } 250*0Sstevel@tonic-gate 251*0Sstevel@tonic-gate /* 252*0Sstevel@tonic-gate * __db_unlinkregion -- 253*0Sstevel@tonic-gate * Remove the shared memory region. 254*0Sstevel@tonic-gate * 255*0Sstevel@tonic-gate * PUBLIC: int __db_unlinkregion __P((char *, REGINFO *)); 256*0Sstevel@tonic-gate */ 257*0Sstevel@tonic-gate int 258*0Sstevel@tonic-gate __db_unlinkregion(name, infop) 259*0Sstevel@tonic-gate char *name; 260*0Sstevel@tonic-gate REGINFO *infop; 261*0Sstevel@tonic-gate { 262*0Sstevel@tonic-gate int called, ret; 263*0Sstevel@tonic-gate 264*0Sstevel@tonic-gate called = 0; 265*0Sstevel@tonic-gate ret = EINVAL; 266*0Sstevel@tonic-gate 267*0Sstevel@tonic-gate if (__db_jump.j_runlink != NULL) 268*0Sstevel@tonic-gate return (__db_jump.j_runlink(name)); 269*0Sstevel@tonic-gate 270*0Sstevel@tonic-gate #ifdef HAVE_SHMGET 271*0Sstevel@tonic-gate if (infop->segid != INVALID_SEGID) { 272*0Sstevel@tonic-gate called = 1; 273*0Sstevel@tonic-gate ret = shmctl(infop->segid, IPC_RMID, NULL) ? errno : 0; 274*0Sstevel@tonic-gate } 275*0Sstevel@tonic-gate #endif 276*0Sstevel@tonic-gate #ifdef HAVE_MMAP 277*0Sstevel@tonic-gate COMPQUIET(infop, NULL); 278*0Sstevel@tonic-gate if (!called) { 279*0Sstevel@tonic-gate called = 1; 280*0Sstevel@tonic-gate ret = 0; 281*0Sstevel@tonic-gate } 282*0Sstevel@tonic-gate #endif 283*0Sstevel@tonic-gate return (ret); 284*0Sstevel@tonic-gate } 285*0Sstevel@tonic-gate 286*0Sstevel@tonic-gate /* 287*0Sstevel@tonic-gate * __db_mapfile -- 288*0Sstevel@tonic-gate * Map in a shared memory file. 289*0Sstevel@tonic-gate * 290*0Sstevel@tonic-gate * PUBLIC: int __db_mapfile __P((char *, int, size_t, int, void **)); 291*0Sstevel@tonic-gate */ 292*0Sstevel@tonic-gate int 293*0Sstevel@tonic-gate __db_mapfile(path, fd, len, is_rdonly, addr) 294*0Sstevel@tonic-gate char *path; 295*0Sstevel@tonic-gate int fd, is_rdonly; 296*0Sstevel@tonic-gate size_t len; 297*0Sstevel@tonic-gate void **addr; 298*0Sstevel@tonic-gate { 299*0Sstevel@tonic-gate if (__db_jump.j_map != NULL) 300*0Sstevel@tonic-gate return (__db_jump.j_map(path, fd, len, 0, 0, is_rdonly, addr)); 301*0Sstevel@tonic-gate 302*0Sstevel@tonic-gate #ifdef HAVE_MMAP 303*0Sstevel@tonic-gate return (__os_map(path, fd, len, 0, 0, is_rdonly, addr)); 304*0Sstevel@tonic-gate #else 305*0Sstevel@tonic-gate return (EINVAL); 306*0Sstevel@tonic-gate #endif 307*0Sstevel@tonic-gate } 308*0Sstevel@tonic-gate 309*0Sstevel@tonic-gate /* 310*0Sstevel@tonic-gate * __db_unmapfile -- 311*0Sstevel@tonic-gate * Unmap the shared memory file. 312*0Sstevel@tonic-gate * 313*0Sstevel@tonic-gate * PUBLIC: int __db_unmapfile __P((void *, size_t)); 314*0Sstevel@tonic-gate */ 315*0Sstevel@tonic-gate int 316*0Sstevel@tonic-gate __db_unmapfile(addr, len) 317*0Sstevel@tonic-gate void *addr; 318*0Sstevel@tonic-gate size_t len; 319*0Sstevel@tonic-gate { 320*0Sstevel@tonic-gate if (__db_jump.j_unmap != NULL) 321*0Sstevel@tonic-gate return (__db_jump.j_unmap(addr, len)); 322*0Sstevel@tonic-gate 323*0Sstevel@tonic-gate #ifdef HAVE_MMAP 324*0Sstevel@tonic-gate return (munmap(addr, len) ? errno : 0); 325*0Sstevel@tonic-gate #else 326*0Sstevel@tonic-gate return (EINVAL); 327*0Sstevel@tonic-gate #endif 328*0Sstevel@tonic-gate } 329*0Sstevel@tonic-gate 330*0Sstevel@tonic-gate #ifdef HAVE_MMAP 331*0Sstevel@tonic-gate /* 332*0Sstevel@tonic-gate * __os_map -- 333*0Sstevel@tonic-gate * Call the mmap(2) function. 334*0Sstevel@tonic-gate */ 335*0Sstevel@tonic-gate static int 336*0Sstevel@tonic-gate __os_map(path, fd, len, is_region, is_anonymous, is_rdonly, addr) 337*0Sstevel@tonic-gate char *path; 338*0Sstevel@tonic-gate int fd, is_region, is_anonymous, is_rdonly; 339*0Sstevel@tonic-gate size_t len; 340*0Sstevel@tonic-gate void **addr; 341*0Sstevel@tonic-gate { 342*0Sstevel@tonic-gate void *p; 343*0Sstevel@tonic-gate int flags, prot; 344*0Sstevel@tonic-gate 345*0Sstevel@tonic-gate COMPQUIET(path, NULL); 346*0Sstevel@tonic-gate 347*0Sstevel@tonic-gate /* 348*0Sstevel@tonic-gate * If it's read-only, it's private, and if it's not, it's shared. 349*0Sstevel@tonic-gate * Don't bother with an additional parameter. 350*0Sstevel@tonic-gate */ 351*0Sstevel@tonic-gate flags = is_rdonly ? MAP_PRIVATE : MAP_SHARED; 352*0Sstevel@tonic-gate 353*0Sstevel@tonic-gate if (is_region && is_anonymous) { 354*0Sstevel@tonic-gate /* 355*0Sstevel@tonic-gate * BSD derived systems use MAP_ANON; Digital Unix and HP/UX 356*0Sstevel@tonic-gate * use MAP_ANONYMOUS. 357*0Sstevel@tonic-gate */ 358*0Sstevel@tonic-gate #ifdef MAP_ANON 359*0Sstevel@tonic-gate flags |= MAP_ANON; 360*0Sstevel@tonic-gate #endif 361*0Sstevel@tonic-gate #ifdef MAP_ANONYMOUS 362*0Sstevel@tonic-gate flags |= MAP_ANONYMOUS; 363*0Sstevel@tonic-gate #endif 364*0Sstevel@tonic-gate fd = -1; 365*0Sstevel@tonic-gate } 366*0Sstevel@tonic-gate #ifdef MAP_FILE 367*0Sstevel@tonic-gate if (!is_region || !is_anonymous) { 368*0Sstevel@tonic-gate /* 369*0Sstevel@tonic-gate * Historically, MAP_FILE was required for mapping regular 370*0Sstevel@tonic-gate * files, even though it was the default. Some systems have 371*0Sstevel@tonic-gate * it, some don't, some that have it set it to 0. 372*0Sstevel@tonic-gate */ 373*0Sstevel@tonic-gate flags |= MAP_FILE; 374*0Sstevel@tonic-gate } 375*0Sstevel@tonic-gate #endif 376*0Sstevel@tonic-gate 377*0Sstevel@tonic-gate /* 378*0Sstevel@tonic-gate * I know of no systems that implement the flag to tell the system 379*0Sstevel@tonic-gate * that the region contains semaphores, but it's not an unreasonable 380*0Sstevel@tonic-gate * thing to do, and has been part of the design since forever. I 381*0Sstevel@tonic-gate * don't think anyone will object, but don't set it for read-only 382*0Sstevel@tonic-gate * files, it doesn't make sense. 383*0Sstevel@tonic-gate */ 384*0Sstevel@tonic-gate #ifdef MAP_HASSEMAPHORE 385*0Sstevel@tonic-gate if (!is_rdonly) 386*0Sstevel@tonic-gate flags |= MAP_HASSEMAPHORE; 387*0Sstevel@tonic-gate #endif 388*0Sstevel@tonic-gate 389*0Sstevel@tonic-gate prot = PROT_READ | (is_rdonly ? 0 : PROT_WRITE); 390*0Sstevel@tonic-gate 391*0Sstevel@tonic-gate /* 392*0Sstevel@tonic-gate * XXX 393*0Sstevel@tonic-gate * Work around a bug in the VMS V7.1 mmap() implementation. To map a file 394*0Sstevel@tonic-gate * into memory on VMS it needs to be opened in a certain way, originally. 395*0Sstevel@tonic-gate * To get the file opened in that certain way, the VMS mmap() closes the 396*0Sstevel@tonic-gate * file and re-opens it. When it does this, it doesn't flush any caches 397*0Sstevel@tonic-gate * out to disk before closing. The problem this causes us is that when the 398*0Sstevel@tonic-gate * memory cache doesn't get written out, the file isn't big enough to match 399*0Sstevel@tonic-gate * the memory chunk and the mmap() call fails. This call to fsync() fixes 400*0Sstevel@tonic-gate * the problem. DEC thinks this isn't a bug because of language in XPG5 401*0Sstevel@tonic-gate * discussing user responsibility for on-disk and in-memory synchronization. 402*0Sstevel@tonic-gate */ 403*0Sstevel@tonic-gate #ifdef VMS 404*0Sstevel@tonic-gate if (__os_fsync(fd) == -1) 405*0Sstevel@tonic-gate return(errno); 406*0Sstevel@tonic-gate #endif 407*0Sstevel@tonic-gate 408*0Sstevel@tonic-gate /* MAP_FAILED was not defined in early mmap implementations. */ 409*0Sstevel@tonic-gate #ifndef MAP_FAILED 410*0Sstevel@tonic-gate #define MAP_FAILED -1 411*0Sstevel@tonic-gate #endif 412*0Sstevel@tonic-gate if ((p = 413*0Sstevel@tonic-gate mmap(NULL, len, prot, flags, fd, (off_t)0)) == (void *)MAP_FAILED) 414*0Sstevel@tonic-gate return (errno); 415*0Sstevel@tonic-gate 416*0Sstevel@tonic-gate *addr = p; 417*0Sstevel@tonic-gate return (0); 418*0Sstevel@tonic-gate } 419*0Sstevel@tonic-gate #endif 420*0Sstevel@tonic-gate 421*0Sstevel@tonic-gate #ifdef HAVE_SHMGET 422*0Sstevel@tonic-gate /* 423*0Sstevel@tonic-gate * __os_shmget -- 424*0Sstevel@tonic-gate * Call the shmget(2) family of functions. 425*0Sstevel@tonic-gate */ 426*0Sstevel@tonic-gate static int 427*0Sstevel@tonic-gate __os_shmget(infop) 428*0Sstevel@tonic-gate REGINFO *infop; 429*0Sstevel@tonic-gate { 430*0Sstevel@tonic-gate if (F_ISSET(infop, REGION_CREATED) && 431*0Sstevel@tonic-gate (infop->segid = shmget(0, infop->size, IPC_PRIVATE | 0600)) == -1) 432*0Sstevel@tonic-gate return (errno); 433*0Sstevel@tonic-gate 434*0Sstevel@tonic-gate if ((infop->addr = shmat(infop->segid, NULL, 0)) == (void *)-1) { 435*0Sstevel@tonic-gate /* 436*0Sstevel@tonic-gate * If we're trying to join the region and failing, assume 437*0Sstevel@tonic-gate * that there was a reboot and the region no longer exists. 438*0Sstevel@tonic-gate */ 439*0Sstevel@tonic-gate if (!F_ISSET(infop, REGION_CREATED)) 440*0Sstevel@tonic-gate errno = EAGAIN; 441*0Sstevel@tonic-gate return (errno); 442*0Sstevel@tonic-gate } 443*0Sstevel@tonic-gate 444*0Sstevel@tonic-gate F_SET(infop, REGION_HOLDINGSYS); 445*0Sstevel@tonic-gate return (0); 446*0Sstevel@tonic-gate } 447*0Sstevel@tonic-gate #endif 448