1*7c478bd9Sstevel@tonic-gate /*-
2*7c478bd9Sstevel@tonic-gate * See the file LICENSE for redistribution information.
3*7c478bd9Sstevel@tonic-gate *
4*7c478bd9Sstevel@tonic-gate * Copyright (c) 1996, 1997, 1998
5*7c478bd9Sstevel@tonic-gate * Sleepycat Software. All rights reserved.
6*7c478bd9Sstevel@tonic-gate */
7*7c478bd9Sstevel@tonic-gate
8*7c478bd9Sstevel@tonic-gate #include "config.h"
9*7c478bd9Sstevel@tonic-gate
10*7c478bd9Sstevel@tonic-gate #ifndef lint
11*7c478bd9Sstevel@tonic-gate static const char sccsid[] = "@(#)os_map.c 10.24 (Sleepycat) 10/12/98";
12*7c478bd9Sstevel@tonic-gate #endif /* not lint */
13*7c478bd9Sstevel@tonic-gate
14*7c478bd9Sstevel@tonic-gate #ifndef NO_SYSTEM_INCLUDES
15*7c478bd9Sstevel@tonic-gate #include <sys/types.h>
16*7c478bd9Sstevel@tonic-gate #ifdef HAVE_MMAP
17*7c478bd9Sstevel@tonic-gate #include <sys/mman.h>
18*7c478bd9Sstevel@tonic-gate #endif
19*7c478bd9Sstevel@tonic-gate
20*7c478bd9Sstevel@tonic-gate #ifdef HAVE_SHMGET
21*7c478bd9Sstevel@tonic-gate #include <sys/ipc.h>
22*7c478bd9Sstevel@tonic-gate #include <sys/shm.h>
23*7c478bd9Sstevel@tonic-gate #endif
24*7c478bd9Sstevel@tonic-gate
25*7c478bd9Sstevel@tonic-gate #include <errno.h>
26*7c478bd9Sstevel@tonic-gate #include <string.h>
27*7c478bd9Sstevel@tonic-gate #endif
28*7c478bd9Sstevel@tonic-gate
29*7c478bd9Sstevel@tonic-gate #include "db_int.h"
30*7c478bd9Sstevel@tonic-gate #include "os_jump.h"
31*7c478bd9Sstevel@tonic-gate #include "common_ext.h"
32*7c478bd9Sstevel@tonic-gate
33*7c478bd9Sstevel@tonic-gate #ifdef HAVE_MMAP
34*7c478bd9Sstevel@tonic-gate static int __os_map __P((char *, int, size_t, int, int, int, void **));
35*7c478bd9Sstevel@tonic-gate #endif
36*7c478bd9Sstevel@tonic-gate #ifdef HAVE_SHMGET
37*7c478bd9Sstevel@tonic-gate static int __os_shmget __P((REGINFO *));
38*7c478bd9Sstevel@tonic-gate #endif
39*7c478bd9Sstevel@tonic-gate
40*7c478bd9Sstevel@tonic-gate /*
41*7c478bd9Sstevel@tonic-gate * __db_mapanon_ok --
42*7c478bd9Sstevel@tonic-gate * Return if this OS can support anonymous memory regions.
43*7c478bd9Sstevel@tonic-gate *
44*7c478bd9Sstevel@tonic-gate * PUBLIC: int __db_mapanon_ok __P((int));
45*7c478bd9Sstevel@tonic-gate */
46*7c478bd9Sstevel@tonic-gate int
__db_mapanon_ok(need_names)47*7c478bd9Sstevel@tonic-gate __db_mapanon_ok(need_names)
48*7c478bd9Sstevel@tonic-gate int need_names;
49*7c478bd9Sstevel@tonic-gate {
50*7c478bd9Sstevel@tonic-gate int ret;
51*7c478bd9Sstevel@tonic-gate
52*7c478bd9Sstevel@tonic-gate ret = EINVAL;
53*7c478bd9Sstevel@tonic-gate
54*7c478bd9Sstevel@tonic-gate /*
55*7c478bd9Sstevel@tonic-gate * If we don't have spinlocks, we have to have a file descriptor
56*7c478bd9Sstevel@tonic-gate * for fcntl(2) locking, which implies using mmap(2) to map in a
57*7c478bd9Sstevel@tonic-gate * regular file. Theoretically, we could probably find ways to
58*7c478bd9Sstevel@tonic-gate * get a file descriptor to lock other types of shared regions,
59*7c478bd9Sstevel@tonic-gate * but I don't see any reason to do so.
60*7c478bd9Sstevel@tonic-gate *
61*7c478bd9Sstevel@tonic-gate * If need_names is set, the application wants to share anonymous
62*7c478bd9Sstevel@tonic-gate * memory among multiple processes, so we have to have a way to
63*7c478bd9Sstevel@tonic-gate * name it. This requires shmget(2), on UNIX systems.
64*7c478bd9Sstevel@tonic-gate */
65*7c478bd9Sstevel@tonic-gate #ifdef HAVE_SPINLOCKS
66*7c478bd9Sstevel@tonic-gate #ifdef HAVE_SHMGET
67*7c478bd9Sstevel@tonic-gate ret = 0;
68*7c478bd9Sstevel@tonic-gate #endif
69*7c478bd9Sstevel@tonic-gate #ifdef HAVE_MMAP
70*7c478bd9Sstevel@tonic-gate #ifdef MAP_ANON
71*7c478bd9Sstevel@tonic-gate if (!need_names)
72*7c478bd9Sstevel@tonic-gate ret = 0;
73*7c478bd9Sstevel@tonic-gate #endif
74*7c478bd9Sstevel@tonic-gate #ifdef MAP_ANONYMOUS
75*7c478bd9Sstevel@tonic-gate if (!need_names)
76*7c478bd9Sstevel@tonic-gate ret = 0;
77*7c478bd9Sstevel@tonic-gate #endif
78*7c478bd9Sstevel@tonic-gate #else
79*7c478bd9Sstevel@tonic-gate COMPQUIET(need_names, 0);
80*7c478bd9Sstevel@tonic-gate #endif /* HAVE_MMAP */
81*7c478bd9Sstevel@tonic-gate #endif /* HAVE_SPINLOCKS */
82*7c478bd9Sstevel@tonic-gate
83*7c478bd9Sstevel@tonic-gate return (ret);
84*7c478bd9Sstevel@tonic-gate }
85*7c478bd9Sstevel@tonic-gate
86*7c478bd9Sstevel@tonic-gate /*
87*7c478bd9Sstevel@tonic-gate * __db_mapinit --
88*7c478bd9Sstevel@tonic-gate * Return if shared regions need to be initialized.
89*7c478bd9Sstevel@tonic-gate *
90*7c478bd9Sstevel@tonic-gate * PUBLIC: int __db_mapinit __P((void));
91*7c478bd9Sstevel@tonic-gate */
92*7c478bd9Sstevel@tonic-gate int
__db_mapinit()93*7c478bd9Sstevel@tonic-gate __db_mapinit()
94*7c478bd9Sstevel@tonic-gate {
95*7c478bd9Sstevel@tonic-gate /*
96*7c478bd9Sstevel@tonic-gate * Historically, some systems required that all of the bytes of the
97*7c478bd9Sstevel@tonic-gate * region be written before it could be mmapped and accessed randomly.
98*7c478bd9Sstevel@tonic-gate * We have the option of setting REGION_INIT_NEEDED at configuration
99*7c478bd9Sstevel@tonic-gate * time if we're running on one of those systems.
100*7c478bd9Sstevel@tonic-gate */
101*7c478bd9Sstevel@tonic-gate #ifdef REGION_INIT_NEEDED
102*7c478bd9Sstevel@tonic-gate return (1);
103*7c478bd9Sstevel@tonic-gate #else
104*7c478bd9Sstevel@tonic-gate return (0);
105*7c478bd9Sstevel@tonic-gate #endif
106*7c478bd9Sstevel@tonic-gate }
107*7c478bd9Sstevel@tonic-gate
108*7c478bd9Sstevel@tonic-gate /*
109*7c478bd9Sstevel@tonic-gate * __db_mapregion --
110*7c478bd9Sstevel@tonic-gate * Attach to a shared memory region.
111*7c478bd9Sstevel@tonic-gate *
112*7c478bd9Sstevel@tonic-gate * PUBLIC: int __db_mapregion __P((char *, REGINFO *));
113*7c478bd9Sstevel@tonic-gate */
114*7c478bd9Sstevel@tonic-gate int
__db_mapregion(path,infop)115*7c478bd9Sstevel@tonic-gate __db_mapregion(path, infop)
116*7c478bd9Sstevel@tonic-gate char *path;
117*7c478bd9Sstevel@tonic-gate REGINFO *infop;
118*7c478bd9Sstevel@tonic-gate {
119*7c478bd9Sstevel@tonic-gate int called, ret;
120*7c478bd9Sstevel@tonic-gate
121*7c478bd9Sstevel@tonic-gate called = 0;
122*7c478bd9Sstevel@tonic-gate ret = EINVAL;
123*7c478bd9Sstevel@tonic-gate
124*7c478bd9Sstevel@tonic-gate /* If the user replaces the map call, call through their interface. */
125*7c478bd9Sstevel@tonic-gate if (__db_jump.j_map != NULL) {
126*7c478bd9Sstevel@tonic-gate F_SET(infop, REGION_HOLDINGSYS);
127*7c478bd9Sstevel@tonic-gate return (__db_jump.j_map(path, infop->fd, infop->size,
128*7c478bd9Sstevel@tonic-gate 1, F_ISSET(infop, REGION_ANONYMOUS), 0, &infop->addr));
129*7c478bd9Sstevel@tonic-gate }
130*7c478bd9Sstevel@tonic-gate
131*7c478bd9Sstevel@tonic-gate if (F_ISSET(infop, REGION_ANONYMOUS)) {
132*7c478bd9Sstevel@tonic-gate /*
133*7c478bd9Sstevel@tonic-gate * !!!
134*7c478bd9Sstevel@tonic-gate * If we're creating anonymous regions:
135*7c478bd9Sstevel@tonic-gate *
136*7c478bd9Sstevel@tonic-gate * If it's private, we use mmap(2). The problem with using
137*7c478bd9Sstevel@tonic-gate * shmget(2) is that we may be creating a region of which the
138*7c478bd9Sstevel@tonic-gate * application isn't aware, and if the application crashes
139*7c478bd9Sstevel@tonic-gate * we'll have no way to remove the system resources for the
140*7c478bd9Sstevel@tonic-gate * region.
141*7c478bd9Sstevel@tonic-gate *
142*7c478bd9Sstevel@tonic-gate * If it's not private, we use the shmget(2) interface if it's
143*7c478bd9Sstevel@tonic-gate * available, because it allows us to name anonymous memory.
144*7c478bd9Sstevel@tonic-gate * If shmget(2) isn't available, use the mmap(2) calls.
145*7c478bd9Sstevel@tonic-gate *
146*7c478bd9Sstevel@tonic-gate * In the case of anonymous memory, using mmap(2) means the
147*7c478bd9Sstevel@tonic-gate * memory isn't named and only the single process and its
148*7c478bd9Sstevel@tonic-gate * threads can access the region.
149*7c478bd9Sstevel@tonic-gate */
150*7c478bd9Sstevel@tonic-gate #ifdef HAVE_MMAP
151*7c478bd9Sstevel@tonic-gate #ifdef MAP_ANON
152*7c478bd9Sstevel@tonic-gate #define HAVE_MMAP_ANONYMOUS 1
153*7c478bd9Sstevel@tonic-gate #else
154*7c478bd9Sstevel@tonic-gate #ifdef MAP_ANONYMOUS
155*7c478bd9Sstevel@tonic-gate #define HAVE_MMAP_ANONYMOUS 1
156*7c478bd9Sstevel@tonic-gate #endif
157*7c478bd9Sstevel@tonic-gate #endif
158*7c478bd9Sstevel@tonic-gate #endif
159*7c478bd9Sstevel@tonic-gate #ifdef HAVE_MMAP_ANONYMOUS
160*7c478bd9Sstevel@tonic-gate if (!called && F_ISSET(infop, REGION_PRIVATE)) {
161*7c478bd9Sstevel@tonic-gate called = 1;
162*7c478bd9Sstevel@tonic-gate ret = __os_map(path,
163*7c478bd9Sstevel@tonic-gate infop->fd, infop->size, 1, 1, 0, &infop->addr);
164*7c478bd9Sstevel@tonic-gate }
165*7c478bd9Sstevel@tonic-gate #endif
166*7c478bd9Sstevel@tonic-gate #ifdef HAVE_SHMGET
167*7c478bd9Sstevel@tonic-gate if (!called) {
168*7c478bd9Sstevel@tonic-gate called = 1;
169*7c478bd9Sstevel@tonic-gate ret = __os_shmget(infop);
170*7c478bd9Sstevel@tonic-gate }
171*7c478bd9Sstevel@tonic-gate #endif
172*7c478bd9Sstevel@tonic-gate #ifdef HAVE_MMAP
173*7c478bd9Sstevel@tonic-gate /*
174*7c478bd9Sstevel@tonic-gate * If we're trying to join an unnamed anonymous region, fail --
175*7c478bd9Sstevel@tonic-gate * that's not possible.
176*7c478bd9Sstevel@tonic-gate */
177*7c478bd9Sstevel@tonic-gate if (!called) {
178*7c478bd9Sstevel@tonic-gate called = 1;
179*7c478bd9Sstevel@tonic-gate
180*7c478bd9Sstevel@tonic-gate if (!F_ISSET(infop, REGION_CREATED)) {
181*7c478bd9Sstevel@tonic-gate __db_err(infop->dbenv,
182*7c478bd9Sstevel@tonic-gate "cannot join region in unnamed anonymous memory");
183*7c478bd9Sstevel@tonic-gate return (EINVAL);
184*7c478bd9Sstevel@tonic-gate }
185*7c478bd9Sstevel@tonic-gate
186*7c478bd9Sstevel@tonic-gate ret = __os_map(path,
187*7c478bd9Sstevel@tonic-gate infop->fd, infop->size, 1, 1, 0, &infop->addr);
188*7c478bd9Sstevel@tonic-gate }
189*7c478bd9Sstevel@tonic-gate #endif
190*7c478bd9Sstevel@tonic-gate } else {
191*7c478bd9Sstevel@tonic-gate /*
192*7c478bd9Sstevel@tonic-gate * !!!
193*7c478bd9Sstevel@tonic-gate * If we're creating normal regions, we use the mmap(2)
194*7c478bd9Sstevel@tonic-gate * interface if it's available because it's POSIX 1003.1
195*7c478bd9Sstevel@tonic-gate * standard and we trust it more than we do shmget(2).
196*7c478bd9Sstevel@tonic-gate */
197*7c478bd9Sstevel@tonic-gate #ifdef HAVE_MMAP
198*7c478bd9Sstevel@tonic-gate if (!called) {
199*7c478bd9Sstevel@tonic-gate called = 1;
200*7c478bd9Sstevel@tonic-gate
201*7c478bd9Sstevel@tonic-gate /* Mmap(2) regions that aren't anonymous can grow. */
202*7c478bd9Sstevel@tonic-gate F_SET(infop, REGION_CANGROW);
203*7c478bd9Sstevel@tonic-gate
204*7c478bd9Sstevel@tonic-gate ret = __os_map(path,
205*7c478bd9Sstevel@tonic-gate infop->fd, infop->size, 1, 0, 0, &infop->addr);
206*7c478bd9Sstevel@tonic-gate }
207*7c478bd9Sstevel@tonic-gate #endif
208*7c478bd9Sstevel@tonic-gate #ifdef HAVE_SHMGET
209*7c478bd9Sstevel@tonic-gate if (!called) {
210*7c478bd9Sstevel@tonic-gate called = 1;
211*7c478bd9Sstevel@tonic-gate ret = __os_shmget(infop);
212*7c478bd9Sstevel@tonic-gate }
213*7c478bd9Sstevel@tonic-gate #endif
214*7c478bd9Sstevel@tonic-gate }
215*7c478bd9Sstevel@tonic-gate return (ret);
216*7c478bd9Sstevel@tonic-gate }
217*7c478bd9Sstevel@tonic-gate
218*7c478bd9Sstevel@tonic-gate /*
219*7c478bd9Sstevel@tonic-gate * __db_unmapregion --
220*7c478bd9Sstevel@tonic-gate * Detach from the shared memory region.
221*7c478bd9Sstevel@tonic-gate *
222*7c478bd9Sstevel@tonic-gate * PUBLIC: int __db_unmapregion __P((REGINFO *));
223*7c478bd9Sstevel@tonic-gate */
224*7c478bd9Sstevel@tonic-gate int
__db_unmapregion(infop)225*7c478bd9Sstevel@tonic-gate __db_unmapregion(infop)
226*7c478bd9Sstevel@tonic-gate REGINFO *infop;
227*7c478bd9Sstevel@tonic-gate {
228*7c478bd9Sstevel@tonic-gate int called, ret;
229*7c478bd9Sstevel@tonic-gate
230*7c478bd9Sstevel@tonic-gate called = 0;
231*7c478bd9Sstevel@tonic-gate ret = EINVAL;
232*7c478bd9Sstevel@tonic-gate
233*7c478bd9Sstevel@tonic-gate if (__db_jump.j_unmap != NULL)
234*7c478bd9Sstevel@tonic-gate return (__db_jump.j_unmap(infop->addr, infop->size));
235*7c478bd9Sstevel@tonic-gate
236*7c478bd9Sstevel@tonic-gate #ifdef HAVE_SHMGET
237*7c478bd9Sstevel@tonic-gate if (infop->segid != INVALID_SEGID) {
238*7c478bd9Sstevel@tonic-gate called = 1;
239*7c478bd9Sstevel@tonic-gate ret = shmdt(infop->addr) ? errno : 0;
240*7c478bd9Sstevel@tonic-gate }
241*7c478bd9Sstevel@tonic-gate #endif
242*7c478bd9Sstevel@tonic-gate #ifdef HAVE_MMAP
243*7c478bd9Sstevel@tonic-gate if (!called) {
244*7c478bd9Sstevel@tonic-gate called = 1;
245*7c478bd9Sstevel@tonic-gate ret = munmap(infop->addr, infop->size) ? errno : 0;
246*7c478bd9Sstevel@tonic-gate }
247*7c478bd9Sstevel@tonic-gate #endif
248*7c478bd9Sstevel@tonic-gate return (ret);
249*7c478bd9Sstevel@tonic-gate }
250*7c478bd9Sstevel@tonic-gate
251*7c478bd9Sstevel@tonic-gate /*
252*7c478bd9Sstevel@tonic-gate * __db_unlinkregion --
253*7c478bd9Sstevel@tonic-gate * Remove the shared memory region.
254*7c478bd9Sstevel@tonic-gate *
255*7c478bd9Sstevel@tonic-gate * PUBLIC: int __db_unlinkregion __P((char *, REGINFO *));
256*7c478bd9Sstevel@tonic-gate */
257*7c478bd9Sstevel@tonic-gate int
__db_unlinkregion(name,infop)258*7c478bd9Sstevel@tonic-gate __db_unlinkregion(name, infop)
259*7c478bd9Sstevel@tonic-gate char *name;
260*7c478bd9Sstevel@tonic-gate REGINFO *infop;
261*7c478bd9Sstevel@tonic-gate {
262*7c478bd9Sstevel@tonic-gate int called, ret;
263*7c478bd9Sstevel@tonic-gate
264*7c478bd9Sstevel@tonic-gate called = 0;
265*7c478bd9Sstevel@tonic-gate ret = EINVAL;
266*7c478bd9Sstevel@tonic-gate
267*7c478bd9Sstevel@tonic-gate if (__db_jump.j_runlink != NULL)
268*7c478bd9Sstevel@tonic-gate return (__db_jump.j_runlink(name));
269*7c478bd9Sstevel@tonic-gate
270*7c478bd9Sstevel@tonic-gate #ifdef HAVE_SHMGET
271*7c478bd9Sstevel@tonic-gate if (infop->segid != INVALID_SEGID) {
272*7c478bd9Sstevel@tonic-gate called = 1;
273*7c478bd9Sstevel@tonic-gate ret = shmctl(infop->segid, IPC_RMID, NULL) ? errno : 0;
274*7c478bd9Sstevel@tonic-gate }
275*7c478bd9Sstevel@tonic-gate #endif
276*7c478bd9Sstevel@tonic-gate #ifdef HAVE_MMAP
277*7c478bd9Sstevel@tonic-gate COMPQUIET(infop, NULL);
278*7c478bd9Sstevel@tonic-gate if (!called) {
279*7c478bd9Sstevel@tonic-gate called = 1;
280*7c478bd9Sstevel@tonic-gate ret = 0;
281*7c478bd9Sstevel@tonic-gate }
282*7c478bd9Sstevel@tonic-gate #endif
283*7c478bd9Sstevel@tonic-gate return (ret);
284*7c478bd9Sstevel@tonic-gate }
285*7c478bd9Sstevel@tonic-gate
286*7c478bd9Sstevel@tonic-gate /*
287*7c478bd9Sstevel@tonic-gate * __db_mapfile --
288*7c478bd9Sstevel@tonic-gate * Map in a shared memory file.
289*7c478bd9Sstevel@tonic-gate *
290*7c478bd9Sstevel@tonic-gate * PUBLIC: int __db_mapfile __P((char *, int, size_t, int, void **));
291*7c478bd9Sstevel@tonic-gate */
292*7c478bd9Sstevel@tonic-gate int
__db_mapfile(path,fd,len,is_rdonly,addr)293*7c478bd9Sstevel@tonic-gate __db_mapfile(path, fd, len, is_rdonly, addr)
294*7c478bd9Sstevel@tonic-gate char *path;
295*7c478bd9Sstevel@tonic-gate int fd, is_rdonly;
296*7c478bd9Sstevel@tonic-gate size_t len;
297*7c478bd9Sstevel@tonic-gate void **addr;
298*7c478bd9Sstevel@tonic-gate {
299*7c478bd9Sstevel@tonic-gate if (__db_jump.j_map != NULL)
300*7c478bd9Sstevel@tonic-gate return (__db_jump.j_map(path, fd, len, 0, 0, is_rdonly, addr));
301*7c478bd9Sstevel@tonic-gate
302*7c478bd9Sstevel@tonic-gate #ifdef HAVE_MMAP
303*7c478bd9Sstevel@tonic-gate return (__os_map(path, fd, len, 0, 0, is_rdonly, addr));
304*7c478bd9Sstevel@tonic-gate #else
305*7c478bd9Sstevel@tonic-gate return (EINVAL);
306*7c478bd9Sstevel@tonic-gate #endif
307*7c478bd9Sstevel@tonic-gate }
308*7c478bd9Sstevel@tonic-gate
309*7c478bd9Sstevel@tonic-gate /*
310*7c478bd9Sstevel@tonic-gate * __db_unmapfile --
311*7c478bd9Sstevel@tonic-gate * Unmap the shared memory file.
312*7c478bd9Sstevel@tonic-gate *
313*7c478bd9Sstevel@tonic-gate * PUBLIC: int __db_unmapfile __P((void *, size_t));
314*7c478bd9Sstevel@tonic-gate */
315*7c478bd9Sstevel@tonic-gate int
__db_unmapfile(addr,len)316*7c478bd9Sstevel@tonic-gate __db_unmapfile(addr, len)
317*7c478bd9Sstevel@tonic-gate void *addr;
318*7c478bd9Sstevel@tonic-gate size_t len;
319*7c478bd9Sstevel@tonic-gate {
320*7c478bd9Sstevel@tonic-gate if (__db_jump.j_unmap != NULL)
321*7c478bd9Sstevel@tonic-gate return (__db_jump.j_unmap(addr, len));
322*7c478bd9Sstevel@tonic-gate
323*7c478bd9Sstevel@tonic-gate #ifdef HAVE_MMAP
324*7c478bd9Sstevel@tonic-gate return (munmap(addr, len) ? errno : 0);
325*7c478bd9Sstevel@tonic-gate #else
326*7c478bd9Sstevel@tonic-gate return (EINVAL);
327*7c478bd9Sstevel@tonic-gate #endif
328*7c478bd9Sstevel@tonic-gate }
329*7c478bd9Sstevel@tonic-gate
330*7c478bd9Sstevel@tonic-gate #ifdef HAVE_MMAP
331*7c478bd9Sstevel@tonic-gate /*
332*7c478bd9Sstevel@tonic-gate * __os_map --
333*7c478bd9Sstevel@tonic-gate * Call the mmap(2) function.
334*7c478bd9Sstevel@tonic-gate */
335*7c478bd9Sstevel@tonic-gate static int
__os_map(path,fd,len,is_region,is_anonymous,is_rdonly,addr)336*7c478bd9Sstevel@tonic-gate __os_map(path, fd, len, is_region, is_anonymous, is_rdonly, addr)
337*7c478bd9Sstevel@tonic-gate char *path;
338*7c478bd9Sstevel@tonic-gate int fd, is_region, is_anonymous, is_rdonly;
339*7c478bd9Sstevel@tonic-gate size_t len;
340*7c478bd9Sstevel@tonic-gate void **addr;
341*7c478bd9Sstevel@tonic-gate {
342*7c478bd9Sstevel@tonic-gate void *p;
343*7c478bd9Sstevel@tonic-gate int flags, prot;
344*7c478bd9Sstevel@tonic-gate
345*7c478bd9Sstevel@tonic-gate COMPQUIET(path, NULL);
346*7c478bd9Sstevel@tonic-gate
347*7c478bd9Sstevel@tonic-gate /*
348*7c478bd9Sstevel@tonic-gate * If it's read-only, it's private, and if it's not, it's shared.
349*7c478bd9Sstevel@tonic-gate * Don't bother with an additional parameter.
350*7c478bd9Sstevel@tonic-gate */
351*7c478bd9Sstevel@tonic-gate flags = is_rdonly ? MAP_PRIVATE : MAP_SHARED;
352*7c478bd9Sstevel@tonic-gate
353*7c478bd9Sstevel@tonic-gate if (is_region && is_anonymous) {
354*7c478bd9Sstevel@tonic-gate /*
355*7c478bd9Sstevel@tonic-gate * BSD derived systems use MAP_ANON; Digital Unix and HP/UX
356*7c478bd9Sstevel@tonic-gate * use MAP_ANONYMOUS.
357*7c478bd9Sstevel@tonic-gate */
358*7c478bd9Sstevel@tonic-gate #ifdef MAP_ANON
359*7c478bd9Sstevel@tonic-gate flags |= MAP_ANON;
360*7c478bd9Sstevel@tonic-gate #endif
361*7c478bd9Sstevel@tonic-gate #ifdef MAP_ANONYMOUS
362*7c478bd9Sstevel@tonic-gate flags |= MAP_ANONYMOUS;
363*7c478bd9Sstevel@tonic-gate #endif
364*7c478bd9Sstevel@tonic-gate fd = -1;
365*7c478bd9Sstevel@tonic-gate }
366*7c478bd9Sstevel@tonic-gate #ifdef MAP_FILE
367*7c478bd9Sstevel@tonic-gate if (!is_region || !is_anonymous) {
368*7c478bd9Sstevel@tonic-gate /*
369*7c478bd9Sstevel@tonic-gate * Historically, MAP_FILE was required for mapping regular
370*7c478bd9Sstevel@tonic-gate * files, even though it was the default. Some systems have
371*7c478bd9Sstevel@tonic-gate * it, some don't, some that have it set it to 0.
372*7c478bd9Sstevel@tonic-gate */
373*7c478bd9Sstevel@tonic-gate flags |= MAP_FILE;
374*7c478bd9Sstevel@tonic-gate }
375*7c478bd9Sstevel@tonic-gate #endif
376*7c478bd9Sstevel@tonic-gate
377*7c478bd9Sstevel@tonic-gate /*
378*7c478bd9Sstevel@tonic-gate * I know of no systems that implement the flag to tell the system
379*7c478bd9Sstevel@tonic-gate * that the region contains semaphores, but it's not an unreasonable
380*7c478bd9Sstevel@tonic-gate * thing to do, and has been part of the design since forever. I
381*7c478bd9Sstevel@tonic-gate * don't think anyone will object, but don't set it for read-only
382*7c478bd9Sstevel@tonic-gate * files, it doesn't make sense.
383*7c478bd9Sstevel@tonic-gate */
384*7c478bd9Sstevel@tonic-gate #ifdef MAP_HASSEMAPHORE
385*7c478bd9Sstevel@tonic-gate if (!is_rdonly)
386*7c478bd9Sstevel@tonic-gate flags |= MAP_HASSEMAPHORE;
387*7c478bd9Sstevel@tonic-gate #endif
388*7c478bd9Sstevel@tonic-gate
389*7c478bd9Sstevel@tonic-gate prot = PROT_READ | (is_rdonly ? 0 : PROT_WRITE);
390*7c478bd9Sstevel@tonic-gate
391*7c478bd9Sstevel@tonic-gate /*
392*7c478bd9Sstevel@tonic-gate * XXX
393*7c478bd9Sstevel@tonic-gate * Work around a bug in the VMS V7.1 mmap() implementation. To map a file
394*7c478bd9Sstevel@tonic-gate * into memory on VMS it needs to be opened in a certain way, originally.
395*7c478bd9Sstevel@tonic-gate * To get the file opened in that certain way, the VMS mmap() closes the
396*7c478bd9Sstevel@tonic-gate * file and re-opens it. When it does this, it doesn't flush any caches
397*7c478bd9Sstevel@tonic-gate * out to disk before closing. The problem this causes us is that when the
398*7c478bd9Sstevel@tonic-gate * memory cache doesn't get written out, the file isn't big enough to match
399*7c478bd9Sstevel@tonic-gate * the memory chunk and the mmap() call fails. This call to fsync() fixes
400*7c478bd9Sstevel@tonic-gate * the problem. DEC thinks this isn't a bug because of language in XPG5
401*7c478bd9Sstevel@tonic-gate * discussing user responsibility for on-disk and in-memory synchronization.
402*7c478bd9Sstevel@tonic-gate */
403*7c478bd9Sstevel@tonic-gate #ifdef VMS
404*7c478bd9Sstevel@tonic-gate if (__os_fsync(fd) == -1)
405*7c478bd9Sstevel@tonic-gate return(errno);
406*7c478bd9Sstevel@tonic-gate #endif
407*7c478bd9Sstevel@tonic-gate
408*7c478bd9Sstevel@tonic-gate /* MAP_FAILED was not defined in early mmap implementations. */
409*7c478bd9Sstevel@tonic-gate #ifndef MAP_FAILED
410*7c478bd9Sstevel@tonic-gate #define MAP_FAILED -1
411*7c478bd9Sstevel@tonic-gate #endif
412*7c478bd9Sstevel@tonic-gate if ((p =
413*7c478bd9Sstevel@tonic-gate mmap(NULL, len, prot, flags, fd, (off_t)0)) == (void *)MAP_FAILED)
414*7c478bd9Sstevel@tonic-gate return (errno);
415*7c478bd9Sstevel@tonic-gate
416*7c478bd9Sstevel@tonic-gate *addr = p;
417*7c478bd9Sstevel@tonic-gate return (0);
418*7c478bd9Sstevel@tonic-gate }
419*7c478bd9Sstevel@tonic-gate #endif
420*7c478bd9Sstevel@tonic-gate
421*7c478bd9Sstevel@tonic-gate #ifdef HAVE_SHMGET
422*7c478bd9Sstevel@tonic-gate /*
423*7c478bd9Sstevel@tonic-gate * __os_shmget --
424*7c478bd9Sstevel@tonic-gate * Call the shmget(2) family of functions.
425*7c478bd9Sstevel@tonic-gate */
426*7c478bd9Sstevel@tonic-gate static int
__os_shmget(infop)427*7c478bd9Sstevel@tonic-gate __os_shmget(infop)
428*7c478bd9Sstevel@tonic-gate REGINFO *infop;
429*7c478bd9Sstevel@tonic-gate {
430*7c478bd9Sstevel@tonic-gate if (F_ISSET(infop, REGION_CREATED) &&
431*7c478bd9Sstevel@tonic-gate (infop->segid = shmget(0, infop->size, IPC_PRIVATE | 0600)) == -1)
432*7c478bd9Sstevel@tonic-gate return (errno);
433*7c478bd9Sstevel@tonic-gate
434*7c478bd9Sstevel@tonic-gate if ((infop->addr = shmat(infop->segid, NULL, 0)) == (void *)-1) {
435*7c478bd9Sstevel@tonic-gate /*
436*7c478bd9Sstevel@tonic-gate * If we're trying to join the region and failing, assume
437*7c478bd9Sstevel@tonic-gate * that there was a reboot and the region no longer exists.
438*7c478bd9Sstevel@tonic-gate */
439*7c478bd9Sstevel@tonic-gate if (!F_ISSET(infop, REGION_CREATED))
440*7c478bd9Sstevel@tonic-gate errno = EAGAIN;
441*7c478bd9Sstevel@tonic-gate return (errno);
442*7c478bd9Sstevel@tonic-gate }
443*7c478bd9Sstevel@tonic-gate
444*7c478bd9Sstevel@tonic-gate F_SET(infop, REGION_HOLDINGSYS);
445*7c478bd9Sstevel@tonic-gate return (0);
446*7c478bd9Sstevel@tonic-gate }
447*7c478bd9Sstevel@tonic-gate #endif
448