* shm.cc (shmat): If shmid is unknown, call a special variation

of shmget to retrieve the shared memory segment from Cygserver
	instead of failing immediately.
	* include/cygwin/ipc.h (IPC_KEY_IS_SHMID): New internal flag for
	shmget when called from shmat.
This commit is contained in:
Corinna Vinschen 2004-03-30 15:20:08 +00:00
parent 66c8e18830
commit 5c7b73ed97
3 changed files with 31 additions and 3 deletions

View File

@ -1,3 +1,11 @@
2004-03-30 Corinna Vinschen <corinna@vinschen.de>
* shm.cc (shmat): If shmid is unknown, call a special variation
of shmget to retrieve the shared memory segment from Cygserver
instead of failing immediately.
* include/cygwin/ipc.h (IPC_KEY_IS_SHMID): New internal flag for
shmget when called from shmat.
2004-03-29 Corinna Vinschen <corinna@vinschen.de> 2004-03-29 Corinna Vinschen <corinna@vinschen.de>
* fhandler.h (class fhandler_socket): Add has_been_closed member. * fhandler.h (class fhandler_socket): Add has_been_closed member.

View File

@ -32,6 +32,9 @@ struct ipc_perm
/* Mode bits: /* Mode bits:
*/ */
#ifdef _KERNEL
#define IPC_KEY_IS_SHMID 0x0100 /* Used in shmget when called from shmat. */
#endif
#define IPC_CREAT 0x0200 /* Create entry if key does not exist. */ #define IPC_CREAT 0x0200 /* Create entry if key does not exist. */
#define IPC_EXCL 0x0400 /* Fail if key exists. */ #define IPC_EXCL 0x0400 /* Fail if key exists. */
#define IPC_NOWAIT 0x0800 /* Error if request must wait. */ #define IPC_NOWAIT 0x0800 /* Error if request must wait. */

View File

@ -160,9 +160,26 @@ shmat (int shmid, const void *shmaddr, int shmflg)
} }
if (!ssh_entry) if (!ssh_entry)
{ {
/* Invalid shmid */ /* The shmid is unknown to this process so far. Try to get it from
set_errno (EINVAL); the server if it exists. Use special internal call to shmget,
return (void *) -1; which interprets the key as a shmid and only returns a valid
shmid if one exists. Since shmctl inserts a new entry for this
shmid into ssh_list automatically, we just have to go through
that list again. If that still fails, well, bad luck. */
if (shmid && shmget ((key_t) shmid, 0, IPC_KEY_IS_SHMID) != -1)
{
SLIST_FOREACH (ssh_entry, &ssh_list, ssh_next)
{
if (ssh_entry->shmid == shmid)
break;
}
}
if (!ssh_entry)
{
/* Invalid shmid */
set_errno (EINVAL);
return (void *) -1;
}
} }
vm_object_t attach_va = NULL; vm_object_t attach_va = NULL;
if (shmaddr) if (shmaddr)