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* sysv_sem.cc: Update to FreeBSD version 1.69.

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1.68: Reduce the overhead of semop() by using the kernel stack
	instead of malloc'd memory to store the operations array if it
	is small enough to fit.
	1.69: Adjust the number of processes waiting on a semaphore properly
	if we're woken up in the middle of sleeping.
This commit is contained in:
Corinna Vinschen 2004-10-01 11:18:10 +00:00
parent 00ee07cb12
commit c6ef5fb7ec
2 changed files with 36 additions and 14 deletions
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9
winsup/cygserver/ChangeLog
View File

@ -1,3 +1,12 @@
2004-10-01 Corinna Vinschen <corinna@vinschen.de>
* sysv_sem.cc: Update to FreeBSD version 1.69.
1.68: Reduce the overhead of semop() by using the kernel stack
instead of malloc'd memory to store the operations array if it
is small enough to fit.
1.69: Adjust the number of processes waiting on a semaphore properly
if we're woken up in the middle of sleeping.
2004-09-23 Corinna Vinschen <corinna@vinschen.de> 2004-09-23 Corinna Vinschen <corinna@vinschen.de>
* sysv_shm.cc (kern_shmat): Avoid compiler warning. * sysv_shm.cc (kern_shmat): Avoid compiler warning.

41
winsup/cygserver/sysv_sem.cc
View File

@ -17,7 +17,7 @@
#ifndef __FBSDID #ifndef __FBSDID
#define __FBSDID(s) const char version[] = (s) #define __FBSDID(s) const char version[] = (s)
#endif #endif
__FBSDID("$FreeBSD: /usr/local/www/cvsroot/FreeBSD/src/sys/kern/sysv_sem.c,v 1.67 2003/11/15 11:56:53 tjr Exp $"); __FBSDID("$FreeBSD: /repoman/r/ncvs/src/sys/kern/sysv_sem.c,v 1.70 2004/05/30 20:34:58 phk Exp $");
#define _KERNEL 1 #define _KERNEL 1
#define __BSD_VISIBLE 1 #define __BSD_VISIBLE 1
@ -953,6 +953,8 @@ struct semop_args {
int int
semop(struct thread *td, struct semop_args *uap) semop(struct thread *td, struct semop_args *uap)
{ {
#define SMALL_SOPS 8
struct sembuf small_sops[SMALL_SOPS];
int semid = uap->semid; int semid = uap->semid;
size_t nsops = uap->nsops; size_t nsops = uap->nsops;
struct sembuf *sops; struct sembuf *sops;
@ -976,16 +978,20 @@ semop(struct thread *td, struct semop_args *uap)
return (EINVAL); return (EINVAL);
/* Allocate memory for sem_ops */ /* Allocate memory for sem_ops */
if (nsops > (unsigned long) seminfo.semopm) { if (nsops <= SMALL_SOPS)
sops = small_sops;
else if (nsops <= (unsigned long) seminfo.semopm)
sops = (struct sembuf *) sys_malloc(nsops * sizeof(*sops), M_SEM, M_WAITOK);
else {
DPRINTF(("too many sops (max=%d, nsops=%d)\n", seminfo.semopm, DPRINTF(("too many sops (max=%d, nsops=%d)\n", seminfo.semopm,
nsops)); nsops));
return (E2BIG); return (E2BIG);
} }
sops = (struct sembuf *) sys_malloc(nsops * sizeof(sops[0]), M_SEM, M_WAITOK);
if ((error = copyin(uap->sops, sops, nsops * sizeof(sops[0]))) != 0) { if ((error = copyin(uap->sops, sops, nsops * sizeof(sops[0]))) != 0) {
DPRINTF(("error = %d from copyin(%08x, %08x, %d)\n", error, DPRINTF(("error = %d from copyin(%08x, %08x, %d)\n", error,
uap->sops, sops, nsops * sizeof(sops[0]))); uap->sops, sops, nsops * sizeof(sops[0])));
sys_free(sops, M_SEM); if (sops != small_sops)
sys_free(sops, M_SEM);
return (error); return (error);
} }
@ -1110,15 +1116,7 @@ semop(struct thread *td, struct semop_args *uap)
error = msleep(semaptr, sema_mtxp, (PZERO - 4) | PCATCH, error = msleep(semaptr, sema_mtxp, (PZERO - 4) | PCATCH,
"semwait", 0); "semwait", 0);
DPRINTF(("semop: good morning (error=%d)!\n", error)); DPRINTF(("semop: good morning (error=%d)!\n", error));
/* return code is checked below, after sem[nz]cnt-- */
if (error != 0) {
#ifdef __CYGWIN__
if (error != EIDRM)
#endif /* __CYGWIN__ */
error = EINTR;
goto done2;
}
DPRINTF(("semop: good morning!\n"));
/* /*
* Make sure that the semaphore still exists * Make sure that the semaphore still exists
@ -1137,6 +1135,20 @@ semop(struct thread *td, struct semop_args *uap)
semptr->semzcnt--; semptr->semzcnt--;
else else
semptr->semncnt--; semptr->semncnt--;
/*
* Is it really morning, or was our sleep interrupted?
* (Delayed check of msleep() return code because we
* need to decrement sem[nz]cnt either way.)
*/
if (error != 0) {
#ifdef __CYGWIN__
if (error != EIDRM)
#endif /* __CYGWIN__ */
error = EINTR;
goto done2;
}
DPRINTF(("semop: good morning!\n"));
} }
done: done:
@ -1216,7 +1228,8 @@ done:
td->td_retval[0] = 0; td->td_retval[0] = 0;
done2: done2:
mtx_unlock(sema_mtxp); mtx_unlock(sema_mtxp);
sys_free(sops, M_SEM); if (sops != small_sops)
sys_free(sops, M_SEM);
return (error); return (error);
} }