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irix-657m-src/irix/cmd/tk/tkc.c
calmsacibis995 8fc8fa8089 Source code upload
2022-09-29 17:59:04 +03:00

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/**************************************************************************
* *
* Copyright (C) 1994-1996 Silicon Graphics, Inc. *
* *
* These coded instructions, statements, and computer programs contain *
* unpublished proprietary information of Silicon Graphics, Inc., and *
* are protected by Federal copyright law. They may not be disclosed *
* to third parties or copied or duplicated in any form, in whole or *
* in part, without the prior written consent of Silicon Graphics, Inc. *
* *
**************************************************************************/
#ident "$Id: tkc.c,v 1.43 1997/09/05 15:55:04 mostek Exp $"
#include "tk_private.h"
/*
* Each token controlled object has a set of up to 10 tokens associated with it.
* The state for entire set of tokens is maintined in the tkci_cstate_t
* data structure. This structure is allocated by the client using
* the TKC_DECL macro.
* Any operation may act on any or all of the tokens for a particular object -
* the interface deals exclusivly with tk_set_t's.
*/
static void tkci_obtainwake(tkci_cstate_t *, int);
static void tkci_obtainwait(tkci_cstate_t *, int, int *);
#if TK_DEBUG
static int tkci_nobtainwaiting(tkci_cstate_t *, int);
#endif
static void tkci_scwake(tkci_cstate_t *, int);
static void tkci_scwait(tkci_cstate_t *, int, int *);
static void tkci_badstate(char *, tkci_cstate_t *, int);
static void __tkc_obtaining(tkc_state_t *, tk_set_t, tk_set_t *,
tk_set_t *, tk_disp_t *, tk_set_t *, tk_set_t *,
int, void *);
static void __tkc_obtained(tkc_state_t *, tk_set_t, tk_set_t,
tk_disp_t, int, void *);
/*
* table lookup for extlev downgrading. Basically WRITE and anything else
* goes back to WRITE
*/
static unsigned char downext[] = {
0, /* No Token */
1, /* READ -> READ */
2, /* WRITE -> WRITE */
2, /* READ|WRITE -> WRITE */
4, /* SWRITE -> SWRITE */
5, /* SWRITE|READ -> ILLEGAL */
2, /* SWRITE|WRITE -> WRITE */
7 /* READ|WRITE|SWRITE -> ILLEGAL */
};
/*
* table lookup for which obtain bit to use. This defines the priority of
* tokens if multiple obtains are outstanding. If we want WRITE then we get
* that in preference, then SWRITE then READ.
*/
static unsigned char obtaintab[] = {
0,
1, /* READ -> READ */
2, /* WRITE -> WRITE */
2, /* READ|WRITE -> WRITE */
4, /* SWRITE -> SWRITE */
4, /* SWRITE|READ -> SWRITE */
2, /* SWRITE|WRITE -> WRITE */
2 /* SWRITE|WRITE|READ -> WRITE */
};
/*
* macro to change states. Automatically calls scwake if the we should
* call it when transitioning out of a state (based on waketab)
*/
#define NEWSTATE(ci,class,tstate,ns) \
{ int wk = waketab[(tstate)->cl_state]; \
(tstate)->cl_state = ns; \
if (wk && (tstate)->cl_scwait) tkci_scwake(ci, class); \
}
static unsigned char waketab[] = {
0, /* 0 */
0, /* IDLE */
0, /* OWNED */
0, /* CACHED */
1, /* REVOKING */
0, /* OBTAINING */
0, /* ALREADY */
1, /* WILLRETURN */
1, /* RETURNING */
1, /* WILLOBTAIN */
0, /* BORROWED */
0, /* BORROWING */
0, /* REJECTED */
1, /* BREVOKING */
1, /* SREVOKING */
0, /* SOBTAINING */
0, /* COBTAINING */
0, /* BOBTAINING */
1, /* SWILLOBTAIN */
1, /* CREVOKING */
0, /* CRESTORE */
0, /* SRESTORE */
0 /* BRESTORE */
};
static void tkc_local_obtain(void *, tk_set_t, tk_set_t, tk_disp_t, tk_set_t *);
static void tkc_local_return(tkc_state_t, void *, tk_set_t, tk_set_t, tk_disp_t);
tkc_ifstate_t tkc_local_iface = {
tkc_local_obtain,
tkc_local_return
};
/*
* testing/asserting state conditions
*/
#ifdef TK_DEBUG
#define CHECK(t) tkci_checkstate(t)
static void
tkci_checkstate(tkci_clstate_t *t)
{
switch(t->cl_state) {
case TK_CL_IDLE:
/*
* IDLE - extlev null; no hold count;
* noone waiting to obtain; possible revoke request.
*/
TK_ASSERT(t->cl_extlev == 0);
TK_ASSERT(t->cl_hold == 0);
TK_ASSERT(t->cl_obtain == 0);
break;
case TK_CL_OWNED:
case TK_CL_BORROWED:
/*
* OWNED - a valid extlev; a hold count; no revokes;
* and the obtain mask shouldn't contain any bits that are
* compatible with what we've already got
*/
TK_ASSERT(t->cl_extlev != (TK_SWRITE|TK_READ) && \
t->cl_extlev != (TK_SWRITE|TK_WRITE|TK_READ) && \
t->cl_extlev != 0);
TK_ASSERT(t->cl_hold > 0);
TK_ASSERT(t->cl_mrecall == 0);
TK_ASSERT((t->cl_obtain & t->cl_extlev) == 0);
break;
case TK_CL_CACHED:
/*
* CACHED - a valid singleton extlev (only one bit set);
* no hold count; noone waiting to obtain;
* noone wanting to revoke
*/
TK_ASSERT((t->cl_extlev & t->cl_extlev - 1) == 0);
TK_ASSERT(t->cl_hold == 0);
TK_ASSERT(t->cl_mrecall == 0);
TK_ASSERT(t->cl_obtain == 0);
break;
case TK_CL_OBTAINING:
case TK_CL_SOBTAINING:
case TK_CL_COBTAINING:
case TK_CL_BOBTAINING:
/*
* OBTAINING - hold count > 0; valid extlev; potential revoke;
* obtain mask may be anything
* SOBTAINING - same.
* COBTAINING - same.
*/
TK_ASSERT(t->cl_extlev != (TK_SWRITE|TK_READ) && \
t->cl_extlev != (TK_SWRITE|TK_WRITE|TK_READ) && \
t->cl_extlev != 0);
TK_ASSERT(t->cl_hold > 0);
break;
case TK_CL_RETURNING:
case TK_CL_CREVOKING:
/*
* RETURNING - hold count == 0; extlev singleton
* CREVOKING -
*/
TK_ASSERT(t->cl_hold == 0);
TK_ASSERT((t->cl_extlev & t->cl_extlev - 1) == 0);
break;
case TK_CL_WILLRETURN:
/*
* WILLRETURN - a valid extlev; a hold count;
* and the obtain mask can be anything
* Unlike OSF - we permit mandatory recalls -
* to make sure that conditional recalls
* always succed
*/
TK_ASSERT(t->cl_extlev != (TK_SWRITE|TK_READ) && \
t->cl_extlev != (TK_SWRITE|TK_WRITE|TK_READ) && \
t->cl_extlev != 0);
TK_ASSERT(t->cl_hold > 0);
break;
case TK_CL_REVOKING:
case TK_CL_SREVOKING:
/*
* REVOKING - a valid extlev; a hold count; no revokes;
* and the obtain mask can be anything
* SREVOKING - same except send a SERVER_MANDATORY msg
*/
TK_ASSERT(t->cl_extlev != (TK_SWRITE|TK_READ) && \
t->cl_extlev != (TK_SWRITE|TK_WRITE|TK_READ) && \
t->cl_extlev != 0);
TK_ASSERT(t->cl_hold > 0);
TK_ASSERT(t->cl_mrecall == 0);
break;
case TK_CL_BREVOKING:
/*
* BREVOKING - same as REVOKING except that
* a) we should send a SERVER_CONDITIONAL msg
* b) an have a 0 hold count since we can transition from
* the CREVOKING state to here in tkci_creturn
*/
TK_ASSERT(t->cl_extlev != (TK_SWRITE|TK_READ) && \
t->cl_extlev != (TK_SWRITE|TK_WRITE|TK_READ) && \
t->cl_extlev != 0);
TK_ASSERT(t->cl_mrecall == 0);
break;
case TK_CL_WILLOBTAIN:
case TK_CL_SWILLOBTAIN:
/*
* WILLOBTAIN - a valid singleton extlev (only one bit set);
* no hold count;
*/
TK_ASSERT(((t->cl_extlev & t->cl_extlev - 1) == 0) || \
t->cl_extlev == 0);
TK_ASSERT(t->cl_hold == 0);
break;
case TK_CL_REJECTED:
TK_ASSERT(t->cl_extlev != (TK_SWRITE|TK_READ) && \
t->cl_extlev != (TK_SWRITE|TK_WRITE|TK_READ));
TK_ASSERT(t->cl_hold > 0);
TK_ASSERT((t->cl_obtain & t->cl_extlev) == 0);
break;
case TK_CL_BORROWING:
/*
* BORROWING - similar to OBTAINING: hold count > 0;
* valid extlev;
* obtain mask may be anything
* XXX hard to say what the token paper means by
* 'extended level may show any non-null set of
* of compatible levels'. Does this mean it can be 0??
* For REJECTED we think so...
*/
TK_ASSERT(t->cl_extlev != (TK_SWRITE|TK_READ) && \
t->cl_extlev != (TK_SWRITE|TK_WRITE|TK_READ));
TK_ASSERT(t->cl_hold > 0);
TK_ASSERT(t->cl_mrecall == 0); \
TK_ASSERT((t->cl_obtain & t->cl_extlev) == 0);
break;
default:
__tk_fatal("unknown state t 0x%x state %s\n",
t, __tkci_prstate(*t));
/* NOTREACHED */
}
}
#else /* TK_DEBUG */
#define CHECK(t)
#endif
/* obtain list manipulation */
static tk_list_t obtainhead;
static tklock_t obtainlock;
/* status change list */
static tk_list_t schead;
static tklock_t sclock;
/*
* tkc_init - one time client side initialization
*/
void
tkc_init(void)
{
__tk_lock_init();
obtainhead.tk_next = obtainhead.tk_prev = &obtainhead;
__tk_create_lock(&obtainlock);
schead.tk_next = schead.tk_prev = &schead;
__tk_create_lock(&sclock);
#if TK_TRC
__tk_trace_init();
#endif
#if TK_METER
__tk_meter_init();
#endif
#ifndef _KERNEL
__tk_ts_init();
#endif
}
/*
* tkc_local_obtain - get a token from a local token server
*/
static void
tkc_local_obtain(
void *tserver,
tk_set_t to_be_obtained,
tk_set_t to_be_returned,
tk_disp_t whyreturn,
tk_set_t *refused)
{
tk_set_t granted, already;
/*
* XXX since we don't have the client tkc pointer, we can't
* really figure out in a generic way, which cell we're on.
* This is easy with an underlying OS, so we simply don't
* don't do this correctly for user level ..
*/
if (to_be_returned != TK_NULLSET)
tks_return(tserver, TK_GETCH(NULL), to_be_returned,
TK_NULLSET, TK_NULLSET, whyreturn);
tks_obtain(tserver, TK_GETCH(NULL), to_be_obtained, &granted,
refused, &already);
TK_ASSERT(already == TK_NULLSET);
}
/*
* tkc_local_return - return a token to a local token server
*
* For client initiated returns we must tell server first (emulating
* an RPC).
* For server initiated returns we must tell the client first since
* once we tell the server, the entire token struct could be
* torn down
*/
static void
tkc_local_return(
tkc_state_t tclient,
void *tserver,
tk_set_t tstoret,
tk_set_t teh,
tk_disp_t why)
{
tk_set_t clientrev;
/*
* compute the subset of tstoret that are to be
* dispositioned as client initiated return
*/
clientrev = why & TK_DISP_CLIENT_ALL;
clientrev |= (clientrev >> 1) | (clientrev >> 2);
clientrev &= tstoret;
if (clientrev != TK_NULLSET) {
tks_return(tserver, TK_GETCH(NULL),
clientrev, TK_NULLSET, TK_NULLSET, why);
tkc_returned(tclient, clientrev, TK_NULLSET);
/* all rest are server initiated */
TK_DIFF_SET(tstoret, clientrev);
}
if (tstoret != TK_NULLSET)
tkc_returned(tclient, tstoret, TK_NULLSET);
tks_return(tserver, TK_GETCH(NULL),
tstoret, TK_NULLSET, teh, why);
}
/*
* tkc_create_local - create a token managed object with local server
*/
void
tkc_create_local(
char *name, /* name for tracing/metering */
tkc_state_t *cs, /* object state to set up */
tks_state_t *ss, /* object server pointer */
int ntokens, /* # of tokens in set */
tk_set_t tsetcached, /* tokens to mark as present */
tk_set_t tset, /* tokens to mark as present and held */
void *tag) /* tag for tracing */
{
tkc_create(name, cs, ss, &tkc_local_iface, ntokens, tsetcached,
tset, tag);
}
/*
* tkc_create - create a token managed object
*/
/* ARGSUSED */
void
tkc_create(
char *name, /* name for tracing/metering */
tkc_state_t *cs, /* object state to set up */
void *o, /* client object pointer */
tkc_ifstate_t *is, /* interface state */
int ntokens, /* # of tokens in set */
tk_set_t tsetcached, /* tokens to mark as present */
tk_set_t tset, /* tokens to mark as present and held */
void *tag) /* tag for tracing */
{
tkci_cstate_t *ci = (tkci_cstate_t *)cs;
TK_METER_DECL /* decls 'tm' */
tk_set_t ts, tsh;
int i, class, level;
tkci_clstate_t *tstate;
TK_LOCKDECL;
/*
* try to catch races by setting ntokens to 0, and only when
* everything is set up setting it to the 'real' number
*/
ci->tkci_ntokens = 0;
ci->tkci_if = is;
ci->tkci_obj = o;
ci->tkci_flags = 0;
ci->tkci_ref = 0;
#if _KERNEL
ci->tkci_origcell = cellid();
#endif
for (i = 0; i < ntokens; i++) {
ci->tkci_state[i].cl_word = 0;
ci->tkci_state[i].cl_state = TK_CL_IDLE;
}
__tk_create_lock(&ci->tkci_lock);
#if TK_METER
tm = NULL;
if (__tk_defaultmeter)
tm = tkc_meteron(cs, name, tag);
#endif
/* eveything wanted to be held must be in first set */
ASSERT((tsetcached & tset) == tset);
TK_LOCK(ci->tkci_lock);
for (ts = tsetcached, tsh = tset, class = 0;
ts;
ts = ts >> TK_LWIDTH, tsh = tsh >> TK_LWIDTH, class++) {
if ((level = ts & TK_SET_MASK) == 0)
continue;
TK_ASSERT(class < ntokens);
TK_ASSERT((level & level - 1) == 0);
tstate = &ci->tkci_state[class];
tstate->cl_extlev = level;
if (tsh & TK_SET_MASK) {
/* wants it held */
tstate->cl_state = TK_CL_OWNED;
tstate->cl_hold = 1;
} else {
/* just cached please */
tstate->cl_state = TK_CL_CACHED;
}
}
TK_UNLOCK(ci->tkci_lock);
ci->tkci_ntokens = ntokens;
TK_TRACE(TKC_CREATE, __return_address, TK_GETCH(ci->tkci_obj),
tsetcached, tset, TK_NULLSET, ci, TK_METER_VAR);
}
/*
* tkc_destroy - stop managing an object.
* It is assumed that NO tokens are held and that NO requests for any
* more tokens can come in.
*/
void
tkc_destroy(tkc_state_t *cs) /* object to be destroyed */
{
tkci_cstate_t *ci = (tkci_cstate_t *)cs;
int i;
tkci_clstate_t *tstate;
TK_METER_DECL /* decls 'tm' */
TKC_METER_VAR_INIT(tm, cs);
ASSERT(ci->tkci_if != &tkc_local_iface);
TK_TRACE(TKC_DESTROY, __return_address, TK_GETCH(ci->tkci_obj),
TK_NULLSET, TK_NULLSET, TK_NULLSET, ci, TK_METER_VAR);
for (i = 0; i < ci->tkci_ntokens; i++) {
tstate = &ci->tkci_state[i];
if (tstate->cl_state != TK_CL_IDLE)
__tk_fatal("tkc_destroy - not idle state cs 0x%x class %d state %s\n",
cs, i, __tkci_prstate(*tstate));
/* NOTREACHED */
}
#if TK_METER
tkc_meteroff(cs);
#endif
ci->tkci_if = NULL;
ci->tkci_obj = NULL;
__tk_destroy_lock(&ci->tkci_lock);
}
/*
* tkc_destroy_local - stop managing a local object.
* It is assumed that NO tokens are held and that NO requests for any
* more tokens can come in.
* Cached tokens are returned to server.
*/
void
tkc_destroy_local(tkc_state_t *cs) /* object to be destroyed */
{
tkci_cstate_t *ci = (tkci_cstate_t *)cs;
int class;
tk_set_t toret = TK_NULLSET;
tkci_clstate_t *tstate;
TK_METER_DECL /* decls 'tm' */
TKC_METER_VAR_INIT(tm, cs);
ASSERT(ci->tkci_if == &tkc_local_iface);
TK_TRACE(TKC_DESTROY, __return_address, TK_GETCH(ci->tkci_obj),
TK_NULLSET, TK_NULLSET, TK_NULLSET, ci, TK_METER_VAR);
for (class = 0; class < ci->tkci_ntokens; class++) {
tstate = &ci->tkci_state[class];
ASSERT(tstate->cl_obtain == 0);
if (tstate->cl_state == TK_CL_CACHED) {
ASSERT(downext[tstate->cl_extlev]);
TK_COMBINE_SET(toret, TK_MAKE(class,
downext[tstate->cl_extlev]));
} else if (tstate->cl_state != TK_CL_IDLE) {
__tk_fatal("tkc_destroy_local - not idle/cached state cs 0x%x class %d state %s\n",
cs, class, __tkci_prstate(*tstate));
/* NOTREACHED */
}
}
if (toret)
tks_return(ci->tkci_obj, TK_GETCH(NULL),
toret, TK_NULLSET, TK_NULLSET,
TK_DISP_CLIENT_ALL);
#if TK_METER
tkc_meteroff(cs);
#endif
ci->tkci_if = NULL;
ci->tkci_obj = NULL;
__tk_destroy_lock(&ci->tkci_lock);
}
/*
* tkc_acquire1 - a fast path acquire
* Returns 0 if got token, -1 if token refused, errno on out of band error.
*/
int
tkc_acquire1(tkc_state_t *cs, tk_singleton_t tsing)
{
tkci_cstate_t *ci = (tkci_cstate_t *)cs;
tkci_clstate_t *tstate;
auto tk_set_t gotten;
TK_METER_DECL /* decls 'tm' */
int class = (tsing >> TK_LWIDTH) & 0xF;
int level = tsing & TK_SET_MASK;
TK_LOCKDECL;
TK_ASSERT(tsing & 0x80000000);/* !passed in a tk_set_t */
TKC_METER_VAR_INIT(tm, cs);
TKC_INC_METER(tm, class, acquire);
TK_ASSERT((level & level - 1) == 0);
TK_LOCK(ci->tkci_lock);
tstate = &ci->tkci_state[class];
CHECK(tstate);
if ((level & tstate->cl_extlev) || (tstate->cl_extlev == TK_WRITE)) {
if ((tstate->cl_state == TK_CL_CACHED) ||
(tstate->cl_state == TK_CL_OWNED)) {
/*
* asking for the level we own OR
* we have the write token - its always
* ok to get a token if we have the write token
* level as no-one else can have a conflicting token
* XXX do we need to turn off obtain bit for the
* OWNED case as in tkc_obtaining??
*/
tstate->cl_hold++;
tstate->cl_state = TK_CL_OWNED;
tstate->cl_extlev |= level;
TKC_INC_METER(tm, class, acq_cached);
TK_TRACE(TKC_FACQUIRE, __return_address,
TK_GETCH(ci->tkci_obj),
TK_MAKE(class, level), TK_NULLSET,
TK_NULLSET, ci, TK_METER_VAR);
TK_UNLOCK(ci->tkci_lock);
return 0;
}
}
TK_UNLOCK(ci->tkci_lock);
tkc_acquire(cs, TK_MAKE(class, level), &gotten);
return gotten == TK_NULLSET ? 1 : 0;
}
void
tkc_release1(tkc_state_t *cs, tk_singleton_t tsing)
{
tkci_cstate_t *ci = (tkci_cstate_t *)cs;
tkci_clstate_t *tstate;
TK_METER_DECL /* decls 'tm' */
int class;
#if TK_DEBUG || TK_TRC
int level;
#endif
TK_LOCKDECL;
#if TK_DEBUG || TK_TRC
level = tsing & TK_SET_MASK;
#endif
TK_ASSERT(tsing & 0x80000000);/* !passed in a tk_set_t */
TKC_METER_VAR_INIT(tm, cs);
TK_ASSERT((level & level - 1) == 0);
TK_LOCK(ci->tkci_lock);
class = (tsing >> TK_LWIDTH) & 0xF;
tstate = &ci->tkci_state[class];
CHECK(tstate);
if (tstate->cl_state == TK_CL_OWNED && !tstate->cl_obtain) {
TK_ASSERT((tsing & TK_SET_MASK) & tstate->cl_extlev);
if (--tstate->cl_hold == 0) {
/* turn off appropriate extlev bits. */
tstate->cl_extlev = downext[tstate->cl_extlev];
tstate->cl_state = TK_CL_CACHED;
}
TK_TRACE(TKC_FRELEASE, __return_address, TK_GETCH(ci->tkci_obj),
TK_MAKE(class, level), TK_NULLSET,
TK_NULLSET, ci, TK_METER_VAR);
TK_UNLOCK(ci->tkci_lock);
} else {
TK_UNLOCK(ci->tkci_lock);
tkc_release(cs, TK_MAKE(class, tsing & TK_SET_MASK));
}
}
/*
* tkc_obtaining - get a token(s)
* The tokens are obtained from the server if they are not present
* on the client cell and held. While held, they cannot be recalled.
* Note that ltoret is only updated when ltoobtain is so we don't
* have to check it.
*/
void
tkc_obtaining(
tkc_state_t *cs, /* object containing tokens */
tk_set_t tset, /* tokens requested */
tk_set_t *tstoobtain, /* tokens to obtain */
tk_set_t *tstoret, /* tokens to return */
tk_disp_t *dofret, /* disposition of tokens to return */
tk_set_t *tsrefused, /* tokens that were refused */
tk_set_t *tslater) /* get later please! */
{
__tkc_obtaining(cs, tset, tstoobtain, tstoret, dofret,
tsrefused, tslater, 1, (void *)__return_address);
}
/* ARGSUSED */
static void
__tkc_obtaining(
tkc_state_t *cs, /* object containing tokens */
tk_set_t tset, /* tokens requested */
tk_set_t *tstoobtain, /* tokens to obtain */
tk_set_t *tstoret, /* tokens to return */
tk_disp_t *dofret, /* disposition of tokens to return */
tk_set_t *tsrefused, /* tokens that were refused */
tk_set_t *tslater, /* get later please! */
int dotrace,
void *ra)
{
tkci_cstate_t *ci = (tkci_cstate_t *)cs;
tkci_clstate_t *tstate;
TK_METER_DECL /* decls 'tm' */
tk_set_t ts;
tk_set_t lrefused, ltoobtain, ltoret;
tk_disp_t ldofret;
int level, class;
int setobtain;
TK_LOCKDECL;
lrefused = TK_NULLSET;
ltoobtain = TK_NULLSET;
ltoret = TK_NULLSET;
ldofret = TK_NULLSET;
TKC_METER_VAR_INIT(tm, cs);
TK_ASSERT((tset & 0x80000000) == 0);/* !passed in a tk_singleton_t */
TK_LOCK(ci->tkci_lock);
if (dotrace)
TK_TRACE(TKC_SOBTAINING, ra, TK_GETCH(ci->tkci_obj), tset,
TK_NULLSET, TK_NULLSET, ci, TK_METER_VAR);
lrefused = TK_NULLSET;
for (ts = tset, class = 0; ts; ts = ts >> TK_LWIDTH, class++) {
if ((level = ts & TK_SET_MASK) == 0)
continue;
TK_ASSERT(class < ci->tkci_ntokens);
TKC_INC_METER(tm, class, acquire);
setobtain = 0;
tryagain:
TK_ASSERT((level & level - 1) == 0);
tstate = &ci->tkci_state[class];
CHECK(tstate);
switch (tstate->cl_state) {
case TK_CL_IDLE:
/*
* we can get here with the setobtain bit on
* if a return was refused - which will place us
* in the cached state. Then, some other thread could
* go ahead and return the token, finally the thread
* sleeping below in RETURNING wakes up and lands here.
*/
setobtain = 0;
tstate->cl_hold++;
tstate->cl_extlev = level;
tstate->cl_state = TK_CL_OBTAINING;
/* update list of tokens to obtain/return */
TK_COMBINE_SET(ltoobtain, TK_MAKE(class, level));
break;
case TK_CL_CACHED:
/*
* we already have the token - if at a compatible
* level, bump hold count and return
*
* We can get here with the setobtain bit on in
* rare instances - if we got into a state
* where we held the WR token and wanted the
* RD and SWR tokens, both RD & SWR would
* be set in the obtain mask. We would then turn
* off the SWR bit and let that get obtained.
* Then we would turn off the RD bit and wake up the
* thread that set the RD bit. Lets assume that it
* doesn't run for a while. Meanwhile the thread that
* got the SWR token could release it - that would
* place the token into the CACHED state.
*/
if (ltoobtain != TK_NULLSET)
goto done;
setobtain = 0;
if (level == tstate->cl_extlev ||
(tstate->cl_extlev == TK_WRITE)) {
/*
* asking for the level we own OR
* we have the write token - its always
* ok to get a token if we have the write token
* level as no-one else can have a conflicting
* token
*/
tstate->cl_hold++;
tstate->cl_state = TK_CL_OWNED;
tstate->cl_extlev |= level;
TKC_INC_METER(tm, class, acq_cached);
} else {
int oextlev;
/* wants a conflicting token */
tstate->cl_hold++;
tstate->cl_state = TK_CL_OBTAINING;
oextlev = tstate->cl_extlev;
tstate->cl_extlev = level;
TKC_INC_METER(tm, class, acq_conflict);
/*
* update list of tokens to obtain/return
*/
TK_COMBINE_SET(ltoret, TK_MAKE(class, downext[oextlev]));
TK_COMBINE_SET(ldofret,
TK_MAKE(class, TK_CLIENT_INITIATED));
TK_COMBINE_SET(ltoobtain, TK_MAKE(class, level));
}
break;
case TK_CL_OWNED:
case TK_CL_BORROWED:
if (ltoobtain != TK_NULLSET)
goto done;
/*
* we already have the token held - if at a compatible
* level, bump hold count and return
*/
if ((level & tstate->cl_extlev) ||
(tstate->cl_extlev == TK_WRITE)) {
/*
* asking for the level we own OR
* got the write token - its always
* ok to get a token if we have the write token
* level as no-one else can have a conflicting
* token
*/
tstate->cl_hold++;
tstate->cl_extlev |= level;
tstate->cl_obtain &= ~level;
setobtain = 0;
TKC_INC_METER(tm, class, acq_cached);
} else {
/*
* wants a conflicting token
* This is equivalent to the client
* calling tkc_recall.
*/
TKC_INC_METER(tm, class, acq_conflict);
if (tstate->cl_state == TK_CL_BORROWED)
tstate->cl_state = TK_CL_BREVOKING;
else
tstate->cl_state = TK_CL_REVOKING;
if ((tstate->cl_obtain & level) == 0) {
setobtain = 1;
tstate->cl_obtain |= level;
}
CHECK(tstate);
tkci_scwait(ci, class, TK_LOCKVARADDR);
/* something has changed - try again */
TK_LOCK(ci->tkci_lock);
goto tryagain;
}
break;
case TK_CL_BORROWING:
case TK_CL_OBTAINING:
case TK_CL_SOBTAINING:
case TK_CL_COBTAINING:
/*
* Should we wait here or go ahead and accumulate
* everything to do? if and when we support
* class acquisition ordering it will be important
* to wait here. It also seems to minimize
* deadlock situations where we have a token
* (because we have already held some) and now
* are waiting for one
*/
if (ltoobtain != TK_NULLSET)
goto done;
if ((level & tstate->cl_extlev) ||
(tstate->cl_extlev == TK_WRITE)) {
/*
* asking for the level we own OR
* got the write token - its always
* ok to get a token if we have the write token
* level as no-one else can have a conflicting
* token
*/
tstate->cl_hold++;
tstate->cl_extlev |= level;
/*
* turn off obtain bit if it is on - this
* could be READ - we might have had
* both WRITE and READ in the obtain mask
* and went after the WRITE token, leaving
* the READ set in obtain. Since WRITE
* implies READ, we certainly don't need to
* 'get' it
*/
tstate->cl_obtain &= ~level;
setobtain = 0;
/* wait for token to arrive */
tkci_obtainwait(ci, class, TK_LOCKVARADDR);
TK_LOCK(ci->tkci_lock);
/*
* unless we got into the REJECTED state
* we should have the token so we can progress
* to the next one
*/
if (tstate->cl_state != TK_CL_REJECTED) {
TK_ASSERT(
tstate->cl_state == TK_CL_OWNED ||
tstate->cl_state == TK_CL_BORROWED ||
tstate->cl_state == TK_CL_WILLRETURN ||
tstate->cl_state == TK_CL_SREVOKING ||
tstate->cl_state == TK_CL_BREVOKING ||
tstate->cl_state == TK_CL_REVOKING);
break;
}
/*
* The obtain was rejected
* undo our hold
* Note that if the hold count goes to zero
* we always need to wake up folks
* To clear a rejection all waiters must
* be finished and the hold count get to 0
*/
TK_COMBINE_SET(lrefused, TK_MAKE(class, level));
if (--tstate->cl_hold > 0)
break;
if (tstate->cl_obtain) {
int toobtain;
/* turn off appropriate extlev bits. */
/* XXXcheck out */
tstate->cl_extlev = downext[tstate->cl_extlev];
toobtain = obtaintab[tstate->cl_obtain];
TK_ASSERT(toobtain);
tstate->cl_obtain &= ~toobtain;
tstate->cl_state = TK_CL_WILLOBTAIN;
} else {
tstate->cl_extlev = 0;
tstate->cl_state = TK_CL_IDLE;
TK_ASSERT(tkci_nobtainwaiting(ci, class) == 0);
}
if (tstate->cl_scwait)
tkci_scwake(ci, class);
} else {
/* wants a conflicting token! */
if ((tstate->cl_obtain & level) == 0) {
setobtain = 1;
tstate->cl_obtain |= level;
}
TKC_INC_METER(tm, class, acq_conflict);
tkci_scwait(ci, class, TK_LOCKVARADDR);
/* something has changed - try again */
TK_LOCK(ci->tkci_lock);
goto tryagain;
}
break;
case TK_CL_WILLOBTAIN:
case TK_CL_SWILLOBTAIN:
{
/*
* This state permits us to proceed to get
* a level - note that the obtain mask may
* have been set to more than one level - the thread
* that sets the WILLOBTAIN state will turn off only
* one bit
* Only the thread that turned on the obtain bit can
* use this state. Consider:
* An initial state:
* we hold SWR
* we want WRITE (this is set in the obtain mask
* and the state set to REVOKING).
* We then release SWR which starts a revoke sequence
* and changes the state to RETURNING.
* The return completes (having sent a one-way
* message to the server), and the state changes to
* WILLOBTAIN (and the WR bit is turned off in
* obtain mask).
* Another thread comes in wanting SWR - if this thread
* gets the WILLOBTAIN state (rather than the thread
* that set the WR bit), it will send an obtain message
* to the server. This obtain message can overtake the
* return message at the server which will confuse the
* server into returning an 'already' indication
* followed by the server removing the fact that
* we own the token!
*
* We are only permitted in this state if we set
* and obtain bit AND that bit has been turned off.
*/
int oextlev;
if (ltoobtain != TK_NULLSET)
goto done;
if (setobtain == 0 ||
(tstate->cl_obtain & level)) {
tkci_scwait(ci, class, TK_LOCKVARADDR);
/* something has changed - try again */
TK_LOCK(ci->tkci_lock);
goto tryagain;
} else {
tstate->cl_hold++;
oextlev = tstate->cl_extlev;
tstate->cl_extlev = level;
setobtain = 0;
/*
* If we're in the SWILLOBTAIN state then
* the server has sent a recall for the
* token we currently have (and will be
* returning). We must of course return
* it with a TK_SERVER_MANDATORY message -
* something a standard returned token
* can't do. So we do a (*tkc_return)
* callout
*/
if (tstate->cl_state == TK_CL_SWILLOBTAIN) {
TK_ASSERT(oextlev != level);
TK_COMBINE_SET(ltoret,
TK_MAKE(class, oextlev));
TK_COMBINE_SET(ldofret,
TK_MAKE(class, TK_SERVER_MANDATORY));
} else if (oextlev != level) {
/*
* we have to return a token if it
* conflicts with the one we want
*/
TK_COMBINE_SET(ltoret,
TK_MAKE(class, oextlev));
TK_COMBINE_SET(ldofret,
TK_MAKE(class, TK_CLIENT_INITIATED));
}
/*
* This wakeup only for folks just above us
* who went to sleep in WILLOBTAIN
*/
NEWSTATE(ci, class, tstate, TK_CL_OBTAINING);
TK_COMBINE_SET(ltoobtain, TK_MAKE(class, level));
}
break;
}
case TK_CL_REJECTED:
case TK_CL_REVOKING:
case TK_CL_BREVOKING:
case TK_CL_SREVOKING:
case TK_CL_CREVOKING:
case TK_CL_WILLRETURN:
case TK_CL_RETURNING:
/*
* In all these state we can't grant the token -
* we must wait until the hold count goes to zero
*/
if (ltoobtain != TK_NULLSET)
goto done;
TKC_INC_METER(tm, class, acq_outbound);
if ((tstate->cl_obtain & level) == 0) {
setobtain = 1;
tstate->cl_obtain |= level;
}
tkci_scwait(ci, class, TK_LOCKVARADDR);
/* something has changed - try again */
TK_LOCK(ci->tkci_lock);
goto tryagain;
default:
tkci_badstate("tkc_obtaining", ci, class);
/* NOTREACHED */
}
CHECK(tstate);
TK_ASSERT(setobtain == 0);
}
done:
if (dotrace) {
TK_TRACE(TKC_EOBTAINING, 0, TK_GETCH(ci->tkci_obj), ltoobtain,
ts << (TK_LWIDTH * class), lrefused, ci,
TK_METER_VAR);
TK_TRACE(TKC_EOBTAINING2, 0, TK_GETCH(ci->tkci_obj), ltoret,
TK_NULLSET, ldofret,
ci, TK_METER_VAR);
}
TK_UNLOCK(ci->tkci_lock);
*tstoobtain = ltoobtain;
*tstoret = ltoret;
*tsrefused = lrefused;
*tslater = ts << (TK_LWIDTH * class);
*dofret = ldofret;
}
/*
* called to initiate obtain/return requests
*/
void
tkc_obtained(
tkc_state_t *cs,
tk_set_t tsobtained,
tk_set_t tsrefused,
tk_disp_t dofref)
{
__tkc_obtained(cs, tsobtained, tsrefused, dofref,
1, (void *)__return_address);
}
/* ARGSUSED */
static void
__tkc_obtained(
tkc_state_t *cs,
tk_set_t tsobtained,
tk_set_t tsrefused,
tk_disp_t dofref,
int dotrace,
void *ra)
{
tkci_cstate_t *ci = (tkci_cstate_t *)cs;
tkci_clstate_t *tstate;
tk_set_t ts;
int class, level, disp;
TK_METER_DECL /* decls 'tm' */
TK_LOCKDECL;
TKC_METER_VAR_INIT(tm, cs);
TK_ASSERT((tsrefused & tsobtained) == 0);
TK_LOCK(ci->tkci_lock);
if (dotrace)
TK_TRACE(TKC_SOBTAINED, ra, TK_GETCH(ci->tkci_obj), \
tsobtained, tsrefused, TK_NULLSET,
ci, TK_METER_VAR);
/*
* Deal with successfully obtained tokens
*/
for (ts = tsobtained, class = 0; ts; ts = ts >> TK_LWIDTH, class++) {
if ((level = ts & TK_SET_MASK) == 0)
continue;
TK_ASSERT(class < ci->tkci_ntokens);
TK_ASSERT((level & level - 1) == 0);
tstate = &ci->tkci_state[class];
CHECK(tstate);
switch (tstate->cl_state) {
case TK_CL_SOBTAINING:
/*
* we got the token but it must be returned as soon
* as possible (server wants it)
*/
tstate->cl_state = TK_CL_SREVOKING;
break;
case TK_CL_COBTAINING:
/*
* we got the token but it must be returned as soon
* as possible (client requested it)
*/
tstate->cl_state = TK_CL_REVOKING;
break;
case TK_CL_BOBTAINING:
/*
* we got the token but it must be returned as soon
* as possible (server recalled it)
*/
tstate->cl_state = TK_CL_BREVOKING;
break;
case TK_CL_BORROWING:
tstate->cl_obtain &= ~level;
tstate->cl_state = TK_CL_BORROWED;
break;
case TK_CL_OBTAINING:
tstate->cl_obtain &= ~level;
tstate->cl_state = TK_CL_OWNED;
break;
default:
tkci_badstate("tkc_obtained", ci, class);
/* NOTREACHED */
}
CHECK(tstate);
/* XXX would be nice to only call wake if we knew
* someone was waiting
*/
tkci_obtainwake(ci, class);
}
/*
* Deal with refused tokens
* In the case of (*tkc_obtain) refusing to return a token,
* the refuse set can have multiple levels on.
*/
for (ts = tsrefused, class = 0; ts; ts = ts >> TK_LWIDTH, class++) {
if ((level = ts & TK_SET_MASK) == 0)
continue;
TK_ASSERT(class < ci->tkci_ntokens);
tstate = &ci->tkci_state[class];
CHECK(tstate);
/*
* If we have a disposition for this token, then
* we must have been trying to return it.
*/
disp = TK_GET_LEVEL(dofref, class);
if (disp) {
TK_ASSERT((disp & disp - 1) == 0);
/*
* since we were returning this, we shouldn't 'have'
* it
*/
TK_ASSERT((level & downext[tstate->cl_extlev]) == 0);
switch (tstate->cl_state) {
case TK_CL_COBTAINING:
case TK_CL_OBTAINING:
if (--tstate->cl_hold == 0) {
} else {
/* put into restore state based
* on disposition
*/
tstate->cl_extlev = level;
if (disp == TK_CLIENT_INITIATED) {
tstate->cl_state = TK_CL_CRESTORE;
} else if (disp == TK_SERVER_MANDATORY) {
tstate->cl_state = TK_CL_SRESTORE;
} else {
TK_ASSERT(disp == TK_SERVER_CONDITIONAL);
tstate->cl_state = TK_CL_BRESTORE;
}
tkci_obtainwake(ci, class);
}
default:
tkci_badstate("tkc_obtained3", ci, class);
/* NOTREACHED */
}
CHECK(tstate);
continue;
}
/*
* standard! refuse of obtain
* Seems like we might be able to get into the COBTAINING
* or BOBTAINING states since it's legal for the client
* to call tkc_recall() on a token being obtained.
* We shouldn't be able to get SOBTAINING - we don't
* have the token so how can the server ask for it back?
* XXX actually for now we can't get into BORROWING nor
* BOBTAINING.
*/
TK_ASSERT((level & level - 1) == 0);
switch (tstate->cl_state) {
case TK_CL_COBTAINING:
/*
* client wanted to revoke token but we refused
* to get it. Sounds like a standoff..
* Ignore revoke.
*/
/* FALLTHROUGH */
case TK_CL_BORROWING:
case TK_CL_OBTAINING:
if (--tstate->cl_hold == 0) {
if (tstate->cl_obtain) {
int toobtain;
/* turn off appropriate extlev bits. */
/* XXXcheckout */
tstate->cl_extlev = downext[tstate->cl_extlev];
toobtain = obtaintab[tstate->cl_obtain];
TK_ASSERT(toobtain);
tstate->cl_obtain &= ~toobtain;
tstate->cl_state = TK_CL_WILLOBTAIN;
if (tstate->cl_scwait)
tkci_scwake(ci, class);
} else {
tstate->cl_extlev = 0;
tstate->cl_state = TK_CL_IDLE;
TK_ASSERT(tkci_nobtainwaiting(ci, class) == 0);
}
} else {
/*
* XX we clearly need to handle either
* extlev or obtain mask here - in the
* OBTAINING or RETURNING state we are
* permitted to have the obtain mask
* overlap the extlev, but not in the
* REJECTED state
*/
tstate->cl_extlev = 0;
tstate->cl_state = TK_CL_REJECTED;
tkci_obtainwake(ci, class);
}
break;
default:
tkci_badstate("tkc_obtained2", ci, class);
/* NOTREACHED */
}
CHECK(tstate);
}
if (dotrace)
TK_TRACE(TKC_EOBTAINED, 0, TK_GETCH(ci->tkci_obj), TK_NULLSET,
TK_NULLSET, TK_NULLSET, ci, TK_METER_VAR);
TK_UNLOCK(ci->tkci_lock);
}
/*
* tkc_acquire - conditionally acquire.
*/
void
tkc_acquire(
tkc_state_t *cs, /* object containing tokens */
tk_set_t tset, /* tokens requested */
tk_set_t *got) /* tokens gotten */
{
tkci_cstate_t *ci = (tkci_cstate_t *)cs;
TK_METER_DECL /* decls 'tm' */
tk_set_t tstoret, tswanted, tstoobtain, obtained;
tk_set_t tsrefused, tslater, gotten;
tk_disp_t dofret;
TKC_METER_VAR_INIT(tm, cs);
TK_TRACE(TKC_SCACQUIRE, __return_address, TK_GETCH(ci->tkci_obj),
tset, TK_NULLSET, TK_NULLSET, ci, TK_METER_VAR);
tswanted = tset;
gotten = TK_NULLSET;
while (tswanted) {
__tkc_obtaining(cs, tswanted, &tstoobtain,
&tstoret, &dofret, &tsrefused, &tslater, 1,
(void *)__return_address);
gotten |= tswanted & ~(tstoobtain | tsrefused | tslater);
if ((tstoobtain | tstoret) != 0) {
/*
* Refusal to return is really just for
* error handling - if the server goes down
* then (*tkc_obtain)() may well refuse all
* returns and obtains.
*/
ci->tkci_if->tkc_obtain(ci->tkci_obj, tstoobtain,
tstoret, dofret, &tsrefused);
TK_ASSERT((tstoobtain & tsrefused) == tsrefused);
#if TK_DEBUG
/*
* if any toreturn tokens were refused, then the obtain
* token that prompted the return must also have
* been refused
*/
if (tsrefused & tstoret) {
tk_set_t ovlp, tsob;
int class, oblevel;
for ( ovlp = (tsrefused & tstoret),
tsob = tstoobtain, class = 0;
ovlp;
ovlp = ovlp >> TK_LWIDTH,
tsob = tsob >> TK_LWIDTH,
class++) {
if ((ovlp & TK_SET_MASK) == 0)
continue;
oblevel = tsob & TK_SET_MASK;
/* must have wanted something */
TK_ASSERT(oblevel);
/* what we wanted must also be refused */
TK_ASSERT(oblevel & TK_GET_LEVEL(tsrefused, class));
}
}
#endif
obtained = tstoobtain & ~tsrefused;
/*
* it's fine to pass more disposition info
* than is needed.
*/
__tkc_obtained(cs, obtained, tsrefused,
dofret, 1, (void *)__return_address);
gotten |= obtained;
}
tswanted = tslater;
}
TK_TRACE(TKC_ECACQUIRE, 0, TK_GETCH(ci->tkci_obj), gotten,
TK_NULLSET, TK_NULLSET, ci, TK_METER_VAR);
*got = gotten;
}
/*
* tkc_release - release a held token
*/
void
tkc_release(
tkc_state_t *cs, /* object containing tokens */
tk_set_t tset) /* tokens to release */
{
tkci_cstate_t *ci = (tkci_cstate_t *)cs;
tkci_clstate_t *tstate;
TK_METER_DECL /* decls 'tm' */
tk_set_t ts;
tk_set_t tstoret = TK_NULLSET;
tk_disp_t dofret = TK_NULLSET;
/* REFERENCED (level) */
int level;
int class;
TK_LOCKDECL;
TK_ASSERT((tset & 0x80000000) == 0);/* !passed in a tk_singleton_t */
TKC_METER_VAR_INIT(tm, cs);
TK_LOCK(ci->tkci_lock);
TK_TRACE(TKC_SRELEASE, __return_address, TK_GETCH(ci->tkci_obj),
tset, TK_NULLSET, TK_NULLSET, ci, TK_METER_VAR);
for (ts = tset, class = 0; ts; ts = ts >> TK_LWIDTH, class++) {
if ((level = ts & TK_SET_MASK) == 0)
continue;
TK_ASSERT(class < ci->tkci_ntokens);
TK_ASSERT((level & level - 1) == 0);
tstate = &ci->tkci_state[class];
TK_ASSERT(tstate->cl_hold > 0);
CHECK(tstate);
switch (tstate->cl_state) {
case TK_CL_BORROWED:
case TK_CL_OWNED:
TK_ASSERT(level & tstate->cl_extlev);
if (--tstate->cl_hold == 0) {
/* turn off appropriate extlev bits. */
tstate->cl_extlev = downext[tstate->cl_extlev];
if (tstate->cl_state == TK_CL_BORROWED) {
tstate->cl_state = TK_CL_RETURNING;
TK_COMBINE_SET(tstoret,
TK_MAKE(class, tstate->cl_extlev));
TK_COMBINE_SET(dofret,
TK_MAKE(class, TK_SERVER_CONDITIONAL));
if (tstate->cl_scwait)
tkci_scwake(ci, class);
} else if (tstate->cl_obtain) {
int toobtain;
toobtain = obtaintab[tstate->cl_obtain];
TK_ASSERT(toobtain);
tstate->cl_obtain &= ~toobtain;
tstate->cl_state = TK_CL_WILLOBTAIN;
if (tstate->cl_scwait)
tkci_scwake(ci, class);
} else {
tstate->cl_state = TK_CL_CACHED;
}
}
break;
case TK_CL_REVOKING:
case TK_CL_SREVOKING:
case TK_CL_BREVOKING:
/*
* token wants to be revoked - if hold count goes to
* zero, call (*tkc_return)() callout.
*/
TK_ASSERT(level & tstate->cl_extlev);
if (--tstate->cl_hold == 0) {
/* turn off appropriate extlev bits. */
tstate->cl_extlev = downext[tstate->cl_extlev];
/*
* XXX OSF seems to permit transition to
* the WILLOBTAIN state if the obtain
* mask is set. This seems to cause some
* problems - extlev is still set so a thread
* trying to get a conflicting token will
* attempt to return it (in tkc_acquire)
* as well as our sending it back
* (via tkc_return)
*/
/*
* the token level to revoke is the extlev
* not what we're returning - we could
* be returning a READ token but have
* the WRITE or SWRITE token cached
*/
TK_COMBINE_SET(tstoret,
TK_MAKE(class, tstate->cl_extlev));
if (tstate->cl_state == TK_CL_BREVOKING) {
TK_COMBINE_SET(dofret,
TK_MAKE(class, TK_SERVER_CONDITIONAL));
} else if (tstate->cl_state == TK_CL_SREVOKING) {
TK_COMBINE_SET(dofret,
TK_MAKE(class, TK_SERVER_MANDATORY));
} else {
TK_COMBINE_SET(dofret,
TK_MAKE(class, TK_CLIENT_INITIATED));
}
NEWSTATE(ci, class, tstate, TK_CL_RETURNING);
}
break;
case TK_CL_WILLRETURN:
/*
* token wants to be returned - if hold count goes to
* zero, wake returner
* We go to a CREVOKING state rather than, like OSF
* to the RETURNING state. We want RETURNING to mean
* that the return message has gone out. Instead,
* depending on which request kicks us out of
* WILLRETURN we go into one of the 3 REVOKING states
* This lets the thread waiting in tkc_returning
* decide whether it needs to send a message.
*/
TK_ASSERT(level & tstate->cl_extlev);
if (--tstate->cl_hold == 0) {
/* turn off appropriate extlev bits. */
tstate->cl_extlev = downext[tstate->cl_extlev];
NEWSTATE(ci, class, tstate, TK_CL_CREVOKING);
}
break;
default:
tkci_badstate("tkc_release", ci, class);
/* NOTREACHED */
}
CHECK(tstate);
}
TK_TRACE(TKC_ERELEASE, 0, TK_GETCH(ci->tkci_obj), tstoret, TK_NULLSET,
dofret, ci, TK_METER_VAR);
TK_UNLOCK(ci->tkci_lock);
if (tstoret) {
TK_TRACE(TKC_RETURN_CALL, __return_address,
TK_GETCH(ci->tkci_obj),
tstoret, TK_NULLSET, dofret, ci, TK_METER_VAR);
ci->tkci_if->tkc_return(ci, ci->tkci_obj, tstoret,
TK_NULLSET, dofret);
}
return;
}
/*
* tkc_hold - hold a token. No attempt is made to acquire the token if
* it is not on the client. The set of successfully held tokens is returned.
*/
tk_set_t
tkc_hold(
tkc_state_t *cs, /* object containing tokens */
tk_set_t tset) /* tokens requested */
{
tkci_cstate_t *ci = (tkci_cstate_t *)cs;
tkci_clstate_t *tstate;
TK_METER_DECL /* decls 'tm' */
tk_set_t ts, gts = TK_NULLSET;
int level, class;
TK_LOCKDECL;
TK_ASSERT((tset & 0x80000000) == 0);/* !passed in a tk_singleton_t */
TKC_METER_VAR_INIT(tm, cs);
TK_LOCK(ci->tkci_lock);
TK_TRACE(TKC_SHOLD, __return_address, TK_GETCH(ci->tkci_obj), tset,
TK_NULLSET, TK_NULLSET, ci, TK_METER_VAR);
for (ts = tset, class = 0; ts; ts = ts >> TK_LWIDTH, class++) {
tryagain:
if ((level = ts & TK_SET_MASK) == 0)
continue;
TK_ASSERT(class < ci->tkci_ntokens);
TK_ASSERT((level & level - 1) == 0);
tstate = &ci->tkci_state[class];
CHECK(tstate);
TKC_INC_METER(tm, class, acquire);
switch (tstate->cl_state) {
case TK_CL_CACHED:
/*
* we already have the token - if at a compatible
* level, bump hold count and return
*/
if (level == tstate->cl_extlev ||
(tstate->cl_extlev == TK_WRITE)) {
/*
* asking for the level we own OR
* got the write token - its always
* ok to get a token if we have the write token
* level as no-one else can have a conflicting
* token
*/
tstate->cl_hold++;
tstate->cl_state = TK_CL_OWNED;
tstate->cl_extlev |= level;
TKC_INC_METER(tm, class, acq_cached);
TK_COMBINE_SET(gts, TK_MAKE(class, level));
}
break;
case TK_CL_OWNED:
case TK_CL_BORROWED:
/*
* we already have the token held - if at a compatible
* level, bump hold count and return
*/
if ((level & tstate->cl_extlev) ||
(tstate->cl_extlev == TK_WRITE)) {
/*
* asking for the level we own OR
* got the write token - its always
* ok to get a token if we have the write token
* level as no-one else can have a conflicting
* token
*/
tstate->cl_hold++;
tstate->cl_extlev |= level;
TK_COMBINE_SET(gts, TK_MAKE(class, level));
TKC_INC_METER(tm, class, acq_cached);
}
break;
case TK_CL_BORROWING:
case TK_CL_OBTAINING:
case TK_CL_COBTAINING:
case TK_CL_BOBTAINING:
if ((level & tstate->cl_extlev) ||
(tstate->cl_extlev == TK_WRITE)) {
tkci_obtainwait(ci, class, TK_LOCKVARADDR);
TK_LOCK(ci->tkci_lock);
goto tryagain;
}
break;
default:
/*
* these are all states for which we won't grant a
* token
*/
#ifdef NEVER
if (tstate->cl_state != TK_CL_IDLE)
printf("tkc_hold - token 0x%x not granted because in state %s\n",
cs, __tkci_prstate(*tstate));
#endif
break;
}
CHECK(tstate);
}
TK_TRACE(TKC_EHOLD, 0, TK_GETCH(ci->tkci_obj), gts, TK_NULLSET,
TK_NULLSET, ci, TK_METER_VAR);
TK_UNLOCK(ci->tkci_lock);
return gts;
}
/* ARGSUSED */
static void
tkci_mreturn(
tkci_cstate_t *ci, /* object containing tokens */
tk_meter_t *tm,
int class,
int level,
tk_set_t *tstoret, /* tokens to return */
tk_set_t *teh,
tk_disp_t *dofret)
{
tkci_clstate_t *tstate;
TKC_INC_METER(tm, class, recall);
tstate = &ci->tkci_state[class];
CHECK(tstate);
switch (tstate->cl_state) {
case TK_CL_IDLE:
/*
* we can get here if the client spontaneously sent
* back a token while the server was revoking it
* but before we got the revoke message
*/
TK_COMBINE_SET(*teh, TK_MAKE(class, level));
TK_COMBINE_SET(*dofret, TK_MAKE(class, TK_SERVER_MANDATORY));
break;
case TK_CL_CACHED:
TK_ASSERT((level & downext[tstate->cl_extlev]));
tstate->cl_state = TK_CL_RETURNING;
TK_COMBINE_SET(*tstoret, TK_MAKE(class, level));
TK_COMBINE_SET(*dofret, TK_MAKE(class, TK_SERVER_MANDATORY));
break;
case TK_CL_OWNED:
TK_ASSERT((level & downext[tstate->cl_extlev]));
tstate->cl_state = TK_CL_SREVOKING;
break;
case TK_CL_OBTAINING:
/*
* If we are in the obtaining state it is because the
* client has voluntarily returned the token after
* the revoke started, and then tried to reacquire
* it. At this point the obtain will be stuck at the
* server waiting for the response to this revoke
* so we say that we don't know where the token is
*/
TK_COMBINE_SET(*teh, TK_MAKE(class, level));
TK_COMBINE_SET(*dofret, TK_MAKE(class, TK_SERVER_MANDATORY));
break;
case TK_CL_COBTAINING:
/*
* client wants to return it and now so does
* the server - server wins
*/
TK_ASSERT(level & downext[tstate->cl_extlev]);
tstate->cl_state = TK_CL_SOBTAINING;
break;
case TK_CL_RETURNING:
TK_COMBINE_SET(*teh, TK_MAKE(class, level));
TK_COMBINE_SET(*dofret, TK_MAKE(class, TK_SERVER_MANDATORY));
break;
case TK_CL_REVOKING:
/*
* client wants to return token - so do we - no
* need for 2 messages, change to server style
* No need to use NEWSTATE - don't need to wake anyone
*/
tstate->cl_state = TK_CL_SREVOKING;
break;
case TK_CL_WILLRETURN:
TK_ASSERT(level & downext[tstate->cl_extlev]);
NEWSTATE(ci, class, tstate, TK_CL_SREVOKING);
break;
case TK_CL_WILLOBTAIN:
/*
* In this state, the thread that set this
* state will ALWAYS be the one to return the current token,
* There are a few possiblities:
* 1) wait for status chg - but tkc_recall
* isn't supposed to sleep
* 2) return an 'eh' indication - this could
* cause storms if the thread that owns the
* WILLOBTAIN state doesn't run for a while
* 3) somehow force the WILLOBTAIN thread to
* place this token into the SREVOKING state.
* 3) of course is the right answer.
*/
if (level & downext[tstate->cl_extlev])
tstate->cl_state = TK_CL_SWILLOBTAIN;
else {
TK_COMBINE_SET(*teh, TK_MAKE(class, level));
TK_COMBINE_SET(*dofret, TK_MAKE(class, TK_SERVER_MANDATORY));
}
break;
case TK_CL_BREVOKING:
case TK_CL_BOBTAINING:
case TK_CL_BORROWED:
case TK_CL_BORROWING:
/* implies a conditional recall - but server can't both
* conditionally and mandatorily ask use for token!
*/
default:
tkci_badstate("tkci_mreturn", ci, class);
/* NOTREACHED */
}
CHECK(tstate);
}
/*
* handle recalls initiated by client - in general these are just hints
*/
/* ARGSUSED */
static void
tkci_recall_client(
tkci_cstate_t *ci, /* object containing tokens */
tk_meter_t *tm,
int class,
int level,
tk_set_t *tset, /* tokens to return */
tk_disp_t *dofset)
{
tkci_clstate_t *tstate;
tstate = &ci->tkci_state[class];
CHECK(tstate);
/* if we don't have it, ignore revoke 'request' */
if (!(level & downext[tstate->cl_extlev]))
return;
switch (tstate->cl_state) {
case TK_CL_CACHED:
TKC_INC_METER(tm, class, recall);
tstate->cl_state = TK_CL_RETURNING;
TK_COMBINE_SET(*tset, TK_MAKE(class, level));
TK_COMBINE_SET(*dofset, TK_MAKE(class, TK_CLIENT_INITIATED));
break;
case TK_CL_BORROWED:
TKC_INC_METER(tm, class, recall);
tstate->cl_state = TK_CL_BREVOKING;
break;
case TK_CL_OWNED:
TKC_INC_METER(tm, class, recall);
tstate->cl_state = TK_CL_REVOKING;
break;
case TK_CL_OBTAINING:
TKC_INC_METER(tm, class, recall);
tstate->cl_state = TK_CL_COBTAINING;
break;
case TK_CL_BORROWING:
TKC_INC_METER(tm, class, recall);
tstate->cl_state = TK_CL_BOBTAINING;
break;
case TK_CL_SOBTAINING:
case TK_CL_COBTAINING:
case TK_CL_RETURNING:
case TK_CL_REVOKING:
case TK_CL_BREVOKING:
case TK_CL_SREVOKING:
case TK_CL_WILLRETURN:
/* seems harmless enough */
break;
case TK_CL_WILLOBTAIN:
#ifdef NEVER
/*
* We may have already revoked and returned
* this token, and just be permitting someone
* else to obtain a token.
* We don't set the mrecall bit - at this point there
* is NO way that the server could believe we have
* a token.
*/
break;
#endif
default:
tkci_badstate("tkci_recall_client", ci, class);
/* NOTREACHED */
}
CHECK(tstate);
}
/*
* tkci_creturn - called in response to a server initiated conditional
* recall message
*/
/* ARGSUSED */
static void
tkci_creturn(
tkci_cstate_t *ci, /* object containing tokens */
tk_meter_t *tm,
int class,
int level,
tk_set_t *tstoret, /* tokens to recall */
tk_set_t *teh,
tk_disp_t *dofsets)
{
tkci_clstate_t *tstate;
tstate = &ci->tkci_state[class];
CHECK(tstate);
/*
* For recall, level doesn't matter. If we don't think
* we have it at all, call it unknown and add it to the 'eh' list.
*/
level = downext[tstate->cl_extlev];
if (level == 0) {
TK_COMBINE_SET(*teh, TK_MAKE(class, level));
TK_COMBINE_SET(*dofsets, TK_MAKE(class, TK_SERVER_CONDITIONAL));
return;
}
switch (tstate->cl_state) {
case TK_CL_CACHED:
tstate->cl_state = TK_CL_RETURNING;
TK_COMBINE_SET(*tstoret, TK_MAKE(class, level));
TK_COMBINE_SET(*dofsets, TK_MAKE(class, TK_SERVER_CONDITIONAL));
break;
case TK_CL_OWNED:
tstate->cl_state = TK_CL_BORROWED;
break;
case TK_CL_OBTAINING:
case TK_CL_RETURNING:
/*
* to avoid a deadlock we need to let this
* recall complete w/o waiting for the client
* to 'finish' the return.
* If, in fact the server still thinks we have
* the token, it'll send us another recall request
*/
TK_COMBINE_SET(*teh, TK_MAKE(class, level));
TK_COMBINE_SET(*dofsets, TK_MAKE(class, TK_SERVER_CONDITIONAL));
break;
case TK_CL_WILLRETURN:
/*
* WILLRETURN is only entered from a client
* initiated return via tkc_returning.
* Since the server wants the token - its better
* to let the return message be the one that
* will satisfy the server rather than a
* client initiated one.
*/
NEWSTATE(ci, class, tstate, TK_CL_BREVOKING);
break;
case TK_CL_REVOKING:
/* no need to wake anyone thus no NEWSTATE */
tstate->cl_state = TK_CL_BREVOKING;
break;
case TK_CL_CREVOKING:
/*
* the hold count is zero and the thread that set
* WILLRETURN in tkc_returning will wake and
* realize that we've have already returned the
* token.
*/
TK_COMBINE_SET(*tstoret, TK_MAKE(class, level));
TK_COMBINE_SET(*dofsets, TK_MAKE(class, TK_SERVER_CONDITIONAL));
NEWSTATE(ci, class, tstate, TK_CL_RETURNING);
break;
case TK_CL_BORROWED:
case TK_CL_BORROWING:
case TK_CL_BOBTAINING:
case TK_CL_BREVOKING:
/* this would imply 2 recalls! */
case TK_CL_SREVOKING:
/* implies both a mandatory and conditional recall */
default:
tkci_badstate("tkci_creturn", ci, class);
/* NOTREACHED */
}
CHECK(tstate);
}
/*
* tkc_recall - called when:
* 1) a client knows that its likely that another client would be acquiring
* a token that would likely cause a recall. This can be a good
* performance win (why == TK_CLIENT_INITIATED)
* 2) in response to a mandatory server request (why == TK_SERVER_MANDATORY)
* 3) in response to a conditional server request (TK_SERVER_CONDITIONAL)
*
* the 'why' argument encodes the reason per token.
*
* Since a CLIENT_INITIATED revoke is just a 'hint' if we don't think
* we have the token, we just ignore it.
* Server initiated recalls we MUST answer at some time - in fact, no
* more acquires on the token will be permitted until we answer.
*/
void
tkc_recall(
tkc_state_t *cs, /* object containing tokens */
tk_set_t tset, /* tokens to return */
tk_disp_t why) /* server or client initiated per token */
{
tkci_cstate_t *ci = (tkci_cstate_t *)cs;
TK_METER_DECL /* decls 'tm' */
tk_set_t ts;
tk_set_t tstoret = TK_NULLSET, eh = TK_NULLSET;
tk_disp_t ds, dofret = TK_NULLSET;
int disp, level, class;
TK_LOCKDECL;
TKC_METER_VAR_INIT(tm, cs);
TK_LOCK(ci->tkci_lock);
TK_TRACE(TKC_SRECALL, __return_address, TK_GETCH(ci->tkci_obj),
tset, TK_NULLSET, why, ci, TK_METER_VAR);
for (ts = tset, ds = why, class = 0; ts;
ts = ts >> TK_LWIDTH, ds = ds >> TK_LWIDTH, class++) {
if ((level = ts & TK_SET_MASK) == 0)
continue;
TK_ASSERT(class < ci->tkci_ntokens);
TK_ASSERT((level & level - 1) == 0);
disp = ds & TK_SET_MASK;
TK_ASSERT(disp);
TK_ASSERT((disp & disp - 1) == 0);
if (disp == TK_SERVER_CONDITIONAL)
tkci_creturn(ci, TK_METER_VAR, class, level, &tstoret,
&eh, &dofret);
else if (disp == TK_SERVER_MANDATORY)
tkci_mreturn(ci, TK_METER_VAR, class, level,
&tstoret, &eh, &dofret);
else
tkci_recall_client(ci, TK_METER_VAR, class, level,
&tstoret, &dofret);
}
TK_TRACE(TKC_ERECALL, 0, TK_GETCH(ci->tkci_obj), tstoret, eh,
dofret, ci, TK_METER_VAR);
TK_UNLOCK(ci->tkci_lock);
if (tstoret || eh) {
TK_TRACE(TKC_RETURN_CALL, __return_address,
TK_GETCH(ci->tkci_obj),
tstoret, eh, dofret, ci, TK_METER_VAR);
ci->tkci_if->tkc_return(ci, ci->tkci_obj, tstoret, eh, dofret);
}
}
/*
* tkc_returned - return a set of tokens
* Used by the client to disposition a set of tokens. It must call this
* in these cases:
* 1) to return tokens required by a call to (*tkc_return)
* 2) to return tokens initiated via tkc_returning()
*
* Note that it is ILLEGAL to refuse to return a token that is server-initiated.
*/
void
tkc_returned(
tkc_state_t *cs, /* object containing tokens */
tk_set_t tset, /* tokens to return */
tk_set_t refused) /* tokens refused */
{
tkci_cstate_t *ci = (tkci_cstate_t *)cs;
tkci_clstate_t *tstate;
TK_METER_DECL /* decls 'tm' */
tk_set_t ts;
/* REFERENCED (level) */
int level;
int class;
TK_LOCKDECL;
TKC_METER_VAR_INIT(tm, cs);
TK_LOCK(ci->tkci_lock);
TK_TRACE(TKC_SRETURNED, __return_address, TK_GETCH(ci->tkci_obj),
tset, refused, TK_NULLSET, ci, TK_METER_VAR);
for (ts = tset, class = 0; ts; ts = ts >> TK_LWIDTH, class++) {
if ((level = ts & TK_SET_MASK) == 0)
continue;
TK_ASSERT(class < ci->tkci_ntokens);
TK_ASSERT((level & level - 1) == 0);
TKC_INC_METER(tm, class, return);
tstate = &ci->tkci_state[class];
CHECK(tstate);
switch (tstate->cl_state) {
case TK_CL_RETURNING:
TK_ASSERT((tstate->cl_extlev & level) != 0);
if (tstate->cl_obtain) {
/*
* There can be multiple bits on - including
* the one for the level we're returning. This
* can happen if say T1 has token for READ,
* T2 wants it for WRITE (which set the
* state to REVOKING and set WRITE in the
* obtain mask); then T3 wants it for READ -
* this will cause READ to get placed into
* the obtain mask.
*/
int toobtain;
toobtain = obtaintab[tstate->cl_obtain];
TK_ASSERT(toobtain);
tstate->cl_obtain &= ~toobtain;
tstate->cl_mrecall = 0;
tstate->cl_extlev = 0;
NEWSTATE(ci, class, tstate, TK_CL_WILLOBTAIN);
} else {
tstate->cl_mrecall = 0;
tstate->cl_extlev = 0;
NEWSTATE(ci, class, tstate, TK_CL_IDLE);
}
break;
case TK_CL_OBTAINING:
/*
* another thread might have just returned a token while
* obtaining a conflicting token
* This can happen if the server recalled a token
* that was in the WILLOBTAIN state (which
* set the state to SWILLOBTAIN). When we change
* the state to OBTAINING we send back the old
* token (via a (*tkc_return)() callout). This
* callout will send back the token and call us
*
* Note that cl_extlev could contain our token if
* for example we are returning RD and another
* thread is OBTAINING WR and a third thread goes
* for RD - the extlev will show WR|RD,
* which has nothing to do with our RD.
*/
TK_ASSERT((level & downext[tstate->cl_extlev]) == 0);
break;
default:
tkci_badstate("tkc_returned", ci, class);
/* NOTREACHED */
}
CHECK(tstate);
}
for (ts = refused, class = 0; ts; ts = ts >> TK_LWIDTH, class++) {
if ((level = ts & TK_SET_MASK) == 0)
continue;
TK_ASSERT(class < ci->tkci_ntokens);
TK_ASSERT((level & level - 1) == 0);
tstate = &ci->tkci_state[class];
CHECK(tstate);
switch (tstate->cl_state) {
case TK_CL_RETURNING:
TK_ASSERT((tstate->cl_extlev & level) != 0);
if (tstate->cl_obtain) {
/*
* There can be multiple bits on - including
* the one for the level we're returning. This
* can happen if say T1 has token for READ,
* T2 wants it for WRITE (which set the
* state to REVOKING and set WRITE in the
* obtain mask); then T3 wants it for READ -
* this will cause READ to get placed into
* the obtain mask.
*/
int toobtain;
toobtain = obtaintab[tstate->cl_obtain];
TK_ASSERT(toobtain);
tstate->cl_obtain &= ~toobtain;
if (tstate->cl_extlev & toobtain) {
/* what we've got and what they want
* are the same - call it CACHED
*/
NEWSTATE(ci, class, tstate, TK_CL_CACHED);
} else {
NEWSTATE(ci, class, tstate, TK_CL_WILLOBTAIN);
}
} else {
NEWSTATE(ci, class, tstate, TK_CL_CACHED);
}
break;
case TK_CL_BORROWING:
case TK_CL_OBTAINING:
default:
tkci_badstate("tkc_return-refused", ci, class);
/* NOTREACHED */
}
CHECK(tstate);
}
TK_TRACE(TKC_ERETURNED, 0, TK_GETCH(ci->tkci_obj),
TK_NULLSET, TK_NULLSET, TK_NULLSET, ci, TK_METER_VAR);
TK_UNLOCK(ci->tkci_lock);
}
/*
* tkc_returning - return a set of tokens
* Used by the client to push tokens back to the server
* We are particularly forgiving in what can be passed in tset -
* it is very reasonable to turn on all 3 levels. We will return the
* one we have ..
*
* If wait_to_resolve is TRUE then we may well sleep - since things can
* change while we sleep, we basically must re-start the loop if we do.
* So, we only return if we get through all of tset w/o sleeping
*
* Note that we use the WILLRETURN state - this basically means that no
* other acquires may be done (they will PANIC)
*/
void
tkc_returning(
tkc_state_t *cs, /* object containing tokens */
tk_set_t tset, /* tokens to return */
tk_set_t *ok, /* OUT:tokens that are ok to return */
tk_disp_t *okwhy, /* OUT:disposition of ok tokens */
int wait_to_resolve) /* if TRUE then wait for tokens in process */
{
tkci_cstate_t *ci = (tkci_cstate_t *)cs;
tkci_clstate_t *tstate;
TK_METER_DECL /* decls 'tm' */
tk_set_t ts;
int level, class;
TK_LOCKDECL;
TKC_METER_VAR_INIT(tm, cs);
*ok = TK_NULLSET;
*okwhy = TK_NULLSET;
TK_LOCK(ci->tkci_lock);
TK_TRACE(TKC_SRETURNING, __return_address, TK_GETCH(ci->tkci_obj),
tset, TK_NULLSET, TK_NULLSET, ci, TK_METER_VAR);
for (ts = tset, class = 0; ts; ts = ts >> TK_LWIDTH, class++) {
tryagain:
if ((level = ts & TK_SET_MASK) == 0)
continue;
/* heck, they can even pass total garbage! */
if (class >= ci->tkci_ntokens)
break;
tstate = &ci->tkci_state[class];
CHECK(tstate);
if ((downext[tstate->cl_extlev] & level) == 0)
/* we don't have it */
continue;
if (tstate->cl_state == TK_CL_CACHED) {
tstate->cl_state = TK_CL_RETURNING;
CHECK(tstate);
TK_COMBINE_SET(*ok, TK_MAKE(class, downext[tstate->cl_extlev]));
TK_COMBINE_SET(*okwhy, TK_MAKE(class, TK_CLIENT_INITIATED));
continue;
}
if (!wait_to_resolve) {
/* thats all */
continue;
}
switch (tstate->cl_state) {
case TK_CL_IDLE:
/* ignore */
break;
case TK_CL_SREVOKING:
case TK_CL_BREVOKING:
case TK_CL_RETURNING:
tkci_scwait(ci, class, TK_LOCKVARADDR);
TK_LOCK(ci->tkci_lock);
goto tryagain;
case TK_CL_BORROWED:
tstate->cl_state = TK_CL_BREVOKING;
tkci_scwait(ci, class, TK_LOCKVARADDR);
TK_LOCK(ci->tkci_lock);
goto tryagain;
case TK_CL_OWNED:
case TK_CL_REVOKING:
/*
* OWNED is changed to WILLRETURN to force no
* more grants.
* REVOKING is changed to WILLRETURN to avoid
* an extra message - the caller has signified
* their desire to send a message
*/
tstate->cl_state = TK_CL_WILLRETURN;
CHECK(tstate);
tkci_scwait(ci, class, TK_LOCKVARADDR);
TK_LOCK(ci->tkci_lock);
if (tstate->cl_state == TK_CL_CREVOKING) {
TK_COMBINE_SET(*ok, TK_MAKE(class, downext[tstate->cl_extlev]));
TK_COMBINE_SET(*okwhy, TK_MAKE(class, TK_CLIENT_INITIATED));
NEWSTATE(ci, class, tstate, TK_CL_RETURNING);
break;
} else {
goto tryagain;
}
case TK_CL_COBTAINING:
case TK_CL_SOBTAINING:
case TK_CL_OBTAINING:
case TK_CL_BORROWING:
/*
* XXX does this really get woken all the time even
* though we don't set a hold count??
*/
tkci_obtainwait(ci, class, TK_LOCKVARADDR);
TK_LOCK(ci->tkci_lock);
goto tryagain;
case TK_CL_WILLOBTAIN:
case TK_CL_SWILLOBTAIN:
case TK_CL_REJECTED:
tkci_scwait(ci, class, TK_LOCKVARADDR);
/* something has changed - try again */
TK_LOCK(ci->tkci_lock);
goto tryagain;
default:
tkci_badstate("tkc_returning", ci, class);
/* NOTREACHED */
}
CHECK(tstate);
}
TK_TRACE(TKC_ERETURNING, 0, TK_GETCH(ci->tkci_obj), *ok, TK_NULLSET,
TK_NULLSET, ci, TK_METER_VAR);
TK_UNLOCK(ci->tkci_lock);
}
/*
* Clear state and destroy.
*/
void
tkc_free(
tkc_state_t *cs) /* object to be freed */
{
tkci_cstate_t *ci = (tkci_cstate_t *)cs;
int i;
for (i = 0; i < ci->tkci_ntokens; i++) {
ci->tkci_state[i].cl_word = 0;
ci->tkci_state[i].cl_state = TK_CL_IDLE;
}
if (ci->tkci_if == &tkc_local_iface)
tkc_destroy_local(cs);
else
tkc_destroy(cs);
}
/*
* Copy token state.
*/
void
tkc_copy(
tkc_state_t *src_cs,
tkc_state_t *dst_cs)
{
tkci_cstate_t *src_ci = (tkci_cstate_t *)src_cs;
tkci_cstate_t *dst_ci = (tkci_cstate_t *)dst_cs;
int i;
for (i = 0; i < src_ci->tkci_ntokens; i++) {
dst_ci->tkci_state[i].cl_word = src_ci->tkci_state[i].cl_word;
}
}
#ifdef _KERNEL
#define OUTPUT qprintf(
void
tkc_print(tkc_state_t *cs, char *fmt, ...)
#else
#define OUTPUT fprintf(f,
void
tkc_print(tkc_state_t *cs, FILE *f, char *fmt, ...)
#endif
{
tkci_cstate_t *ci = (tkci_cstate_t *)cs;
tkci_clstate_t tstate;
int i;
char buf[512], *p;
va_list ap;
p = buf;
if (fmt) {
va_start(ap, fmt);
vsprintf(p, fmt, ap);
p += strlen(p);
}
p = __tk_sprintf(p, "obj 0x%x ref %d ntokens %d origcell %d\n", ci->tkci_obj,
ci->tkci_ref,
ci->tkci_ntokens,
#if (_MIPS_SZPTR == 64)
ci->tkci_origcell
#else
0
#endif
);
for (i = 0; i < ci->tkci_ntokens; i++) {
tstate = ci->tkci_state[i];
p = __tk_sprintf(p, "\tclass %d:level %s hold %d state %s mrecall %s obtain %s\n",
i,
__tk_levtab[tstate.cl_extlev],
tstate.cl_hold,
__tkci_prstate(tstate),
__tk_levtab[tstate.cl_mrecall],
__tk_levtab[tstate.cl_obtain]);
}
OUTPUT buf);
#if TK_METER
if (ci->tkci_flags & TKC_METER) {
tk_meter_t *tm = tkc_meter(cs);
OUTPUT " meter @0x%p tag 0x%lx name \"%s\"\n",
tm, tm->tm_tag, tm->tm_name);
for (i = 0; i < ci->tkci_ntokens; i++) {
OUTPUT " Cl:%d acq %d cached %d conflict %d outbound %d\n",
i,
TKC_GET_METER(tm, i, acquire),
TKC_GET_METER(tm, i, acq_cached),
TKC_GET_METER(tm, i, acq_conflict),
TKC_GET_METER(tm, i, acq_outbound));
OUTPUT " recall %d return %d\n",
TKC_GET_METER(tm, i, recall),
TKC_GET_METER(tm, i, return));
}
}
#endif
}
static char *cstates[] = {
"BAD-0",
"IDLE",
"OWNED",
"CACHED",
"REVOKING",
"OBTAINING",
"ALREADY",
"WILLRETURN",
"RETURNING",
"WILLOBTAIN",
"BORROWED",
"BORROWING",
"REJECTED",
"BREVOKING",
"SREVOKING",
"SOBTAINING",
"COBTAINING",
"BOBTAINING",
"SWILLOBTAIN",
"CREVOKING",
"CRESTORE",
"SRESTORE",
"BRESTORE",
};
char *
__tkci_prstate(tkci_clstate_t s)
{
return (cstates[s.cl_state]);
}
static void
tkci_badstate(char *s, tkci_cstate_t *ci, int class)
{
tkci_clstate_t tstate;
tstate = ci->tkci_state[class];
__tk_fatal("%s - bad state %s for class %d - ci 0x%x\n",
s, __tkci_prstate(tstate), class, ci);
/* NOTREACHED */
}
/*
* tkci_obtainwait - wait until a token is obtained - there is already a
* client that has done the appropriate RPC
* The token object lock is held across until we sleep.
*/
/* ARGSUSED */
static void
tkci_obtainwait(tkci_cstate_t *ci, int class, int *l)
{
tk_list_t *tl;
TK_LOCKDECL;
TK_LOCK(obtainlock);
for (tl = obtainhead.tk_next; tl != &obtainhead; tl = tl->tk_next) {
if (tl->tk_tag1 == (void *)ci && tl->tk_tag2 == class)
break;
}
if (tl != &obtainhead) {
/* someone already waiting - queue up on that sema */
TK_ASSERT(tl->tk_nwait > 0);
tl->tk_nwait++;
TK_UNLOCK(obtainlock);
} else {
/* we can unlock the obtainlock across the malloc, etc
* since we are protected via the token object lock.
* this means that noone can attempt to wake us.
*/
TK_UNLOCK(obtainlock);
/* XXX don't malloc with lock held */
tl = TK_NODEMALLOC(sizeof(*tl));
tl->tk_tag1 = (void *)ci;
tl->tk_tag2 = class;
tl->tk_nwait = 1;
TK_CREATE_SYNC(tl->tk_wait);
/* link onto global class wait list */
TK_LOCK(obtainlock);
tl->tk_next = obtainhead.tk_next;
tl->tk_prev = &obtainhead;
obtainhead.tk_next->tk_prev = tl;
obtainhead.tk_next = tl;
TK_UNLOCK(obtainlock);
}
TK_UNLOCKVAR(ci->tkci_lock, *l);
/* wait */
TK_SYNC(tl->tk_wait);
TK_LOCK(obtainlock);
TK_ASSERT(tl->tk_nwait > 0);
if (--tl->tk_nwait == 0) {
TK_DESTROY_SYNC(tl->tk_wait);
TK_NODEFREE(tl);
}
TK_UNLOCK(obtainlock);
}
/*
* tkci_obtainwake - wake all threads waiting for an obtain
*/
static void
tkci_obtainwake(tkci_cstate_t *ci, int class)
{
int i;
tk_list_t *tl;
TK_LOCKDECL
TK_LOCK(obtainlock);
for (tl = obtainhead.tk_next; tl != &obtainhead; tl = tl->tk_next) {
if (tl->tk_tag1 == (void *)ci && tl->tk_tag2 == class)
break;
}
if (tl == &obtainhead) {
TK_UNLOCK(obtainlock);
return;
}
/* remove from list */
tl->tk_next->tk_prev = tl->tk_prev;
tl->tk_prev->tk_next = tl->tk_next;
TK_ASSERT(tl->tk_nwait > 0);
/* wake them all up */
for (i = 0; i < tl->tk_nwait; i++)
TK_WAKE(tl->tk_wait);
TK_UNLOCK(obtainlock);
}
#if TK_DEBUG
static int
tkci_nobtainwaiting(tkci_cstate_t *ci, int class)
{
int i;
tk_list_t *tl;
TK_LOCKDECL
TK_LOCK(obtainlock);
for (tl = obtainhead.tk_next; tl != &obtainhead; tl = tl->tk_next) {
if (tl->tk_tag1 == (void *)ci && tl->tk_tag2 == class)
break;
}
if (tl == &obtainhead) {
TK_UNLOCK(obtainlock);
return 0;
}
i = tl->tk_nwait;
TK_UNLOCK(obtainlock);
return i;
}
#endif
/*
* tkci_scwait - wait for status change
* The token object lock is held across until we sleep.
*/
/* ARGSUSED */
static void
tkci_scwait(tkci_cstate_t *ci, int class, int *l)
{
tk_list_t *tl;
TK_LOCKDECL
tkci_clstate_t *tstate;
tstate = &ci->tkci_state[class];
if (tstate->cl_scwait == 1) {
/* someone already waiting - queue up on that sema */
TK_LOCK(sclock);
for (tl = schead.tk_next; tl != &schead; tl = tl->tk_next) {
if (tl->tk_tag1 == (void *)ci && tl->tk_tag2 == class)
break;
}
TK_ASSERT(tl != &schead);
TK_ASSERT(tl->tk_nwait > 0);
tl->tk_nwait++;
TK_UNLOCK(sclock);
} else {
/* XXX don't malloc with lock held */
tl = TK_NODEMALLOC(sizeof(*tl));
tl->tk_tag1 = (void *)ci;
tl->tk_tag2 = class;
tl->tk_nwait = 1;
TK_CREATE_SYNC(tl->tk_wait);
/* link onto global status change wait list */
TK_LOCK(sclock);
tl->tk_next = schead.tk_next;
tl->tk_prev = &schead;
schead.tk_next->tk_prev = tl;
schead.tk_next = tl;
TK_UNLOCK(sclock);
tstate->cl_scwait = 1;
}
TK_UNLOCKVAR(ci->tkci_lock, *l);
/* wait */
TK_SYNC(tl->tk_wait);
TK_LOCK(sclock);
TK_ASSERT(tl->tk_nwait > 0);
if (--tl->tk_nwait == 0) {
TK_DESTROY_SYNC(tl->tk_wait);
TK_NODEFREE(tl);
}
TK_UNLOCK(sclock);
}
/*
* tkci_scwake - wake all threads waiting for a status change
* Note that token lock must be held across entire operation
*/
static void
tkci_scwake(tkci_cstate_t *ci, int class)
{
tk_list_t *tl;
int i;
TK_LOCKDECL;
TK_ASSERT(ci->tkci_state[class].cl_scwait);
TK_LOCK(sclock);
for (tl = schead.tk_next; tl != &schead; tl = tl->tk_next) {
if (tl->tk_tag1 == (void *)ci && tl->tk_tag2 == class)
break;
}
TK_ASSERT(tl != &schead);
/* remove from list */
tl->tk_next->tk_prev = tl->tk_prev;
tl->tk_prev->tk_next = tl->tk_next;
TK_ASSERT(tl->tk_nwait > 0);
/* wake them all up */
for (i = 0; i < tl->tk_nwait; i++)
TK_WAKE(tl->tk_wait);
TK_UNLOCK(sclock);
/* noone waiting */
ci->tkci_state[class].cl_scwait = 0;
}
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