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#include <u.h>
#include <libc.h>
/*
* The function pointers are supplied by the thread
* library during its initialization. If there is no thread
* library, there is no multithreading.
*/
int (*_lock)(Lock*, int, ulong);
void (*_unlock)(Lock*, ulong);
int (*_qlock)(QLock*, int, ulong); /* do not use */
void (*_qunlock)(QLock*, ulong);
void (*_rsleep)(Rendez*, ulong); /* do not use */
int (*_rwakeup)(Rendez*, int, ulong);
int (*_rlock)(RWLock*, int, ulong); /* do not use */
int (*_wlock)(RWLock*, int, ulong);
void (*_runlock)(RWLock*, ulong);
void (*_wunlock)(RWLock*, ulong);
void
lock(Lock *l)
{
if(_lock)
(*_lock)(l, 1, getcallerpc(&l));
else
l->held = 1;
}
int
canlock(Lock *l)
{
if(_lock)
return (*_lock)(l, 0, getcallerpc(&l));
else{
if(l->held)
return 0;
l->held = 1;
return 1;
}
}
void
unlock(Lock *l)
{
if(_unlock)
(*_unlock)(l, getcallerpc(&l));
else
l->held = 0;
}
void
qlock(QLock *l)
{
if(_qlock)
(*_qlock)(l, 1, getcallerpc(&l));
else
l->l.held = 1;
}
int
canqlock(QLock *l)
{
if(_qlock)
return (*_qlock)(l, 0, getcallerpc(&l));
else{
if(l->l.held)
return 0;
l->l.held = 1;
return 1;
}
}
void
qunlock(QLock *l)
{
if(_qunlock)
(*_qunlock)(l, getcallerpc(&l));
else
l->l.held = 0;
}
void
rlock(RWLock *l)
{
if(_rlock)
(*_rlock)(l, 1, getcallerpc(&l));
else
l->readers++;
}
int
canrlock(RWLock *l)
{
if(_rlock)
return (*_rlock)(l, 0, getcallerpc(&l));
else{
if(l->writer)
return 0;
l->readers++;
return 1;
}
}
void
runlock(RWLock *l)
{
if(_runlock)
(*_runlock)(l, getcallerpc(&l));
else
l->readers--;
}
void
wlock(RWLock *l)
{
if(_wlock)
(*_wlock)(l, 1, getcallerpc(&l));
else
l->writer = (void*)1;
}
int
canwlock(RWLock *l)
{
if(_wlock)
return (*_wlock)(l, 0, getcallerpc(&l));
else{
if(l->writer || l->readers)
return 0;
l->writer = (void*)1;
return 1;
}
}
void
wunlock(RWLock *l)
{
if(_wunlock)
(*_wunlock)(l, getcallerpc(&l));
else
l->writer = nil;
}
void
rsleep(Rendez *r)
{
if(_rsleep)
(*_rsleep)(r, getcallerpc(&r));
}
int
rwakeup(Rendez *r)
{
if(_rwakeup)
return (*_rwakeup)(r, 0, getcallerpc(&r));
return 0;
}
int
rwakeupall(Rendez *r)
{
if(_rwakeup)
return (*_rwakeup)(r, 1, getcallerpc(&r));
return 0;
}
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