DirectResult
fusion_property_purchase (FusionProperty *property)
{
int count = 0;
D_ASSERT( property != NULL );
if (property->multi.builtin.destroyed)
return DR_DESTROYED;
D_ASSUME( property->multi.builtin.owner != direct_gettid() );
asm( "" ::: "memory" );
while (property->multi.builtin.state == FUSION_PROPERTY_LEASED) {
/* Check whether owner exited without releasing. */
if (kill( property->multi.builtin.owner, 0 ) < 0 && errno == ESRCH) {
property->multi.builtin.state = FUSION_PROPERTY_AVAILABLE;
property->multi.builtin.requested = false;
break;
}
property->multi.builtin.requested = true;
asm( "" ::: "memory" );
if (++count > 1000) {
usleep( 10000 );
count = 0;
}
else {
direct_sched_yield();
}
if (property->multi.builtin.destroyed)
return DR_DESTROYED;
}
if (property->multi.builtin.state == FUSION_PROPERTY_PURCHASED) {
/* Check whether owner exited without releasing. */
if (!(kill( property->multi.builtin.owner, 0 ) < 0 && errno == ESRCH))
return DR_BUSY;
}
property->multi.builtin.state = FUSION_PROPERTY_PURCHASED;
property->multi.builtin.owner = direct_gettid();
asm( "" ::: "memory" );
return DR_OK;
}
DirectResult
fusion_property_cede (FusionProperty *property)
{
D_ASSERT( property != NULL );
if (property->multi.builtin.destroyed)
return DR_DESTROYED;
D_ASSUME( property->multi.builtin.state != FUSION_PROPERTY_AVAILABLE );
D_ASSUME( property->multi.builtin.owner == direct_gettid() );
property->multi.builtin.state = FUSION_PROPERTY_AVAILABLE;
property->multi.builtin.owner = 0;
asm( "" ::: "memory" );
if (property->multi.builtin.requested) {
property->multi.builtin.requested = false;
asm( "" ::: "memory" );
direct_sched_yield();
}
DirectResult
fusion_skirmish_prevail( FusionSkirmish *skirmish )
{
D_ASSERT( skirmish != NULL );
if (skirmish->multi.builtin.destroyed)
return DR_DESTROYED;
asm( "" ::: "memory" );
if (skirmish->multi.builtin.locked &&
skirmish->multi.builtin.owner != direct_gettid())
{
int count = 0;
while (skirmish->multi.builtin.locked) {
/* Check whether owner exited without unlocking. */
if (kill( skirmish->multi.builtin.owner, 0 ) < 0 && errno == ESRCH) {
skirmish->multi.builtin.locked = 0;
skirmish->multi.builtin.requested = false;
break;
}
skirmish->multi.builtin.requested = true;
asm( "" ::: "memory" );
if (++count > 1000) {
usleep( 10000 );
count = 0;
}
else {
direct_sched_yield();
}
if (skirmish->multi.builtin.destroyed)
return DR_DESTROYED;
}
}