+ Promise(ModelAction *act, uint64_t value, modelclock_t expiration) :
+ value(value), expiration(expiration), read(act), numthreads(1)
+ { }
+ modelclock_t get_expiration() const {return expiration;}
+ ModelAction * get_action() const { return read; }
+ int increment_threads() { return ++numthreads; }
+ uint64_t get_value() const { return value; }
+