1. An apparatus, comprising: a lock to: enforce a first quota to control a number of threads allowed to concurrently speculatively execute after being placed in a queue; enable a first thread to speculatively execute to increase a number of threads that are concurrently speculatively executing; in response to the number of threads that are concurrently speculatively executing not satisfying the first quota dequeue the first thread from a head node of the queue; in response to the number of threads that are concurrently speculatively executing satisfying the first quota, maintain the first thread at the head node of the queue; and an adjuster to change a first value of the first quota based on a result of the speculative execution of the first thread, wherein at least one of the lock or the adjuster is implemented via a logic circuit.