1. A computer-implemented method, comprising: performing, by each of a plurality of crawlers, a random walk of a plurality of objects in a heap, wherein the plurality of objects are memory objects allocated for execution of an application, and wherein the plurality of objects form a tree; associating a probability with each directed edge of the tree; wherein a total probability of directed edges entering each object of the plurality of objects equals a total probability of directed edges exiting the object; wherein each object of one or more objects, from among the plurality of objects, comprises a loop edge both entering and exiting the object; wherein a transition matrix representing the tree is doubly stochastic; updating a timestamp of each object of the plurality of objects, when the object is visited by a crawler of the plurality of crawlers; identifying, by a computer processor, garbage based at least in part on the timestamp of each object of the plurality of objects; and reclaiming the garbage identified.