1. A system for dynamically adjusting global heap allocation in multi-thread environment, comprising a data processor coupled to a storage device having program code embodied therein that includes: an identifying module configured to identify a global heap allocation method in an application program, wherein the global heap allocation method is a method used by the application program to allocate memory space from a global heap memory space shared by a plurality of threads in the multi-threaded environment; a judging module configured to judge whether the global heap allocation method is a multi-thread conflict hot point by monitoring multi-thread conflict parameters of the global heap allocation method in real time, wherein the multi-thread conflict parameters comprise one or more of the following parameters: (i) times of the global heap allocation method having been called in a unit time; (ii) an amount of the memory space requested by the global heap allocation method for allocation; (iii) times of lock contention of the global heap allocation method having occurred in a unit time; and (iv) lock wait time waiting for a lock; and an adjusting module configured to use a local stack in lieu of the global heap memory space to allocate the memory space requested by the global heap allocation method in response to a judging result that indicates that the global heap allocation method is the multi-thread conflict hot point.