Techniques For Deterministically Terminating A Phase Of Concurrent Operations

A method comprising:

• executing a concurrent marking phase of a garbage collection process, wherein at least one garbage collector thread is marking runtime objects in a set of runtime objects that are concurrently being manipulated by at least one program thread that is executing a program instance;
• generating, during the concurrent marking phase, a first data structure, the first data structure comprising a first set of reachability information corresponding to the set of runtime objects, the first set of reachability information indicating that a first runtime object is accessible through a first chain of one or more references originating from a root object, wherein each reference comprised within the first chain of one or more references is classified as a first reference type;
• generating, during the concurrent marking phase, a second data structure, the second data structure comprising a second set of reachability information corresponding to the set of runtime objects, the second set of reachability information indicating that a second runtime object is accessible through a second chain of one or more references originating from the root object, wherein (a) the second chain of one or more references comprises at least one reference comprised within a reference object and (b) the at least one reference is classified as a second reference type;
• wherein subsequent to the second data structure being generated:
• a program thread, while executing the program instance, resurrects the second runtime object by calling a method of the reference object;
• and
• subsequent to the concurrent marking phase:
• based, at least in part, on the second set of reachability information, updating the first set of reachability information to further reflect that the second runtime object is accessible through a third chain of one or more references, wherein each reference comprised within the third chain of one or more references is classified as the first reference type;
• wherein the method is performed by at least one device including a hardware processor.

A system comprising:

• at least one device including a hardware processor;
• the system being configured to perform operations comprising:
• executing a concurrent marking phase of a garbage collection process, wherein at least one garbage collector thread is marking runtime objects in a set of runtime objects that are concurrently being manipulated by at least one program thread that is executing a program instance;
• generating, during the concurrent marking phase, a first data structure, the first data structure comprising a first set of reachability information corresponding to the set of runtime objects, the first set of reachability information indicating that a first runtime object is accessible through a first chain of one or more references originating from a root object, wherein each reference comprised within the first chain of one or more references is classified as a first reference type;
• generating, during the concurrent marking phase, a second data structure, the second data structure comprising a second set of reachability information corresponding to the set of runtime objects, the second set of reachability information indicating that a second runtime object is accessible through a second chain of one or more references originating from the root object, wherein (a) the second chain of one or more references comprises at least one reference comprised within a reference object and (b) the at least one reference is classified as a second reference type;
• wherein subsequent to the second data structure being generated:
• a program thread, while executing the program instance, resurrects the second runtime object by calling a method of the reference object;
• and
• subsequent to the concurrent marking phase:
• based, at least in part, on the second set of reachability information, updating the first set of reachability information to further reflect that the second runtime object is accessible through a third chain of one or more references, wherein each reference comprised within the third chain of one or more references is classified as the first reference type.