Synchronizing object promotion in a multi-tasking virtual machine with generational garbage collection

A system, comprising:

• a processor;
• a memory;
• a plurality of concurrently executing tasks executing on the processor, wherein each of the plurality of concurrently executing tasks is associated with a private young generation memory;
• a virtual machine configured to execute the plurality of concurrently executing tasks on the processor;
• and
• an automatic memory management system (AMMS) operatively connected to the virtual machine and configured to:
• manage the memory;
• suspend a first task of a plurality of concurrently executing tasks;
• promote at least one object associated with the first task to an old generation located in the memory using a gap buffer to obtain a promoted object, wherein the gap buffer stores a gap inserted by objects directly allocated by at least one of the plurality of concurrently executing tasks, and wherein directly allocated objects are objects that are allocated to the old generation upon creation and without surviving a garbage collection;
• locate the promoted object using the gap buffer;
• traverse the promoted object to determine whether a first referenced object exists;
• promote the first referenced object using the gap buffer, if the first referenced object exists;
• initialize the gap buffer, wherein the gap buffer comprises a pointer to a lower bound and a pointer to an upper bound of the gap;
• and
• initialize a value of an upper bound of a last promoted object, wherein the upper bound of the last promoted object references a memory address associated with the completion of a promotion in the old generation,
• wherein a current object pointer references the promoted object in the old generation,
• wherein a gap buffer pointer references a current gap in the gap buffer, and
• wherein locating the promoted object comprises:
• comparing the current object pointer to a lower bound of the current gap;
• and
• passing over the current gap created by concurrently executing tasks, wherein the current gap is created when one of the concurrently executing tasks directly allocates an object to the old generation, if the current object pointer is equal to the lower bound of the current gap, wherein passing over the current gap comprises updating the current object pointer to reference an upper bound of the current gap.