摘要:
A method, apparatus and computer program product for providing page-protection based memory access barrier traps is presented. A value for a user-mode bit (u-bit) is computed for each extant virtual page in an address space, the u-bit indicative that an object on the virtual page is being moved by a Garbage Collector process. An instruction is executed which causes an access protection fault. The state of the u-bit for the virtual page associated with the access protection fault is consulted when the access protection fault is encountered. Additionally, the access protection fault is translated into a user-trap (utrap) and the utrap is serviced when the u-bit is set.
摘要:
A method for queuing update buffers to enhance garbage collection. The method includes running an application thread and providing, for the application thread, a data structure including current and finished update buffer slots. The method includes providing an update buffer for the application thread and storing a pointer to the update buffer in the current update buffer slot. The method includes storing null in the finished update buffer slot and, with the application thread, writing to the update buffer. The thread may write a pointer to the filled update buffer in the finished update buffer slot after the buffer is filled. The method includes using a garbage collector thread to inspect the finished update buffer slot and claim filled buffers and change the pointer to null. The thread then obtains an empty update buffer and updates the current update buffer slot to point to the new buffer.
摘要:
A technique for establishing a dense prefix for a memory in a computer system. Memory is divided into a plurality of chunks. An efficiency factor is generated for each chunk in one or more chunks contained in the plurality of chunks. The efficiency factor may be based on an amount of memory to be reclaimed, an amount of memory to be scanned and an amount of memory to be copied relative to the chunk. A dense prefix is then established for the memory based on an efficiency factor associated with a chunk.
摘要:
In a generational, copying garbage collector, young generation collection may be made more efficient by dynamically measuring object survival rates as a function of “fine-grained” allocation age, and choosing, on the basis of these survival rates, part of the young generation that will be not be collected, but instead scanned for pointers to objects in the rest of the young generation. The rest of the young generation, including objects referenced by the pointers, is then collected.
摘要:
A system and method for asynchronously graying and blackening objects in the marking phase of parallel garbage collection. The system and method use a matrix to control a series of linked list of work to be grayed and blackened. The threads of the garbage collector are each assigned entries within the matrix upon which they may either gray an entry in the linked list or blacken and entry on the linked list. Further restrictions upon the use of the matrix allow non-garbage collection thread to asynchronously or synchronously add objects to be processed by the garbage collector.
摘要:
The invention relates to a method for performing generational garbage collection on a heap comprising a plurality of generations. The method involves dividing a young generation of the heap into a first young generation and a second young generation, evacuating the first young generation concurrently with allocating the second young generation, and evacuating the second young generation concurrently with allocating the first young generation and subsequent to fully evacuating the first young generation.
摘要:
A garbage collector keeps a log of recent system usage. From that usage thus recorded, it determines whether a time slice whose duration a maximum-mutator-utilization (“MMU”) specification prescribes and whose end time is the same as a prospective future collection pause will contain more than the maximum imposed by the MMU specification on the time slice's garbage collector time. The collector uses that determination to arrive at a compliant length for a pause that is to start at a predetermined time or to find a time at which a pause of a predetermined length can start without violating the MMU specification.
摘要:
In a generational, copying garbage collector, young generation collection may be made more efficient by dynamically measuring object survival rates as a function of “fine-grained” allocation age, and choosing, on the basis of these survival rates, part of the young generation that will be not be collected, but instead scanned for pointers to objects in the rest of the young generation. The rest of the young generation, including objects referenced by the pointers, is then collected.