Storage space is reclaimed by cleaning and compacting data objects where data objects are stored by immutable storage. A storage area of which space needs to be reclaimed is identified. Active and stale data objects stored in a storage area are identified, and only active data objects are transferred to a shadow storage area from the storage area when recovering storage space. I/O operations can be fulfilled from the storage area and the shadow storage area. Compaction requests and I/O requests are throttled according to QOS parameters. Recovery of storage space does not cause a failure to meet performance requirements for any storage volume.

An apparatus, a method, and computer program product are provided that track build identifications of a project to determine when their associated files should be deallocated by a garbage collection system. The method includes receiving, by a continuous integration server, a payload from a source control management (SCM) system. The method also includes detecting at least one build identification (ID) within the payload and analyzing metadata contained within the payload to determine an adjustment to the reference counter for the build ID. The method further includes adjusting, based on the analysis, the reference counter relating to the build ID in a reference table, and passing the table to a garbage collection system for memory management purposes of the continuous integration server. The garbage collection system can then delete files associated with the build IDs that have reference counters at or below zero.

A method for extending data lifetime for reference in deduplication is provided. The method includes determining that a quantity of user data has at least a threshold amount of data that is re-created in a storage system. The method includes protecting at least portions of the quantity of user data from erasure by garbage collection in the storage system during a predetermined time interval, wherein the protected at least portions are available for data deduplication of further user data in the storage system during the predetermined time interval.

A request is received, from a mutator thread, to load a first reference to a first object from a heap memory onto a call stack of the application thread. Responsive to receiving the request, a system retrieves the first reference from the heap memory. The system executes a bitwise shift operation that (a) removes one or more bits representing the first garbage collection state and (b) generates a second reference from the first reference. Based on a particular bit, of the one or more bits removed from the first reference by the shift operation, the system determines whether to perform a set of garbage collection operations on the first reference to bring the first reference to a good state. The second reference, without any indication of any of the plurality of garbage collection states, is stored to the call stack.

A query for opaque objects stored within a data store and not currently cached within a cache is received from an application. The query to the data store is passed to the data store, and a handle to memory location is received from the data store at which the data store has temporarily stored a message including the opaque objects. The opaque objects are added to the cache by treating the memory location as a cache entry for the opaque objects. Cache metadata for the cache entry is generated, and along with the handle is stored within a metadata cache entry of a metadata cache structure separate from the message. The handle and the cache metadata can be returned to the application, where the cache metadata can be returned as an opaque context of the cache entry.

A system comprising a processor and a memory storing instructions that, when executed, cause the system to receive a request for garbage collection, identify a range of physical blocks in a storage device, query a bitmap, the bitmap having a bit for each physical block in the range of physical blocks, determine a status associated with a first bit from the bitmap, in response to determining the status associated with the first bit is a first state, add a first physical block associated with the first bit to a list of physical blocks for relocation, and relocate the list of physical blocks.

Systems and methods for managing concurrent access to a shared resource in a distributed computing environment are provided. A reference counter counts is incremented for every use of an object subtype in a session and decremented for every release of an object subtype in a session. A session counter is incremented upon the first instance of fetching an object type into a session cache and decremented upon having no instances of the object type in use in the session. When both the reference counter and the session counter are zero, the object type may be removed from the cache.

Methods and apparatus for merging tasks in a graphics pipeline in which, subsequent to a trigger to flush a tag buffer, one or more tasks from the flushed tag buffer are generated, each task comprising a reference to a program and plurality of fragments on which the program is to be executed, wherein a fragment is an element of a primitive at a sample position. It is then determined whether merging criteria are satisfied and if satisfied, one or more fragments from a next tag buffer flush are added to a last task of the one or more tasks generated from the flushed tag buffer.

A request is received, from a mutator thread, to load a first reference to a first object from a heap memory onto a call stack of the application thread. Responsive to receiving the request, a system retrieves the first reference from the heap memory. The system executes a bitwise shift operation that (a) removes one or more bits representing the first garbage collection state and (b) generates a second reference from the first reference. Based on a particular bit, of the one or more bits removed from the first reference by the shift operation, the system determines whether to perform a set of garbage collection operations on the first reference to bring the first reference to a good state. The second reference, without any indication of any of the plurality of garbage collection states, is stored to the call stack.

During execution of garbage collection marking, an application thread receives a first request to overwrite a reference field of an object, the object comprising at least a first reference and the first request comprising a second reference to be written to the reference field. Responsive to receiving the first request, the application thread determines a marking parity for objects being traversed by the garbage collection marking process and loads the first reference from the heap. The application thread determines that marking metadata of the first reference does not match the marking parity. Responsive to that determination, the application thread adds the first reference to a marking list, modifies the second reference to include the current marking parity as the marking metadata, and stores the modified second reference to the first reference field. In subsequent writes to the reference field, the application thread refrains from adding to the marking list.