Streamline your patent due diligence with deep analytics for patents, inventors, and attorneys

Compare patents by technology sector

Deep Analytics

Quickly evaluate patents of interest

► Want to see more? Join for free!

PatentQuant Patent Profile
Generated January 22, 2018

Computer system with heap and card table

Patent Number: 6,845,437

Patent Information

A computer system has a heap for storing objects and a card table for tracking updates to objects on the heap, typically for garbage collection purposes. In particular, the heap is divided into segments, each corresponding to a card in the card table, and any update to a segment in the heap triggers a write barrier to mark the corresponding card in the card table. It is important that this write barrier is as efficient as possible to optimize system performance. In some circumstances an object update may be made to an address outside the heap. To ensure that this still properly maps to a card in the card table, the entire memory space is folded cyclically, so that any given memory address corresponds to one, and only one card, in the card table.
Patent Number: 6,845,437
Issue Date: 2005-01-18

Primary Category

Executive Summary


This patent was granted in ► Log In, which is ► Log In speed.

It has ► Log In claims, which is ► Log In than average for this category.

Its proximity to basic research is ► Log In than others in this category, and it displays ► Log In technology cycle time.

This patent received ► Log In citations from other patents, and references ► Log In other patents, as compared to other patents in this category.

Grant Time

► Log In


► Log In

► Want to see more? Join for free!

PatentStat Scores in Not categorized
These scores show the percentile ranks for each metric.
For example, a score of 90 means that 90% of similar patents had lower scores.

Patent Grant Time

This patent had ► Log In grant time compared to others in this category.

Patent grant time can be influenced by many factors. Activities within the USPTO that are beyond the control of patent attornies can influence grant time, but short grant times can also indicate well-written patents and dedicated efforts to respond rapidly to USPTO office actions with strong arguments. Shorter grant times are preferable, and the scores for this section are inverse measures — higher scores are better.

Patent Claims

This patent has ► Log In claims compared to others in this category.

The number of claims in a patent is correlated with its strength. Because greater claim counts increase the cost of a patent, more claims can indicate the importance an applicant assigns to a patent. Importantly, some may elect to file claims across multiple patents. A higher score in this metric indicates more claims, relative to others in this category.

Citations From Other Patents

This patent has received ► Log In citations from other patents, than others in this category.

Citations from other patents are an important measure of the significance of a patent. More citations indicate that other technologies build on a patent. Higher scores in this metric are better, and indicate more citations from other patents.

Citations to Other Patents

This patent referenced ► Log In citations to other patents, than others in this category.

A lower number of citations to other patents can be a sign of diminished patent strength. More citations indicate dependence on more other technologies. Higher scores in this category are better, and indicate fewer citations to other patents.

Research and Innovation Indicators
These are percentile ranks — they indicate the percentage of peers with lower scores.

Proximity to Basic Research

► Log In


Proximity to Basic Research

This patent has ► Log In proximity to basic research compared to others in this category.

Proximity to basic research is measured by comparing the number of citations to non-patent literature among a cohort of patents. Because most non-patent citations are primary research papers, a higher count indicates greater proximity to basic research.

► Want to see more? Join for free!


Patents cited by this patent

Patent Title
6,249,793 Mostly concurrent compaction in a garbage collection system
6,173,294 Method for combining card marking with remembered set for generational garbage collection with more than two generations
6,098,089 Generation isolation system and method for garbage collection
5,953,736 Write barrier system and method including pointer-specific instruction variant replacement mechanism
5,845,298 Write barrier system and method for trapping garbage collection page boundary crossing pointer stores

Patents that cite this patent

Patent Title
8,412,971 Method and apparatus for cache control
8,255,922 Mechanism for enabling multiple processes to share physical memory
8,131,955 Ephemeral garbage collection using a tracking mechanism on a card table to determine marked bundles
7,882,505 Method and apparatus for switching between per-thread and per-processor resource pools in multi-threaded programs
7,650,350 Method and apparatus for concurrently processing remembered sets in a space-incremental garbage collector
7,565,499 Method and apparatus for recording modified reference locations in garbage-collected heap memory
7,412,580 Concurrent incremental garbage collector with a card table summarizing modified reference locations
7,313,566 Method and apparatus for isolating selected heap objects using a faulting address trap
7,284,108 Systems and methods for multiprocessor scalable write barrier
7,272,695 Hot-card caching to avoid excessive remembered-set updating
7,225,439 Combining write-barriers within an inner loop with fixed step
7,058,670 Scalable, space-efficient, parallel remembered-sets
7,039,664 Combining entries in a card object table
6,965,905 Lock-free, parallel remembered sets
6,928,460 Method and apparatus for performing generational garbage collection in a segmented heap

► Want to see more? Join for free!

Information presented on this site is collected from the USPTO and other sources. Errors may have been introduced in the original assembly or analysis of the data.
No warranties are expressed or implied.The content of this site is not a substitute for skilled legal, financial, or other guidance.
Copyright thinkBiotech LLC. All rights reserved.
Privacy policy.