| Patent application number | Description | Published |
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| 20090007077 | AUTOMATICALLY GENERATING TEST CASES FOR BINARY CODE - The present invention extends to methods, systems, and computer program products for automatically generating test cases for binary code. Embodiments of the present invention can automatically generate test inputs for systematically covering program execution paths within binary code. By monitoring program execution of the binary code on existing or random test cases, branch predicates on execution paths can be dynamically inferred. These inferred branch predicates can then be used to drive the program along previously unexplored execution paths, enabling the learning of further execution paths. Embodiments of the invention can be used in combination with other analysis and testing techniques to provide better test coverage and expose program errors. | 01-01-2009 |
| 20090178044 | FAIR STATELESS MODEL CHECKING - Techniques for providing a fair stateless model checker are disclosed. In some aspects, a schedule is generated to allocate resources for threads of a multi-thread program in lieu of having an operating system allocate resources for the threads. The generated schedule is both fair and exhaustive. In an embodiment, a priority graph may be implemented to reschedule a thread when a different thread is determined not to be making progress. A model checker may then implement one of the generated schedules in the program in order to determine if a bug or a livelock occurs during the particular execution of the program. An output by the model checker may facilitate identifying bugs and/or livelocks, or authenticate a program as operating correctly. | 07-09-2009 |
| 20090328045 | TECHNIQUE FOR FINDING RELAXED MEMORY MODEL VULNERABILITIES - A system and method capable of finding relaxed memory-model vulnerabilities in a computer program caused by running on a machine having a relaxed memory model. A relaxed memory model vulnerability in a computer program includes the presence of program executions that are not sequentially consistent. In one embodiment, non-sequentially consistent executions are detected by exploring sequentially consistent executions. | 12-31-2009 |
| 20100131931 | SAMPLING TECHNIQUES FOR DYNAMIC DATA-RACE DETECTION - This document describes a dynamic data race detector that utilizes adaptive sampling techniques. The adaptive sampling techniques include locating threads during execution of a multi-threaded program and identifying thread-specific hot paths, thread-specific cold paths and lockset paths during execution of the program. Once these paths are identified, they are sampled, potentially at different rates. Any information gained during the sampling may be stored in a data race log, which a developer may use to correct any identified program bugs | 05-27-2010 |
| 20100153928 | Developing and Maintaining High Performance Network Services - A network service runtime module executing on a processor is configured to accept a directed acyclic service graph representing elements of a network service application. During execution of the service graph, runtime events are stored. The service graph may by optimized by generating alternate service graphs, and simulating performance of the alternate service graphs in a simulator using the stored runtime events. A hill climber algorithm may be used in conjunction with the simulator to vary alternate service graphs and determine which alternate service graphs provide the greatest utility. Once determined, an alternate service graph with the greatest utility may be loaded into the network service runtime module for execution. | 06-17-2010 |
| Patent application number | Description | Published |
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| 20080271042 | TESTING MULTI-THREAD SOFTWARE USING PRIORITIZED CONTEXT SWITCH LIMITS - Testing multithreaded application programs for errors can be carried out in an efficient and productive manner at least in part by prioritizing thread schedules based on numbers of context switches between threads therein. In particular, each thread schedule in a multithreaded application program can be prioritized based on whether a given thread schedule has the same as or less than some maximum value. A model checker module can then iteratively execute thread schedules that fit within a given context switch maximum value, or a progressively higher value up to some limit. In one implementation, for example, the model checker module executes all thread schedules that have zero preempting context switches, then all thread schedules that have only one preempting context switch, etc. Most errors in an application program can be identified by executing only those thread schedule with relatively few preempting context switches. | 10-30-2008 |
| 20110131550 | Concurrency Software Testing with Probabilistic Bounds on Finding Bugs - Described is a probabilistic concurrency testing mechanism for testing a concurrent software program that provides a probabilistic guarantee of finding any concurrent software bug at or below a bug depth (that corresponds to a complexity level for finding the bug). A scheduler/algorithm inserts priority lowering points into the code and runs the highest priority thread based upon initially randomly distributed priorities. When that thread reaches a priority lowering point, its priority is lowered to a value associated (e.g., by random distribution) with that priority lowering point, whereby a different thread now has the currently highest priority. That thread is run until its priority is similarly lowered, and so on, whereby all schedules needed to find a concurrency bug are run. | 06-02-2011 |
| 20110258490 | Testing Components for Thread Safety - A checking system is described for determining whether a component is thread safe in the course of interacting with two or threads in a client environment. The checking system uses a manual, automatic, or semi-automatic technique to generate a test. The checking system then defines a set of coarse-grained observations for the test, in which the component is assumed to exhibit linearizability when interacting with threads. The set of coarse-grained observations may include both complete and “stuck” histories. The checking system then generates a set of fine-grained observations for the tests; here, the checking system makes no assumptions as to the linearizability of the component. The checking system identifies potential linearizability errors as those entries in the set of fine-grained observations that have no counterpart entries in the set of coarse-grained observations. The checking system may rely on a stateless model checking module to perform its functions. | 10-20-2011 |
