Microsoft Technology Licensing, LLC

Dinghao Wu

Shaz Qadeer

Henning Korsholm Rohde

Yue Yang

Anna Gringauze

Mechanisms for analyzing computer instructions implementing a program in which typestate analysis is informed by concurrency analysis. The concurrency-guided typestate analysis may simulate the 'worst case' scenario due to thread interleaving by transitioning a simulated state of the variable to a special state whenever the variable is not guarded by its intended guarding lock. While in the special state, the analysis may assume that the state of the simulated variable is the worst possible state with respect to processing operations that may lead to an error depending on the state of the variable. Thus, the analysis performed may assume that referencing the variable in a state-dependent operation while the simulated state of the variable is in the special state may lead to an error, and the analysis may generate a warning, accordingly. The analysis may process the computer instructions to infer which lock is intended to guard a shared variable.

Detecting data race and atomicity violation via typestate-guided static analysis

A concurrent program is analyzed for the presence of data races by the creation of a sequential program from the concurrent program. The sequential program contains assertions which can be verified by a sequential program analysis tool, and which, when violated, indicate the presence of a data race. The sequential program emulates multiple executions of the concurrent program by nondeterministically scheduling asynchronous threads of the concurrent program on a single runtime stack and nondeterministically removing the currently-executing thread from the stack before instructions of the program. Checking functions are used to provide assertions for data races, along with a global access variable, which indicates if a variable being analyzed for data races is currently being accessed by any threads.

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Dinghao Wu