Abstract: A method is provided for generating a test case for testing a program, which can include analyzing instructions of the program to identify basic blocks and superblocks, each basic block containing at least one executable instruction, and each superblock containing a plurality of basic blocks. The method can include executing instructions by a processor to perform determining respective weights of superblocks, each weight representing a number of basic blocks which require execution when the superblock is executed; determining the constraints which cause a superblock having a high weight to be executed, and using the determined constraints to generate a test case which, upon execution of the program, causes the high weight superblock to be executed.

Abstract: A staggered execution environment is provided to safely execute an application program against software failures. In an embodiment, the staggered execution environment includes one or more probe virtual machines that execute various portions of an application program and an execution virtual machine that executes the same application program within a time delay behind the probe virtual machines. A virtualization supervisor coordinates the execution of the application program on one or more probe virtual machines. The probe virtual machines are used to detect and correct software failures prior to the execution virtual machine encountering them. The virtualization supervisor embargos output data in order to ensure that erroneous data is not released which may adversely affect external processes.

Abstract: A staggered execution environment is provided to safely execute an application program against software failures. In an embodiment, the staggered execution environment includes one or more probe virtual machines that execute various portions of an application program and an execution virtual machine that executes the same application program within a time delay behind the probe virtual machines. A virtualization supervisor coordinates the execution of the application program on one or more probe virtual machines. The probe virtual machines are used to detect and correct software failures prior to the execution virtual machine encountering them. The virtualization supervisor embargos output data in order to ensure that erroneous data is not released which may adversely affect external processes.

Abstract: A staggered execution environment is provided to safely execute an application program against software failures. In an embodiment, the staggered execution environment includes one or more probe virtual machines that execute various portions of an application program and an execution virtual machine that executes the same application program within a time delay behind the probe virtual machines. A virtualization supervisor coordinates the execution of the application program on one or more probe virtual machines. The probe virtual machines are used to detect and correct software failures prior to the execution virtual machine encountering them. The virtualization supervisor embargos output data in order to ensure that erroneous data is not released which may adversely affect external processes.

Abstract: A staggered execution environment is provided to safely execute an application program against software failures. In an embodiment, the staggered execution environment includes one or more probe virtual machines that execute various portions of an application program and an execution virtual machine that executes the same application program within a time delay behind the probe virtual machines. A virtualization supervisor coordinates the execution of the application program on one or more probe virtual machines. The probe virtual machines are used to detect and correct software failures prior to the execution virtual machine encountering them. The virtualization supervisor embargos output data in order to ensure that erroneous data is not released which may adversely affect external processes.

Abstract: A method is provided for generating a test case for testing a program, which can include analyzing instructions of the program to identify basic blocks and superblocks, each basic block containing at least one executable instruction, and each superblock containing a plurality of basic blocks. The method can include executing instructions by a processor to perform determining respective weights of superblocks, each weight representing a number of basic blocks which require execution when the superblock is executed; determining the constraints which cause a superblock having a high weight to be executed, and using the determined constraints to generate a test case which, upon execution of the program, causes the high weight superblock to be executed.