Microsoft Technology Licensing, LLC

Eric H Feiveson

Jackson Michael Davis

Gregg Bernard Miskelly

Patrick Nelson

Jonathon Michael Stall

Gregory Bernard Miskelly

Mikhail V Leonov

Richard Byers

Azeemullah Khan

Lucian Wischik

Systems, methods and computer program products are described that enable a diagnostic tool, such as a debugger, to evaluate an expression based on the state of a target program process where the expression to be evaluated includes a call to a first function that exists in the target program process but where evaluation of such first function requires evaluation of a second function that does not exist in the target program process. For an expression such as this, the diagnostic tool emulates execution of the first function within a process other than the target program process, such as within the diagnostic tool process. In other embodiments, the emulation capability of the diagnostic tool is leveraged to enable a user thereof to simulate a modification of the target program process without making actual changes to the target program process.

Emulation-based expression evaluation for diagnostic tools

Embodiments provide call stacks for asynchronous programming. A set of all asynchronous call stacks is found by first identifying all threads and all outstanding tasks that have not yet been completed. Optionally, all outstanding continuation-delegates or lambdas that are in the windows queue waiting to be scheduled and/or all outstanding delegates or lambdas in a language-specific queue are also identified. Next, for each thread, identify whether it was invoked by a continuation-callback and, if so, find the corresponding task/promise. Next, given a task/promise, identify the logical parent task/promise. Optionally, given a delegate or lambda, identify its logical parent task/promise. The sequence of logical tasks/promises constitutes an asynchronous call stack in a program. Further information may optionally be retrieved to make the asynchronous call stack more useful. Finally, given a task/promise, identify the corresponding line number and location in source code.

Call stacks for asynchronous programs

An expression can be evaluated in a remote debugging environment with one single round trip across the network. An expression evaluator on a local machine can compile the expression into a language-independent intermediate language (IL) that encodes all the information needed to evaluate the expression in the absence of a symbol table. The IL can include instructions that manipulate state inside the debuggee process, as well as logical operations needed to process the information. The IL language can be turing complete so that any computation needed to determine the state to read and write and how the information gathered is to be combined can be performed. The IL can be sent to the remote computer and can be interpreted on the remote computer. The IL can be interpreted on the remote computer using a stack based mechanism, without the need to access symbolic information on the local computer.

Reducing network trips for remote expression evaluation

Instruction sets in computing environments may execute within one of several domains, such as a natively executing domain, an interpretively executing domain, and a debugging executing domain. These domains may store values in a shared region of memory in different ways. It may be difficult to perform operations on such values, particularly if a domain that generated a particular value cannot be identified or no longer exist, which may obstruct shared accessing of values and evaluative tasks such as stack walks. Instead, accessors may be associated with a stored value that perform various operations (such as low-level assembly instructions like Load, Store, and Compare) according to the standards of the value-generating domain, and domains may be configured to operate on the value through the accessors. This configuration may promote consistent accessing of values without having to identify or consult the value-generating domain or reconfiguring the instruction sets.

Stored value accessors in shared memory regions

A computer system that is configured to conduct communications between a client process and a server process is disclosed. To conduct such communications, an inter-process communication thread is initiated that is separate from a main client inter-process communication thread and operates to establish a connection with a server. A client communication port is created during the establishment of the connection with the server. One or more non-blocking asynchronous communications are transmitted to a server communication port. Responses to the one or more non-blocking asynchronous communications are awaited for receipt by the client communication port.

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Eric H Feiveson