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This Undo release introduces a number of headline product improvements and updated system requirements.

Improvements in UDB

UDB 8.1 benefits from the improvements listed below.

Support for applications using the ARM Scalable Vector Extension (SVE)

The Scalable Vector Extension (SVE) is an optional extension to the ARMV.8.2-A architecture and newer. It is enabled in the Neoverse V1 microarchitecture which is used by the AWS Graviton3 processor.

In previous Undo releases, attempting to record an application using SVE would result in an “unsupported instruction” error. With the 8.1 release, no such error occurs and applications using SVE are fully supported in record and replay use cases.

As a result of this change, typical applications can be recorded and replayed by the Undo Suite on the Neoverse V1 architecture.

Improved integration with Visual Studio Code

When using release 8.1 in Visual Studio Code using Undo’s Time Travel Debug for C/C++ extension, two new panels are shown in the debug side bar which display static and global variables. Variables can be expanded individually and their child variables are then displayed.

In addition, the last command has a more intuitive user interface when used through Visual Studio Code. Upon reaching the change of value, a CodeLens indicator is inserted next to the source line showing Last, Next, and Done options, allowing you to quickly jump between changes. The last button in the Visual Studio Code user interface remains fully usable while this indicator is displayed.

CodeLens indicator for navigating between changes in a variable’s value

Finally, a number of bugs have been fixed in the Time Travel Debug for C/C++ extension – see the changelog for more information.

Improved handling of futex system calls

A number of bugs have been fixed in the Undo Engine’s handling of priority-inheritance futex system calls. These caused intermittent crashes during replay:

• if the program received a signal during a futex system call with the option FUTEX_UNLOCK_PI;
• if the program made a  futex system call with the option FUTEX_UNLOCK_PI on a futex word in shared memory.

More…

Further product changes relating to UDB are described in the CHANGELOG-udb.txt file included in your Undo release archive.

Improvements in Undo Team & OEM Editions

Undo Team & OEM Editions v8.1 benefit from the improvements in UDB described above, in addition to those listed below.

Automatic use of remote replay service to load incompatible recordings

In previous releases, Undo introduced a new recording replay service which can be deployed within your network to allow recordings to be replayed remotely, avoiding portability problems when recordings use CPU features that are unavailable on the local system.

In release 8.1, UDB now automatically uses a replay service, if one is configured, to load recordings using CPU instructions not supported by the local machine. For instance, this allows UDB to load recordings using the Intel AVX-512 instructions on machines with CPUs that don’t support such instructions.

Release 8.1 also improves the load time when using a replay service, in particular when symbols included in the recordings are large.

To deploy the replay service, please contact us at [email protected].