Welcome
What's New
View new features for FlowTracer 2025.1.0.
FlowTracer Overview
An advanced mission critical dependency management platform for developing and executing flows.
FlowTracer Tutorials
Discover FlowTracer functionality with interactive tutorials.
Altair FlowTracer User Guide
FlowTracer is a complete system to create, manage, and execute design flows.
Altair FlowTracer Administrator Guide
This manual is aimed at the person who will be the administrator for FlowTracer. This person will be responsible for configuring the network resources, setting up the licensing, and establishing security and access rules for the system.
Altair FlowTracer Developer Guide
- FlowTracer Roles
  When using FlowTracer in large deployments, three main roles emerge: Administrator, Developer and User. In smaller organizations, a given person may have multiple roles, but the duties of each role still exist.
- Environment Management
  To ensure the correct and repeatable behavior of the tools, the environment must be controlled. This chapter explains how VOV supports multiple reusable environments.
- Execute Jobs From the Command Line
- Flowbuilding
  The trace is built using a combination of techniques.
- Flow Description Language (FDL)
- Tool Integration
  - Wrappers
  - Track the Origins of Dependencies
  - Integration by Interception
  - Library-based Interception
  - Integration by Instrumentation
  - VOV Instrumentation Library (VIL)
  - Instrumentation Procedure
  - VILtools
  - Integration by Encapsulation
  - Encapsulation Procedures
    In an encapsulation script, you can use the following Tcl procedures:
  - Capsule Post-Processing
  - Capsule On-the-Fly
  - Capsules for VHDL and Verilog Tools
- Integrate Difficult Tools
- Runtime Change Propagation Control
  The patented technique of Runtime Change Propagation Control (RCPC) provides the ability to stop the propagation of insignificant changes through the flow.
- Flow Library
  FlowTracer captures your design in design flows described by Flow.tcl files. The Flow Library is meant to help users locate and deploy instances of packaged flows bound to their specific design data.
- Files, Equivalences, Exclusions
  The files used in a project reside in one or more directories spread all around your filesystems. Each logical name defined in the equiv.tcl file implicitly declares the root of a workspace. You can browse the workspaces using the browser interface.
- Makefile Conversion
- Advanced Tasker Topics
- Resource Management
  The Resource Map Set represents the collection of resource maps that have been assigned to a project and the constraints associated with such resources.
- CGI Interface
- Events
  Every change in the trace is recorded as an event, which is then sent to all clients that subscribe to them.
- Miscellaneous

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Integration by Interception

This section discusses the integration technique called interception, which captures the most complete IO behavior of your programs. This gives the most correct dependency graph for the flow, but in some cases this may be more detail than is wanted.

By interception, we mean that FlowTracer interposes a thin layer between your tool or program and the operating system itself, so that whenever the tool uses a file, that IO behavior is reported to FlowTracer.

There are two kinds of interception available, library-based interception and OS-based interception.

Library-based Interception

Most modern operating systems support the concept of dynamic-link libraries. Programs using dynamic-link libraries do not contain all the code necessary to execute, but have external references which are satisfied by the dynamic linker at the time the program is launched. There are many benefits to dynamically-linked programs, including smaller executable sizes, reduced memory consumption due to shared code, and easier maintenance.

When using library-based interception, FlowTracer installs its IO library before the system standard IO library. The FlowTracer library picks off the names and opening modes of the files your tool uses, then passes the call on to the regular system library. This way, your program does not need to be relinked or otherwise modified, and it behaves the same as when not using FlowTracer. More platform-specific information about library-based interception is available. Library-based interception is activated by using the FlowTracer vrt wrapper program in front of tool command lines.