REACT for IRIX®


Real Time Solution Components

Components of a real-time solution from SGI

We build support for deterministic real-time operation into the hardware and software of every SGI® multiprocessor system. On top of this basic functionality, you can add optional software products to create a highly efficient real-time development environment. Supported VME and PCI interfaces are available from the industry's leading suppliers to meet practically any hardware connectivity requirement. Together, these pieces make up the industry's best real-time solution!

  • IRIXTM with REACTTM - included in every version of IRIX, REACT enables you to configure any multiprocessor system for guaranteed real-time operation. Now fully conformant with POSIX 1003.1b and .1c.
  • REACTTM /pro - a collection of advanced software features useful in many real-time applications.
  • Development Tools - compilers, libraries, and tools that provide a highly productive development environment for all types of applications, plus tools that meet the specialized requirements of real-time developers.
  • I/O Subsystems

IRIX with REACT - Standard UNIX® with Deterministic Performance

REACT provides deterministic system behavior by allowing you to

  • Restrict UNIX® system overhead
  • Allocate processors
  • Direct interrupts to processors
  • Lock memory
  • Assign real-time process priorities
  • Control process scheduling

POSIX 1003.1b features offer both high performance and portability

  • Clocks and timers (hardware assisted)
  • Inter-process communication:
    • Semaphores
    • Real-time signals
    • Shared memory objects
    • Message queues
  • Real-time disk I/O:
    • Asynchronous
    • Synchronous
    • Memory-mapped files
  • Process memory locking
  • Execution scheduling
    • FIFO
    • Round-robin

Advanced hardware support boosts performance and simplifies integration

  • Memory-mapped I/O allows VME or PCI bus access without system calls
  • DMA engine speeds data transfer to/from slave-only VME devices
  • External interrupt input synchronizes user process execution with external events

REACT/pro - Advanced Real-Time Software

User-Level Interrupts (ULIs)

  • User-level code executes directly in response to an interrupt
  • Typical interrupt response time <20 microseconds
  • Avoids kernel-level driver development for non-dma devices

Frame Rate Scheduler (FRS)

  • Interrupt-driven scheduling of IRIX processes and sproc's
  • Choice of interrupt sources
  • Choice of scheduling behaviors
  • Choice of frame overrun behaviors
  • Lowest latency scheduling

Development Tools

  • ProDev WorkShopTM - Silicon Graphic's complete set of software development tools and libraries, with compilers for C, C++, Ada 95, and Fortran 77/90.

I/O Subsystems