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Randomize

procedure Randomize;

Example​

procedure ScriptEvent(var Value: variant);
begin
  Randomize;
  Value := Random;
end;

Usage​

Randomize reseeds Velox's shared pseudo-random generator from current Windows timing. The new state affects subsequent Random and RandomInt calls throughout the same Designer, Service or API Service process.

Additional Technical Info​

vxCommonNumber.Randomize now calls System.Randomize directly. It no longer assigns GetTickCount to RandSeed first, removing the range-check failure that could occur during the upper half of the 32-bit tick-count cycle.

Call it only when that shared reseed is intended. Repeated row/event calls can degrade predictability and couple otherwise unrelated flows. The example is fictional and source-reviewed only.

Implementation

  1. vxCommonNumber.Randomize calls System.Randomize.
  2. On Windows, System.Randomize obtains a high-resolution QueryPerformanceCounter value and falls back to GetTickCount if necessary.
  3. It combines one generated value with that counter.
  4. DefaultRandomize XORs the high and low 32-bit halves and replaces RandSeed.

State and concurrency

  • The mutation is process-global and unprotected. Concurrent random calls/reseeds can interleave.
  • Calling from one action changes sequences observed by all other actions in the same Designer/Service/API Service process.
  • There is no per-flow generator instance, lock, audit record or previous-seed return.
  • The Windows fallback tick count wraps approximately every 49.7 days, but the normal high-resolution counter and generated-state mix add other variation.
  • Timing-based seeding does not make the underlying 32-bit linear-congruential generator cryptographically secure.

Errors and platform assumptions

The reviewed product uses the Windows implementation. Performance-counter failure is handled by System.Randomize using its tick-count fallback. Velox does not catch or separately log this call.

Related entries

  • Random consumes the shared state.
  • RandomInt consumes the same state with biased rounding.
  • RandomizeSeed directly sets a repeatable signed 32-bit seed, subject to shared-state interference.

External references

Created 2026-07-15