---

When working on performance-sensitive code in Unreal Engine whether it’s in AI, procedural generation, or heavy background processing, you often need to respect a strict time budget per frame.

Traditionally, you might have handled this by manually capturing the start time, calculating the end time, and checking if you’re still within your budget:

const double StartTime = FPlatformTime::Seconds();
const double EndTime = StartTime + BudgetSeconds;

if (FPlatformTime::Seconds() < EndTime)
{
    // Still within the budget
}

While this works, it’s a bit verbose and easy to get wrong. Fortunately, Unreal Engine offers a more convenient approach: FTimeout.

---

Introducing FTimeout

FTimeout is a small utility that encapsulates a timeout duration and makes it easy to:

• Track how much time has elapsed.
• Check whether the timeout has expired.
• Avoid manual StartTime/EndTime calculations.

To use it, include the header:

#include "Misc/Timeout.h"

You can create a timeout with a duration specified as an FTimespan:

UE::FTimeout Timeout(FTimespan::FromSeconds(TimeoutInSeconds));

---

Measuring Elapsed Time

Once the timeout is created, you can check how long it has been running:

const double ElapsedMs = Timeout.GetElapsedTime().GetTotalMilliseconds();

This can be useful for debugging or for adaptive algorithms that adjust based on how much time is left.

---

Checking Expiration

Instead of manually comparing timestamps, FTimeout provides a straightforward method:

if (Timeout.IsExpired())
{
    // Time budget exceeded
}
else
{
    // Still within the time limit
}

---

Why Use FTimeout?

• Cleaner code – No need to manually store and compare timestamps.
• Less error-prone – Avoids common mistakes with unit conversions or wrong variable naming.
• More expressive – Your code reads closer to intent: “check if timeout expired” instead of “compare two doubles.”

---

Example in Context

UE::FTimeout Timeout(FTimespan::FromSeconds(0.001)); // 1 ms budget

while (!Timeout.IsExpired())
{
    // Perform work until time runs out
}

This makes it crystal clear that the loop will only run for 1 millisecond, without juggling StartTime and EndTime variables.