Class: fcf::NTest::Duration
Package: fcfTest
File: test.hpp
Available from version: 1.1.7
Calculates the average duration of a single iteration within the last active execution segment.
The lastDuration method provides the average time taken by a single iteration during the most recent execution segment. A segment is defined as the interval between the last resume (or begin) and the last end call.
The calculation is performed as: lastTotalDuration() / iterationCount(). This is particularly useful when benchmarking code that runs in a loop, as it allows you to isolate the performance of a specific batch of iterations from the total accumulated time.
Result
std::chrono::nanoseconds
- The average duration of one iteration within the last segment in nanoseconds.
Example: Average iteration time in a specific segment
Demonstrating how to use lastDuration to find the average time per iteration for a specific batch of work, excluding previous segments.
#define FCF_TEST_IMPLEMENTATION
#include <fcfTest/test.hpp>
#include <iostream>
FCF_TEST_DECLARE("Benchmark", "Average", "LastDurationTest") {
// Create a duration object for 1000 iterations
fcf::NTest::Duration bench(1000);
// 1. First segment: Warm-up (not measured for average)
bench.begin();
for(int i = 0; i < 1000; ++i) { /* warm-up work */ }
bench.end();
// 2. Second segment: Actual measurement
bench.resume();
for(volatile int i = 0; i < 1000; ++i) {
// Perform actual work
volatile int a = i * 2;
volatile int b = i + 5;
volatile int c = a + b;
FCF_TEST(c == (i * 2 + i + 5));
}
bench.end();
// Retrieve the average duration of a single iteration in the LAST segment
std::chrono::nanoseconds avgLast = bench.lastDuration();
fcf::NTest::log() << "Average time per iteration in last segment: " << avgLast.count() << " ns" << std::endl;
FCF_TEST(avgLast.count() > 0, avgLast.count());
}
int main(int a_argc, char* a_argv[]) {
bool error = false;
fcf::NTest::cmdRun(a_argc, a_argv, fcf::NTest::CRM_RUN, &error);
return error ? 1 : 0;
}
Output:
Performing the test: "Benchmark" -> "Average" -> "LastDurationTest" ...
> Average time per iteration in last segment: 8 ns
[SUCCESS] Test completed successfully (0.000`025`810 sec)
[SUCCESS] All tests were completed.
Tests: 1 passed, 0 failed, 0 skipped, 1 total
Duration: 0.000`025`810 sec
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