function::cpu_clock_us - Linux

Overview

The function::cpu_clock_us command provides a high-resolution timestamp in microseconds since the last system boot. This timestamp is typically used for benchmarking, profiling, and synchronizing events across different processes.

Syntax

function::cpu_clock_us()

Options/Flags

There are no options or flags available for this command.

Examples

Example 1: Measuring Execution Time

start_time=$(function::cpu_clock_us)
# Execute the code to be timed
end_time=$(function::cpu_clock_us)

elapsed_time=$((end_time - start_time))

echo "Elapsed time: ${elapsed_time} microseconds"

Example 2: Synchronizing Events

# Process 1
timestamp=$(function::cpu_clock_us)

# Share the timestamp with Process 2 using inter-process communication

# Process 2
received_timestamp=$(function::cpu_clock_us)

# Calculate the time elapsed since Process 1 sent the timestamp
elapsed_time=$((received_timestamp - timestamp))

echo "Time elapsed since event in Process 1: ${elapsed_time} microseconds"

Common Issues

Incorrect Timestamp

If the system clock has been adjusted (e.g., by NTP), the timestamp may not be accurate. To ensure an accurate timestamp, use function::cpu_clock_ns instead, which provides a timestamp in nanoseconds and is not affected by clock adjustments.

Integration

function::cpu_clock_us can be integrated into various scenarios:

• Profiling: Measuring the execution time of code segments for performance analysis.
• Benchmarking: Comparing the performance of different implementations or systems.
• Synchronization: Coordinating events across multiple processes or threads.

Related Commands

• function::cpu_clock_ns: Provides a high-resolution timestamp in nanoseconds.
• time: Executes a command and measures its execution time.
• perf: A powerful performance profiling tool.