README.md

Cpu Watcher

A Java Library/App to monitor/limit another process CPU usage.

Why use it?

• Limit any process cpu time usage in a multiplatform way.

How it works?

Using a new thread to each external process that you want to monitor/limit this library watches cpu times and sends signals according with cpu specified limit and timelapse.

• SIGSTOP/SIGCONT on macos/linux
• NtSuspendProcess/NtResumeProcess on Windows.

Usage

As Java library:

// Create a new CpuWatcher object with target PID (own pid throws exception to prevents deadlock). 
// Target percentage is not per core, is always over the entire system load, 
// on example above we want 50% of 1 core only, and host cpu has 8 cores (4 phisical, 4 HT).
// 50%/8 = 6.25%
CpuWatcher cpuWatcher = new CpuWatcher(pid, 50f * CpuWatcher.getOneCoreOnePercent());
// start watcher thread
cpuWatcher.start();
// You can monitor current cpu usage too!
cpuWatcher.getCpuUsage();
// ... or change usage limit at runtime (null to disable limiter)
cpuWatcher.setUsageLimit(null);
// Wait for process (optional);
cpuWatcher.join();

As Standalone App:

java -jar cpu-watcher-$VERSION.jar $PID $MAX_CPU

Maven

<dependency>
    <groupId>com.github.dyorgio.runtime</groupId>
    <artifactId>cpu-watcher</artifactId>
    <version>1.3.1</version>
</dependency>