Most platforms typically build on the features of other platforms.

By understanding the Gradle platforms and their relationships, you can get a feel for where in the Gradle source a particular feature might be implemented.

See [Gradle platform architecture](platforms.md) for a list of the platforms and more details.

## Gradle runtimes

fun Requirements.requiresNotEc2Agent() {
    doesNotContain("teamcity.agent.name", "ec2")
    // US region agents have name "EC2-XXX"
    doesNotContain("teamcity.agent.name", "EC2")
}

/**
 * We have some "shared" host where a Linux build agent and a Windows build agent
 * both run on the same bare metal. Some builds require exclusive access to the
 * hardware resources (e.g. performance test).
 */
fun Requirements.requiresNotSharedHost() {

  - Suppose the VCS root you just create is `MyNewVcsRoot`. Set "default branch" to `myTestBranch` where your code exists.
- Click `Create subproject` button at the bottom of the "Subprojects" region of [this page](https://builds.gradle.org/admin/editProject.html?projectId=Gradle&tab=projectGeneralTab)
  - Select `Manually`.

    launcherJar.from(tasks.jar)
    agentJars.from(agentsClasspath)
    // The trick below is to use the templates from the current code instead of the wrapper. It does not cover the case where the generation logic is updated though.
    unixScriptTemplate.from(layout.projectDirectory.file("../../../platforms/jvm/plugins-application/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt"))

Java serialization does not enforce type safety as strictly as some alternatives, potentially leading to runtime errors.

## Decision

We do not use Java serialization.
Instead, we use custom serialization where we explicitly describe how data objects should be serialized and deserialized.

For internal purposes, we use binary formats for their brevity.

### Testing changes

After making changes, you can test your code in 2 ways:

1. Run tests.
- Run `./gradlew :<subproject>:quickTest` where `<subproject>` is the name of the subproject you've changed. 
- For example: `./gradlew :launcher:quickTest`.
2. Install Gradle locally and try out a change in behavior manually. 

     *
     * Here we automatically accept the following cases:
     * - A setter `setX` of an upgraded property is removed
     * - A boolean `isX` of an upgraded property is removed
     * - A new getter `getX` is added, where the old getter is a boolean getter `isX` of an upgraded property
     * - A return type is changed for a getter `getX` of an upgraded property
     *