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Drill4J JVM-based shared libraries

The JVM-based shared libraries for Drill4J, used in java-agent, test2code-plugin and admin components of Drill4J.

Modules

• agent: Contains the abstract agent core used to create platform specific JVMTI agents (Java, .NET), , see more in here
• agent-runner-common: Common part of plugins for build tools (gradle and maven) to easily run autotest agents
• agent-runner-gradle: Gradle part of plugins for build tools to easily run autotest agents
• common: Common back-end related Drill4J project parts (common part)
• drill-hook: Library for intercepting system functions.
• http-clients-instrumentation: Common instrumentation for http clients
• interceptor-http: Library for intercepting http protocols calls
• interceptor-http-test: Tests for interceptor-http
• interceptor-http2: Library (v2) for intercepting http protocols calls
• interceptor-http2-test: Tests for interceptor-http2
• interceptor-http2-test-grpc: Tests for interceptor-http2
• jvmapi: Library to simplify JVMTI calls from java-agent code
• knasm: Port of Java ASM library to Kotlin native
• kni-plugin: Gradle plugin for KNI classes (stub classes to simplify JVMTI calls) generation
• kni-runtime: Annotation and interface classes to use with KNI plugin
• ktor-swagger: Library for ktor with swagger integration
• ktor-swagger-sample: Sample implementation for ktor-swagger
• logging: Pre-configuration tier for microutils kotlin-logging library (useful for multiplatform modules)
• test-data: Test data for admin/test2code-plugin testing
• test-plugin: Module for test-plugin distribution generation (includes test-plugin-admin and test-plugin-agent jars)
• test-plugin-admin: Test-plugin for admin component tests (admin-part)
• test-plugin-agent: Test-plugin for admin component tests (agent-part)
• test2code-api: Classes for working with admin. It analyzes probes and send metrics & statistics.
• transport: Library with transport protocol for backend communication

Modules kni-plugin and kni-runtime

Kni-runtime module container two classes:

• annotation class Kni: To mark classes for which kni-stub classes should be generated. Generated stub classes used for 2 purposes:
  • Call JVM methods from native code, example: actual fun retrieveClassesData(config: String): ByteArray { return DataServiceStub.retrieveClassesData(config) }
  • Call native methods from JVM code, example: actual external fun adminAddressHeader(): String?
• interface JvmtiAgent: Interface should be implemented by JVMTI-agent class which will be called in kni-generated function:

@CName("Agent_OnLoad")
public fun agentOnLoad(
    vmPointer: CPointer<JavaVMVar>,
    options: String,
    reservedPtr: Long
): Int = memScoped {
    com.epam.drill.agent.jvmapi.vmGlobal.value = vmPointer.freeze()
    val vm = vmPointer.pointed
    val jvmtiEnvPtr = alloc<CPointerVar<jvmtiEnvVar>>()
    vm.value!!.pointed.GetEnv!!(vm.ptr, jvmtiEnvPtr.ptr.reinterpret(),
        com.epam.drill.agent.jvmapi.gen.JVMTI_VERSION.convert())
    com.epam.drill.agent.jvmapi.jvmti.value = jvmtiEnvPtr.value
    jvmtiEnvPtr.value.freeze()
    com.epam.drill.agent.Agent.agentOnLoad(options) // call method of class configured in gradle file using kni-block 
}

Kni-plugin module contains classes for kni-stubs and JVMTI entry-point generation, generation details should be configured in gradle file using kni block, like:

    kni {
        jvmTargets = sequenceOf(jvm)
        jvmtiAgentObjectPath = "com.epam.drill.agent.Agent"
        nativeCrossCompileTarget = sequenceOf(linuxX64, mingwX64, macosX64)
    }