Call graph for some key methods in JVM startup:

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main()  [src/java.base/share/native/launcher/main.c]
  │
  └─▶ JLI_Launch()  [src/java.base/share/native/libjli/java.c]
        │
        ├─▶ LoadJavaVM(jvmpath, &ifn)          // dlopen libjvm; bind JNI functions
        │
        ├─▶ ParseArguments()                   // Parse args; populate options[]
        │
        └─▶ JVMInit(&ifn, ...)                 // [src/java.base/unix/native/libjli/java_md.c]
               │
               └─▶ ContinueInNewThread()
                      │
                      └─▶ CallJavaMainInNewThread()   // Create thread for JavaMain
                             │
                             └─▶ JavaMain(void* _args)   [src/java.base/share/native/libjli/java.c]
                                    │
                                    ├─▶ InitializeJVM()      // Calls ifn->CreateJavaVM
                                    │      │
                                    │      └─▶ Threads::create_vm()   [src/hotspot/share/runtime/threads.cpp]
                                    │             ├─▶ init_globals()    // JIT, GC, modules, CDS
                                    │             └─▶ VMThread::create()
                                    │
                                    ├─▶ LoadMainClass()
                                    │
                                    │
                                    └─▶ invokeStaticMainWithArgs()
                                           │
                                           └─▶ (*env)->CallStaticVoidMethod

Files involved:

  • src/java.base/share/native/launcher/main.c

    The entry point of the launcher. As the filename suggests, this contains the main function.

  • src/java.base/share/native/libjli/java.c

    The platform-independent portion of the JVM startup sequence. This orchestrates argument parsing, VM initialization, and eventually calling into Java.

  • src/java.base/unix/native/libjli/java_md.c

    The platform-specific layer supporting java.c. It implements OS-dependent functionality such as thread creation and process setup on Unix-like systems.

  • src/hotspot/share/runtime/threads.cpp

    The VM-internal logic for creating and managing various JVM threads, including the JIT compiler threads, GC threads, and the VM thread itself.