示例
/* Callback for JVMTI_EVENT_VM_INIT */
static void JNICALL vm_init(jvmtiEnv* jvmti, JNIEnv* env, jthread thread)
{
jint runtime_version;
jvmti->GetVersionNumber(&runtime_version);
stdout_message("JVMTI Version: %d\n", runtime_verision);
}
/* Agent_OnLoad() is called first, we prepare for a VM_INIT event here. */
JNIEXPORT jint JNICALL
Agent_OnLoad(JavaVM* vm, char* options, void* reserved)
{
jint rc;
jvmtiEventCallbacks callbacks;
jvmtiCapabilities capabilities;
jvmtiEnv* jvmti;
/* Get JVMTI environment */
rc = vm->GetEnv(reinterpret_cast<void **>(&jvmti), JVMTI_VERSION);
if (rc != JNI_OK)
{
return -1;
}
/* Immediately after getting the jvmtiEnv* we need to ask for the
* capabilities this agent will need.
*/
jvmti->GetCapabilities(&capabilities);
capabilities.can_tag_objects= 1;
jvmti->AddCapabilities(&capabilities);
/* Set callbacks and enable event notifications */
memset(&callbacks, 0, sizeof(callbacks));
callbacks.VMInit= &vm_init;
jvmti->SetEventCallbacks(&callbacks, sizeof(callbacks));
jvmti->SetEventNotificationMode(JVMTI_ENABLE, JVMTI_EVENT_VM_INIT, nullptr);
return JNI_OK;
}
