From e64161d02857ae1e82b075ea3fe0bbc47f2e1695 Mon Sep 17 00:00:00 2001
From: prasun3 <prasun3@gmail.com>
Date: Sat, 9 Nov 2019 16:03:12 +0530
Subject: [PATCH] Allow perf-map-agent to be loaded at startup

Implemented Agent_OnLoad so that the agent may be loaded at startup.
Previously the agent could only be attached at runtime
---
 src/c/perf-map-agent.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/src/c/perf-map-agent.c b/src/c/perf-map-agent.c
index a5dea76..b28ddda 100644
--- a/src/c/perf-map-agent.c
+++ b/src/c/perf-map-agent.c
@@ -337,6 +337,21 @@ jvmtiError set_callbacks(jvmtiEnv *jvmti) {
     return (*jvmti)->SetEventCallbacks(jvmti, &callbacks, (jint)sizeof(callbacks));
 }
 
+JNIEXPORT jint JNICALL 
+Agent_OnLoad(JavaVM *vm, char *options, void *reserved)
+{
+    open_map_file();
+
+    jvmtiEnv *jvmti;
+    (*vm)->GetEnv(vm, (void **)&jvmti, JVMTI_VERSION_1);
+    enable_capabilities(jvmti);
+    set_callbacks(jvmti);
+    set_notification_mode(jvmti, JVMTI_ENABLE);
+
+    return 0;
+}
+
+
 JNIEXPORT jint JNICALL
 Agent_OnAttach(JavaVM *vm, char *options, void *reserved) {
     open_map_file();