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#include <jni.h>
#include <jvmti.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include "getstacktrace.h"
void
printStackTrace (jvmtiFrameInfo *frames, jint frame_cnt)
{
printf ("Thread has %d frames\n", static_cast<int> (frame_cnt));
for (int i = 0; i < frame_cnt; i++)
{
jmethodID method = frames[i].method;
jlocation location = frames[i].location;
if (location == -1)
{
printf ("Frame %d is native\n", i);
}
else
{
printf ("Frame %d is interpreted\n", i);
}
}
}
JNIEXPORT void JNICALL Java_getstacktrace_natPlaceholder (JNIEnv *env, jobject obj)
{
jclass klass = env->GetObjectClass (obj);
jfieldID done_id = env->GetFieldID (klass, "done", "Z");
jfieldID num_frames_id = env->GetFieldID (klass, "num_frames", "I");
jfieldID thread_num_id = env->GetFieldID (klass, "thread_num", "I");
// num_frames--
jint n_frames = env->GetIntField (obj, num_frames_id);
n_frames--;
env->SetIntField (obj, num_frames_id, n_frames);
jint t_num = env->GetIntField (obj, thread_num_id);
if (n_frames <= 1)
{
if (t_num % 2 == 1)
{
jmethodID natRunner_id = env->GetMethodID (klass, "natRunner", "()V");
env->CallVoidMethod (obj, natRunner_id);
}
else
{
jmethodID runner_id = env->GetMethodID (klass, "runner", "()V");
env->CallVoidMethod (obj, runner_id);
}
}
else
{
if (t_num % 2 == 0)
{
jmethodID natPlaceholder_id = env->GetMethodID (klass,
"natPlaceholder",
"()V");
env->CallVoidMethod (obj, natPlaceholder_id);
}
else
{
jmethodID placeholder_id = env->GetMethodID (klass, "placeholder",
"()V");
env->CallVoidMethod (obj, placeholder_id);
}
}
}
JNIEXPORT void JNICALL Java_getstacktrace_natRunner (JNIEnv *env, jobject obj)
{
jclass klass = env->GetObjectClass (obj);
jfieldID done_id = env->GetFieldID (klass, "done", "Z");
jboolean done;
done = true;
env->SetBooleanField (obj, done_id, done);
do
{
done = env->GetBooleanField (obj, done_id);
if (done == false)
break;
usleep (40);
}
while (done != false);
}
JNIEXPORT jint JNICALL Java_getstacktrace_do_1getstacktrace_1tests
(JNIEnv *env, jclass klass, jobjectArray thr_arr)
{
JavaVM *vm;
jint err = env->GetJavaVM (&vm);
if (err < 0)
{
fprintf (stderr, "error getting VM\n");
exit (1);
}
jvmtiEnv *jvmti = NULL;
vm->GetEnv ((void **) &jvmti, JVMTI_VERSION_1_0);
if (jvmti == NULL)
{
fprintf (stderr, "error getting jvmti environment\n");
exit (1);
}
jint frame_cnt;
jvmtiFrameInfo frames[30];
jvmtiError jerr;
jthread thr;
jsize num_threads = env->GetArrayLength (thr_arr);
for (int i = 0; i < num_threads; i++)
{
thr = reinterpret_cast<jthread>
(env->GetObjectArrayElement (thr_arr, static_cast<jsize> (i)));
fflush (stdout);
jerr = jvmti->GetStackTrace (thr, 0, 30, frames, &frame_cnt);
if (jerr != JVMTI_ERROR_NONE)
{
char *error_name;
jvmti->GetErrorName (jerr, &error_name);
fprintf (stderr, "JVMTI Error: %s\n", error_name);
jvmti->Deallocate (reinterpret_cast<unsigned char *> (error_name));
}
else
{
printStackTrace (frames, frame_cnt);
}
}
}
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