v2

Author: zhengyu123

ddprof-lib/src/main/cpp/javaApi.cpp

@@ -409,8 +409,8 @@ Java_com_datadoghq_profiler_JVMAccess_healthCheck0(JNIEnv *env,
 
 extern "C" DLLEXPORT jlong JNICALL
 Java_com_datadoghq_profiler_ActiveBitmap_bitmapAddressFor0(JNIEnv *env,
-		                                     jclass unused,
-						     jint tid) {
+		                                                    jclass unused,
+						                                    jint tid) {
   u64* bitmap = Profiler::instance()->threadFilter()->bitmapAddressFor((int)tid);
   return (jlong)bitmap;
 }
@@ -426,4 +426,12 @@ extern "C" DLLEXPORT jlong JNICALL
 Java_com_datadoghq_profiler_ActiveBitmap_getActiveCountAddr0(JNIEnv *env,
                                                               jclass unused) {
   return (jlong)Profiler::instance()->threadFilter()->addressOfSize();
+}
+
+extern "C" DLLEXPORT jlong JNICALL
+Java_com_datadoghq_profiler_ActiveBitmap_getBitmapValue0(JNIEnv *env,
+                jclass unused,
+                jint tid,
+                jlong v) {
+  return (jlong)Profiler::instance()->threadFilter()->getBitmapValue((int)tid, (long)v);
 }

ddprof-lib/src/main/cpp/threadFilter.cpp

@@ -21,6 +21,7 @@
 #include <cassert>
 #include <stdlib.h>
 #include <string.h>
+#include <iostream>
 
 void trackPage() {
   Counters::increment(THREAD_FILTER_PAGES, 1);
@@ -117,21 +118,32 @@ u64* ThreadFilter::getBitmapFor(int thread_id) {
 }
 
 u64* ThreadFilter::bitmapAddressFor(int thread_id) {
-  u64* bitmap = getBitmapFor(thread_id);
+  u64* b = getBitmapFor(thread_id);
   thread_id = mapThreadId(thread_id);
-  return wordAddress(bitmap, thread_id);
+  assert(b == bitmap(thread_id));
+  return wordAddress(b, thread_id);
 }
 
+u64 ThreadFilter::getBitmapValue(int thread_id, long v) {
+  thread_id = mapThreadId(thread_id);
+  u64 *b = bitmap(thread_id);
+  if (b == NULL) return 0;
+  assert((long)word(b, thread_id) == v);
+  return word(b, thread_id);
+}
+
+
 bool ThreadFilter::accept(int thread_id) {
   thread_id = mapThreadId(thread_id);
   u64 *b = bitmap(thread_id);
   return b != NULL && (word(b, thread_id) & (1ULL << (thread_id & 0x3f)));
 }
 
 void ThreadFilter::add(int thread_id) {
-  thread_id = mapThreadId(thread_id);
   u64 *b = getBitmapFor(thread_id);
   assert (b != NULL);
+  thread_id = mapThreadId(thread_id);
+  assert(b == bitmap(thread_id));
   u64 bit = 1ULL << (thread_id & 0x3f);
   if (!(__sync_fetch_and_or(&word(b, thread_id), bit) & bit)) {
     atomicInc(_size);

ddprof-lib/src/main/cpp/threadFilter.h

@@ -74,6 +74,7 @@ class ThreadFilter {
   void add(int thread_id);
   void remove(int thread_id);
   u64* bitmapAddressFor(int thread_id);
+  u64 getBitmapValue(int thread_id, long v);
 
   void collect(std::vector<int> &v);
 };

ddprof-lib/src/main/java/com/datadoghq/profiler/ActiveBitmap.java

@@ -26,12 +26,11 @@ public static void initialize() {
     static long getBitmask(int tid) {
         int tmp = (tid >> 8) & 0xff ;
         int bits = 0;
-        for (int index = 0; index < 7 ; index++) {
+        for (int index = 0; index <= 7; index++) {
             if ((tmp & 0x01) == 0x01) {
-                bits |= 0x01;
+                bits |= 1 << (7 - index);
             }
-            tmp >>= 1;
-            bits <<= 1;
+            tmp >>>= 1;
         }
         return 1L << (bits & 0x3f);
     }
@@ -44,25 +43,23 @@ static void setActive(int tid, boolean active) {
         }
         long bitmask = getBitmask(tid);
         long value = UNSAFE.getLong(addr);
-        long newVal;
-        if (active) {
-            newVal = value | bitmask;
-        } else {
-            newVal = value & ~bitmask;
-        }
+        long newVal = active ? (value | bitmask) : (value & ~bitmask);
+
         while (!UNSAFE.compareAndSwapLong(null, addr, value, newVal)) {
             value = UNSAFE.getLong(addr);
             newVal = active ? (value | bitmask) : (value & ~bitmask);
         }
         int delta = active ? 1 : -1;
         assert activeCountAddr != 0;
         UNSAFE.getAndAddInt(null, activeCountAddr, delta);
+        if (isActive0(tid) != active) {
+            throw new RuntimeException("SetActive Failed");
+        }
 
         assert isActive0(tid) == active;
     }
 
 
-
     // Address of bitmap word that contains the active bit of this thread Id
     private static native long bitmapAddressFor0(int tid);