Minor tweaks

Author: jbachorik

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

@@ -164,7 +164,7 @@ class Recording {
 public:
  Recording(int fd, Arguments &args);
  ~Recording();
- 
+
  void copyTo(int target_fd);
  off_t finishChunk();
 

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

@@ -125,6 +125,8 @@ bool ThreadFilter::accept(SlotID slot_id) const {
  int slot_idx = slot_id & kChunkMask;
 
  if (chunk_idx >= kMaxChunks) return false;
+ if (slot_idx >= kChunkSize) return false;
+
  ChunkStorage* chunk = _chunks[chunk_idx].load(std::memory_order_relaxed);
  if (chunk == nullptr) return false; // Fail-fast if not allocated
 
@@ -138,6 +140,8 @@ void ThreadFilter::add(int tid, SlotID slot_id) {
  int slot_idx = slot_id & kChunkMask;
 
  if (chunk_idx >= kMaxChunks) return;
+ if (slot_idx >= kChunkSize) return;
+
  ChunkStorage* chunk = _chunks[chunk_idx].load(std::memory_order_relaxed);
  if (chunk == nullptr) return; // Fail-fast if not allocated
 
@@ -152,6 +156,8 @@ void ThreadFilter::remove(SlotID slot_id) {
  int slot_idx = slot_id & kChunkMask;
 
  if (chunk_idx >= kMaxChunks) return;
+ if (slot_idx >= kChunkSize) return;
+
  ChunkStorage* chunk = _chunks[chunk_idx].load(std::memory_order_relaxed);
  if (chunk == nullptr) return; // Fail-fast if not allocated
 

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

@@ -13,7 +13,10 @@
 // Signal-safe thread ID table with fixed size
 class ThreadIdTable {
 private:
- static const int TABLE_SIZE = 256; // Should handle most realistic thread counts
+ // We have 256 slots per concurrency level (currently 16)
+ // This should cater for 4096 threads - if it turns out to be too small, we
+ // can increase it or make it configurable
+ static const int TABLE_SIZE = 256;
  std::atomic<int> table[TABLE_SIZE];
 
  int hash(int tid) const {