Leak detection: Avoid unbounded growth of address map

include/live_allocation-c.hpp

@@ -0,0 +1,12 @@
+// Unless explicitly stated otherwise all files in this repository are licensed
+// under the Apache License Version 2.0. This product includes software
+// developed at Datadog (https://www.datadoghq.com/). Copyright 2021-Present
+// Datadog, Inc.
+
+#pragma once
+
+namespace ddprof {
+namespace liveallocation {
+static constexpr auto kMaxTracked = 200000;
+}
+}

include/live_allocation.hpp

@@ -1,16 +1,21 @@
+// Unless explicitly stated otherwise all files in this repository are licensed
+// under the Apache License Version 2.0. This product includes software
+// developed at Datadog (https://www.datadoghq.com/). Copyright 2021-Present
+// Datadog, Inc.
+
 #pragma once
 
 #include "ddprof_defs.hpp"
 #include "logger.hpp"
 #include "unwind_output.hpp"
+#include "live_allocation-c.hpp"
 
 #include <unordered_map>
 
 namespace ddprof {
 
 class LiveAllocation {
 public:
-  static constexpr auto kMaxTracked = 200000;
   void register_allocation(const UnwindOutput &stack, uintptr_t addr,
                            size_t size, int watcher_pos, pid_t pid) {
     StackMap &stack_map = _pid_map[pid];

src/ddprof_worker.cc

@@ -386,7 +386,7 @@ static DDRes aggregate_live_allocations(DDProfContext *ctx) {
     LG_NTC("Number of Live allocations for PID%d = %lu ", stack_map.first,
            stack_map.second.size());
     // Safety to avoid spending all the time reporting allocations
-    if (stack_map.second.size() >= LiveAllocation::kMaxTracked) {
+    if (stack_map.second.size() >= liveallocation::kMaxTracked) {
       stack_map.second.clear();
     }
   }

src/lib/allocation_tracker.cc

@@ -14,6 +14,7 @@
 #include "ringbuffer_utils.hpp"
 #include "savecontext.hpp"
 #include "syscalls.hpp"
+#include "live_allocation-c.hpp"
 
 #include <atomic>
 #include <cassert>
@@ -225,6 +226,10 @@ void AllocationTracker::track_deallocation(uintptr_t addr,
 
   // Inserting / Erasing addresses is done within the lock
   if (_address_set.erase(addr)) {
+    if (_address_set.size() >= liveallocation::kMaxTracked) {
+      // avoid unbounded growth
+      _address_set.clear();
+    }
     bool success = IsDDResOK(push_dealloc_sample(addr, tl_state));
     free_on_consecutive_failures(success);
   }