Limit concurrent destruction

Summary: A recent change caused excessive parallelism during the RedexContext destruction. This is being fixed here, by clearing concurrent containers sequentially (as part of the already ongoing massively parallel destruction effort).

Reviewed By: agampe

Differential Revision: D50819506

fbshipit-source-id: e08de44047bd6970ae6c85b694bc80bd3f931573

libredex/PassManager.cpp

@@ -66,6 +66,7 @@
 #include "ScopedMetrics.h"
 #include "Show.h"
 #include "SourceBlocks.h"
+#include "ThreadPool.h"
 #include "Timer.h"
 #include "Walkers.h"
 

libredex/RedexContext.cpp

@@ -76,14 +76,14 @@ RedexContext::~RedexContext() {
                   s_type_map.clear();
                 },
                 [&] {
-                  Timer timer("DexTypeLists", /* indent */ false);
+                  Timer timer("Delete DexTypeLists", /* indent */ false);
                   for (auto const& p : s_typelist_map) {
                     delete p.second;
                   }
                   s_typelist_map.clear();
                 },
                 [&] {
-                  Timer timer("Delete DexProtos.", /* indent */ false);
+                  Timer timer("Delete DexProtos", /* indent */ false);
                   for (auto* proto : s_proto_set) {
                     delete proto;
                   }
@@ -185,7 +185,10 @@ RedexContext::~RedexContext() {
         for (size_t i = 0; i < s_small_string_set.size(); ++i) {
           auto* small_string_set = s_small_string_set[i];
           small_strings_size += small_string_set->size();
-          fns.push_back([small_string_set]() { delete small_string_set; });
+          fns.push_back([small_string_set]() {
+            small_string_set->clear();
+            delete small_string_set;
+          });
         }
         for (auto& segment : s_large_string_set) {
           large_strings_size += segment.size();