Add callgrind client requests

Internal.h

@@ -18,6 +18,11 @@
 #include <utility>
 #include <vector>
 
+#if __has_include(<valgrind/callgrind.h>)
+#define CALLGRIND
+#include <valgrind/callgrind.h>
+#endif
+
 #define DEBUG_VERBOSE 0
 
 [[nodiscard]] inline auto
@@ -556,7 +561,13 @@ template <class ConflictSetImpl> struct TestDriver {
       assert(iter == keys.end());
       assert(i == numPointWrites + numRangeWrites);
 
+#ifdef CALLGRIND
+      CALLGRIND_START_INSTRUMENTATION;
+#endif
       cs.addWrites(writes, numPointWrites + numRangeWrites);
+#ifdef CALLGRIND
+      CALLGRIND_STOP_INSTRUMENTATION;
+#endif
       refImpl.addWrites(writes, numPointWrites + numRangeWrites);
     }
     {
@@ -618,7 +629,13 @@ template <class ConflictSetImpl> struct TestDriver {
           new (arena) ConflictSet::Result[numPointReads + numRangeReads];
       auto *results2 =
           new (arena) ConflictSet::Result[numPointReads + numRangeReads];
+#ifdef CALLGRIND
+      CALLGRIND_START_INSTRUMENTATION;
+#endif
       cs.check(reads, results1, numPointReads + numRangeReads);
+#ifdef CALLGRIND
+      CALLGRIND_STOP_INSTRUMENTATION;
+#endif
       refImpl.check(reads, results2, numPointReads + numRangeReads);
       for (int i = 0; i < numPointReads + numRangeReads; ++i) {
         if (results1[i] != results2[i]) {