bench: Add benchmark for lockedpool allocation/deallocation

src/Makefile.bench.include

@@ -17,7 +17,8 @@ bench_bench_bitcoin_SOURCES = \
   bench/ccoins_caching.cpp \
   bench/mempool_eviction.cpp \
   bench/verify_script.cpp \
-  bench/base58.cpp
+  bench/base58.cpp \
+  bench/lockedpool.cpp
 
 bench_bench_bitcoin_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES) $(EVENT_CLFAGS) $(EVENT_PTHREADS_CFLAGS) -I$(builddir)/bench/
 bench_bench_bitcoin_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)

src/bench/lockedpool.cpp

@@ -0,0 +1,47 @@
+// Copyright (c) 2016 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include "bench.h"
+
+#include "support/lockedpool.h"
+
+#include <iostream>
+#include <vector>
+
+#define ASIZE 2048
+#define BITER 5000
+#define MSIZE 2048
+
+static void LockedPool(benchmark::State& state)
+{
+    void *synth_base = reinterpret_cast<void*>(0x08000000);
+    const size_t synth_size = 1024*1024;
+    Arena b(synth_base, synth_size, 16);
+
+    std::vector<void*> addr;
+    for (int x=0; x<ASIZE; ++x)
+        addr.push_back(0);
+    uint32_t s = 0x12345678;
+    while (state.KeepRunning()) {
+        for (int x=0; x<BITER; ++x) {
+            int idx = s & (addr.size()-1);
+            if (s & 0x80000000) {
+                b.free(addr[idx]);
+                addr[idx] = 0;
+            } else if(!addr[idx]) {
+                addr[idx] = b.alloc((s >> 16) & (MSIZE-1));
+            }
+            bool lsb = s & 1;
+            s >>= 1;
+            if (lsb)
+                s ^= 0xf00f00f0; // LFSR period 0xf7ffffe0
+        }
+    }
+    for (void *ptr: addr)
+        b.free(ptr);
+    addr.clear();
+}
+
+BENCHMARK(LockedPool);
+