Auto merge of #1376 - str4d:1191-improve-multithreaded-benchmark, r=daira

Measure multithreaded solveequihash time per-thread

Continuation of #1213
Closes #1191

src/wallet/rpcwallet.cpp

@@ -2447,10 +2447,11 @@ Value zc_benchmark(const json_spirit::Array& params, bool fHelp)
             sample_times.push_back(benchmark_verify_joinsplit(samplejoinsplit));
         } else if (benchmarktype == "solveequihash") {
             if (params.size() < 3) {
-                sample_times.push_back(benchmark_solve_equihash(true));
+                sample_times.push_back(benchmark_solve_equihash());
             } else {
                 int nThreads = params[2].get_int();
-                sample_times.push_back(benchmark_solve_equihash_threaded(nThreads));
+                std::vector<double> vals = benchmark_solve_equihash_threaded(nThreads);
+                sample_times.insert(sample_times.end(), vals.begin(), vals.end());
             }
         } else if (benchmarktype == "verifyequihash") {
             sample_times.push_back(benchmark_verify_equihash());
@@ -2462,9 +2463,9 @@ Value zc_benchmark(const json_spirit::Array& params, bool fHelp)
     }
 
     Array results;
-    for (int i = 0; i < samplecount; i++) {
+    for (auto time : sample_times) {
         Object result;
-        result.push_back(Pair("runningtime", sample_times.at(i)));
+        result.push_back(Pair("runningtime", time));
         results.push_back(result);
     }
 

src/zcbenchmarks.cpp

@@ -1,6 +1,8 @@
+#include <future>
+#include <thread>
 #include <unistd.h>
 #include <boost/filesystem.hpp>
-#include <boost/thread.hpp>
+
 #include "coins.h"
 #include "util.h"
 #include "init.h"
@@ -24,14 +26,12 @@
 
 using namespace libzcash;
 
-struct timeval tv_start;
-
-void timer_start()
+void timer_start(timeval &tv_start)
 {
     gettimeofday(&tv_start, 0);
 }
 
-double timer_stop()
+double timer_stop(timeval &tv_start)
 {
     double elapsed;
     struct timeval tv_end;
@@ -43,9 +43,10 @@ double timer_stop()
 
 double benchmark_sleep()
 {
-    timer_start();
+    struct timeval tv_start;
+    timer_start(tv_start);
     sleep(1);
-    return timer_stop();
+    return timer_stop(tv_start);
 }
 
 double benchmark_parameter_loading()
@@ -54,7 +55,8 @@ double benchmark_parameter_loading()
     boost::filesystem::path pk_path = ZC_GetParamsDir() / "z9-proving.key";
     boost::filesystem::path vk_path = ZC_GetParamsDir() / "z9-verifying.key";
 
-    timer_start();
+    struct timeval tv_start;
+    timer_start(tv_start);
 
     auto newParams = ZCJoinSplit::Unopened();
 
@@ -62,7 +64,7 @@ double benchmark_parameter_loading()
     newParams->setProvingKeyPath(pk_path.string());
     newParams->loadProvingKey();
 
-    double ret = timer_stop();
+    double ret = timer_stop(tv_start);
 
     delete newParams;
 
@@ -76,7 +78,8 @@ double benchmark_create_joinsplit()
     /* Get the anchor of an empty commitment tree. */
     uint256 anchor = ZCIncrementalMerkleTree().root();
 
-    timer_start();
+    struct timeval tv_start;
+    timer_start(tv_start);
     JSDescription jsdesc(*pzcashParams,
                          pubKeyHash,
                          anchor,
@@ -84,7 +87,7 @@ double benchmark_create_joinsplit()
                          {JSOutput(), JSOutput()},
                          0,
                          0);
-    double ret = timer_stop();
+    double ret = timer_stop(tv_start);
 
     assert(jsdesc.Verify(*pzcashParams, pubKeyHash));
     return ret;
@@ -92,13 +95,14 @@ double benchmark_create_joinsplit()
 
 double benchmark_verify_joinsplit(const JSDescription &joinsplit)
 {
-    timer_start();
+    struct timeval tv_start;
+    timer_start(tv_start);
     uint256 pubKeyHash;
     joinsplit.Verify(*pzcashParams, pubKeyHash);
-    return timer_stop();
+    return timer_stop(tv_start);
 }
 
-double benchmark_solve_equihash(bool time)
+double benchmark_solve_equihash()
 {
     CBlock pblock;
     CEquihashInput I{pblock};
@@ -117,25 +121,33 @@ double benchmark_solve_equihash(bool time)
                                     nonce.begin(),
                                     nonce.size());
 
-    if (time)
-        timer_start();
+    struct timeval tv_start;
+    timer_start(tv_start);
     std::set<std::vector<unsigned int>> solns;
     EhOptimisedSolveUncancellable(n, k, eh_state,
                                   [](std::vector<unsigned char> soln) { return false; });
-    if (time)
-        return timer_stop();
-    else
-        return 0;
+    return timer_stop(tv_start);
 }
 
-double benchmark_solve_equihash_threaded(int nThreads)
+std::vector<double> benchmark_solve_equihash_threaded(int nThreads)
 {
-    boost::thread_group solverThreads;
-    timer_start();
-    for (int i = 0; i < nThreads; i++)
-        solverThreads.create_thread(boost::bind(&benchmark_solve_equihash, false));
-    solverThreads.join_all();
-    return timer_stop();
+    std::vector<double> ret;
+    std::vector<std::future<double>> tasks;
+    std::vector<std::thread> threads;
+    for (int i = 0; i < nThreads; i++) {
+        std::packaged_task<double(void)> task(&benchmark_solve_equihash);
+        tasks.emplace_back(task.get_future());
+        threads.emplace_back(std::move(task));
+    }
+    std::future_status status;
+    for (auto it = tasks.begin(); it != tasks.end(); it++) {
+        it->wait();
+        ret.push_back(it->get());
+    }
+    for (auto it = threads.begin(); it != threads.end(); it++) {
+        it->join();
+    }
+    return ret;
 }
 
 double benchmark_verify_equihash()
@@ -143,9 +155,10 @@ double benchmark_verify_equihash()
     CChainParams params = Params(CBaseChainParams::MAIN);
     CBlock genesis = Params(CBaseChainParams::MAIN).GenesisBlock();
     CBlockHeader genesis_header = genesis.GetBlockHeader();
-    timer_start();
+    struct timeval tv_start;
+    timer_start(tv_start);
     CheckEquihashSolution(&genesis_header, params);
-    return timer_stop();
+    return timer_stop(tv_start);
 }
 
 double benchmark_large_tx()
@@ -197,7 +210,8 @@ double benchmark_large_tx()
     CTransaction final_spending_tx(spending_tx);
 
     // Benchmark signature verification costs:
-    timer_start();
+    struct timeval tv_start;
+    timer_start(tv_start);
     for (size_t i = 0; i < NUM_INPUTS; i++) {
         ScriptError serror = SCRIPT_ERR_OK;
         assert(VerifyScript(final_spending_tx.vin[i].scriptSig,
@@ -206,6 +220,6 @@ double benchmark_large_tx()
                             TransactionSignatureChecker(&final_spending_tx, i),
                             &serror));
     }
-    return timer_stop();
+    return timer_stop(tv_start);
 }
 

src/zcbenchmarks.h

@@ -7,8 +7,8 @@
 extern double benchmark_sleep();
 extern double benchmark_parameter_loading();
 extern double benchmark_create_joinsplit();
-extern double benchmark_solve_equihash(bool time);
-extern double benchmark_solve_equihash_threaded(int nThreads);
+extern double benchmark_solve_equihash();
+extern std::vector<double> benchmark_solve_equihash_threaded(int nThreads);
 extern double benchmark_verify_joinsplit(const JSDescription &joinsplit);
 extern double benchmark_verify_equihash();
 extern double benchmark_large_tx();