[libFuzzer] control the reload interval by a flag, make it 10 seconds by default

llvm-svn: 283676

diff --git a/llvm/lib/Fuzzer/FuzzerDriver.cpp b/llvm/lib/Fuzzer/FuzzerDriver.cpp
index 336bdf0..a00e49e 100644 (file)
--- a/llvm/lib/Fuzzer/FuzzerDriver.cpp
+++ b/llvm/lib/Fuzzer/FuzzerDriver.cpp
@@ -401,7 +401,7 @@ int FuzzerDriver(int *argc, char ***argv, UserCallback Callback) {
   Options.Shrink = Flags.shrink;
   Options.ShuffleAtStartUp = Flags.shuffle;
   Options.PreferSmall = Flags.prefer_small;
-  Options.Reload = Flags.reload;
+  Options.ReloadIntervalSec = Flags.reload;
   Options.OnlyASCII = Flags.only_ascii;
   Options.OutputCSV = Flags.output_csv;
   Options.DetectLeaks = Flags.detect_leaks;

diff --git a/llvm/lib/Fuzzer/FuzzerFlags.def b/llvm/lib/Fuzzer/FuzzerFlags.def
index ea998bb..03db9ad 100644 (file)
--- a/llvm/lib/Fuzzer/FuzzerFlags.def
+++ b/llvm/lib/Fuzzer/FuzzerFlags.def
@@ -56,9 +56,9 @@ FUZZER_FLAG_INT(jobs, 0, "Number of jobs to run. If jobs >= 1 we spawn"
 FUZZER_FLAG_INT(workers, 0,
             "Number of simultaneous worker processes to run the jobs."
             " If zero, \"min(jobs,NumberOfCpuCores()/2)\" is used.")
-FUZZER_FLAG_INT(reload, 1,
-                "Reload the main corpus periodically to get new units"
-                " discovered by other processes.")
+FUZZER_FLAG_INT(reload, 10,
+                "Reload the main corpus every <N> seconds to get new units"
+                " discovered by other processes. If 0, disabled")
 FUZZER_FLAG_INT(report_slow_units, 10,
     "Report slowest units if they run for more than this number of seconds.")
 FUZZER_FLAG_INT(only_ascii, 0,

diff --git a/llvm/lib/Fuzzer/FuzzerLoop.cpp b/llvm/lib/Fuzzer/FuzzerLoop.cpp
index 49b58dd..be006ce 100644 (file)
--- a/llvm/lib/Fuzzer/FuzzerLoop.cpp
+++ b/llvm/lib/Fuzzer/FuzzerLoop.cpp
@@ -149,7 +149,7 @@ Fuzzer::Fuzzer(UserCallback CB, InputCorpus &Corpus, MutationDispatcher &MD,
 
   if (Options.Verbosity)
     TPC.PrintModuleInfo();
-  if (!Options.OutputCorpus.empty() && Options.Reload)
+  if (!Options.OutputCorpus.empty() && Options.ReloadIntervalSec)
     EpochOfLastReadOfOutputCorpus = GetEpoch(Options.OutputCorpus);
   MaxInputLen = MaxMutationLen = Options.MaxLen;
   AllocateCurrentUnitData();
@@ -383,22 +383,25 @@ void Fuzzer::CheckExitOnSrcPos() {
 }
 
 void Fuzzer::RereadOutputCorpus(size_t MaxSize) {
-  if (Options.OutputCorpus.empty() || !Options.Reload) return;
+  if (Options.OutputCorpus.empty() || !Options.ReloadIntervalSec) return;
   std::vector<Unit> AdditionalCorpus;
   ReadDirToVectorOfUnits(Options.OutputCorpus.c_str(), &AdditionalCorpus,
                          &EpochOfLastReadOfOutputCorpus, MaxSize);
   if (Options.Verbosity >= 2)
     Printf("Reload: read %zd new units.\n", AdditionalCorpus.size());
+  bool Reloaded = false;
   for (auto &U : AdditionalCorpus) {
     if (U.size() > MaxSize)
       U.resize(MaxSize);
     if (!Corpus.HasUnit(U)) {
       if (size_t NumFeatures = RunOne(U)) {
         Corpus.AddToCorpus(U, NumFeatures);
-        PrintStats("RELOAD");
+        Reloaded = true;
       }
     }
   }
+  if (Reloaded)
+    PrintStats("RELOAD");
 }
 
 void Fuzzer::ShuffleCorpus(UnitVector *V) {
@@ -705,7 +708,8 @@ void Fuzzer::Loop() {
     MD.SetCorpus(&Corpus);
   while (true) {
     auto Now = system_clock::now();
-    if (duration_cast<seconds>(Now - LastCorpusReload).count()) {
+    if (duration_cast<seconds>(Now - LastCorpusReload).count() >=
+        Options.ReloadIntervalSec) {
       RereadOutputCorpus(MaxInputLen);
       LastCorpusReload = Now;
     }

diff --git a/llvm/lib/Fuzzer/FuzzerOptions.h b/llvm/lib/Fuzzer/FuzzerOptions.h
index 04a44d8..ed31fa2 100644 (file)
--- a/llvm/lib/Fuzzer/FuzzerOptions.h
+++ b/llvm/lib/Fuzzer/FuzzerOptions.h
@@ -32,7 +32,7 @@ struct FuzzingOptions {
   bool UseMemmem = true;
   bool UseValueProfile = false;
   bool Shrink = false;
-  bool Reload = true;
+  int ReloadIntervalSec = 1;
   bool ShuffleAtStartUp = true;
   bool PreferSmall = true;
   size_t MaxNumberOfRuns = -1L;