3 files changed, 21 insertions, 25 deletions

diff --git a/src/build.cc b/src/build.cc
index f04e2f2..3b1a3f4 100644
--- a/src/build.cc
+++ b/src/build.cc
@@ -81,7 +81,7 @@ bool DryRunCommandRunner::WaitForCommand(Result* result) {
 
 BuildStatus::BuildStatus(const BuildConfig& config)
     : config_(config),
-      started_edges_(0), finished_edges_(0), total_edges_(0),
+      started_edges_(0), finished_edges_(0), total_edges_(0), running_edges_(0),
       time_millis_(0), progress_status_format_(NULL),
       current_rate_(config.parallelism) {
   // Don't do anything fancy in verbose mode.
@@ -103,7 +103,7 @@ void BuildStatus::BuildEdgeStarted(const Edge* edge,
   time_millis_ = start_time_millis;
 
   if (edge->use_console() || printer_.is_smart_terminal())
-    PrintStatus(edge, start_time_millis, kEdgeStarted);
+    PrintStatus(edge, start_time_millis);
 
   if (edge->use_console())
     printer_.SetConsoleLocked(true);
@@ -122,7 +122,12 @@ void BuildStatus::BuildEdgeFinished(Edge* edge, int64_t end_time_millis,
     return;
 
   if (!edge->use_console())
-    PrintStatus(edge, end_time_millis, kEdgeFinished);
+    PrintStatus(edge, end_time_millis);
+
+  // Update running_edges_ after PrintStatus so that the number of running
+  // edges doesn't oscillate between config.parallelism_ and
+  // config.parallelism_ - 1.
+  --running_edges_;
 
   // Print the command that is spewing before printing its output.
   if (!success) {
@@ -185,6 +190,9 @@ void BuildStatus::BuildLoadDyndeps() {
 }
 
 void BuildStatus::BuildStarted() {
+  started_edges_ = 0;
+  finished_edges_ = 0;
+  running_edges_ = 0;
 }
 
 void BuildStatus::BuildFinished() {
@@ -193,7 +201,7 @@ void BuildStatus::BuildFinished() {
 }
 
 string BuildStatus::FormatProgressStatus(
-    const char* progress_status_format, int64_t time, EdgeStatus status) const {
+    const char* progress_status_format, int64_t time) const {
   string out;
   char buf[32];
   for (const char* s = progress_status_format; *s != '\0'; ++s) {
@@ -218,11 +226,7 @@ string BuildStatus::FormatProgressStatus(
 
         // Running edges.
       case 'r': {
-        int running_edges = started_edges_ - finished_edges_;
-        // count the edge that just finished as a running edge
-        if (status == kEdgeFinished)
-          running_edges++;
-        snprintf(buf, sizeof(buf), "%d", running_edges);
+        snprintf(buf, sizeof(buf), "%d", running_edges_);
         out += buf;
         break;
       }
@@ -278,7 +282,7 @@ string BuildStatus::FormatProgressStatus(
   return out;
 }
 
-void BuildStatus::PrintStatus(const Edge* edge, int64_t time, EdgeStatus status) {
+void BuildStatus::PrintStatus(const Edge* edge, int64_t time) {
   if (config_.verbosity == BuildConfig::QUIET)
     return;
 
@@ -288,7 +292,7 @@ void BuildStatus::PrintStatus(const Edge* edge, int64_t time, EdgeStatus status)
   if (to_print.empty() || force_full_command)
     to_print = edge->GetBinding("command");
 
-  to_print = FormatProgressStatus(progress_status_format_, time, status) + to_print;
+  to_print = FormatProgressStatus(progress_status_format_, time) + to_print;
 
   printer_.Print(to_print,
                  force_full_command ? LinePrinter::FULL : LinePrinter::ELIDE);
diff --git a/src/build.h b/src/build.h
index 6935086..265723a 100644
--- a/src/build.h
+++ b/src/build.h
@@ -252,25 +252,20 @@ struct BuildStatus {
   void BuildStarted();
   void BuildFinished();
 
-  enum EdgeStatus {
-    kEdgeStarted,
-    kEdgeFinished,
-  };
-
   /// Format the progress status string by replacing the placeholders.
   /// See the user manual for more information about the available
   /// placeholders.
   /// @param progress_status_format The format of the progress status.
   /// @param status The status of the edge.
   std::string FormatProgressStatus(const char* progress_status_format,
-                                   int64_t time, EdgeStatus status) const;
+                                   int64_t time) const;
 
  private:
-  void PrintStatus(const Edge* edge, int64_t time, EdgeStatus status);
+  void PrintStatus(const Edge* edge, int64_t time);
 
   const BuildConfig& config_;
 
-  int started_edges_, finished_edges_, total_edges_;
+  int started_edges_, finished_edges_, total_edges_, running_edges_;
   int64_t time_millis_;
 
   /// Prints progress output.
diff --git a/src/build_test.cc b/src/build_test.cc
index 4ccb2c4..1baec65 100644
--- a/src/build_test.cc
+++ b/src/build_test.cc
@@ -1400,8 +1400,7 @@ TEST_F(BuildWithLogTest, RestatTest) {
   ASSERT_EQ("", err);
   EXPECT_TRUE(builder_.Build(&err));
   ASSERT_EQ("", err);
-  EXPECT_EQ("[3/3]", builder_.status_->FormatProgressStatus("[%s/%t]", 0,
-      BuildStatus::kEdgeStarted));
+  EXPECT_EQ("[3/3]", builder_.status_->FormatProgressStatus("[%s/%t]", 0));
   command_runner_.commands_ran_.clear();
   state_.Reset();
 
@@ -1843,14 +1842,12 @@ TEST_F(BuildTest, StatusFormatElapsed) {
   status_.BuildStarted();
   // Before any task is done, the elapsed time must be zero.
   EXPECT_EQ("[%/e0.000]",
-            status_.FormatProgressStatus("[%%/e%e]", 0,
-                BuildStatus::kEdgeStarted));
+            status_.FormatProgressStatus("[%%/e%e]", 0));
 }
 
 TEST_F(BuildTest, StatusFormatReplacePlaceholder) {
   EXPECT_EQ("[%/s0/t0/r0/u0/f0]",
-            status_.FormatProgressStatus("[%%/s%s/t%t/r%r/u%u/f%f]", 0,
-                BuildStatus::kEdgeStarted));
+            status_.FormatProgressStatus("[%%/s%s/t%t/r%r/u%u/f%f]", 0));
 }
 
 TEST_F(BuildTest, FailedDepsParse) {