Release the pool slot held by an edge whether it succeeds or fails

When an edge finishes building, it should be release from its pool.
Make sure that this also is the case when an edge fails to build.

The bug can be shown with a pool has size N, then `ninja -k N+1` will
still stop after N failing commands for that pool, even if there are
many more jobs to be done for that pool:

    pool mypool
      depth = 1
    rule bad_rule
      command = false
      pool = mypool
    build a : bad_rule
    build b : bad_rule

Current behaviour:

    $ ninja -k 0
    [1/2] false
    FAILED: false
    ninja: build stopped: cannot make progress due to previous errors.

Expected behaviour:

    $ ninja -k 0
    [1/2] false
    FAILED: false
    [2/2] false
    FAILED: false
    ninja: build stopped: cannot make progress due to previous errors.

Signed-off-by: Fredrik Medley <fredrik.medley@gmail.com>

3 files changed, 84 insertions, 36 deletions

diff --git a/src/build.cc b/src/build.cc
index 2df5c1a..dae1e18 100644
--- a/src/build.cc
+++ b/src/build.cc
@@ -382,20 +382,25 @@ void Plan::ScheduleWork(Edge* edge) {
   }
 }
 
-void Plan::EdgeFinished(Edge* edge) {
+void Plan::EdgeFinished(Edge* edge, bool success) {
   map<Edge*, bool>::iterator e = want_.find(edge);
   assert(e != want_.end());
   bool directly_wanted = e->second;
-  if (directly_wanted)
-    --wanted_edges_;
-  want_.erase(e);
-  edge->outputs_ready_ = true;
 
   // See if this job frees up any delayed jobs.
   if (directly_wanted)
     edge->pool()->EdgeFinished(*edge);
   edge->pool()->RetrieveReadyEdges(&ready_);
 
+  // The rest of this function only applies to successful commands.
+  if (!success)
+    return;
+
+  if (directly_wanted)
+    --wanted_edges_;
+  want_.erase(e);
+  edge->outputs_ready_ = true;
+
   // Check off any nodes we were waiting for with this edge.
   for (vector<Node*>::iterator o = edge->outputs_.begin();
        o != edge->outputs_.end(); ++o) {
@@ -418,7 +423,7 @@ void Plan::NodeFinished(Node* node) {
       } else {
         // We do not need to build this edge, but we might need to build one of
         // its dependents.
-        EdgeFinished(*oe);
+        EdgeFinished(*oe, true);
       }
     }
   }
@@ -651,7 +656,7 @@ bool Builder::Build(string* err) {
         }
 
         if (edge->is_phony()) {
-          plan_.EdgeFinished(edge);
+          plan_.EdgeFinished(edge, true);
         } else {
           ++pending_commands;
         }
@@ -770,8 +775,10 @@ bool Builder::FinishCommand(CommandRunner::Result* result, string* err) {
                              &start_time, &end_time);
 
   // The rest of this function only applies to successful commands.
-  if (!result->success())
+  if (!result->success()) {
+    plan_.EdgeFinished(edge, false);
     return true;
+  }
 
   // Restat the edge outputs, if necessary.
   TimeStamp restat_mtime = 0;
@@ -820,7 +827,7 @@ bool Builder::FinishCommand(CommandRunner::Result* result, string* err) {
     }
   }
 
-  plan_.EdgeFinished(edge);
+  plan_.EdgeFinished(edge, true);
 
   // Delete any left over response file.
   string rspfile = edge->GetUnescapedRspfile();
diff --git a/src/build.h b/src/build.h
index 8106faa..3a7183f 100644
--- a/src/build.h
+++ b/src/build.h
@@ -56,9 +56,8 @@ struct Plan {
   /// Dumps the current state of the plan.
   void Dump();
 
-  /// Mark an edge as done building.  Used internally and by
-  /// tests.
-  void EdgeFinished(Edge* edge);
+  /// Mark an edge as done building (whether it succeeded or failed).
+  void EdgeFinished(Edge* edge, bool success);
 
   /// Clean the given node during the build.
   /// Return false on error.
diff --git a/src/build_test.cc b/src/build_test.cc
index 7c6060d..261268a 100644
--- a/src/build_test.cc
+++ b/src/build_test.cc
@@ -68,14 +68,14 @@ TEST_F(PlanTest, Basic) {
 
   ASSERT_FALSE(plan_.FindWork());
 
-  plan_.EdgeFinished(edge);
+  plan_.EdgeFinished(edge, true);
 
   edge = plan_.FindWork();
   ASSERT_TRUE(edge);
   ASSERT_EQ("mid", edge->inputs_[0]->path());
   ASSERT_EQ("out", edge->outputs_[0]->path());
 
-  plan_.EdgeFinished(edge);
+  plan_.EdgeFinished(edge, true);
 
   ASSERT_FALSE(plan_.more_to_do());
   edge = plan_.FindWork();
@@ -99,11 +99,11 @@ TEST_F(PlanTest, DoubleOutputDirect) {
   Edge* edge;
   edge = plan_.FindWork();
   ASSERT_TRUE(edge);  // cat in
-  plan_.EdgeFinished(edge);
+  plan_.EdgeFinished(edge, true);
 
   edge = plan_.FindWork();
   ASSERT_TRUE(edge);  // cat mid1 mid2
-  plan_.EdgeFinished(edge);
+  plan_.EdgeFinished(edge, true);
 
   edge = plan_.FindWork();
   ASSERT_FALSE(edge);  // done
@@ -129,19 +129,19 @@ TEST_F(PlanTest, DoubleOutputIndirect) {
   Edge* edge;
   edge = plan_.FindWork();
   ASSERT_TRUE(edge);  // cat in
-  plan_.EdgeFinished(edge);
+  plan_.EdgeFinished(edge, true);
 
   edge = plan_.FindWork();
   ASSERT_TRUE(edge);  // cat a1
-  plan_.EdgeFinished(edge);
+  plan_.EdgeFinished(edge, true);
 
   edge = plan_.FindWork();
   ASSERT_TRUE(edge);  // cat a2
-  plan_.EdgeFinished(edge);
+  plan_.EdgeFinished(edge, true);
 
   edge = plan_.FindWork();
   ASSERT_TRUE(edge);  // cat b1 b2
-  plan_.EdgeFinished(edge);
+  plan_.EdgeFinished(edge, true);
 
   edge = plan_.FindWork();
   ASSERT_FALSE(edge);  // done
@@ -167,19 +167,19 @@ TEST_F(PlanTest, DoubleDependent) {
   Edge* edge;
   edge = plan_.FindWork();
   ASSERT_TRUE(edge);  // cat in
-  plan_.EdgeFinished(edge);
+  plan_.EdgeFinished(edge, true);
 
   edge = plan_.FindWork();
   ASSERT_TRUE(edge);  // cat mid
-  plan_.EdgeFinished(edge);
+  plan_.EdgeFinished(edge, true);
 
   edge = plan_.FindWork();
   ASSERT_TRUE(edge);  // cat mid
-  plan_.EdgeFinished(edge);
+  plan_.EdgeFinished(edge, true);
 
   edge = plan_.FindWork();
   ASSERT_TRUE(edge);  // cat a1 a2
-  plan_.EdgeFinished(edge);
+  plan_.EdgeFinished(edge, true);
 
   edge = plan_.FindWork();
   ASSERT_FALSE(edge);  // done
@@ -257,7 +257,7 @@ void PlanTest::TestPoolWithDepthOne(const char* test_case) {
   // This will be false since poolcat is serialized
   ASSERT_FALSE(plan_.FindWork());
 
-  plan_.EdgeFinished(edge);
+  plan_.EdgeFinished(edge, true);
 
   edge = plan_.FindWork();
   ASSERT_TRUE(edge);
@@ -266,7 +266,7 @@ void PlanTest::TestPoolWithDepthOne(const char* test_case) {
 
   ASSERT_FALSE(plan_.FindWork());
 
-  plan_.EdgeFinished(edge);
+  plan_.EdgeFinished(edge, true);
 
   ASSERT_FALSE(plan_.more_to_do());
   edge = plan_.FindWork();
@@ -342,7 +342,7 @@ TEST_F(PlanTest, PoolsWithDepthTwo) {
   ASSERT_EQ("outb3", edge->outputs_[0]->path());
 
   // finish out1
-  plan_.EdgeFinished(edges.front());
+  plan_.EdgeFinished(edges.front(), true);
   edges.pop_front();
 
   // out3 should be available
@@ -353,19 +353,19 @@ TEST_F(PlanTest, PoolsWithDepthTwo) {
 
   ASSERT_FALSE(plan_.FindWork());
 
-  plan_.EdgeFinished(out3);
+  plan_.EdgeFinished(out3, true);
 
   ASSERT_FALSE(plan_.FindWork());
 
   for (deque<Edge*>::iterator it = edges.begin(); it != edges.end(); ++it) {
-    plan_.EdgeFinished(*it);
+    plan_.EdgeFinished(*it, true);
   }
 
   Edge* last = plan_.FindWork();
   ASSERT_TRUE(last);
   ASSERT_EQ("allTheThings", last->outputs_[0]->path());
 
-  plan_.EdgeFinished(last);
+  plan_.EdgeFinished(last, true);
 
   ASSERT_FALSE(plan_.more_to_do());
   ASSERT_FALSE(plan_.FindWork());
@@ -407,7 +407,7 @@ TEST_F(PlanTest, PoolWithRedundantEdges) {
 
   edge = initial_edges[1];  // Foo first
   ASSERT_EQ("foo.cpp", edge->outputs_[0]->path());
-  plan_.EdgeFinished(edge);
+  plan_.EdgeFinished(edge, true);
 
   edge = plan_.FindWork();
   ASSERT_TRUE(edge);
@@ -415,11 +415,11 @@ TEST_F(PlanTest, PoolWithRedundantEdges) {
   ASSERT_EQ("foo.cpp", edge->inputs_[0]->path());
   ASSERT_EQ("foo.cpp", edge->inputs_[1]->path());
   ASSERT_EQ("foo.cpp.obj", edge->outputs_[0]->path());
-  plan_.EdgeFinished(edge);
+  plan_.EdgeFinished(edge, true);
 
   edge = initial_edges[0];  // Now for bar
   ASSERT_EQ("bar.cpp", edge->outputs_[0]->path());
-  plan_.EdgeFinished(edge);
+  plan_.EdgeFinished(edge, true);
 
   edge = plan_.FindWork();
   ASSERT_TRUE(edge);
@@ -427,7 +427,7 @@ TEST_F(PlanTest, PoolWithRedundantEdges) {
   ASSERT_EQ("bar.cpp", edge->inputs_[0]->path());
   ASSERT_EQ("bar.cpp", edge->inputs_[1]->path());
   ASSERT_EQ("bar.cpp.obj", edge->outputs_[0]->path());
-  plan_.EdgeFinished(edge);
+  plan_.EdgeFinished(edge, true);
 
   edge = plan_.FindWork();
   ASSERT_TRUE(edge);
@@ -435,20 +435,62 @@ TEST_F(PlanTest, PoolWithRedundantEdges) {
   ASSERT_EQ("foo.cpp.obj", edge->inputs_[0]->path());
   ASSERT_EQ("bar.cpp.obj", edge->inputs_[1]->path());
   ASSERT_EQ("libfoo.a", edge->outputs_[0]->path());
-  plan_.EdgeFinished(edge);
+  plan_.EdgeFinished(edge, true);
 
   edge = plan_.FindWork();
   ASSERT_TRUE(edge);
   ASSERT_FALSE(plan_.FindWork());
   ASSERT_EQ("libfoo.a", edge->inputs_[0]->path());
   ASSERT_EQ("all", edge->outputs_[0]->path());
-  plan_.EdgeFinished(edge);
+  plan_.EdgeFinished(edge, true);
 
   edge = plan_.FindWork();
   ASSERT_FALSE(edge);
   ASSERT_FALSE(plan_.more_to_do());
 }
 
+TEST_F(PlanTest, PoolWithFailingEdge) {
+  ASSERT_NO_FATAL_FAILURE(AssertParse(&state_,
+    "pool foobar\n"
+    "  depth = 1\n"
+    "rule poolcat\n"
+    "  command = cat $in > $out\n"
+    "  pool = foobar\n"
+    "build out1: poolcat in\n"
+    "build out2: poolcat in\n"));
+  GetNode("out1")->MarkDirty();
+  GetNode("out2")->MarkDirty();
+  string err;
+  EXPECT_TRUE(plan_.AddTarget(GetNode("out1"), &err));
+  ASSERT_EQ("", err);
+  EXPECT_TRUE(plan_.AddTarget(GetNode("out2"), &err));
+  ASSERT_EQ("", err);
+  ASSERT_TRUE(plan_.more_to_do());
+
+  Edge* edge = plan_.FindWork();
+  ASSERT_TRUE(edge);
+  ASSERT_EQ("in",  edge->inputs_[0]->path());
+  ASSERT_EQ("out1", edge->outputs_[0]->path());
+
+  // This will be false since poolcat is serialized
+  ASSERT_FALSE(plan_.FindWork());
+
+  plan_.EdgeFinished(edge, false);
+
+  edge = plan_.FindWork();
+  ASSERT_TRUE(edge);
+  ASSERT_EQ("in", edge->inputs_[0]->path());
+  ASSERT_EQ("out2", edge->outputs_[0]->path());
+
+  ASSERT_FALSE(plan_.FindWork());
+
+  plan_.EdgeFinished(edge, false);
+
+  ASSERT_TRUE(plan_.more_to_do()); // Jobs have failed
+  edge = plan_.FindWork();
+  ASSERT_EQ(0, edge);
+}
+
 /// Fake implementation of CommandRunner, useful for tests.
 struct FakeCommandRunner : public CommandRunner {
   explicit FakeCommandRunner(VirtualFileSystem* fs) :