Efficiency: On the Taskmaster's Walker's out-of-date checks, don't return any childr...

git-svn-id: http://scons.tigris.org/svn/scons/trunk@266 fdb21ef1-2011-0410-befe-b5e4ea1792b1

diff --git a/src/CHANGES.txt b/src/CHANGES.txt
index d3f6aa0d231f3011a9af003a63f252a1ddcf750c..b364ac7036e39371b20c126f4151ae165b9dc606 100644 (file)
--- a/src/CHANGES.txt
+++ b/src/CHANGES.txt
@@ -65,6 +65,9 @@ RELEASE 0.05 -
 
   - Add preliminary support for Unicode strings.
 
+  - Efficiency:  don't scan dependencies more than once during the
+    walk of a tree.
+
   From Anthony Roach:
 
   - Make the scons script return an error code on failures.

diff --git a/src/engine/SCons/Taskmaster.py b/src/engine/SCons/Taskmaster.py
index 558845db035f0687bee54ad498cc511f8bb667f1..cdee37811daca5a5e4c6f5ffeb7db15708573584 100644 (file)
--- a/src/engine/SCons/Taskmaster.py
+++ b/src/engine/SCons/Taskmaster.py
@@ -166,6 +166,10 @@ class Taskmaster:
     def __init__(self, targets=[], tasker=Task, calc=Calc()):
         
         def out_of_date(node):
+            if node.get_state():
+                # The state is set, so someone has already been here
+                # (finished or currently executing).  Find another one.
+                return []
             # Scan the file before fetching its children().
             node.scan()
             return filter(lambda x: x.get_state() != SCons.Node.up_to_date,

diff --git a/src/engine/SCons/TaskmasterTests.py b/src/engine/SCons/TaskmasterTests.py
index 0d7a7ad423be8ba9d97356b964ec038d8b0f08d9..32a111010dbce54824e0e06802455924677fa915 100644 (file)
--- a/src/engine/SCons/TaskmasterTests.py
+++ b/src/engine/SCons/TaskmasterTests.py
@@ -32,6 +32,7 @@ import SCons.Errors
 
 built = None
 executed = None
+scan_called = 0
 
 class Node:
     def __init__(self, name, kids = [], scans = []):
@@ -58,6 +59,8 @@ class Node:
        return self.kids
 
     def scan(self):
+       global scan_called
+       scan_called = scan_called + 1
         self.kids = self.kids + self.scans
         for scan in self.scans:
             scan.parents.append(self)
@@ -240,6 +243,36 @@ class TaskmasterTestCase(unittest.TestCase):
         assert t.get_target() == n3
         t.executed()
         assert tm.next_task() == None
+
+       n1 = Node("n1")
+       n2 = Node("n2")
+       n3 = Node("n3", [n1, n2])
+       n4 = Node("n4", [n3])
+       n5 = Node("n5", [n3])
+       global scan_called
+       scan_called = 0
+       tm = SCons.Taskmaster.Taskmaster([n4])
+       t = tm.next_task()
+        assert t.get_target() == n1
+       t.executed()
+       t = tm.next_task()
+        assert t.get_target() == n2
+       t.executed()
+       t = tm.next_task()
+        assert t.get_target() == n3
+       t.executed()
+       t = tm.next_task()
+        assert t.get_target() == n4
+       t.executed()
+       assert tm.next_task() == None
+       assert scan_called == 4, scan_called
+
+       tm = SCons.Taskmaster.Taskmaster([n5])
+       t = tm.next_task()
+        assert t.get_target() == n5, t.get_target()
+       t.executed()
+       assert tm.next_task() == None
+       assert scan_called == 5, scan_called
     
     def test_cycle_detection(self):
         n1 = Node("n1")