Merged revisions 1884-1905 via svnmerge from

http://scons.tigris.org/svn/scons/branches/core

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  r1891 | stevenknight | 2007-04-24 08:57:03 -0500 (Tue, 24 Apr 2007) | 1 line

  0.96.D632 - Fix 0.96.96 reference count regression during parallel builds.
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  r1892 | stevenknight | 2007-04-24 12:51:05 -0500 (Tue, 24 Apr 2007) | 1 line

  0.96.D633 - Fix documented default value(s) of $MSVS_USE_MFC_DIRS.
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  r1893 | stevenknight | 2007-04-24 16:12:14 -0500 (Tue, 24 Apr 2007) | 1 line

  0.96.D634 - Make the DirEntryScanner tolerant of non-Dir nodes.
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  r1898 | stevenknight | 2007-05-09 15:07:15 -0500 (Wed, 09 May 2007) | 1 line

  0.96.D635 - Portability fixes in test scripts.
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  r1899 | stevenknight | 2007-05-12 08:19:13 -0500 (Sat, 12 May 2007) | 1 line

  0.96.D636 - Update documentation with rudimentary Tool module descriptions.
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  r1901 | stevenknight | 2007-05-17 14:32:14 -0500 (Thu, 17 May 2007) | 1 line

  0.97.D001 - Initialize 0.97 for release.
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1 files changed, 153 insertions, 0 deletions

diff --git a/test/Parallel/ref_count.py b/test/Parallel/ref_count.py
new file mode 100644
index 0000000..93b6142
--- /dev/null
+++ b/test/Parallel/ref_count.py
@@ -0,0 +1,153 @@
+#!/usr/bin/env python
+#
+# __COPYRIGHT__
+#
+# Permission is hereby granted, free of charge, to any person obtaining
+# a copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish,
+# distribute, sublicense, and/or sell copies of the Software, and to
+# permit persons to whom the Software is furnished to do so, subject to
+# the following conditions:
+#
+# The above copyright notice and this permission notice shall be included
+# in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+# KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+# WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+#
+
+__revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
+
+"""
+Test for a specific race condition that used to stop a build cold when
+a Node's ref_count would get decremented past 0 and "disappear" from
+the Taskmaster's walk of the dependency graph.
+
+Note that this test does not fail every time, but would at least fail
+more than 60%-70% of the time on the system(s) I tested.
+
+The rather complicated set up here creates a condition where,
+after building four "object files" simultaneously while running with
+-j4, sets up a race condition amongst the three dependencies of the
+c6146/cpumanf.out file, where two of the dependencies are built at the
+same time (that is, by the same command) and one is built separately.
+
+We used to detect Nodes that had been started but not finished building
+and just set the waiting ref_count to the number of Nodes.  In this case,
+if we got unlucky, we'd re-visit the Nodes for the two files first and
+set the ref_count to two *before* the command that built individual node
+completed and decremented the ref_count from two to one.  Then when the
+two files completed, we'd update the ref_count to 1 - 2 = -1, which would
+cause the Taskmaster to *not* "wake up" the Node because it's ref_count
+hadn't actually reached 0.
+
+(The solution was to not set the ref_count, but to add to it only the
+Nodes that were, in fact, added to the waiting_parents lists of various
+child Nodes.)
+"""
+
+import TestSCons
+
+_python_ = TestSCons._python_
+
+test = TestSCons.TestSCons()
+
+test.write('build.py', """\
+import string
+import sys
+import time
+args = sys.argv[1:]
+outputs = []
+while args:
+    if args[0][0] != '-':
+        break
+    arg = args.pop(0)
+    if arg == '-o':
+        outputs.append(args.pop(0))
+        continue
+    if arg == '-s':
+        time.sleep(int(args.pop(0)))
+contents = ''
+for ifile in args:
+    contents = contents + open(ifile, 'rb').read()
+for ofile in outputs:
+    ofp = open(ofile, 'wb')
+    ofp.write('%s:  building from %s\\n' % (ofile, string.join(args)))
+    ofp.write(contents)
+    ofp.close()
+""")
+
+#
+#
+#
+
+test.write('SConstruct', """\
+env = Environment()
+cmd = r'%(_python_)s build.py -o $TARGET $SOURCES'
+f1 = env.Command('c6416/cpumanf/file1.obj', 'file1.c', cmd)
+f2 = env.Command('c6416/cpumanf/file2.obj', 'file2.c', cmd)
+f3 = env.Command('c6416/cpumanf/file3.obj', 'file3.c', cmd)
+f4 = env.Command('c6416/cpumanf/file4.obj', 'file4.c', cmd)
+f5 = env.Command('c6416/cpumanf/file5.obj', 'file5.c', cmd)
+f6 = env.Command('c6416/cpumanf/file6.obj', 'file6.c', cmd)
+
+objs = f1 + f2 + f3 + f4 + f5 + f6
+
+btc = env.Command('build/target/cpumanf.out', 'c6416/cpumanf.out', cmd)
+
+addcheck_obj = env.Command('addcheck.obj', 'addcheck.c', cmd)
+
+addcheck_exe = env.Command('addcheck.exe', addcheck_obj, cmd)
+
+cmd2 = r'%(_python_)s build.py -s 2 -o ${TARGETS[0]} -o ${TARGETS[1]} $SOURCES'
+
+cksums = env.Command(['c6416/cpumanf_pre_cksum.out',
+                     'c6416/cpumanf_pre_cksum.map'],
+                    objs,
+                    cmd2)
+
+cpumanf_out = env.Command('c6416/cpumanf.out',
+                          cksums + addcheck_exe,
+                          cmd)
+
+cpumanf = env.Alias('cpumanf', objs + btc)
+
+env.Command('after.out', cpumanf, r'%(_python_)s build.py -o $TARGET after.in')
+""" % locals())
+
+test.write('file1.c', "file1.c\n")
+test.write('file2.c', "file2.c\n")
+test.write('file3.c', "file3.c\n")
+test.write('file4.c', "file4.c\n")
+test.write('file5.c', "file5.c\n")
+test.write('file6.c', "file6.c\n")
+
+test.write('addcheck.c', "addcheck.c\n")
+
+test.write('after.in', "after.in\n")
+
+test.run(arguments = '-j4 after.out')
+
+test.must_match('after.out', """\
+after.out:  building from after.in
+after.in
+""")
+
+test.write('file5.c', "file5.c modified\n")
+
+test.write('after.in', "after.in modified\n")
+
+test.run(arguments = '-j4 after.out')
+
+test.must_match('after.out', """\
+after.out:  building from after.in
+after.in modified
+""")
+
+test.pass_test()