From 03a054ca79f8c83e39f71be1cc7e5735231fe54a Mon Sep 17 00:00:00 2001
From: Avery Pennarun <apenwarr@gmail.com>
Date: Sun, 21 Nov 2010 06:23:41 -0800
Subject: [PATCH] Add a --debug-locks option.

Get rid of the "locked..." and "...unlocked!" messages by default, since
they're not usually interesting.  But add a new option to bring them back in
case we end up with trouble debugging the locking stuff.  (I don't really
100% trust it yet, although I haven't had a problem for a while now.)
---
 builder.py | 6 ++++--
 redo.py    | 3 +++
 vars.py    | 1 +
 3 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/builder.py b/builder.py
index fd5a0f3..71d539d 100644
--- a/builder.py
+++ b/builder.py
@@ -127,7 +127,8 @@ def main(targets, buildfunc):
         lock = state.Lock(t)
         lock.trylock()
         if not lock.owned:
-            log('%s (locked...)\n' % _nice(t))
+            if vars.DEBUG_LOCKS:
+                log('%s (locked...)\n' % _nice(t))
             locked.append(t)
         else:
             jwack.start_job(t, lock,
@@ -142,7 +143,8 @@ def main(targets, buildfunc):
                 lock.wait()
                 lock.trylock()
             assert(lock.owned)
-            log('%s (...unlocked!)\n' % _nice(t))
+            if vars.DEBUG_LOCKS:
+                log('%s (...unlocked!)\n' % _nice(t))
             if state.stamped(t) == None:
                 err('%s: failed in another thread\n' % _nice(t))
                 retcode[0] = 2
diff --git a/redo.py b/redo.py
index c232244..86874af 100755
--- a/redo.py
+++ b/redo.py
@@ -9,6 +9,7 @@ j,jobs=    maximum number of jobs to build at once
 d,debug    print dependency checks as they happen
 v,verbose  print commands as they are run
 shuffle    randomize the build order to find dependency bugs
+debug-locks  print messages about file locking (useful for debugging)
 """
 o = options.Options('redo', optspec)
 (opt, flags, extra) = o.parse(sys.argv[1:])
@@ -21,6 +22,8 @@ if opt.verbose:
     os.environ['REDO_VERBOSE'] = '1'
 if opt.shuffle:
     os.environ['REDO_SHUFFLE'] = '1'
+if opt.debug_locks:
+    os.environ['REDO_DEBUG_LOCKS'] = '1'
 
 is_root = not os.environ.get('REDO', '')
 
diff --git a/vars.py b/vars.py
index ae7ad0a..9c0b888 100644
--- a/vars.py
+++ b/vars.py
@@ -5,6 +5,7 @@ PWD = os.environ.get('REDO_PWD', '')
 TARGET = os.environ.get('REDO_TARGET', '')
 DEPTH = os.environ.get('REDO_DEPTH', '')
 DEBUG = atoi.atoi(os.environ.get('REDO_DEBUG', ''))
+DEBUG_LOCKS = os.environ.get('REDO_DEBUG_LOCKS', '') and 1 or 0
 VERBOSE = os.environ.get('REDO_VERBOSE', '') and 1 or 0
 SHUFFLE = os.environ.get('REDO_SHUFFLE', '') and 1 or 0
 STARTDIR = os.environ['REDO_STARTDIR']