Move general utility functions out of sim.py into tools.

The enable_debug_on_crash() function sets the exception hook to start
up PDB on uncaught exceptions

The @profile_if_possible decorator applies the kernprof.py @profile
decorator if available (because of profiling in progress), otherwise
does nothing.

2 files changed, 27 insertions, 23 deletions

diff --git a/sim.py b/sim.py
index 0bd335d..579dae8 100755
--- a/sim.py
+++ b/sim.py
@@ -11,34 +11,14 @@ import generator
 from generator import constant
 import gpu
 from fileio import root
-import ROOT
+from tools import profile_if_possible, enable_debug_on_crash
 
 def pick_seed():
     '''Returns a seed for a random number generator selected using
     a mixture of the current time and the current process ID.'''
     return int(time.time()) ^ (os.getpid() << 16)
 
-def info(type, value, tb):
-    if hasattr(sys, 'ps1') or not sys.stderr.isatty():
-       # we are in interactive mode or we don't have a tty-like
-       # device, so we call the default hook
-       sys.__excepthook__(type, value, tb)
-    else:
-       import traceback, pdb
-       # we are NOT in interactive mode, print the exception...
-       traceback.print_exception(type, value, tb)
-       print
-       # ...then start the debugger in post-mortem mode.
-       pdb.pm()
-
-
-# Allow profile decorator to exist, but do nothing if not running under kernprof
-try:
-    profile = profile
-except NameError:
-    profile = lambda x: x
-
-@profile
+@profile_if_possible
 def main():
     parser = optparse.OptionParser('%prog')
     parser.add_option('-b', type='int', dest='nbits', default=10)
@@ -148,5 +128,5 @@ def main():
     print >>sys.stderr, 'Done. %1.1f events/sec, %1.0f photons/sec.' % (options.nevents/(end_sim - start_sim), nphotons/(end_sim - start_sim))
 
 if __name__ == '__main__':
-    sys.excepthook = info
+    enable_debug_on_crash()
     main()
diff --git a/tools.py b/tools.py
index 6835228..ba36f6d 100644
--- a/tools.py
+++ b/tools.py
@@ -1,6 +1,30 @@
 import numpy as np
 import time
 import datetime
+import sys
+
+def debugger_hook(type, value, tb):
+    if hasattr(sys, 'ps1') or not sys.stderr.isatty():
+       # we are in interactive mode or we don't have a tty-like
+       # device, so we call the default hook
+       sys.__excepthook__(type, value, tb)
+    else:
+       import traceback, pdb
+       # we are NOT in interactive mode, print the exception...
+       traceback.print_exception(type, value, tb)
+       print
+       # ...then start the debugger in post-mortem mode.
+       pdb.pm()
+
+def enable_debug_on_crash():
+    '''Start the PDB console when an uncaught exception propagates to the top.'''
+    sys.excepthook = debugger_hook
+
+# Allow profile decorator to exist, but do nothing if not running under kernprof
+try:
+    profile_if_possible = profile
+except NameError:
+    profile_if_possible = lambda x: x
 
 def timeit(func):
     def f(*args, **kwargs):