SF patch #489173: Make os.spawnv not block the interpreter, from

Anthony Roach.
Release the global interpreter lock around platform spawn calls.
Bugfix candidate?  Hard to say; I favor "yes, bugfix".
These clearly *should* have been releasing the GIL all along, if for no
other reason than compatibility with the similar os.system().  But it's
possible some program out there is (a) multithreaded, (b) calling a spawn
function with P_WAIT, and (c) relying on the spawn call to block all their
threads until the spawned program completes.  I think it's very unlikely
anyone is doing that on purpose, but someone may be doing so by accident.

1 files changed, 7 insertions, 0 deletions

diff --git a/Misc/NEWS b/Misc/NEWS
index 6dd9957..6df0b52 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -52,6 +52,13 @@ Extension modules
 
 Library
 
+- Functions in the os.spawn() family now release the global interpreter
+  lock around calling the platform spawn.  They should always have done
+  this, but did not before 2.2c1.  Multithreaded programs calling
+  an os.spawn function with P_WAIT will no longer block all Python threads
+  until the spawned program completes.  It's possible that some programs
+  relies on blocking, although more likely by accident than by design.
+
 - webbrowser defaults to netscape.exe on OS/2 now.
 
 - Tix.ResizeHandle exposes detach_widget, hide, and show.