[bitbake-devel] [PATCH 1/8] bitbake: Unbuffer stdout for log files

[Jason Wessel]

It is possible to lose critical log data when python exits in an
unorderly fashion via segmentation fault or certain types of crashes.
This is because the buffer characteristics are inherited from the top
level stdout, which should be set to unbuffered, for the purpose of
all the forked children.

This pushes the buffering to the OS, instead of having python managing
the buffers in its stream handler class.

This change is also to provide the ability to tail logs written from
processes in "real time" because they would be written in an orderly
fashion depending upon the OS characteristics for the file I/O.

(LOCAL REV ONLY: NOT UPSTREAM)

Signed-off-by: Jason Wessel <jason.wessel at windriver.com>
---
 bin/bitbake |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/bin/bitbake b/bin/bitbake
index ed2ff06..c000d98 100755
--- a/bin/bitbake
+++ b/bin/bitbake
@@ -43,6 +43,14 @@ from bb import server
 __version__ = "1.15.3"
 logger = logging.getLogger("BitBake")
 
+# Unbuffer stdout to avoid log truncation in the event
+# of an unorderly exit as well as to provide timely
+# updates to log files for use with tail
+try:
+    if sys.stdout.name == '<stdout>':
+        sys.stdout = os.fdopen(sys.stdout.fileno(), 'w', 0)
+except:
+    pass
 
 class BBConfiguration(object):
     """
-- 
1.7.1