diff options
Diffstat (limited to 'poky/bitbake/lib/bb/daemonize.py')
-rw-r--r-- | poky/bitbake/lib/bb/daemonize.py | 25 |
1 files changed, 18 insertions, 7 deletions
diff --git a/poky/bitbake/lib/bb/daemonize.py b/poky/bitbake/lib/bb/daemonize.py index 8300d1d0f..c937675eb 100644 --- a/poky/bitbake/lib/bb/daemonize.py +++ b/poky/bitbake/lib/bb/daemonize.py @@ -16,6 +16,10 @@ def createDaemon(function, logfile): background as a daemon, returning control to the caller. """ + # Ensure stdout/stderror are flushed before forking to avoid duplicate output + sys.stdout.flush() + sys.stderr.flush() + try: # Fork a child process so the parent can exit. This returns control to # the command-line or shell. It also guarantees that the child will not @@ -49,8 +53,8 @@ def createDaemon(function, logfile): # exit() or _exit()? # _exit is like exit(), but it doesn't call any functions registered # with atexit (and on_exit) or any registered signal handlers. It also - # closes any open file descriptors. Using exit() may cause all stdio - # streams to be flushed twice and any temporary files may be unexpectedly + # closes any open file descriptors, but doesn't flush any buffered output. + # Using exit() may cause all any temporary files to be unexpectedly # removed. It's therefore recommended that child branches of a fork() # and the parent branch(es) of a daemon use _exit(). os._exit(0) @@ -61,17 +65,19 @@ def createDaemon(function, logfile): # The second child. # Replace standard fds with our own - si = open('/dev/null', 'r') - os.dup2(si.fileno(), sys.stdin.fileno()) + with open('/dev/null', 'r') as si: + os.dup2(si.fileno(), sys.stdin.fileno()) try: so = open(logfile, 'a+') - se = so os.dup2(so.fileno(), sys.stdout.fileno()) - os.dup2(se.fileno(), sys.stderr.fileno()) + os.dup2(so.fileno(), sys.stderr.fileno()) except io.UnsupportedOperation: sys.stdout = open(logfile, 'a+') - sys.stderr = sys.stdout + + # Have stdout and stderr be the same so log output matches chronologically + # and there aren't two seperate buffers + sys.stderr = sys.stdout try: function() @@ -79,4 +85,9 @@ def createDaemon(function, logfile): traceback.print_exc() finally: bb.event.print_ui_queue() + # os._exit() doesn't flush open files like os.exit() does. Manually flush + # stdout and stderr so that any logging output will be seen, particularly + # exception tracebacks. + sys.stdout.flush() + sys.stderr.flush() os._exit(0) |