Set O_NONBLOCK just for read calls (uses fewer fcntl calls).

svn path=/main/trunk/; revision=7393

1 files changed, 5 insertions, 16 deletions

diff --git a/pym/portage/__init__.py b/pym/portage/__init__.py
index d7af652c6..54ef005a4 100644
--- a/pym/portage/__init__.py
+++ b/pym/portage/__init__.py
@@ -2484,48 +2484,37 @@ def spawn(mystring, mysettings, debug=0, free=0, droppriv=0, sesandbox=0, fakero
 		owtd = []
 		ewtd = []
 		import array, fcntl, select
-		# Use non-blocking mode to prevent read
-		# calls from blocking indefinitely.
 		fd_flags = {}
 		for f in iwtd:
 			fd_flags[f] = fcntl.fcntl(f.fileno(), fcntl.F_GETFL)
-			fcntl.fcntl(f.fileno(), fcntl.F_SETFL,
-				fd_flags[f] | os.O_NONBLOCK)
 		buffsize = 65536
 		eof = False
 		while not eof:
 			events = select.select(iwtd, owtd, ewtd)
 			for f in events[0]:
+				# Use non-blocking mode to prevent read
+				# calls from blocking indefinitely.
+				fcntl.fcntl(f.fileno(), fcntl.F_SETFL,
+					fd_flags[f] | os.O_NONBLOCK)
 				buf = array.array('B')
 				try:
 					buf.fromfile(f, buffsize)
 				except EOFError:
 					pass
+				fcntl.fcntl(f.fileno(), fcntl.F_SETFL, fd_flags[f])
 				if not buf:
 					eof = True
 					break
 				# Use blocking mode for writes since we'd rather block than
 				# trigger a EWOULDBLOCK error.
 				if f is stdin_file:
-					fcntl.fcntl(master_file.fileno(),
-						fcntl.F_SETFL, fd_flags[f])
 					buf.tofile(master_file)
 					master_file.flush()
-					fcntl.fcntl(master_file.fileno(),
-						fcntl.F_SETFL, fd_flags[f] | os.O_NONBLOCK)
 				else:
-					# stdout usually shares the O_NONBLOCK flag with stdin
-					fcntl.fcntl(stdin_file.fileno(),
-						fcntl.F_SETFL, fd_flags[f])
 					buf.tofile(stdout_file)
 					stdout_file.flush()
-					fcntl.fcntl(stdin_file.fileno(),
-						fcntl.F_SETFL, fd_flags[f] | os.O_NONBLOCK)
 					buf.tofile(log_file)
 					log_file.flush()
-		# Restore them to blocking mode.
-		for f in iwtd:
-			fcntl.fcntl(f.fileno(), fcntl.F_SETFL, fd_flags[f])
 		log_file.close()
 		stdin_file.close()
 		stdout_file.close()