Use a select loop for moving input and ouput when logging is enabled in portage.spawn().

svn path=/main/trunk/; revision=7389

diff --git a/pym/portage/__init__.py b/pym/portage/__init__.py
index 4dcbec1eb9a2c00f97e9938736bde433afaa1ade..77492dfef298c0451f494267223dbcb778f6b852 100644 (file)
--- a/pym/portage/__init__.py
+++ b/pym/portage/__init__.py
@@ -2378,11 +2378,10 @@ def spawn(mystring, mysettings, debug=0, free=0, droppriv=0, sesandbox=0, fakero
        # pseudo-terminal that connects two domains.
        logfile = keywords.get("logfile")
        mypids = []
+       master_fd = None
        slave_fd = None
-       output_pid = None
-       input_pid = None
        stdin_termios = None
-       stdin_fd = None
+       fd_pipes_orig = None
        if logfile:
                del keywords["logfile"]
                fd_pipes = keywords.get("fd_pipes")
@@ -2393,6 +2392,7 @@ def spawn(mystring, mysettings, debug=0, free=0, droppriv=0, sesandbox=0, fakero
                from pty import openpty
                master_fd, slave_fd = openpty()
                fd_pipes.setdefault(0, sys.stdin.fileno())
+               fd_pipes_orig = fd_pipes.copy()
                stdin_fd = fd_pipes[0]
                if os.isatty(stdin_fd):
                        # Copy the termios attributes from stdin_fd to the slave_fd and put
@@ -2427,18 +2427,6 @@ def spawn(mystring, mysettings, debug=0, free=0, droppriv=0, sesandbox=0, fakero
                                if pre_exec:
                                        pre_exec()
                        keywords["pre_exec"] = setup_ctty
-               # tee will always exit with an IO error, so ignore it's stderr.
-               null_file = open('/dev/null', 'w')
-               mypids.extend(portage.process.spawn(['tee', '-i', '-a', logfile],
-                       returnpid=True, fd_pipes={0:master_fd, 1:fd_pipes[1],
-                       2:null_file.fileno()}))
-               output_pid = mypids[-1]
-               mypids.extend(portage.process.spawn(['cat'],
-                       returnpid=True, fd_pipes={0:fd_pipes[0], 1:master_fd,
-                       2:null_file.fileno()}))
-               input_pid = mypids[-1]
-               os.close(master_fd)
-               null_file.close()
                fd_pipes[0] = slave_fd
                fd_pipes[1] = slave_fd
                fd_pipes[2] = slave_fd
@@ -2487,26 +2475,53 @@ def spawn(mystring, mysettings, debug=0, free=0, droppriv=0, sesandbox=0, fakero
        if returnpid:
                return mypids
 
-       if output_pid:
-               # tee will exit when the other end of the pseudo-terminal is closed.
-               os.waitpid(output_pid, 0)
-               portage.process.spawned_pids.remove(output_pid)
-       if input_pid:
-               # cat is blocking on stdin, so it must be killed.
-               import signal
-               try:
-                       os.kill(input_pid, signal.SIGTERM)
-               except OSError:
-                       pass # it died by itself
-               os.waitpid(input_pid, 0)
-               portage.process.spawned_pids.remove(input_pid)
+       if logfile:
+               log_file = open(logfile, 'a')
+               import array, fcntl, select
+               # Use non-blocking mode to prevent read
+               # calls from blocking indefinitely.
+               for fd in fd_pipes_orig[0], master_fd:
+                       fd_flags = fcntl.fcntl(fd, fcntl.F_GETFL)
+                       fcntl.fcntl(fd, fcntl.F_SETFL, fd_flags | os.O_NONBLOCK)
+               stdin_file = os.fdopen(os.dup(fd_pipes_orig[0]), 'r')
+               stdout_file = os.fdopen(os.dup(fd_pipes_orig[1]), 'w')
+               master_file = os.fdopen(master_fd, 'w+')
+               iwtd = [stdin_file, master_file]
+               owtd = []
+               ewtd = []
+               buffsize = 65536
+               eof = False
+               while not eof:
+                       events = select.select(iwtd, owtd, ewtd)
+                       for f in events[0]:
+                               buf = array.array('B')
+                               try:
+                                       buf.fromfile(f, buffsize)
+                               except EOFError:
+                                       pass
+                               if not buf:
+                                       eof = True
+                                       break
+                               if f is stdin_file:
+                                       buf.tofile(master_file)
+                                       master_file.flush()
+                               else:
+                                       buf.tofile(stdout_file)
+                                       stdout_file.flush()
+                                       buf.tofile(log_file)
+                                       log_file.flush()
+               log_file.close()
+               stdin_file.close()
+               stdout_file.close()
+               master_file.close()
        pid = mypids[-1]
        try:
                retval = os.waitpid(pid, 0)[1]
                portage.process.spawned_pids.remove(pid)
        finally:
                if stdin_termios:
-                       termios.tcsetattr(stdin_fd, termios.TCSAFLUSH, stdin_termios)
+                       termios.tcsetattr(fd_pipes_orig[0],
+                               termios.TCSAFLUSH, stdin_termios)
        if retval != os.EX_OK:
                if retval & 0xff:
                        return (retval & 0xff) << 8