bitbake: bitbake:process: flush stderr/stdout to log

When a process terminates, some messages may still remain in stdout or
stderr and do not make it into the log file.
In addition, the messages that do make it to the log file may end up in
the log file in incorrect order.
This patch flushes all messages into the log file after the
process terminates. Some additional log flushing is also needed
to keep the various messages showing up in the log file in proper order.

[YOCTO#10785]

(Bitbake rev: 1f6e6aa8262369eafc3bbf9f01f8d981f90becdf)

Signed-off-by: Juro Bystricky <juro.bystricky@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/process.py

@@ -94,17 +94,19 @@ def _logged_communicate(pipe, log, input, extrafiles):
                 if data is not None:
                     func(data)
 
-    try:
+    def read_all_pipes(log, rin, outdata, errdata):
-        while pipe.poll() is None:
         rlist = rin
         stdoutbuf = b""
         stderrbuf = b""
+
         try:
             r,w,e = select.select (rlist, [], [], 1)
         except OSError as e:
             if e.errno != errno.EINTR:
                 raise
 
+        readextras(r)
+
         if pipe.stdout in r:
             data = stdoutbuf + pipe.stdout.read()
             if data is not None and len(data) > 0:
@@ -112,6 +114,7 @@ def _logged_communicate(pipe, log, input, extrafiles):
                     data = data.decode("utf-8")
                     outdata.append(data)
                     log.write(data)
+                    log.flush()
                     stdoutbuf = b""
                 except UnicodeDecodeError:
                     stdoutbuf = data
@@ -123,17 +126,21 @@ def _logged_communicate(pipe, log, input, extrafiles):
                     data = data.decode("utf-8")
                     errdata.append(data)
                     log.write(data)
+                    log.flush()
                     stderrbuf = b""
                 except UnicodeDecodeError:
                     stderrbuf = data
 
-            readextras(r)
+    try:
+        # Read all pipes while the process is open
+        while pipe.poll() is None:
+            read_all_pipes(log, rin, outdata, errdata)
 
+        # Pocess closed, drain all pipes...
+        read_all_pipes(log, rin, outdata, errdata)
     finally:
         log.flush()
 
-    readextras([fobj for fobj, _ in extrafiles])
-
     if pipe.stdout is not None:
         pipe.stdout.close()
     if pipe.stderr is not None: