qemurunner: Improve stdout logging handling

We need to ensure we read from and log the output from qemu stdout
as otherwise the buffers can fill and block, leading qemu to hang.
Use our existing logging thread to do this.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
(From OE-Core rev: a9c46ee014ef1e6436b39fdd4fd15d15388ea795)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/lib/oeqa/utils/qemurunner.py

@@ -29,6 +29,15 @@ control_chars = [chr(x) for x in control_range
                 if chr(x) not in string.printable]
 re_control_char = re.compile('[%s]' % re.escape("".join(control_chars)))
 
+def getOutput(o):
+    import fcntl
+    fl = fcntl.fcntl(o, fcntl.F_GETFL)
+    fcntl.fcntl(o, fcntl.F_SETFL, fl | os.O_NONBLOCK)
+    try:
+        return os.read(o.fileno(), 1000000).decode("utf-8")
+    except BlockingIOError:
+        return ""
+
 class QemuRunner:
 
     def __init__(self, machine, rootfs, display, tmpdir, deploy_dir_image, logfile, boottime, dump_dir, use_kvm, logger, use_slirp=False,
@@ -55,6 +64,7 @@ class QemuRunner:
         self.boottime = boottime
         self.logged = False
         self.thread = None
+        self.threadsock = None
         self.use_kvm = use_kvm
         self.use_ovmf = use_ovmf
         self.use_slirp = use_slirp
@@ -119,21 +129,11 @@ class QemuRunner:
                 f.write(msg)
         self.msg += self.decode_qemulog(msg)
 
-    def getOutput(self, o):
-        import fcntl
-        fl = fcntl.fcntl(o, fcntl.F_GETFL)
-        fcntl.fcntl(o, fcntl.F_SETFL, fl | os.O_NONBLOCK)
-        try:
-            return os.read(o.fileno(), 1000000).decode("utf-8")
-        except BlockingIOError:
-            return ""
-
-
     def handleSIGCHLD(self, signum, frame):
         if self.runqemu and self.runqemu.poll():
             if self.runqemu.returncode:
                 self.logger.error('runqemu exited with code %d' % self.runqemu.returncode)
-                self.logger.error('Output from runqemu:\n%s' % self.getOutput(self.runqemu.stdout))
+                self.logger.error('Output from runqemu:\n%s' % getOutput(self.runqemu.stdout))
                 self.stop()
 
     def start(self, qemuparams = None, get_ip = True, extra_bootparams = None, runqemuparams='', launch_cmd=None, discard_writes=True):
@@ -282,7 +282,7 @@ class QemuRunner:
                 if self.runqemu.returncode:
                     # No point waiting any longer
                     self.logger.warning('runqemu exited with code %d' % self.runqemu.returncode)
-                    self.logger.warning("Output from runqemu:\n%s" % self.getOutput(output))
+                    self.logger.warning("Output from runqemu:\n%s" % getOutput(output))
                     self.stop()
                     return False
             time.sleep(0.5)
@@ -309,7 +309,7 @@ class QemuRunner:
             ps = subprocess.Popen(['ps', 'axww', '-o', 'pid,ppid,pri,ni,command '], stdout=subprocess.PIPE).communicate()[0]
             processes = ps.decode("utf-8")
             self.logger.debug("Running processes:\n%s" % processes)
-            op = self.getOutput(output)
+            op = getOutput(output)
             self.stop()
             if op:
                 self.logger.error("Output from runqemu:\n%s" % op)
@@ -387,7 +387,7 @@ class QemuRunner:
                            time.time() - connect_time))
 
         # We are alive: qemu is running
-        out = self.getOutput(output)
+        out = getOutput(output)
         netconf = False # network configuration is not required by default
         self.logger.debug("qemu started in %.2f seconds - qemu procces pid is %s (%s)" %
                           (time.time() - (endtime - self.runqemutime),
@@ -430,9 +430,10 @@ class QemuRunner:
         self.logger.debug("Target IP: %s" % self.ip)
         self.logger.debug("Server IP: %s" % self.server_ip)
 
+        self.thread = LoggingThread(self.log, self.threadsock, self.logger, self.runqemu.stdout)
+        self.thread.start()
+
         if self.serial_ports >= 2:
-            self.thread = LoggingThread(self.log, self.threadsock, self.logger)
-            self.thread.start()
             if not self.thread.connection_established.wait(self.boottime):
                 self.logger.error("Didn't receive a console connection from qemu. "
                              "Here is the qemu command line used:\n%s\nand "
@@ -444,7 +445,7 @@ class QemuRunner:
         self.logger.debug("Waiting at most %d seconds for login banner (%s)" %
                           (self.boottime, time.strftime("%D %H:%M:%S")))
         endtime = time.time() + self.boottime
-        filelist = [self.server_socket, self.runqemu.stdout]
+        filelist = [self.server_socket]
         reachedlogin = False
         stopread = False
         qemusock = None
@@ -564,7 +565,7 @@ class QemuRunner:
                 self.logger.debug("Sending SIGKILL to runqemu")
                 os.killpg(os.getpgid(self.runqemu.pid), signal.SIGKILL)
             if not self.runqemu.stdout.closed:
-                self.logger.info("Output from runqemu:\n%s" % self.getOutput(self.runqemu.stdout))
+                self.logger.info("Output from runqemu:\n%s" % getOutput(self.runqemu.stdout))
             self.runqemu.stdin.close()
             self.runqemu.stdout.close()
             self.runqemu_exited = True
@@ -700,9 +701,11 @@ class QemuRunner:
 # event loop. The mechanism for stopping the thread is a simple pipe which
 # will wake up the poll and allow for tearing everything down.
 class LoggingThread(threading.Thread):
-    def __init__(self, logfunc, sock, logger):
+    def __init__(self, logfunc, sock, logger, qemuoutput):
         self.connection_established = threading.Event()
+
         self.serversock = sock
+        self.qemuoutput = qemuoutput
         self.logfunc = logfunc
         self.logger = logger
         self.readsock = None
@@ -732,7 +735,8 @@ class LoggingThread(threading.Thread):
 
     def teardown(self):
         self.logger.debug("Tearing down logging thread")
-        self.close_socket(self.serversock)
+        if self.serversock:
+            self.close_socket(self.serversock)
 
         if self.readsock is not None:
             self.close_socket(self.readsock)
@@ -747,7 +751,9 @@ class LoggingThread(threading.Thread):
     def eventloop(self):
         poll = select.poll()
         event_read_mask = self.errorevents | self.readevents
-        poll.register(self.serversock.fileno())
+        if self.serversock:
+            poll.register(self.serversock.fileno())
+        poll.register(self.qemuoutput.fileno())
         poll.register(self.readpipe, event_read_mask)
 
         breakout = False
@@ -767,7 +773,7 @@ class LoggingThread(threading.Thread):
                     break
 
                 # A connection request was received
-                elif self.serversock.fileno() == event[0]:
+                elif self.serversock and self.serversock.fileno() == event[0]:
                     self.logger.debug("Connection request received")
                     self.readsock, _ = self.serversock.accept()
                     self.readsock.setblocking(0)
@@ -781,6 +787,10 @@ class LoggingThread(threading.Thread):
                 elif self.readsock.fileno() == event[0]:
                     data = self.recv(1024)
                     self.logfunc(data)
+                elif self.qemuoutput.fileno() == event[0]:
+                    data = self.qemuoutput.read()
+                    self.logger.debug("Data received on qemu stdout %s" % data)
+                    self.logfunc(data, ".stdout")
 
     # Since the socket is non-blocking make sure to honor EAGAIN
     # and EWOULDBLOCK.