diff --git a/artiq/frontend/artiq_ctlmgr.py b/artiq/frontend/artiq_ctlmgr.py
index f73bbde87..d6e7a299c 100755
--- a/artiq/frontend/artiq_ctlmgr.py
+++ b/artiq/frontend/artiq_ctlmgr.py
@@ -12,8 +12,7 @@ import platform
 
 from artiq.protocols.sync_struct import Subscriber
 from artiq.protocols.pc_rpc import AsyncioClient, Server
-from artiq.protocols.logging import (LogForwarder,
-                                     parse_log_message, log_with_name,
+from artiq.protocols.logging import (LogForwarder, LogParser,
                                      SourceFilter)
 from artiq.tools import *
 
@@ -79,22 +78,8 @@ class Controller:
             else:
                 break
 
-    async def forward_logs(self, stream):
-        source = "controller({})".format(self.name)
-        while True:
-            try:
-                entry = (await stream.readline())
-                if not entry:
-                    break
-                entry = entry[:-1]
-                level, name, message = parse_log_message(entry.decode())
-                log_with_name(name, level, message, extra={"source": source})
-            except:
-                logger.debug("exception in log forwarding", exc_info=True)
-                break
-        logger.debug("stopped log forwarding of stream %s of %s",
-            stream, self.name)
-
+    def _get_log_source(self):
+        return "controller({})".format(self.name)
 
     async def launcher(self):
         try:
@@ -105,10 +90,12 @@ class Controller:
                     self.process = await asyncio.create_subprocess_exec(
                         *shlex.split(self.command),
                         stdout=subprocess.PIPE, stderr=subprocess.PIPE)
-                    asyncio.ensure_future(self.forward_logs(
-                        self.process.stdout))
-                    asyncio.ensure_future(self.forward_logs(
-                        self.process.stderr))
+                    asyncio.ensure_future(
+                        LogParser(self._get_log_source).stream_task(
+                            self.process.stdout))
+                    asyncio.ensure_future(
+                        LogParser(self._get_log_source).stream_task(
+                            self.process.stderr))
                     await self._wait_and_ping()
                 except FileNotFoundError:
                     logger.warning("Controller %s failed to start", self.name)
diff --git a/artiq/frontend/artiq_master.py b/artiq/frontend/artiq_master.py
index 54b4a5670..4fdc7e9d5 100755
--- a/artiq/frontend/artiq_master.py
+++ b/artiq/frontend/artiq_master.py
@@ -9,7 +9,7 @@ from artiq.tools import *
 from artiq.protocols.pc_rpc import Server as RPCServer
 from artiq.protocols.sync_struct import Publisher
 from artiq.protocols.logging import Server as LoggingServer
-from artiq.master.log import log_args, init_log, log_worker
+from artiq.master.log import log_args, init_log
 from artiq.master.databases import DeviceDB, DatasetDB
 from artiq.master.scheduler import Scheduler
 from artiq.master.worker_db import get_last_rid
@@ -63,8 +63,7 @@ def main():
         repo_backend = GitBackend(args.repository)
     else:
         repo_backend = FilesystemBackend(args.repository)
-    experiment_db = ExperimentDB(repo_backend, device_db.get_device_db,
-                                 log_worker)
+    experiment_db = ExperimentDB(repo_backend, device_db.get_device_db)
     atexit.register(experiment_db.close)
     experiment_db.scan_repository_async()
 
@@ -72,8 +71,7 @@ def main():
         "get_device_db": device_db.get_device_db,
         "get_device": device_db.get,
         "get_dataset": dataset_db.get,
-        "update_dataset": dataset_db.update,
-        "log": log_worker
+        "update_dataset": dataset_db.update
     }
     scheduler = Scheduler(get_last_rid() + 1, worker_handlers, experiment_db)
     worker_handlers.update({
diff --git a/artiq/master/experiments.py b/artiq/master/experiments.py
index 0edce0976..f9f113210 100644
--- a/artiq/master/experiments.py
+++ b/artiq/master/experiments.py
@@ -3,7 +3,6 @@ import os
 import tempfile
 import shutil
 import logging
-from functools import partial
 
 from artiq.protocols.sync_struct import Notifier
 from artiq.master.worker import (Worker, WorkerInternalException,
@@ -15,13 +14,10 @@ logger = logging.getLogger(__name__)
 
 
 async def _get_repository_entries(entry_dict,
-                                  root, filename, get_device_db, log):
-    worker = Worker({
-        "get_device_db": get_device_db,
-        "log": partial(log, "scan", os.path.basename(filename))
-    })
+                                  root, filename, get_device_db):
+    worker = Worker({"get_device_db": get_device_db})
     try:
-        description = await worker.examine(os.path.join(root, filename))
+        description = await worker.examine("scan", os.path.join(root, filename))
     except:
         log_worker_exception()
         raise
@@ -49,7 +45,7 @@ async def _get_repository_entries(entry_dict,
         entry_dict[name] = entry
 
 
-async def _scan_experiments(root, get_device_db, log, subdir=""):
+async def _scan_experiments(root, get_device_db, subdir=""):
     entry_dict = dict()
     for de in os.scandir(os.path.join(root, subdir)):
         if de.name.startswith("."):
@@ -58,13 +54,13 @@ async def _scan_experiments(root, get_device_db, log, subdir=""):
             filename = os.path.join(subdir, de.name)
             try:
                 await _get_repository_entries(
-                    entry_dict, root, filename, get_device_db, log)
+                    entry_dict, root, filename, get_device_db)
             except Exception as exc:
                 logger.warning("Skipping file '%s'", filename,
                     exc_info=not isinstance(exc, WorkerInternalException))
         if de.is_dir():
             subentries = await _scan_experiments(
-                root, get_device_db, log,
+                root, get_device_db,
                 os.path.join(subdir, de.name))
             entries = {de.name + "/" + k: v for k, v in subentries.items()}
             entry_dict.update(entries)
@@ -81,10 +77,9 @@ def _sync_explist(target, source):
 
 
 class ExperimentDB:
-    def __init__(self, repo_backend, get_device_db_fn, log_fn):
+    def __init__(self, repo_backend, get_device_db_fn):
         self.repo_backend = repo_backend
         self.get_device_db_fn = get_device_db_fn
-        self.log_fn = log_fn
 
         self.cur_rev = self.repo_backend.get_head_rev()
         self.repo_backend.request_rev(self.cur_rev)
@@ -106,8 +101,7 @@ class ExperimentDB:
             wd, _ = self.repo_backend.request_rev(new_cur_rev)
             self.repo_backend.release_rev(self.cur_rev)
             self.cur_rev = new_cur_rev
-            new_explist = await _scan_experiments(wd, self.get_device_db_fn,
-                                                  self.log_fn)
+            new_explist = await _scan_experiments(wd, self.get_device_db_fn)
 
             _sync_explist(self.explist, new_explist)
         finally:
@@ -122,12 +116,9 @@ class ExperimentDB:
             revision = self.cur_rev
             wd, _ = self.repo_backend.request_rev(revision)
             filename = os.path.join(wd, filename)
-        worker = Worker({
-            "get_device_db": self.get_device_db_fn,
-            "log": partial(self.log_fn, "examine", os.path.basename(filename))
-        })
+        worker = Worker({"get_device_db": self.get_device_db_fn})
         try:
-            description = await worker.examine(filename)
+            description = await worker.examine("examine", filename)
         finally:
             await worker.close()
         if use_repository:
diff --git a/artiq/master/log.py b/artiq/master/log.py
index 78def9d21..d542eac08 100644
--- a/artiq/master/log.py
+++ b/artiq/master/log.py
@@ -2,7 +2,7 @@ import logging
 import logging.handlers
 
 from artiq.protocols.sync_struct import Notifier
-from artiq.protocols.logging import parse_log_message, log_with_name, SourceFilter
+from artiq.protocols.logging import SourceFilter
 
 
 class LogBuffer:
@@ -28,14 +28,6 @@ class LogBufferHandler(logging.Handler):
             self.log_buffer.log(record.levelno, record.source, record.created,
                                 part)
 
-
-def log_worker(rid, filename, message):
-    level, name, message = parse_log_message(message)
-    log_with_name(name, level, message,
-                  extra={"source": "worker({},{})".format(rid, filename)})
-log_worker.worker_pass_runinfo = True
-
-
 def log_args(parser):
     group = parser.add_argument_group("logging")
     group.add_argument("-v", "--verbose", default=0, action="count",
diff --git a/artiq/master/worker.py b/artiq/master/worker.py
index 16b782a54..c0c5c95a1 100644
--- a/artiq/master/worker.py
+++ b/artiq/master/worker.py
@@ -7,7 +7,8 @@ import traceback
 import time
 from functools import partial
 
-from artiq.protocols import pyon
+from artiq.protocols import pipe_ipc, pyon
+from artiq.protocols.logging import LogParser
 from artiq.tools import asyncio_wait_or_cancel
 
 
@@ -47,7 +48,7 @@ class Worker:
 
         self.rid = None
         self.filename = None
-        self.process = None
+        self.ipc = None
         self.watchdogs = dict()  # wid -> expiration (using time.monotonic)
 
         self.io_lock = asyncio.Lock()
@@ -72,15 +73,25 @@ class Worker:
         else:
             return None
 
+    def _get_log_source(self):
+        return "worker({},{})".format(self.rid, self.filename)
+
     async def _create_process(self, log_level):
         await self.io_lock.acquire()
         try:
             if self.closed.is_set():
                 raise WorkerError("Attempting to create process after close")
-            self.process = await asyncio.create_subprocess_exec(
+            self.ipc = pipe_ipc.AsyncioParentComm()
+            await self.ipc.create_subprocess(
                 sys.executable, "-m", "artiq.master.worker_impl",
-                str(log_level),
-                stdout=subprocess.PIPE, stdin=subprocess.PIPE)
+                self.ipc.get_address(), str(log_level),
+                stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+            asyncio.ensure_future(
+                LogParser(self._get_log_source).stream_task(
+                    self.ipc.process.stdout))
+            asyncio.ensure_future(
+                LogParser(self._get_log_source).stream_task(
+                    self.ipc.process.stderr))
         finally:
             self.io_lock.release()
 
@@ -93,15 +104,15 @@ class Worker:
         self.closed.set()
         await self.io_lock.acquire()
         try:
-            if self.process is None:
-                # Note the %s - self.rid can be None
+            if self.ipc is None:
+                # Note the %s - self.rid can be None or a user string
                 logger.debug("worker was not created (RID %s)", self.rid)
                 return
-            if self.process.returncode is not None:
+            if self.ipc.process.returncode is not None:
                 logger.debug("worker already terminated (RID %s)", self.rid)
-                if self.process.returncode != 0:
+                if self.ipc.process.returncode != 0:
                     logger.warning("worker finished with status code %d"
-                                   " (RID %s)", self.process.returncode,
+                                   " (RID %s)", self.ipc.process.returncode,
                                    self.rid)
                 return
             obj = {"action": "terminate"}
@@ -111,21 +122,21 @@ class Worker:
                 logger.debug("failed to send terminate command to worker"
                              " (RID %s), killing", self.rid, exc_info=True)
                 try:
-                    self.process.kill()
+                    self.ipc.process.kill()
                 except ProcessLookupError:
                     pass
-                await self.process.wait()
+                await self.ipc.process.wait()
                 return
             try:
-                await asyncio.wait_for(self.process.wait(), term_timeout)
+                await asyncio.wait_for(self.ipc.process.wait(), term_timeout)
             except asyncio.TimeoutError:
                 logger.debug("worker did not exit by itself (RID %s), killing",
                              self.rid)
                 try:
-                    self.process.kill()
+                    self.ipc.process.kill()
                 except ProcessLookupError:
                     pass
-                await self.process.wait()
+                await self.ipc.process.wait()
             else:
                 logger.debug("worker exited by itself (RID %s)", self.rid)
         finally:
@@ -134,9 +145,8 @@ class Worker:
     async def _send(self, obj, cancellable=True):
         assert self.io_lock.locked()
         line = pyon.encode(obj)
-        self.process.stdin.write(line.encode())
-        self.process.stdin.write("\n".encode())
-        ifs = [self.process.stdin.drain()]
+        self.ipc.write((line + "\n").encode())
+        ifs = [self.ipc.drain()]
         if cancellable:
             ifs.append(self.closed.wait())
         fs = await asyncio_wait_or_cancel(
@@ -153,7 +163,7 @@ class Worker:
     async def _recv(self, timeout):
         assert self.io_lock.locked()
         fs = await asyncio_wait_or_cancel(
-            [self.process.stdout.readline(), self.closed.wait()],
+            [self.ipc.readline(), self.closed.wait()],
             timeout=timeout, return_when=asyncio.FIRST_COMPLETED)
         if all(f.cancelled() for f in fs):
             raise WorkerTimeout("Timeout receiving data from worker")
@@ -193,8 +203,6 @@ class Worker:
                 func = self.register_experiment
             else:
                 func = self.handlers[action]
-            if getattr(func, "worker_pass_runinfo", False):
-                func = partial(func, self.rid, self.filename)
             try:
                 data = func(*obj["args"], **obj["kwargs"])
                 reply = {"status": "ok", "data": data}
@@ -266,7 +274,10 @@ class Worker:
         await self._worker_action({"action": "write_results"},
                                   timeout)
 
-    async def examine(self, file, timeout=20.0):
+    async def examine(self, rid, file, timeout=20.0):
+        self.rid = rid
+        self.filename = os.path.basename(file)
+
         await self._create_process(logging.WARNING)
         r = dict()
         def register(class_name, name, arginfo):
diff --git a/artiq/master/worker_impl.py b/artiq/master/worker_impl.py
index d8bf5cb82..164bf7cc4 100644
--- a/artiq/master/worker_impl.py
+++ b/artiq/master/worker_impl.py
@@ -6,8 +6,8 @@ import traceback
 from collections import OrderedDict
 
 import artiq
-from artiq.protocols import pyon
-from artiq.tools import file_import
+from artiq.protocols import pipe_ipc, pyon
+from artiq.tools import multiline_log_config, file_import
 from artiq.master.worker_db import DeviceManager, DatasetManager, get_hdf5_output
 from artiq.language.environment import is_experiment
 from artiq.language.core import set_watchdog_factory, TerminationRequested
@@ -15,16 +15,16 @@ from artiq.coredevice.core import CompileError, host_only, _render_diagnostic
 from artiq import __version__ as artiq_version
 
 
+ipc = None
+
 def get_object():
-    line = sys.__stdin__.readline()
+    line = ipc.readline().decode()
     return pyon.decode(line)
 
 
 def put_object(obj):
     ds = pyon.encode(obj)
-    sys.__stdout__.write(ds)
-    sys.__stdout__.write("\n")
-    sys.__stdout__.flush()
+    ipc.write((ds + "\n").encode())
 
 
 class ParentActionError(Exception):
@@ -53,23 +53,6 @@ def make_parent_action(action, exception=None):
     return parent_action
 
 
-class LogForwarder:
-    def __init__(self):
-        self.buffer = ""
-
-    to_parent = staticmethod(make_parent_action("log"))
-
-    def write(self, data):
-        self.buffer += data
-        while "\n" in self.buffer:
-            i = self.buffer.index("\n")
-            self.to_parent(self.buffer[:i])
-            self.buffer = self.buffer[i+1:]
-
-    def flush(self):
-        pass
-
-
 class ParentDeviceDB:
     get_device_db = make_parent_action("get_device_db")
     get = make_parent_action("get_device", KeyError)
@@ -202,9 +185,10 @@ def setup_diagnostics(experiment_file, repository_path):
 
 
 def main():
-    sys.stdout = LogForwarder()
-    sys.stderr = LogForwarder()
-    logging.basicConfig(level=int(sys.argv[1]))
+    global ipc
+
+    multiline_log_config(level=int(sys.argv[2]))
+    ipc = pipe_ipc.ChildComm(sys.argv[1])
 
     start_time = None
     rid = None
@@ -268,7 +252,11 @@ def main():
         # When we get CompileError, a more suitable diagnostic has already
         # been printed.
         if not isinstance(exc, CompileError):
-            lines = ["Terminating with exception\n"]
+            short_exc_info = type(exc).__name__
+            exc_str = str(exc)
+            if exc_str:
+                short_exc_info += ": " + exc_str
+            lines = ["Terminating with exception ("+short_exc_info+")\n"]
             lines += traceback.format_exception_only(type(exc), exc)
             if hasattr(exc, "parent_traceback"):
                 lines += exc.parent_traceback
@@ -277,6 +265,7 @@ def main():
         put_object({"action": "exception"})
     finally:
         device_mgr.close_devices()
+        ipc.close()
 
 
 if __name__ == "__main__":
diff --git a/artiq/protocols/logging.py b/artiq/protocols/logging.py
index e8fa71e66..b6ddb9bb6 100644
--- a/artiq/protocols/logging.py
+++ b/artiq/protocols/logging.py
@@ -1,8 +1,9 @@
 import asyncio
 import logging
+import re
 
 from artiq.protocols.asyncio_server import AsyncioServer
-from artiq.tools import TaskObject
+from artiq.tools import TaskObject, MultilineFormatter
 
 
 logger = logging.getLogger(__name__)
@@ -25,15 +26,64 @@ _name_to_level = {
 
 
 def parse_log_message(msg):
-    for name, level in _name_to_level.items():
-        if msg.startswith(name + ":"):
-            remainder = msg[len(name) + 1:]
+    lr = "|".join(_name_to_level.keys())
+    m = re.fullmatch('('+lr+')(<\d+>)?:([^:]*):(.*)', msg)
+    if m is None:
+        return 0, logging.INFO, "print", msg
+    level = _name_to_level[m.group(1)]
+    if m.group(2):
+        multiline = int(m.group(2)[1:-1]) - 1
+    else:
+        multiline = 0
+    name = m.group(3)
+    message = m.group(4)
+    return multiline, level, name, message
+
+
+class LogParser:
+    def __init__(self, source_cb):
+        self.source_cb = source_cb
+        self.multiline_count = 0
+        self.multiline_level = None
+        self.multiline_name = None
+        self.multiline_message = None
+
+    def line_input(self, msg):
+        if self.multiline_count:
+            self.multiline_message += "\n" + msg
+            self.multiline_count -= 1
+            if not self.multiline_count:
+                log_with_name(
+                    self.multiline_name,
+                    self.multiline_level,
+                    self.multiline_message,
+                    extra={"source": self.source_cb()})
+                self.multiline_level = None
+                self.multiline_name = None
+                self.multiline_message = None
+        else:
+            multiline, level, name, message = parse_log_message(msg)
+            if multiline:
+                self.multiline_count = multiline
+                self.multiline_level = level
+                self.multiline_name = name
+                self.multiline_message = message
+            else:
+                log_with_name(name, level, message,
+                              extra={"source": self.source_cb()})
+
+    async def stream_task(self, stream):
+        while True:
             try:
-                idx = remainder.index(":")
+                entry = (await stream.readline())
+                if not entry:
+                    break
+                self.line_input(entry[:-1].decode())
             except:
-                continue
-            return level, remainder[:idx], remainder[idx+1:]
-    return logging.INFO, "print", msg
+                logger.debug("exception in log forwarding", exc_info=True)
+                break
+        logger.debug("stopped log forwarding of stream %s of %s",
+            stream, self.source_cb())
 
 
 _init_string = b"ARTIQ logging\n"
@@ -42,8 +92,10 @@ _init_string = b"ARTIQ logging\n"
 class Server(AsyncioServer):
     """Remote logging TCP server.
 
-    Takes one log entry per line, in the format:
-        source:levelno:name:message
+    Log entries are in the format:
+        source:levelno<total_lines>:name:message
+        continuation...
+        ...continuation
     """
     async def _handle_connection_cr(self, reader, writer):
         try:
@@ -51,6 +103,9 @@ class Server(AsyncioServer):
             if line != _init_string:
                 return
 
+            source = None
+            parser = LogParser(lambda: source)
+
             while True:
                 line = await reader.readline()
                 if not line:
@@ -60,20 +115,16 @@ class Server(AsyncioServer):
                 except:
                     return
                 line = line[:-1]
-                linesplit = line.split(":", 3)
-                if len(linesplit) != 4:
-                    logger.warning("received improperly formatted message, "
-                                   "dropping connection")
-                    return
-                source, level, name, message = linesplit
-                try:
-                    level = int(level)
-                except:
-                    logger.warning("received improperly formatted level, "
-                                   "dropping connection")
-                    return
-                log_with_name(name, level, message,
-                              extra={"source": source})
+                if parser.multiline_count:
+                    parser.line_input(line)
+                else:
+                    linesplit = line.split(":", maxsplit=1)
+                    if len(linesplit) != 2:
+                        logger.warning("received improperly formatted message, "
+                                       "dropping connection")
+                        return
+                    source, remainder = linesplit
+                    parser.line_input(remainder)
         finally:
             writer.close()
 
@@ -100,19 +151,12 @@ class LogForwarder(logging.Handler, TaskObject):
         logging.Handler.__init__(self, **kwargs)
         self.host = host
         self.port = port
-        self.setFormatter(logging.Formatter(
-            "%(name)s:%(message)s"))
+        self.setFormatter(MultilineFormatter())
         self._queue = asyncio.Queue(queue_size)
         self.reconnect_timer = reconnect_timer
 
     def emit(self, record):
-        message = self.format(record)
-        for part in message.split("\n"):
-            part = "{}:{}:{}".format(record.source, record.levelno, part)
-            try:
-                self._queue.put_nowait(part)
-            except asyncio.QueueFull:
-                break
+        self._queue.put_nowait(record.source + ":" + self.format(record))
 
     async def _do(self):
         while True:
diff --git a/artiq/test/worker.py b/artiq/test/worker.py
index 94c7d8897..efc2fa6e2 100644
--- a/artiq/test/worker.py
+++ b/artiq/test/worker.py
@@ -71,7 +71,7 @@ def _run_experiment(class_name):
         "arguments": dict()
     }
     loop = asyncio.get_event_loop()
-    worker = Worker(handlers={"log": lambda message: None})
+    worker = Worker({})
     loop.run_until_complete(_call_worker(worker, expid))
 
 
diff --git a/artiq/tools.py b/artiq/tools.py
index addd5d55c..d8abc603a 100644
--- a/artiq/tools.py
+++ b/artiq/tools.py
@@ -133,8 +133,30 @@ def simple_network_args(parser, default_port):
             group.add_argument("--port-" + name, default=default, type=int,
                            help=h)
 
+class MultilineFormatter(logging.Formatter):
+    def __init__(self):
+        logging.Formatter.__init__(
+            self, "%(levelname)s:%(name)s:%(message)s")
+
+    def format(self, record):
+        r = logging.Formatter.format(self, record)
+        linebreaks = r.count("\n")
+        if linebreaks:
+            i = r.index(":")
+            r = r[:i] + "<" + str(linebreaks + 1) + ">" + r[i:]
+        return r
+
+
+def multiline_log_config(level):
+    root_logger = logging.getLogger()
+    root_logger.setLevel(level)
+    handler = logging.StreamHandler()
+    handler.setFormatter(MultilineFormatter())
+    root_logger.addHandler(handler)
+
+
 def init_logger(args):
-    logging.basicConfig(level=logging.WARNING + args.quiet*10 - args.verbose*10)
+    multiline_log_config(level=logging.WARNING + args.quiet*10 - args.verbose*10)
 
 
 def bind_address_from_args(args):