support exceptions raised by RPCs

artiq/coredevice/comm_serial.py

@@ -10,6 +10,7 @@ from artiq.language import units
 from artiq.language.context import *
 from artiq.coredevice.runtime import Environment
 from artiq.coredevice import runtime_exceptions
+from artiq.coredevice.rpc_wrapper import RPCWrapper
 
 
 logger = logging.getLogger(__name__)
@@ -69,6 +70,7 @@ class Comm(AutoContext):
         self.port.flush()
         self.set_remote_baud(self.baud_rate)
         self.set_baud(self.baud_rate)
+        self.rpc_wrapper = RPCWrapper()
 
     def set_baud(self, baud):
         self.port.baudrate = baud
@@ -183,19 +185,18 @@ class Comm(AutoContext):
             if type_tag == "l":
                 r.append(self._receive_rpc_values())
 
-    def _serve_rpc(self, rpc_map):
-        (rpc_num, ) = struct.unpack(">h", _read_exactly(self.port, 2))
+    def _serve_rpc(self, rpc_map, user_exception_map):
+        rpc_num = struct.unpack(">h", _read_exactly(self.port, 2))[0]
         args = self._receive_rpc_values()
         logger.debug("rpc service: {} ({})".format(rpc_num, args))
-        r = rpc_map[rpc_num](*args)
-        if r is None:
-            r = 0
-        _write_exactly(self.port, struct.pack(">l", r))
+        eid, r = self.rpc_wrapper.run_rpc(user_exception_map, rpc_map[rpc_num], args)
+        _write_exactly(self.port, struct.pack(">ll", eid, r))
         logger.debug("rpc service: {} ({}) == {}".format(
             rpc_num, args, r))
 
     def _serve_exception(self, user_exception_map):
-        (eid, ) = struct.unpack(">l", _read_exactly(self.port, 4))
+        eid = struct.unpack(">l", _read_exactly(self.port, 4))[0]
+        self.rpc_wrapper.filter_rpc_exception(eid)
         if eid < core_language.first_user_eid:
             exception = runtime_exceptions.exception_map[eid]
         else:
@@ -206,7 +207,7 @@ class Comm(AutoContext):
         while True:
             msg = self._get_device_msg()
             if msg == _D2HMsgType.RPC_REQUEST:
-                self._serve_rpc(rpc_map)
+                self._serve_rpc(rpc_map, user_exception_map)
             elif msg == _D2HMsgType.KERNEL_EXCEPTION:
                 self._serve_exception(user_exception_map)
             elif msg == _D2HMsgType.KERNEL_FINISHED:

artiq/coredevice/rpc_wrapper.py

@@ -0,0 +1,40 @@
+from artiq.coredevice.runtime_exceptions import exception_map, _RPCException
+
+
+def _lookup_exception(d, e):
+    for eid, exception in d.items():
+        if isinstance(e, exception):
+            return eid
+    return 0
+
+
+class RPCWrapper:
+    def __init__(self):
+        self.last_exception = None
+
+    def run_rpc(self, user_exception_map, fn, args):
+        eid = 0
+        r = None
+
+        try:
+            r = fn(*args)
+        except Exception as e:
+            eid = _lookup_exception(user_exception_map, e)
+            if not eid:
+                eid = _lookup_exception(exception_map, e)
+            if eid:
+                self.last_exception = None
+            else:
+                self.last_exception = e
+                eid = _RPCException.eid
+
+        if r is None:
+            r = 0
+        else:
+            r = int(r)
+
+        return eid, r
+
+    def filter_rpc_exception(self, eid):
+        if eid == _RPCException.eid:
+            raise self.last_exception

artiq/coredevice/runtime_exceptions.py

@@ -9,7 +9,11 @@ class OutOfMemory(RuntimeException):
     """Raised when the runtime fails to allocate memory.
 
     """
-    eid = 0
+    eid = 1
+
+
+class _RPCException(RuntimeException):
+    eid = 2
 
 
 class RTIOUnderflow(RuntimeException):
@@ -19,11 +23,9 @@ class RTIOUnderflow(RuntimeException):
     The offending event is discarded and the RTIO core keeps operating.
 
     """
-    eid = 1
+    eid = 3
 
 
-# Raised by RTIO driver for regular RTIO.
-# Raised by runtime for DDS FUD.
 class RTIOSequenceError(RuntimeException):
     """Raised when an event is submitted on a given channel with a timestamp
     not larger than the previous one.
@@ -31,7 +33,7 @@ class RTIOSequenceError(RuntimeException):
     The offending event is discarded and the RTIO core keeps operating.
 
     """
-    eid = 2
+    eid = 4
 
 
 class RTIOOverflow(RuntimeException):
@@ -43,7 +45,7 @@ class RTIOOverflow(RuntimeException):
     the exception is caught, and events will be partially retrieved.
 
     """
-    eid = 3
+    eid = 5
 
 
 exception_map = {e.eid: e for e in globals().values()

artiq/test/full_stack.py

@@ -170,6 +170,25 @@ class _Exceptions(AutoContext):
                 self.trace.append(104)
 
 
+class _RPCExceptions(AutoContext):
+    def build(self):
+        self.success = False
+
+    def exception_raiser(self):
+        raise _MyException
+
+    @kernel
+    def do_not_catch(self):
+        self.exception_raiser()
+
+    @kernel
+    def catch(self):
+        try:
+            self.exception_raiser()
+        except _MyException:
+            self.success = True
+
+
 @unittest.skipIf(no_hardware, "no hardware")
 class ExecutionCase(unittest.TestCase):
     def test_primes(self):
@@ -219,6 +238,17 @@ class ExecutionCase(unittest.TestCase):
             _run_on_host(_Exceptions, trace=t_host)
         self.assertEqual(t_device, t_host)
 
+    def test_rpc_exceptions(self):
+        comm = comm_serial.Comm()
+        try:
+            uut = _RPCExceptions(core=core.Core(comm=comm))
+            with self.assertRaises(_MyException):
+                uut.do_not_catch()
+            uut.catch()
+            self.assertTrue(uut.success)
+        finally:
+            comm.close()
+
 
 class _RTIOLoopback(AutoContext):
     i = Device("ttl_in")

soc/runtime/comm_serial.c

@@ -4,6 +4,7 @@
 #include <generated/csr.h>
 
 #include "comm.h"
+#include "exceptions.h"
 
 /* host to device */
 enum {
@@ -224,6 +225,8 @@ static int send_value(int type_tag, void *value)
 int comm_rpc(int rpc_num, ...)
 {
     int type_tag;
+    int eid;
+    int retval;
 
     send_char(MSGTYPE_RPC_REQUEST);
     send_sint(rpc_num);
@@ -235,7 +238,13 @@ int comm_rpc(int rpc_num, ...)
     va_end(args);
     send_char(0);
 
-    return receive_int();
+    eid = receive_int();
+    retval = receive_int();
+
+    if(eid != EID_NONE)
+        exception_raise(eid);
+
+    return retval;
 }
 
 void comm_log(const char *fmt, ...)

soc/runtime/exceptions.h

@@ -2,10 +2,12 @@
 #define __EXCEPTIONS_H
 
 enum {
-	EID_OUT_OF_MEMORY = 0,
-	EID_RTIO_UNDERFLOW = 1,
-	EID_RTIO_SEQUENCE_ERROR = 2,
-	EID_RTIO_OVERFLOW = 3,
+    EID_NONE = 0,
+    EID_OUT_OF_MEMORY = 1,
+    EID_RPC_EXCEPTION = 2,
+    EID_RTIO_UNDERFLOW = 3,
+    EID_RTIO_SEQUENCE_ERROR = 4,
+    EID_RTIO_OVERFLOW = 5,
 };
 
 int exception_setjmp(void *jb) __attribute__((returns_twice));