fix pserver with condition block

paddle/fluid/operators/listen_and_serv_op.cc

@@ -61,6 +61,8 @@ static void ParallelExecuteBlocks(
         framework::Async([&executor, &prepared, &program, &scope, idx]() {
           int run_block = idx;  // thread local
           try {
+            VLOG(3) << "running server block: " << run_block
+                    << "pointer: " << prepared[run_block].get();
             executor->RunPreparedContext(prepared[run_block].get(), scope);
           } catch (const std::exception &e) {
             LOG(ERROR) << "run sub program error " << e.what();
@@ -107,12 +109,14 @@ void ListenAndServOp::RunSyncLoop(
   PADDLE_ENFORCE_GE(num_blocks, 2,
                     "server program should have at least 2 blocks");
 
-  std::vector<int> optimize_blocks_idx;
-  for (auto blk : optimize_blocks) {
-    optimize_blocks_idx.push_back(blk->ID());
+  // Prepare all the server block
+  std::vector<int> optimize_blocks_list;
+  for (size_t i = 1; i < program->Size(); ++i) {
+    optimize_blocks_list.push_back(i);
   }
-  auto optimize_prepared = executor->Prepare(*program, optimize_blocks_idx);
-  // Insert placeholder for block0 which holds current op itself.
+  auto optimize_prepared = executor->Prepare(*program, optimize_blocks_list);
+  // Insert placeholder for block0 which holds current op itself,
+  // NOTE the first block in `optimize_prepared` should never be ran.
   optimize_prepared.insert(
       optimize_prepared.begin(),
       std::shared_ptr<framework::ExecutorPrepareContext>(nullptr));

python/paddle/fluid/tests/unittests/test_dist_transpiler.py

@@ -304,10 +304,50 @@ class TestL2Decay(TranspilerTest):
         # TODO(typhoonzero): test clipping and L2Decay ops are removed from trainer
 
 
-    # FIXME(typhoonzero): need to add test for async case:
-    # see https://github.com/PaddlePaddle/Paddle/issues/11691
-class TestAsyncSGD(TranspilerTest):
-    pass
+class TestL2DecayWithPiecewise(TranspilerTest):
+    def net_conf(self):
+        x = fluid.layers.data(name='x', shape=[1000], dtype='float32')
+        y_predict = fluid.layers.fc(input=x,
+                                    size=1000,
+                                    act=None,
+                                    param_attr=fluid.ParamAttr(name='fc_w'),
+                                    bias_attr=fluid.ParamAttr(name='fc_b'))
+        y = fluid.layers.data(name='y', shape=[1], dtype='float32')
+        cost = fluid.layers.square_error_cost(input=y_predict, label=y)
+        avg_cost = fluid.layers.mean(cost)
+        base_lr = 1.0
+        bd = [1, 10, 20, 30]
+        lr = [base_lr * (0.1**i) for i in range(len(bd) + 1)]
+        sgd_optimizer = fluid.optimizer.Momentum(
+            learning_rate=fluid.layers.piecewise_decay(
+                boundaries=bd, values=lr),
+            momentum=0.9,
+            regularization=fluid.regularizer.L2Decay(1e-4))
+        sgd_optimizer.minimize(avg_cost)
+        return
+
+    def test_transpiler(self):
+        pserver, startup = self.get_pserver(self.pserver1_ep)
+        trainer = self.get_trainer()
+
+        self.assertEqual(len(pserver.blocks), 9)
+        self.assertEqual([op.type for op in pserver.blocks[1].ops], [
+            "increment", "cast", "fill_constant", "fill_constant", "less_than",
+            "logical_not", "conditional_block", "fill_constant",
+            "fill_constant", "less_than", "logical_not", "logical_and",
+            "logical_and", "conditional_block", "fill_constant",
+            "fill_constant", "less_than", "logical_not", "logical_and",
+            "logical_and", "conditional_block", "fill_constant",
+            "fill_constant", "less_than", "logical_not", "logical_and",
+            "logical_and", "conditional_block", "fill_constant",
+            "conditional_block"
+        ])
+        self.assertEqual(
+            [op.type for op in pserver.blocks[7].ops],
+            ["sum", "scale", "scale", "elementwise_add", "momentum"])
+        self.assertEqual(
+            [op.type for op in pserver.blocks[8].ops],
+            ["sum", "scale", "scale", "elementwise_add", "momentum"])
 
 
 if __name__ == "__main__":

python/paddle/fluid/transpiler/distribute_transpiler.py

@@ -461,6 +461,8 @@ class DistributeTranspiler(object):
             per_opt_block = pserver_program.create_block(pre_block_idx)
             optimize_blocks.append(per_opt_block)
             # append grad merging ops before clip and weight decay
+            # cases may like: 
+            # L2Decay op -> clip op -> optimize
             for _, op in enumerate(self.optimize_ops):
                 # find the origin @GRAD var before clipping
                 grad_varname_for_block = __op_have_grad_input__(op)
@@ -468,6 +470,7 @@ class DistributeTranspiler(object):
                     merged_var = self._append_pserver_grad_merge_ops(
                         per_opt_block, grad_varname_for_block, endpoint,
                         grad_to_block_id, self.origin_program)
+                    break  # append optimize op once then append other ops.
             for _, op in enumerate(self.optimize_ops):
                 # optimizer is connected to itself
                 if ufind.is_connected(op, opt_op) and op not in global_ops: