Add OpenMP support to CTC wrapper

theano/tensor/nnet/ctc.py

@@ -12,7 +12,7 @@ from theano.gradient import grad_undefined
 ctc_enabled = config.ctc.enabled
 
 
-class ConnectionistTemporalClassification(gof.COp):
+class ConnectionistTemporalClassification(gof.COp, gof.OpenMPOp):
     __props__ = ('compute_grad',)
 
     func_file = "./ctc_wrapper.c"
@@ -22,8 +22,8 @@ class ConnectionistTemporalClassification(gof.COp):
         if not compute_grad:
             self.func_name = "APPLY_SPECIFIC(ctc_cost_cpu_no_grad)"
 
-        super(ConnectionistTemporalClassification, self).__init__(self.func_file,
-                                                                  self.func_name)
+        gof.COp.__init__(self, self.func_file, self.func_name)
+        gof.OpenMPOp.__init__(self)
 
         self.compute_grad = compute_grad
         self.costs = T.fvector(name="ctc_cost")
@@ -54,8 +54,11 @@ class ConnectionistTemporalClassification(gof.COp):
             dirs.append(os.path.join(config.ctc.root, "include"))
         return dirs
 
+    def c_compile_args(self):
+        return gof.OpenMPOp.c_compile_args(self)
+
     def c_headers(self):
-        return ["ctc.h"]
+        return ["ctc.h"] + gof.OpenMPOp.c_headers(self)
 
     def make_node(self, activations, labels, input_lengths):
         if not ctc_enabled:

theano/tensor/nnet/ctc_wrapper.c

@@ -13,8 +13,11 @@ void ctc_context_init(ctc_context_t * context)
     struct ctcOptions * options = &(context->options);
     memset(options, 0, sizeof(struct ctcOptions));
     options->loc = CTC_CPU;
+#if defined(_OPENMP)
+    options->num_threads = omp_get_num_threads();
+#else
     options->num_threads = 1;
-
+#endif
     context->workspace = NULL;
     context->input_lengths = NULL;
     context->flat_labels = NULL;