Make a method to list all registered context and use it in NoCudnnRaise.

theano/sandbox/gpuarray/dnn.py

@@ -16,7 +16,7 @@ from theano.tensor.signal.downsample import (
     DownsampleFactorMax, MaxPoolGrad, AveragePoolGrad)
 
 from . import pygpu
-from .type import get_context, gpu_context_type
+from .type import get_context, gpu_context_type, list_contexts
 from .basic_ops import (as_gpuarray_variable, infer_context_name,
                         gpu_contiguous, HostFromGpu,
                         GpuAllocEmpty, empty_like)
@@ -82,26 +82,31 @@ def _dnn_check_version():
     return True, None
 
 
-def dnn_available(context_name):
-    if dnn_available.avail is False:
-        return False
+def dnn_present():
+    if dnn_present.avail is not None:
+        return dnn_present.avail
 
     if pygpu is None:
-        dnn_available.msg = "PyGPU not available"
-        dnn_available.avail = False
+        dnn_present.msg = "PyGPU not available"
+        dnn_present.avail = False
         return False
 
-    # If we haven't checked yet, check if we can compile.
-    if dnn_available.avail is None:
-        dnn_available.avail, dnn_available.msg = _dnn_check_compile()
-        if dnn_available.avail:
-            dnn_available.avail, dnn_available.msg = _dnn_check_version()
-            if not dnn_available.avail:
-                raise RuntimeError(dnn_available.msg)
-        if not dnn_available.avail:
+    dnn_present.avail, dnn_present.msg = _dnn_check_compile()
+    if dnn_present.avail:
+        dnn_present.avail, dnn_present.msg = _dnn_check_version()
+        if not dnn_present.avail:
+            raise RuntimeError(dnn_present.msg)
+
+    return dnn_present.avail
+
+dnn_present.avail = None
+dnn_present.msg = None
+
+
+def dnn_available(context_name):
+    if not dnn_present():
         return False
 
-    # Don't cache these checks since they depend on the context
     ctx = get_context(context_name)
 
     if not ctx.kind == 'cuda':
@@ -116,9 +121,6 @@ def dnn_available(context_name):
 
     return True
 
-dnn_available.avail = None
-dnn_available.msg = None
-
 
 class DnnBase(COp):
     """
@@ -203,9 +205,7 @@ def version():
 
     This also does a check that the header version matches the runtime version.
     """
-    if dnn_available.avail is None:
-        raise RuntimeError("called version() before dnn_available()")
-    if not dnn_available.avail:
+    if not dnn_present():
         raise Exception(
             "We can't determine the cudnn version as it is not available",
             dnn_available.msg)
@@ -1407,17 +1407,15 @@ def local_softmax_dnn(node):
 @register_opt('cudnn')
 @local_optimizer([GpuElemwise])
 def local_log_softmax_dnn(node):
+    if version() < 3000:
+        # No log-softmax before cudnn v3
+        return
     # This looks for GpuDnnSoftmax so we know that we have cudnn.
     if (isinstance(node.op, GpuElemwise) and
             isinstance(node.op.scalar_op, Log) and
             node.inputs[0].owner and
             isinstance(node.inputs[0].owner.op, GpuDnnSoftmax) and
             len(node.inputs[0].clients) == 1):
-        # Don't move this call to version outside the condition, it
-        # needs to be here.
-        if version() < 3000:
-            # No log-softmax before cudnn v3
-            return
         softmax_node = node.inputs[0].owner
         new_softmax = GpuDnnSoftmax('log', softmax_node.op.mode)
         return [new_softmax(softmax_node.inputs[0])]
@@ -1429,14 +1427,8 @@ class NoCuDNNRaise(Optimizer):
         Raise a RuntimeError if cudnn can't be used.
 
         """
-        try:
-            dnn_available(None)
-        except ValueError:
-            # This is most likely due to get_context()
-            pass
-
-        # This means we will have a problem no matter what context.
-        if not dnn_available.avail:
+        for c in list_contexts():
+            if not dnn_available(c):
                 # Make an assert error as we want Theano to fail, not
                 # just skip this optimization.
                 raise AssertionError(

theano/sandbox/gpuarray/type.py

@@ -60,6 +60,10 @@ def get_context(name):
     return _context_reg[name]
 
 
+def list_contexts():
+    return _context_reg.values()
+
+
 # Private method
 def _name_for_ctx(ctx):
     for k, v in _context_reg: