Allocate moments buffer only on device

1 files changed, 10 insertions, 10 deletions

diff --git a/codegen_lbm.py b/codegen_lbm.py
index 6b36c23..e1906dc 100644
--- a/codegen_lbm.py
+++ b/codegen_lbm.py
@@ -135,18 +135,16 @@ class D2Q9_BGK_Lattice:
         self.context  = cl.Context(properties=[(cl.context_properties.PLATFORM, self.platform)])
         self.queue = cl.CommandQueue(self.context)
 
-        self.np_moments  = numpy.ndarray(shape=(3, self.nCells), dtype=numpy.float32)
+        self.np_moments = []
         self.np_material = numpy.ndarray(shape=(self.nCells, 1), dtype=numpy.int32)
 
-        self.np_stat_moments = []
-
         self.setup_geometry()
 
         self.cl_pop_a = cl.Buffer(self.context, mf.READ_WRITE, size=9*self.nCells*numpy.float32(0).nbytes)
         self.cl_pop_b = cl.Buffer(self.context, mf.READ_WRITE, size=9*self.nCells*numpy.float32(0).nbytes)
 
+        self.cl_moments  = cl.Buffer(self.context, mf.WRITE_ONLY, size=3*self.nCells*numpy.float32(0).nbytes)
         self.cl_material = cl.Buffer(self.context, mf.READ_ONLY  | mf.USE_HOST_PTR, hostbuf=self.np_material)
-        self.cl_moments  = cl.Buffer(self.context, mf.READ_WRITE | mf.USE_HOST_PTR, hostbuf=self.np_moments)
 
         self.build_kernel()
 
@@ -178,13 +176,15 @@ class D2Q9_BGK_Lattice:
         self.program = cl.Program(self.context, program_src).build()
 
     def collect_moments(self):
+        moments = numpy.ndarray(shape=(3, self.nCells), dtype=numpy.float32)
+
         if self.tick:
             self.program.collect_moments(self.queue, (self.nX,self.nY), (32,1), self.cl_pop_b, self.cl_moments)
         else:
             self.program.collect_moments(self.queue, (self.nX,self.nY), (32,1), self.cl_pop_a, self.cl_moments)
 
-        cl.enqueue_copy(LBM.queue, self.np_moments, LBM.cl_moments).wait();
-        self.np_stat_moments.append(self.np_moments.copy())
+        cl.enqueue_copy(LBM.queue, moments, LBM.cl_moments).wait();
+        self.np_moments.append(moments)
 
     def evolve(self):
         if self.tick:
@@ -198,19 +198,19 @@ class D2Q9_BGK_Lattice:
         self.queue.finish()
 
     def generate_moment_plots(self):
-        for i, np_moments in enumerate(self.np_stat_moments):
-            print("Generating plot %d of %d." % (i+1, len(self.np_stat_moments)))
+        for i, moments in enumerate(self.np_moments):
+            print("Generating plot %d of %d." % (i+1, len(self.np_moments)))
 
             density = numpy.ndarray(shape=(self.nY-2, self.nX-2))
             for y in range(1,self.nY-1):
                 for x in range(1,self.nX-1):
-                    density[y-1,x-1] = np_moments[0,self.idx(x,y)]
+                    density[y-1,x-1] = moments[0,self.idx(x,y)]
 
             plt.figure(figsize=(10, 10))
             plt.imshow(density, origin='lower', vmin=0.2, vmax=2.0, cmap=plt.get_cmap('seismic'))
             plt.savefig("result/density_" + str(i) + ".png", bbox_inches='tight', pad_inches=0)
 
-        self.np_stat_moments = []
+        self.np_moments = []
 
 
 def MLUPS(cells, steps, time):