1 // Copyright 2010 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 #include <assert.h> 6 #include "life.h" 7 #include "_cgo_export.h" 8 9 const int MYCONST = 0; 10 11 // Do the actual manipulation of the life board in C. This could be 12 // done easily in Go, we are just using C for demonstration 13 // purposes. 14 void 15 Step(int x, int y, int *a, int *n) 16 { 17 struct GoStart_return r; 18 19 // Use Go to start 4 goroutines each of which handles 1/4 of the 20 // board. 21 r = GoStart(0, x, y, 0, x / 2, 0, y / 2, a, n); 22 assert(r.r0 == 0 && r.r1 == 100); // test multiple returns 23 r = GoStart(1, x, y, x / 2, x, 0, y / 2, a, n); 24 assert(r.r0 == 1 && r.r1 == 101); // test multiple returns 25 GoStart(2, x, y, 0, x / 2, y / 2, y, a, n); 26 GoStart(3, x, y, x / 2, x, y / 2, y, a, n); 27 GoWait(0); 28 GoWait(1); 29 GoWait(2); 30 GoWait(3); 31 } 32 33 // The actual computation. This is called in parallel. 34 void 35 DoStep(int xdim, int ydim, int xstart, int xend, int ystart, int yend, int *a, int *n) 36 { 37 int x, y, c, i, j; 38 39 for(x = xstart; x < xend; x++) { 40 for(y = ystart; y < yend; y++) { 41 c = 0; 42 for(i = -1; i <= 1; i++) { 43 for(j = -1; j <= 1; j++) { 44 if(x+i >= 0 && x+i < xdim && 45 y+j >= 0 && y+j < ydim && 46 (i != 0 || j != 0)) 47 c += a[(x+i)*xdim + (y+j)] != 0; 48 } 49 } 50 if(c == 3 || (c == 2 && a[x*xdim + y] != 0)) 51 n[x*xdim + y] = 1; 52 else 53 n[x*xdim + y] = 0; 54 } 55 } 56 } 57
