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go/misc/cgo/life/c-life.c
2010-04-09 13:31:26 -07:00

55 lines
1.4 KiB
C

// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
#include <assert.h>
#include "life.h"
#include "_cgo_export.h"
// Do the actual manipulation of the life board in C. This could be
// done easily in Go, we are just using C for demonstration
// purposes.
void
Step(int x, int y, int *a, int *n)
{
struct GoStart_return r;
// Use Go to start 4 goroutines each of which handles 1/4 of the
// board.
r = GoStart(0, x, y, 0, x / 2, 0, y / 2, a, n);
assert(r.r0 == 0 && r.r1 == 100); // test multiple returns
r = GoStart(1, x, y, x / 2, x, 0, y / 2, a, n);
assert(r.r0 == 1 && r.r1 == 101); // test multiple returns
GoStart(2, x, y, 0, x / 2, y / 2, y, a, n);
GoStart(3, x, y, x / 2, x, y / 2, y, a, n);
GoWait(0);
GoWait(1);
GoWait(2);
GoWait(3);
}
// The actual computation. This is called in parallel.
void
DoStep(int xdim, int ydim, int xstart, int xend, int ystart, int yend, int *a, int *n)
{
int x, y, c, i, j;
for(x = xstart; x < xend; x++) {
for(y = ystart; y < yend; y++) {
c = 0;
for(i = -1; i <= 1; i++) {
for(j = -1; j <= 1; j++) {
if(x+i >= 0 && x+i < xdim &&
y+j >= 0 && y+j < ydim &&
(i != 0 || j != 0))
c += a[(x+i)*xdim + (y+j)] != 0;
}
}
if(c == 3 || (c == 2 && a[x*xdim + y] != 0))
n[x*xdim + y] = 1;
else
n[x*xdim + y] = 0;
}
}
}