diff --git a/misc/cgo/life/Makefile b/misc/cgo/life/Makefile new file mode 100644 index 0000000000..cbcdc99275 --- /dev/null +++ b/misc/cgo/life/Makefile @@ -0,0 +1,31 @@ +# 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 ../../../src/Make.$(GOARCH) + +TARG=life + +CGOFILES=\ + life.go + +LDPATH_freebsd=-Wl,-R,`pwd` +LDPATH_linux=-Wl,-R,`pwd` +LDPATH_darwin= + +CGO_LDFLAGS=_cgo_export.o c-life.so $(LDPATH_$(GOOS)) +CGO_DEPS=_cgo_export.o c-life.so + +CLEANFILES += life + +include ../../../src/Make.pkg + +c-life.o: c-life.c _cgo_export.h + gcc $(_CGO_CFLAGS_$(GOARCH)) -g -c -fPIC $(CFLAGS) c-life.c + +c-life.so: c-life.o + gcc $(_CGO_CFLAGS_$(GOARCH)) -o $@ c-life.o $(_CGO_LDFLAGS_$(GOOS)) + +life: install main.go + $(GC) main.go + $(LD) -o $@ main.$O diff --git a/misc/cgo/life/c-life.c b/misc/cgo/life/c-life.c new file mode 100644 index 0000000000..71555a9c7a --- /dev/null +++ b/misc/cgo/life/c-life.c @@ -0,0 +1,54 @@ +// 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 +#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; + } + } +} diff --git a/misc/cgo/life/life.go b/misc/cgo/life/life.go new file mode 100644 index 0000000000..0368028537 --- /dev/null +++ b/misc/cgo/life/life.go @@ -0,0 +1,39 @@ +// 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. + +package life + +// #include "life.h" +import "C" + +import "unsafe" + +func Run(gen, x, y int, a []int) { + n := make([]int, x*y) + for i := 0; i < gen; i++ { + C.Step(C.int(x), C.int(y), (*C.int)(unsafe.Pointer(&a[0])), (*C.int)(unsafe.Pointer(&n[0]))) + copy(a, n) + } +} + +// Keep the channels visible from Go. +var chans [4]chan bool + +//export GoStart +// Double return value is just for testing. +func GoStart(i, xdim, ydim, xstart, xend, ystart, yend C.int, a *C.int, n *C.int) (int, int) { + c := make(chan bool) + go func() { + C.DoStep(xdim, ydim, xstart, xend, ystart, yend, a, n) + c <- true + }() + chans[i] = c + return int(i), int(i + 100) +} + +//export GoWait +func GoWait(i C.int) { + <-chans[i] + chans[i] = nil +} diff --git a/misc/cgo/life/life.h b/misc/cgo/life/life.h new file mode 100644 index 0000000000..b6e94cf1d3 --- /dev/null +++ b/misc/cgo/life/life.h @@ -0,0 +1,6 @@ +// 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. + +extern void Step(int, int, int *, int *); +extern void DoStep(int, int, int, int, int, int, int *, int *); diff --git a/misc/cgo/life/main.go b/misc/cgo/life/main.go new file mode 100644 index 0000000000..7c2c0c73ef --- /dev/null +++ b/misc/cgo/life/main.go @@ -0,0 +1,44 @@ +// 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. + +// Run the game of life in C using Go for parallelization. + +package main + +import ( + "flag" + "fmt" + "life" +) + +const MAXDIM = 100 + +var dim = flag.Int("dim", 16, "board dimensions") +var gen = flag.Int("gen", 10, "generations") + +func main() { + flag.Parse() + + var a [MAXDIM * MAXDIM]int + for i := 2; i < *dim; i += 8 { + for j := 2; j < *dim-3; j += 8 { + for y := 0; y < 3; y++ { + a[i**dim+j+y] = 1 + } + } + } + + life.Run(*gen, *dim, *dim, &a) + + for i := 0; i < *dim; i++ { + for j := 0; j < *dim; j++ { + if a[i**dim+j] == 0 { + fmt.Print(" ") + } else { + fmt.Print("X") + } + } + fmt.Print("\n") + } +}