func flattenIntoSlice(src [][]int, dest []cl.CL_uint) {
dest[0] = cl.CL_uint(len(src))
i := 1
for _, node := range src {
j := 0
numMasks := 0
start := i // Reserve index for number of masks.
i++
for j < len(node) {
maskIndex := uint32(node[j] >> 5) // index of mask to create
mask := uint32(0)
// Create a mask from all indices belonging to the block of bits.
for j < len(node) && (uint32(node[j])>>5) == maskIndex {
mask |= 1 << (uint32(node[j]) & 31)
j++
}
// Append the mask to the flattened FOS.
dest[i] = cl.CL_uint(maskIndex)
dest[i+1] = cl.CL_uint(mask)
i += 2
numMasks++
}
dest[start] = cl.CL_uint(numMasks)
}
}
func populationToSlice(pop *ga.Population, dest []cl.CL_uint) {
destPtr := 0
length := pop.Length()
numBlocks := blocksPerSolution(pop)
for _, solution := range pop.Solutions {
toCopy := length
for j := 0; j < numBlocks; j++ {
// Determine the number of bits to copy.
blockSize := 32
if toCopy < 32 {
blockSize = toCopy
}
toCopy -= blockSize
// Copy the bits into 32-bit integer.
var raw uint32
raw = 0
for k := 0; k < blockSize; k++ {
index := j*32 + k
if solution.Bits.Has(index) {
raw |= (1 << uint32(k))
}
}
dest[destPtr] = cl.CL_uint(raw)
destPtr++
}
}
}
func setKernelArg(kernel cl.CL_kernel, pos int, data interface{}) {
var status cl.CL_int
switch data := data.(type) {
case *cl.CL_mem:
status = cl.CLSetKernelArg(
kernel, cl.CL_uint(pos), cl.CL_size_t(unsafe.Sizeof(data)),
unsafe.Pointer(data))
case *cl.CL_uint:
status = cl.CLSetKernelArg(
kernel, cl.CL_uint(pos), cl.CL_size_t(unsafe.Sizeof(*data)),
unsafe.Pointer(data))
default:
log.Fatalf("Fatal error: setting kernel arg for unknown type %t.", data)
}
if status != cl.CL_SUCCESS {
log.Printf("%v", cl.ERROR_CODES_STRINGS[-status])
log.Fatalf("Fatal error: could not set arg %d for OpenCL kernel.", pos)
}
}
func runOpenCL() {
var status cl.CL_int
var numPlatforms cl.CL_uint
//---------------------------------------------------
// Step 1: Discover and retrieve OpenCL platforms.
//---------------------------------------------------
status = cl.CLGetPlatformIDs(0, nil, &numPlatforms)
platforms := make([]cl.CL_platform_id, numPlatforms)
requireSuccess(cl.CLGetPlatformIDs(numPlatforms, platforms, nil),
"could not retrieve OpenCL platform IDs.")
if verbosity >= 4 {
printPlatforms(platforms)
}
//---------------------------------------------------
// Step 2: Discover and retrieve OpenCL devices.
//---------------------------------------------------
var preferredType cl.CL_device_type
if useCPU {
preferredType = cl.CL_DEVICE_TYPE_CPU
} else {
preferredType = cl.CL_DEVICE_TYPE_GPU
}
_, gpuDevice := findDevice(platforms, preferredType)
gpuDevices := make([]cl.CL_device_id, 1)
gpuDevices[0] = gpuDevice
if verbosity >= 4 {
printDeviceInfo(gpuDevice)
}
//---------------------------------------------------
// Step 3: Create an OpenCL context.
//---------------------------------------------------
context := cl.CLCreateContext(nil, 1, gpuDevices, nil, nil, &status)
requireSuccess(status, "could not create OpenCL context.")
defer cl.CLReleaseContext(context)
//---------------------------------------------------
// Step 3: Create an OpenCL command queue.
//---------------------------------------------------
commandQueue := cl.CLCreateCommandQueue(context, gpuDevice, 0, &status)
requireSuccess(status, "could not create OpenCL command queue.")
defer cl.CLReleaseCommandQueue(commandQueue)
//---------------------------------------------------
// Step 4: Create OpenCL program and kernel.
//---------------------------------------------------
var clSourceData [3][]byte
var clSourceLengths [3]cl.CL_size_t
var err error
clSourceFiles := []string{
"kernels/" + problems[problemIndex].clSource,
"kernels/rng.cl",
"kernels/gom.cl",
}
for i, s := range clSourceFiles {
clSourceData[i], err = ioutil.ReadFile(s)
if err != nil {
log.Fatalf("Could not read the kernel source file %s.", s)
}
clSourceLengths[i] = cl.CL_size_t(len(clSourceData[i]))
}
program := cl.CLCreateProgramWithSource(context, 3, clSourceData[:], clSourceLengths[:], &status)
requireSuccess(status, "could not compile an OpenCL kernel from source.")
status = cl.CLBuildProgram(program, 1, gpuDevices, nil, nil, nil)
if status != cl.CL_SUCCESS {
printProgramBuildInfo(program, gpuDevice)
}
kernel := cl.CLCreateKernel(program, []byte("gom"), &status)
requireSuccess(status, "could not create OpenCL kernel.")
//---------------------------------------------------
// Step 6: Initialize OpenCL memory.
//---------------------------------------------------
if verbosity >= 4 {
printKernelWorkGroup(kernel, gpuDevice)
}
//---------------------------------------------------
// Step 7: Initialize OpenCL memory.
//---------------------------------------------------
var size cl.CL_uint
length := cl.CL_size_t(problemLength)
pop := ga.NewPopulation(populationSize, problemLength)
numBlocks := blocksPerSolution(pop) * pop.Size()
dataSize := cl.CL_size_t(unsafe.Sizeof(size)) * cl.CL_size_t(numBlocks)
populationData := make([]cl.CL_uint, numBlocks)
offspringData := make([]cl.CL_uint, numBlocks)
populationBuffer := cl.CLCreateBuffer(
context, cl.CL_MEM_READ_ONLY, dataSize, nil, &status)
requireSuccess(status, "could not allocate an OpenCL memory buffer.")
cloneBuffer := cl.CLCreateBuffer(
context, cl.CL_MEM_READ_WRITE, dataSize, nil, &status)
requireSuccess(status, "could not allocate an OpenCL memory buffer.")
// Maximum bound on the number of elements in the LT + node sizes.
boundSum := (length*length+3*length-2)/2 + (2*length - 1) + 1
ltSize := cl.CL_size_t(unsafe.Sizeof(length)) * boundSum
ltData := make([]cl.CL_uint, boundSum)
ltBuffer := cl.CLCreateBuffer(context, cl.CL_MEM_READ_ONLY, ltSize, nil, &status)
requireSuccess(status, "could not allocate an OpenCL memory buffer.")
var dummyCLBool cl.CL_char
improvsSize := cl.CL_size_t(unsafe.Sizeof(dummyCLBool)) * cl.CL_size_t(pop.Size())
improvsData := make([]cl.CL_char, pop.Size())
improvsBuffer := cl.CLCreateBuffer(context, cl.CL_MEM_WRITE_ONLY, improvsSize, nil, &status)
requireSuccess(status, "could not allocate an OpenCL memory buffer.")
offspringBuffer := cl.CLCreateBuffer(
context, cl.CL_MEM_WRITE_ONLY, dataSize, nil, &status)
requireSuccess(status, "could not allocate an OpenCL memory buffer.")
//---------------------------------------------------
// Step 8: Perform GOMEA.
//---------------------------------------------------
if randomSeed == 0 {
rand.Seed(time.Now().Unix())
} else {
rand.Seed(int64(randomSeed))
}
done := false
generationsPassed := 0
if verbosity >= 3 {
printGeneration(0, pop)
}
for !done {
// Build the linkage tree and upload a flattened version to the compute device.
freqs := Frequencies(pop)
lt := LinkageTree(pop, freqs)
flattenIntoSlice(lt, ltData)
requireSuccess(cl.CLEnqueueWriteBuffer(
commandQueue, ltBuffer, cl.CL_TRUE, 0,
ltSize, unsafe.Pointer(<Data[0]), 0, nil, nil),
"could not write data to an OpenCL memory buffer.")
// Store a flattened version of the population on the compute device.
populationToSlice(pop, populationData)
requireSuccess(cl.CLEnqueueWriteBuffer(
commandQueue, populationBuffer, cl.CL_TRUE, 0,
dataSize, unsafe.Pointer(&populationData[0]), 0, nil, nil),
"could not write data to an OpenCL memory buffer.")
// Set the GOM kernel arguments.
popSize := cl.CL_uint(pop.Size())
solLength := cl.CL_uint(pop.Length())
setKernelArg(kernel, 0, &populationBuffer)
setKernelArg(kernel, 1, &popSize)
setKernelArg(kernel, 2, &solLength)
setKernelArg(kernel, 3, &cloneBuffer)
setKernelArg(kernel, 4, <Buffer)
setKernelArg(kernel, 5, &improvsBuffer)
setKernelArg(kernel, 6, &offspringBuffer)
var globalWorkSize [1]cl.CL_size_t
globalWorkSize[0] = cl.CL_size_t(pop.Size())
// Perform GOM crossover.
requireSuccess(cl.CLEnqueueNDRangeKernel(
commandQueue, kernel, 1, nil, globalWorkSize[:],
nil, 0, nil, nil),
"could not enqueue OpenCL kernel.")
requireSuccess(cl.CLFinish(commandQueue), "could not finish command queue.")
// Retrieve the offspring population from the compute device.
requireSuccess(cl.CLEnqueueReadBuffer(
commandQueue, offspringBuffer, cl.CL_TRUE, 0,
dataSize, unsafe.Pointer(&offspringData[0]), 0, nil, nil),
"reading a buffer failed.")
requireSuccess(cl.CLEnqueueReadBuffer(
commandQueue, improvsBuffer, cl.CL_TRUE, 0,
improvsSize, unsafe.Pointer(&improvsData[0]), 0, nil, nil),
"reading improvs buffer failed.")
foundOptimal := sliceToPopulation(offspringData, pop)
generationsPassed++
if (verbosity == 2 && done) || (verbosity == 3) {
printGeneration(generationsPassed, pop)
}
// TODO: Termination Criterion
if generationsPassed == numGenerations {
done = true
}
improved := false
for _, b := range improvsData {
if b > 0 {
improved = true
break
}
}
if !improved {
if verbosity >= 2 {
log.Println("Terminated after the population did not improve for one generation.")
}
done = true
}
if foundOptimal {
if verbosity >= 2 {
log.Printf("Optimal solution found after %d generations.\n", generationsPassed)
}
done = true
}
}
}
