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/*
* Copyright (C) 2017 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "util.h"
#include <err.h>
#include <math.h>
#include <sched.h>
#include <stdio.h>
#include <string.h>
#include <wchar.h>
#include <cstdlib>
// This function returns a pointer less than 2 * alignment + or_mask bytes into the array.
char* GetAlignedMemory(char* orig_ptr, size_t alignment, size_t or_mask) {
if ((alignment & (alignment - 1)) != 0) {
errx(1, "warning: alignment passed into GetAlignedMemory is not a power of two.");
}
if (or_mask > alignment) {
errx(1, "warning: or_mask passed into GetAlignedMemory is too high.");
}
uintptr_t ptr = reinterpret_cast<uintptr_t>(orig_ptr);
if (alignment > 0) {
// When setting the alignment, set it to exactly the alignment chosen.
// The pointer returned will be guaranteed not to be aligned to anything
// more than that.
ptr += alignment - (ptr & (alignment - 1));
ptr |= alignment | or_mask;
}
return reinterpret_cast<char*>(ptr);
}
char* GetAlignedPtr(std::vector<char>* buf, size_t alignment, size_t nbytes) {
buf->resize(nbytes + 3 * alignment);
return GetAlignedMemory(buf->data(), alignment, 0);
}
wchar_t* GetAlignedPtr(std::vector<wchar_t>* buf, size_t alignment, size_t nchars) {
buf->resize(nchars + ceil((3 * alignment) / sizeof(wchar_t)));
return reinterpret_cast<wchar_t*>(GetAlignedMemory(reinterpret_cast<char*>(buf->data()),
alignment, 0));
}
char* GetAlignedPtrFilled(std::vector<char>* buf, size_t alignment, size_t nbytes, char fill_byte) {
char* buf_aligned = GetAlignedPtr(buf, alignment, nbytes);
memset(buf_aligned, fill_byte, nbytes);
return buf_aligned;
}
#if defined(__APPLE__)
// Darwin doesn't support this, so do nothing.
bool LockToCPU(int) {
return false;
}
#else
bool LockToCPU(int cpu_to_lock) {
cpu_set_t cpuset;
CPU_ZERO(&cpuset);
CPU_SET(cpu_to_lock, &cpuset);
if (sched_setaffinity(0, sizeof(cpuset), &cpuset) != 0) {
if (errno == EINVAL) {
printf("Invalid cpu %d\n", cpu_to_lock);
} else {
perror("sched_setaffinity failed");
}
return false;
}
return true;
}
#endif