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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at https://mozilla.org/MPL/2.0/. */
#include "BaseAlloc.h"
#include <cstring>
#include "Globals.h"
using namespace mozilla;
MOZ_CONSTINIT BaseAlloc sBaseAlloc;
// Initialize base allocation data structures.
void BaseAlloc::Init() MOZ_REQUIRES(gInitLock) { mMutex.Init(); }
bool BaseAlloc::pages_alloc(size_t minsize) MOZ_REQUIRES(mMutex) {
MOZ_ASSERT(minsize != 0);
size_t csize = CHUNK_CEILING(minsize);
uintptr_t base_pages =
reinterpret_cast<uintptr_t>(chunk_alloc(csize, kChunkSize, true));
if (base_pages == 0) {
return false;
}
mNextAddr = reinterpret_cast<uintptr_t>(base_pages);
mPastAddr = base_pages + csize;
// Leave enough pages for minsize committed, since otherwise they would
// have to be immediately recommitted.
size_t pminsize = REAL_PAGE_CEILING(minsize);
mNextDecommitted = base_pages + pminsize;
if (pminsize < csize) {
pages_decommit(reinterpret_cast<void*>(mNextDecommitted), csize - pminsize);
}
mStats.mMapped += csize;
mStats.mCommitted += pminsize;
return true;
}
void* BaseAlloc::alloc(size_t aSize) {
// Round size up to nearest multiple of the cacheline size.
size_t csize = CACHELINE_CEILING(aSize);
MutexAutoLock lock(mMutex);
// Make sure there's enough space for the allocation.
if (mNextAddr + csize > mPastAddr) {
if (!pages_alloc(csize)) {
return nullptr;
}
}
// Allocate.
void* ret = reinterpret_cast<void*>(mNextAddr);
mNextAddr = mNextAddr + csize;
// Make sure enough pages are committed for the new allocation.
if (mNextAddr > mNextDecommitted) {
uintptr_t pbase_next_addr = REAL_PAGE_CEILING(mNextAddr);
if (!pages_commit(reinterpret_cast<void*>(mNextDecommitted),
mNextAddr - mNextDecommitted)) {
return nullptr;
}
mStats.mCommitted += pbase_next_addr - mNextDecommitted;
mNextDecommitted = pbase_next_addr;
}
return ret;
}
void* BaseAlloc::calloc(size_t aNumber, size_t aSize) {
void* ret = alloc(aNumber * aSize);
if (ret) {
memset(ret, 0, aNumber * aSize);
}
return ret;
}
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