Method ensureCommitted

Libraries/Await/Await.cpp:520–586

}

bool AwaitAllocator::ensureCommitted(size_t sizeInBytes)
{
    if (currentMode != AwaitAllocatorMode::Virtual or virtualMemory == nullptr)
    {
        return false;
    }
    if (sizeInBytes <= virtualCommittedBytes)
    {
        return true;
    }
    if (sizeInBytes > virtualReservedBytes)
    {
        return false;
    }

    const size_t previousCommittedBytes = virtualCommittedBytes;
    const size_t targetCommittedBytes   = roundUpToAwaitAllocatorPageSize(sizeInBytes);
    void*        commitAddress          = static_cast<char*>(virtualMemory) + previousCommittedBytes;
    const size_t bytesToCommit          = targetCommittedBytes - previousCommittedBytes;
#if SC_PLATFORM_WINDOWS
    if (::VirtualAlloc(commitAddress, bytesToCommit, MEM_COMMIT, PAGE_READWRITE) == nullptr)
    {
        return false;
    }
#else
    if (::mprotect(commitAddress, bytesToCommit, PROT_READ | PROT_WRITE) != 0)
    {
        return false;
    }
#endif
    virtualCommittedBytes = targetCommittedBytes;

    if (firstBlock == nullptr)
    {
        firstBlock             = static_cast<BlockHeader*>(virtualMemory);
        firstBlock->allocator  = this;
        firstBlock->previous   = nullptr;
        firstBlock->next       = nullptr;
        firstBlock->blockBytes = virtualCommittedBytes;
        firstBlock->free       = true;
        return true;
    }

    BlockHeader* lastBlock = firstBlock;
    while (lastBlock->next != nullptr)
    {
        lastBlock = lastBlock->next;
    }

    const size_t addedBytes = virtualCommittedBytes - previousCommittedBytes;
    if (lastBlock->free)
    {
        lastBlock->blockBytes += addedBytes;
    }
    else
    {
        BlockHeader* nextBlock =
            reinterpret_cast<BlockHeader*>(static_cast<char*>(virtualMemory) + previousCommittedBytes);