ruby: reduce the memory usage of ruby by making memory vector page based

This commit is contained in:
Derek Hower 2009-11-13 09:43:39 -06:00
parent ceb8fde914
commit 2ee04d6587

View file

@ -22,60 +22,104 @@ class MemoryVector {
uint8* read(const Address & paddr, uint8* data, int len);
private:
uint8* getBlockPtr(const Address & paddr);
uint8* getBlockPtr(const PhysAddress & addr);
uint32 m_size;
uint8* m_vec;
uint8** m_pages;
uint32 m_num_pages;
const uint32 m_page_offset_mask;
};
inline
MemoryVector::MemoryVector()
: m_page_offset_mask(4095)
{
m_size = 0;
m_vec = NULL;
m_num_pages = 0;
m_pages = NULL;
}
inline
MemoryVector::MemoryVector(uint32 size)
: m_page_offset_mask(4095)
{
m_size = size;
m_vec = new uint8[size];
setSize(size);
}
inline
MemoryVector::~MemoryVector()
{
delete [] m_vec;
for (int i=0; i<m_num_pages; i++) {
if (m_pages[i] != 0) {
delete [] m_pages[i];
}
}
delete [] m_pages;
}
inline
void MemoryVector::setSize(uint32 size)
{
if (m_pages != NULL){
for (int i=0; i<m_num_pages; i++) {
if (m_pages[i] != 0) {
delete [] m_pages[i];
}
}
delete [] m_pages;
}
m_size = size;
if (m_vec != NULL)
delete [] m_vec;
m_vec = new uint8[size];
assert(size%4096 == 0);
m_num_pages = size >> 12;
m_pages = new uint8*[m_num_pages];
memset(m_pages, 0, m_num_pages * sizeof(uint8*));
}
inline
void MemoryVector::write(const Address & paddr, uint8* data, int len)
{
assert(paddr.getAddress() + len <= m_size);
memcpy(m_vec + paddr.getAddress(), data, len);
uint32 page_num = paddr.getAddress() >> 12;
if (m_pages[page_num] == 0) {
bool all_zeros = true;
for (int i=0;i<len;i++) {
if (data[i] != 0) {
all_zeros = false;
break;
}
}
if (all_zeros) return;
m_pages[page_num] = new uint8[4096];
memset(m_pages[page_num], 0, 4096);
uint32 offset = paddr.getAddress() & m_page_offset_mask;
memcpy(&m_pages[page_num][offset], data, len);
} else {
memcpy(&m_pages[page_num][paddr.getAddress()&m_page_offset_mask], data, len);
}
}
inline
uint8* MemoryVector::read(const Address & paddr, uint8* data, int len)
{
assert(paddr.getAddress() + len <= m_size);
memcpy(data, m_vec + paddr.getAddress(), len);
uint32 page_num = paddr.getAddress() >> 12;
if (m_pages[page_num] == 0) {
memset(data, 0, len);
} else {
memcpy(data, &m_pages[page_num][paddr.getAddress()&m_page_offset_mask], len);
}
return data;
}
inline
uint8* MemoryVector::getBlockPtr(const Address & paddr)
uint8* MemoryVector::getBlockPtr(const PhysAddress & paddr)
{
return m_vec + paddr.getAddress();
uint32 page_num = paddr.getAddress() >> 12;
if (m_pages[page_num] == 0) {
m_pages[page_num] = new uint8[4096];
memset(m_pages[page_num], 0, 4096);
}
return &m_pages[page_num][paddr.getAddress()&m_page_offset_mask];
}
#endif // MEMORYVECTOR_H