117 lines
2.9 KiB
C++
117 lines
2.9 KiB
C++
namespace tracy
|
|
{
|
|
|
|
template<size_t Size>
|
|
class RingBuffer
|
|
{
|
|
public:
|
|
RingBuffer( int fd )
|
|
: m_fd( fd )
|
|
{
|
|
const auto pageSize = uint32_t( getpagesize() );
|
|
assert( Size >= pageSize );
|
|
assert( __builtin_popcount( Size ) == 1 );
|
|
m_mapSize = Size + pageSize;
|
|
auto mapAddr = mmap( nullptr, m_mapSize, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0 );
|
|
if( !mapAddr )
|
|
{
|
|
m_fd = 0;
|
|
close( fd );
|
|
return;
|
|
}
|
|
m_metadata = (perf_event_mmap_page*)mapAddr;
|
|
assert( m_metadata->data_offset == pageSize );
|
|
m_buffer = ((char*)mapAddr) + pageSize;
|
|
}
|
|
|
|
~RingBuffer()
|
|
{
|
|
if( m_metadata ) munmap( m_metadata, m_mapSize );
|
|
if( m_fd ) close( m_fd );
|
|
}
|
|
|
|
RingBuffer( const RingBuffer& ) = delete;
|
|
RingBuffer& operator=( const RingBuffer& ) = delete;
|
|
|
|
RingBuffer( RingBuffer&& other )
|
|
{
|
|
memcpy( (char*)&other, (char*)this, sizeof( RingBuffer ) );
|
|
m_metadata = nullptr;
|
|
m_fd = 0;
|
|
}
|
|
|
|
RingBuffer& operator=( RingBuffer&& other )
|
|
{
|
|
memcpy( (char*)&other, (char*)this, sizeof( RingBuffer ) );
|
|
m_metadata = nullptr;
|
|
m_fd = 0;
|
|
return *this;
|
|
}
|
|
|
|
bool IsValid() const { return m_metadata != nullptr; }
|
|
|
|
void Enable()
|
|
{
|
|
ioctl( m_fd, PERF_EVENT_IOC_ENABLE, 0 );
|
|
}
|
|
|
|
bool HasData() const
|
|
{
|
|
const auto head = LoadHead();
|
|
return head > m_metadata->data_tail;
|
|
}
|
|
|
|
void Read( void* dst, uint64_t offset, uint64_t cnt )
|
|
{
|
|
auto src = ( m_metadata->data_tail + offset ) % Size;
|
|
if( src + cnt <= Size )
|
|
{
|
|
memcpy( dst, m_buffer + src, cnt );
|
|
}
|
|
else
|
|
{
|
|
const auto s0 = Size - src;
|
|
memcpy( dst, m_buffer + src, s0 );
|
|
memcpy( (char*)dst + s0, m_buffer, cnt - s0 );
|
|
}
|
|
}
|
|
|
|
void Advance( uint64_t cnt )
|
|
{
|
|
StoreTail( m_metadata->data_tail + cnt );
|
|
}
|
|
|
|
bool CheckTscCaps() const
|
|
{
|
|
return m_metadata->cap_user_time_zero;
|
|
}
|
|
|
|
int64_t ConvertTimeToTsc( int64_t timestamp ) const
|
|
{
|
|
assert( m_metadata->cap_user_time_zero );
|
|
const auto time = timestamp - m_metadata->time_zero;
|
|
const auto quot = time / m_metadata->time_mult;
|
|
const auto rem = time % m_metadata->time_mult;
|
|
return ( quot << m_metadata->time_shift ) + ( rem << m_metadata->time_shift ) / m_metadata->time_mult;
|
|
}
|
|
|
|
private:
|
|
uint64_t LoadHead() const
|
|
{
|
|
return std::atomic_load_explicit( (const volatile std::atomic<uint64_t>*)&m_metadata->data_head, std::memory_order_acquire );
|
|
}
|
|
|
|
void StoreTail( uint64_t tail )
|
|
{
|
|
std::atomic_store_explicit( (volatile std::atomic<uint64_t>*)&m_metadata->data_tail, tail, std::memory_order_release );
|
|
}
|
|
|
|
perf_event_mmap_page* m_metadata;
|
|
char* m_buffer;
|
|
|
|
size_t m_mapSize;
|
|
int m_fd;
|
|
};
|
|
|
|
}
|