mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-18 21:51:57 +00:00
44 lines
787 B
C++
44 lines
787 B
C++
#pragma once
|
|
#if defined(OS_LINUX)
|
|
#include <cstdint>
|
|
|
|
|
|
namespace DB
|
|
{
|
|
|
|
/** Opens a file /proc/self/mstat. Keeps it open and reads memory statistics via 'pread'.
|
|
* This is Linux specific.
|
|
* See: man procfs
|
|
*
|
|
* Note: a class is used instead of a single function to avoid excessive file open/close on every use.
|
|
* pread is used to avoid lseek.
|
|
*
|
|
* Actual performance is from 1 to 5 million iterations per second.
|
|
*/
|
|
class MemoryStatisticsOS
|
|
{
|
|
public:
|
|
/// In number of bytes.
|
|
struct Data
|
|
{
|
|
uint64_t virt;
|
|
uint64_t resident;
|
|
uint64_t shared;
|
|
uint64_t code;
|
|
uint64_t data_and_stack;
|
|
};
|
|
|
|
MemoryStatisticsOS();
|
|
~MemoryStatisticsOS();
|
|
|
|
/// Thread-safe.
|
|
Data get() const;
|
|
|
|
private:
|
|
int fd;
|
|
};
|
|
|
|
}
|
|
|
|
#endif
|