cpp/src/plasma/malloc.h

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//   http://www.apache.org/licenses/LICENSE-2.0
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#ifndef PLASMA_MALLOC_H
#define PLASMA_MALLOC_H

#include <inttypes.h>
#include <stddef.h>

#include <unordered_map>

namespace plasma {

/// Gap between two consecutive mmap regions allocated by fake_mmap.
/// This ensures that the segments of memory returned by
/// fake_mmap are never contiguous and dlmalloc does not coalesce it
/// (in the client we cannot guarantee that these mmaps are contiguous).
constexpr int64_t kMmapRegionsGap = sizeof(size_t);

void GetMallocMapinfo(void* addr, int* fd, int64_t* map_length, ptrdiff_t* offset);

/// Get the mmap size corresponding to a specific file descriptor.
///
/// @param fd The file descriptor to look up.
/// @return The size of the corresponding memory-mapped file.
int64_t GetMmapSize(int fd);

struct MmapRecord {
  int fd;
  int64_t size;
};

/// Hashtable that contains one entry per segment that we got from the OS
/// via mmap. Associates the address of that segment with its file descriptor
/// and size.
extern std::unordered_map<void*, MmapRecord> mmap_records;

}  // namespace plasma

#endif  // PLASMA_MALLOC_H