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/* Memory mapping wrappers.
* ARM and MinGW ports contributed by Hideo Okuma and Tomoyuki Yoshimura at
* NICT.
*/
#include "util/mmap.hh"
#include "util/exception.hh"
#include "util/file.hh"
#include "util/scoped.hh"
#include <iostream>
#include <assert.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <stdlib.h>
#if defined(_WIN32) || defined(_WIN64)
#include <windows.h>
#include <io.h>
#else
#include <sys/mman.h>
#include <unistd.h>
#endif
namespace util {
long SizePage() {
#if defined(_WIN32) || defined(_WIN64)
SYSTEM_INFO si;
GetSystemInfo(&si);
return si.dwAllocationGranularity;
#else
return sysconf(_SC_PAGE_SIZE);
#endif
}
void SyncOrThrow(void *start, size_t length) {
#if defined(_WIN32) || defined(_WIN64)
UTIL_THROW_IF(!::FlushViewOfFile(start, length), ErrnoException, "Failed to sync mmap");
#else
UTIL_THROW_IF(msync(start, length, MS_SYNC), ErrnoException, "Failed to sync mmap");
#endif
}
void UnmapOrThrow(void *start, size_t length) {
#if defined(_WIN32) || defined(_WIN64)
UTIL_THROW_IF(!::UnmapViewOfFile(start), ErrnoException, "Failed to unmap a file");
#else
UTIL_THROW_IF(munmap(start, length), ErrnoException, "munmap failed");
#endif
}
scoped_mmap::~scoped_mmap() {
if (data_ != (void*)-1) {
try {
// Thanks Denis Filimonov for pointing out NFS likes msync first.
SyncOrThrow(data_, size_);
UnmapOrThrow(data_, size_);
} catch (const util::ErrnoException &e) {
std::cerr << e.what();
abort();
}
}
}
void scoped_memory::reset(void *data, std::size_t size, Alloc source) {
switch(source_) {
case MMAP_ALLOCATED:
scoped_mmap(data_, size_);
break;
case ARRAY_ALLOCATED:
delete [] reinterpret_cast<char*>(data_);
break;
case MALLOC_ALLOCATED:
free(data_);
break;
case NONE_ALLOCATED:
break;
}
data_ = data;
size_ = size;
source_ = source;
}
void scoped_memory::call_realloc(std::size_t size) {
assert(source_ == MALLOC_ALLOCATED || source_ == NONE_ALLOCATED);
void *new_data = realloc(data_, size);
if (!new_data) {
reset();
} else {
data_ = new_data;
size_ = size;
source_ = MALLOC_ALLOCATED;
}
}
void *MapOrThrow(std::size_t size, bool for_write, int flags, bool prefault, int fd, uint64_t offset) {
#ifdef MAP_POPULATE // Linux specific
if (prefault) {
flags |= MAP_POPULATE;
}
#endif
#if defined(_WIN32) || defined(_WIN64)
int protectC = for_write ? PAGE_READWRITE : PAGE_READONLY;
int protectM = for_write ? FILE_MAP_WRITE : FILE_MAP_READ;
uint64_t total_size = size + offset;
HANDLE hMapping = CreateFileMapping((HANDLE)_get_osfhandle(fd), NULL, protectC, total_size >> 32, static_cast<DWORD>(total_size), NULL);
UTIL_THROW_IF(!hMapping, ErrnoException, "CreateFileMapping failed");
LPVOID ret = MapViewOfFile(hMapping, protectM, offset >> 32, offset, size);
CloseHandle(hMapping);
UTIL_THROW_IF(!ret, ErrnoException, "MapViewOfFile failed");
#else
int protect = for_write ? (PROT_READ | PROT_WRITE) : PROT_READ;
void *ret;
UTIL_THROW_IF((ret = mmap(NULL, size, protect, flags, fd, offset)) == MAP_FAILED, ErrnoException, "mmap failed for size " << size << " at offset " << offset);
# ifdef MADV_HUGEPAGE
/* We like huge pages but it's fine if we can't have them. Note that huge
* pages are not supported for file-backed mmap on linux.
*/
madvise(ret, size, MADV_HUGEPAGE);
# endif
#endif
return ret;
}
const int kFileFlags =
#if defined(_WIN32) || defined(_WIN64)
0 // MapOrThrow ignores flags on windows
#elif defined(MAP_FILE)
MAP_FILE | MAP_SHARED
#else
MAP_SHARED
#endif
;
void MapRead(LoadMethod method, int fd, uint64_t offset, std::size_t size, scoped_memory &out) {
switch (method) {
case LAZY:
out.reset(MapOrThrow(size, false, kFileFlags, false, fd, offset), size, scoped_memory::MMAP_ALLOCATED);
break;
case POPULATE_OR_LAZY:
#ifdef MAP_POPULATE
case POPULATE_OR_READ:
#endif
out.reset(MapOrThrow(size, false, kFileFlags, true, fd, offset), size, scoped_memory::MMAP_ALLOCATED);
break;
#ifndef MAP_POPULATE
case POPULATE_OR_READ:
#endif
case READ:
out.reset(MallocOrThrow(size), size, scoped_memory::MALLOC_ALLOCATED);
SeekOrThrow(fd, offset);
ReadOrThrow(fd, out.get(), size);
break;
}
}
// Allocates zeroed memory in to.
void MapAnonymous(std::size_t size, util::scoped_memory &to) {
to.reset();
#if defined(_WIN32) || defined(_WIN64)
to.reset(calloc(1, size), size, scoped_memory::MALLOC_ALLOCATED);
#else
to.reset(MapOrThrow(size, true,
# if defined(MAP_ANONYMOUS)
MAP_ANONYMOUS | MAP_PRIVATE // Linux
# else
MAP_ANON | MAP_PRIVATE // BSD
# endif
, false, -1, 0), size, scoped_memory::MMAP_ALLOCATED);
#endif
}
void *MapZeroedWrite(int fd, std::size_t size) {
ResizeOrThrow(fd, 0);
ResizeOrThrow(fd, size);
return MapOrThrow(size, true, kFileFlags, false, fd, 0);
}
void *MapZeroedWrite(const char *name, std::size_t size, scoped_fd &file) {
file.reset(CreateOrThrow(name));
try {
return MapZeroedWrite(file.get(), size);
} catch (ErrnoException &e) {
e << " in file " << name;
throw;
}
}
} // namespace util
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