Add some comments/documentation

This commit is contained in:
j.laycock 2019-09-11 10:41:59 +01:00
parent 9ea9a5e97a
commit c1a928887a

View File

@ -71,6 +71,8 @@ func (mMap *MemoryMap) CreateMemoryMap(file *os.File, maxLength uint64) {
}
func (mMap *MemoryMap) DeleteFileAndMemoryMap() {
//First we close the file handles first to delete the file,
//Then we unmap the memory to ensure the unmapping process doesn't write the data to disk
windows.CloseHandle(windows.Handle(mMap.file_memory_map_handle))
windows.CloseHandle(windows.Handle(mMap.File.Fd()))
@ -145,7 +147,6 @@ func (mBuffer *MemoryBuffer) ReleaseMemory() {
}
func allocateChunk(mMap *MemoryMap) {
start := uint64(len(mMap.write_map_views)) * chunkSize
mBuffer, err := allocate(windows.Handle(mMap.file_memory_map_handle), start, chunkSize, true)
@ -159,6 +160,7 @@ func allocate(hMapFile windows.Handle, offset uint64, length uint64, write bool)
mBuffer := MemoryBuffer{}
//align memory allocations to the minium virtal memory allocation size
dwSysGran := systemInfo.dwAllocationGranularity
start := (offset / uint64(dwSysGran)) * uint64(dwSysGran)
@ -177,6 +179,8 @@ func allocate(hMapFile windows.Handle, offset uint64, length uint64, write bool)
currentMinWorkingSet = currentMinWorkingSet + aligned_length
currentMaxWorkingSet = currentMaxWorkingSet + aligned_length
// increase the process working set size to hint to windows memory manager to
// prioritise keeping this memory mapped in physical memory over other standby memory
var _ = setProcessWorkingSetSize(uintptr(currentProcess), uintptr(currentMinWorkingSet), uintptr(currentMaxWorkingSet))
addr_ptr, errno := windows.MapViewOfFile(hMapFile,
@ -254,6 +258,7 @@ func getSystemInfo() (_SYSTEM_INFO, error) {
// PSIZE_T lpMinimumWorkingSetSize,
// PSIZE_T lpMaximumWorkingSetSize
// );
// https://docs.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-getprocessworkingsetsize
func getProcessWorkingSetSize(process uintptr, dwMinWorkingSet *uint64, dwMaxWorkingSet *uint64) error {
r1, _, err := syscall.Syscall(procGetProcessWorkingSetSize.Addr(), 3, process, uintptr(unsafe.Pointer(dwMinWorkingSet)), uintptr(unsafe.Pointer(dwMaxWorkingSet)))
@ -270,6 +275,7 @@ func getProcessWorkingSetSize(process uintptr, dwMinWorkingSet *uint64, dwMaxWor
// SIZE_T dwMinimumWorkingSetSize,
// SIZE_T dwMaximumWorkingSetSize
// );
// https://docs.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-setprocessworkingsetsize
func setProcessWorkingSetSize(process uintptr, dwMinWorkingSet uintptr, dwMaxWorkingSet uintptr) error {
r1, _, err := syscall.Syscall(procSetProcessWorkingSetSize.Addr(), 3, process, (dwMinWorkingSet), (dwMaxWorkingSet))