Documentation
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Overview ¶
Package shm implements shared memory objects.
Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func DestroyMemoryObject ¶
DestroyMemoryObject permanently removes given memory object.
Types ¶
type MemoryObject ¶
type MemoryObject struct {
// contains filtered or unexported fields
}
MemoryObject represents an object which can be used to map shared memory regions into the process' address space.
func NewMemoryObject ¶
NewMemoryObject creates a new shared memory object.
name - a name of the object. should not contain '/' and exceed 255 symbols (30 on darwin). size - object size. flag - flag is a combination of open flags from 'os' package. perm - object's permission bits.
func (*MemoryObject) Close ¶
func (obj *MemoryObject) Close() error
Close closes object's underlying file object. Darwin: a call to Close() causes invalid argument error, if the object was not truncated. So, in this case we return nil as an error.
func (*MemoryObject) Destroy ¶
func (obj *MemoryObject) Destroy() error
Destroy closes the object and removes it permanently.
func (*MemoryObject) Fd ¶
func (obj *MemoryObject) Fd() uintptr
Fd returns a descriptor of the object's underlying file object.
func (*MemoryObject) Name ¶
func (obj *MemoryObject) Name() string
Name returns the name of the object as it was given to NewMemoryObject().
func (*MemoryObject) Size ¶
func (obj *MemoryObject) Size() int64
Size returns the current object size. Darwin: it may differ from the size passed passed to Truncate.
func (*MemoryObject) Truncate ¶
func (obj *MemoryObject) Truncate(size int64) error
Truncate resizes the shared memory object. Darwin: it is possible to truncate an object only once after it was created. Darwin: the size should be divisible by system page size, otherwise the size is set to the nearest page size divider greater, then the given size.
type SharedMemoryObject ¶
SharedMemoryObject is an interface, which must be implemented by any implemetation of an object used for mapping into memory.
func NewMemoryObjectSize ¶ added in v0.2.0
func NewMemoryObjectSize(name string, flag int, perm os.FileMode, size int64) (SharedMemoryObject, bool, error)
NewMemoryObjectSize opens or creates a shared memory object with the given name. If the object was created, it is truncated to 'size'. Otherwise, checks, that the existing object is at least 'size' bytes long. Returns an object, true, if it was created, and an error.
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