A data object has a lock and a condition indicator associated with it. Based at least partly on detecting a first setting of the condition indicator, a reader stores an indication that the reader has obtained read access to the data object in an element of a readers structure and reads the data object without acquiring the lock. A writer detects the first setting and replaces it with a second setting, indicating that the lock is to be acquired by readers before reading the data object. Prior to performing a write on the data object, the writer verifies that one or more elements of the readers structure have been cleared.

according to one embodiment, in a storage device, a selection circuit selects one mapping rule from a plurality of mapping rules in which each of bit labels having a bit length of (n+1) or more is mapped to n M-ary symbols, when M is defined as an integer of 3 or more and n is defined as an integer of or more. A first conversion circuit converts a data block in data into an M-ary symbol sequence using the selected one mapping rule. A second conversion circuit converts the converted M-ary symbol sequence into an M-step pulse width signal. The recording medium records the converted M-step pulse width signal. A readback circuit equalizes the signal read from the recording medium to the M-ary symbol sequence and restores the data.

A reader of a set of data accessors that includes readers and writer detects that a particular lock of a first collection of non-global locks associated with a data object of a computing environment is held by another accessor. After checking a blocking indicator, the reader uses a second lock (which is not part of the first collection) to obtain read access to the data object and implements its reads without acquiring the particular lock. Prior to implementing a write on the data object, a writer acquires at least some locks of the first collection, and sets the blocking indicator to prevent readers from using the second lock to obtain read access to the data object.

A magnetic data processing device may include an encryption magnetic head structured to read the magnetic data recorded on the medium. The encryption magnetic head may include a magnetic data reading part structured to read the magnetic data of the medium to output an analog output signal; a demodulation electronic component structured to demodulate the analog output signal outputted from the magnetic data reading part to generate a digital demodulated signal; and an encryption electronic component structured to generate an encrypted signal obtained by encrypting the demodulated signal demodulated by the demodulation electronic component. The encryption electronic component may include at least a first buffer, a second buffer and a third buffer structured to store data having been read at an insertion time and an ejection time of the medium.

A peak detecting unit includes: a judging section, judging whether a current digital value produced by an AD converter has changed from a prior digital value; a holding section, being capable of holding the digital value output from the AD converter as an extreme value and its position information; and an updating section which, when the current digital value has changed from the prior digital value, updating the extreme value and its position information held in the holding section with the current digital value as a current extreme value and its position information, or when the current digital value matches the prior digital value, acquiring the intermediate position between the position of the current digital value and the position of the prior digital value as a current extreme value position, holding the matching digital value as a current extreme value, and updating the position information with the intermediate position information.

An erasure code-based partial write-in method and apparatus are provided. According to the method, a data node receives a first updating request carrying updating data and first version information from a client, wherein the first version information is information stored by the client and indicating a version of a target data block to be updated with the updating data, a data amount of the updating data is less than a data amount of one erasure code group which comprises m data blocks and k check data blocks, both m and k being natural numbers; the data node acquires second version information in response to the first updating request, wherein the second version information is information stored in the node and indicating the version of the target data block; the data node processes the updating data according to a matching result of the first version information and second version information.

A data object has a lock and a condition indicator associated with it. Based at least partly on detecting a first setting of the condition indicator, a reader stores an indication that the reader has obtained read access to the data object in an element of a readers structure and reads the data object without acquiring the lock. A writer detects the first setting and replaces it with a second setting, indicating that the lock is to be acquired by readers before reading the data object. Prior to performing a write on the data object, the writer verifies that one or more elements of the readers structure have been cleared.

Provided is a signal detection method of a staggered two-dimensional bit-patterned media and a recording medium and an apparatus for performing the method. The signal detection method of staggered two-dimensional bit-patterned media includes the down-track detection step, which detects a signal through a horizontal direction (x) path along the down-track, the first cross-track detection step, which detects a signal through a first vertical direction (z.sub.1) path that allows for passing through of a plurality of pixels arranged on a same line along cross-track perpendicular to the down-track and a plurality of pixels arranged in a staggered manner toward the horizontal direction (x) path with respect to the cross-track, and the second cross-track detection step, which detects a signal through a second vertical direction (z.sub.2) path that allows for passing through of a plurality of pixels arranged on a same line along the cross-track and a plurality of pixels arranged in a staggered manner toward an opposite path to the horizontal direction (x) path with respect to the cross-track.

Systems, devices, and method for phase slip recovery may include reading a plurality of data portions of a data block and positioning a mask over one or more data portions of the data block. The data portions following the mask may be shifted to provide a masked, reframed data block, and then the data block may be attempted to be decoded, which may be repeated until the data block is decoded.

A magnetic data processing device may include an encryption magnetic head structured to read the magnetic data recorded on the medium. The encryption magnetic head may include a magnetic data reading part structured to read the magnetic data of the medium to output an analog output signal; a demodulation electronic component structured to demodulate the analog output signal outputted from the magnetic data reading part to generate a digital demodulated signal; and an encryption electronic component structured to generate an encrypted signal obtained by encrypting the demodulated signal demodulated by the demodulation electronic component. The encryption electronic component may include at least a first buffer, a second buffer and a third buffer structured to store data having been read at an insertion time and an ejection time of the medium.