Abstract: A method for automatic verification of optimization of high level constructs includes generating a first executable code by compiling a computer program that includes a high level construct. The compiling includes generating a first set of machine instructions for the high level construct and storing compile-time information for the high level construct. The method further includes optimizing the first executable code which includes converting the first executable code into an intermediate language representation. The optimization further includes generating a second executable code. For this, the method includes generating a second set of machine instructions for the high level construct from the intermediate language representation. If the behavior of the first set of machine instructions and the second set of machine instructions matches, the second set of machine instructions is included in the second executable code, otherwise the first set of machine instructions is included.

Abstract: A method of operating a resource lock for controlling access to a resource by a plurality of resource requesters, the resource lock operating in a contention efficient (heavyweight) operating mode, and the method being responsive to a request from a resource requester to acquire the resource lock, the method comprising the steps of: incrementing a count of a total number of acquisitions of the resource lock in the contention efficient operating mode, in response to a determination that access to the resource is not contended by more than one resource requester, performing the steps of: a) incrementing a count of a number of uncontended acquisitions of the resource lock in the contention efficient operating mode; b) calculating a contention rate as the number of uncontended acquisitions in the contention efficient operating mode divided by the total number of acquisitions in the contention efficient operating mode; and c) in response to a determination that the contention rate meets a threshold contention rate

Abstract: A method, apparatus and computer instructions for application based tracing and for normalization of processor clocks in a symmetric multiprocessor environment. By deliberately establishing a large skew among processor clocks, it is possible to perform application based tracing by directly using the processors. In addition, the identity, time stamp, and drift information of each processor may be used to create a time library. The time library is used to adjust a measured time to execute a program or software routine. The adjusted time is a normalized time that is statistically more accurate than the measured time alone. The adjusted time is then reported as the time to execute the program or software routine.

Abstract: A method for determining if a measurement of an elapsed time for an execution of a software routine in a computer system is valid. A clock skew is used between the clocks of two processors such that the size of the clock skew is greater than the maximum possible elapsed time for the execution of the software routine. The software routine is executed with a clock value recorded before (start time) and after (end time) execution. An elapsed time is calculated as a difference between the start time and the end time. Whether the elapsed time is valid is determined by checking for a positive value of the elapsed time and comparing the value of the elapsed time with the clock skew.

Abstract: A method for storing an identity of a processor in a multiprocessor computer system, the processor including a high frequency clock having a clock value represented as a set of binary digits, the method comprising encoding an identifier of the processor in a subset of the set of binary digits. It is therefore possible to retrieve a value of a time represented by a high frequency clock in a processor and an identification of the corresponding processor in a single indivisible operation by encoding the processor identifier in the clock value.

Abstract: A passive infrared detector has a first sensor (1) for generating an infrared signal, representative of the difference in temperature between a heat source and the background environment of the detector, a second sensor (3), influenced by the ambient temperature in the detector, and an evaluation circuit (2) for processing the infrared signal. The evaluation circuit contains a temperature compensation (4) for influencing the sensitivity of the detector as a function of the ambient temperature. The temperature compensation (4) is designed in such a way that the sensitivity of the detector is not directly influenced by changes in the ambient temperature. Influencing of the sensitivity of the detector takes place with delay and/or as a function of the speed of the change in the ambient temperature.

Abstract: A passive infrared detector has a first sensor (1) for generating an infrared signal, representative of the difference in temperature between a heat source and the background environment of the detector, a second sensor (3), influenced by the ambient temperature in the detector, and an evaluation circuit (2) for processing the infrared signal. The evaluation circuit contains a temperature compensation (4) for influencing the sensitivity of the detector as a function of the ambient temperature. The temperature compensation (4) is designed in such a way that the sensitivity of the detector is not directly influenced by changes in the ambient temperature. Influencing of the sensitivity of the detector takes place with delay and/or as a function of the speed of the change in the ambient temperature.

Abstract: An intrusion detector has a housing with an infrared device disposed therein, an infrared sensor, a detector window provided in the housing wall for the passage of infrared radiation from the external space onto the infrared sensor, an element for focusing the infrared radiation incident through the detector window onto the infrared sensor and having a sabotage surveillance device including an infrared transmitter and an infrared receiver. The infrared transmitter and the infrared receiver are disposed inside the housing and the detector window is substantially transparent to radiation emitted by the infrared transmitter. The sabotage surveillance of the detector takes place by measuring the proportion of the radiation reflected onto the infrared receiver from the inside of the detector window and the radiation transmitted onto the infrared receiver from the surrounding space.

Abstract: The monitoring of intrusion detectors is effected by an apparatus for testing the responsiveness to environment-caused, detector-specific useful and spurious signals. This testing apparatus is arranged inside of the intrusion detector and ensures that during installation and during the operation of the intrusion detector its electrical parameters are optimally adjusted. Deviations of these parameters from their nominal values and the location of these deviations are indicated.

Abstract: In an ultrasonic alarm installation, ultrasonic waves are continuously emitted into a monitored region and a frequency shift caused by a moving object, e.g. an intruder, is received by an ultrasonic receiver and evaluated by virtue of the Doppler effect for generating an alarm signal. For testing the ultrasonic alarm installation the emitted ultrasonic waves are modulated by a plurality of modulation frequencies in the range of the frequency shifts effective for triggering the alarm signal. Thus, the function test can be carried out using the same electrical evaluation circuit as for generating the alarm signal. The plurality of modulation frequencies conjointly with the switch-off of the transmitter signal has the effect that the reflected signals, which arrive at the ultrasonic receiver with different phase relationships, are not vectorially added to the ultrasonic transmitter signal to yield zero, so that a reliable function control is always ensured.

Abstract: In an ultrasonic alarm installation ultrasonic waves are continuously emitted into a monitored region and a frequency shift due to a moving object, e.g. an intruder, by virtue of the Doppler effect is evaluated for giving an alarm signal. The function control in this installation occurs during a test phase by means of brief aperiodic modulation of the emitted ultrasonic waves. The resulting brief frequency broadening generates in the same evaluating circuit a signal if the installation is functioning correctly. The time duration of the aperiodic modulation is selected to be so short that no standing waves can form, so that the function control can also work faultlessly if the installation, because of vectorial addition of the received ultrasonic waves, accidentally is in an insensitive state. Thus even coverings of the ultrasonic transmitter during a sabotage attempt can be recognized and distinguished from an insensitive state.