1. An optical head comprising a semiconductor laser for emitting a laser beam to read or write the information from or into a disc, a laser driver IC for driving the semiconductor laser, a photo detector for converting a reflected light beam from the disc into an electric signal, an object lens actuator for guiding the laser beam to a predetermined position on the disc, and a plurality of bearings for movement in the radial direction of the disc, wherein the semiconductor laser and the photo detector are arranged on one side with respect to a straight line through the center of the object lens of the object lens actuator and in parallel to the axis contacted with the bearings, and the laser driver IC is arranged on the other side with respect to the straight line, and wherein the object lens actuator comprises an object lens for focusing the laser beam on the recording surface of the disc, a holding means for holding the object lens, cantilever beams with their own open ends connected with the holding means, and a fixed part connected with the fixed ends of the cantilever beams, the laser driver IC being arranged between the cantilever beams in the fixed part.
2. The optical head according to claim 1, wherein the fixed part has a dent for arranging the laser driver IC.
3. An optical disc driver comprising the optical head according to claim 1, and a metal cover provided between the optical head and a disc, wherein the metal cover has an opening part between the disc and the object lens, and between the disc and the laser driver IC.
4. An optical head comprising a semiconductor laser for emitting a laser beam to read or write the information from or into a disc, a laser driver IC for driving the semiconductor laser, a photo detector for converting a reflected light beam from the disc into an electric signal, an object lens actuator for guiding the laser beam to a predetermined position on the disc, and a plurality of bearings for movement in the radial direction of the disc, wherein the semiconductor laser and the photo detector are arranged on one side with respect to a straight line through the center of the object lens of the object lens actuator and in parallel to the axis contacted with the bearings, and the laser driver IC is arranged on the other side with respect to the straight line, and a metal cover provided between the optical head and a disc, wherein the metal cover has an opening part between the disc and the object lens, and between the disc and the laser driver IC, and wherein the both ends of a metal member are bent in a U-shape so as to surround the fixed part for bonding and fixing the bent portions of the metal member and the side walls of the housing of the optical head facing the bent portions.
5. The optical disc drive according to claim 4, wherein a metal plate is provided between the metal member and the fixed part, and the laser drive IC such that the metal plate is contacted and fixed to the housing of the optical head without contacting with the metal member and the fixed part.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method performed by a computer processor, said method comprising:
receiving a first executable code;
monitoring said first executable code in a first execution environment, said first executable code having a plurality of processes;
receiving a set of process classifications, each of said process classifications having a set of garbage collection settings;
classifying each of said plurality of processes and assigning a process classification, each of said plurality of processes having a process classification;
creating a tagged version of said first executable code comprising tags for each of said processes identifying said process classification; and
executing said tagged version of said first executable code such that each process is executed using a set of garbage collection settings associated with said process classification.
2. The method of claim 1, said tagged version being executed in a second execution environment.
3. The method of claim 2, said first execution environment being an instrumented execution environment.
4. The method of claim 3, said second execution environment having less instrumentation than said first execution environment.
5. The method of claim 1, said executable code being compiled prior to executing.
6. The method of claim 5 further comprising:
compiling said tagged version of said first executable code to produce tagged compiled code.
7. The method of claim 6, said tagged compiled code being executed in a second execution environment, said second execution environment:
recognizing a first tag associated with a first process;
determining that said first tag is associated with a first set of garbage collection settings; and
executing said first process using said first set of garbage collection settings.
8. The method of claim 1, said tagged version of said first executable code comprising said first executable code and a metadata file, said metadata file comprising tags for each of said plurality of processes.
9. The method of claim 1, said set of garbage collection settings comprising defining a garbage collection method.
10. The method of claim 9, a first process being executed with a first garbage collection method and a second process being executed with a second garbage collection method.
11. The method of claim 10, said first process and said second process having identical source code.
12. The method of claim 1, said set of garbage collection settings comprising a condition to launch garbage collection.
13. The method of claim 1, said first execution environment being an interpreted execution environment.
14. A system comprising:
a processor;
an optimization system executing on said processor, said optimization system that:
receives observations from executing a first executable code;
determines a set of optimized memory management settings;
generates metadata associating said optimized memory management settings for each of a plurality of processes executed with said first executable code;
tags each process within said first executable code with a separate set of said optimized memory management settings; and
causes said first executable code to be executed with said optimized memory management settings.
15. The system of claim 14, said separate set of said optimized memory management settings being stored in a metadata file.
16. The system of claim 15, said metadata file being consumed by a compiler to generate a second executable code.
17. The system of claim 15, said metadata file being consumed by an interpreter to execute said first executable code.
18. The system of claim 14, said optimized memory management settings comprising memory allocation settings.
19. The system of claim 14, said optimized memory management settings comprising garbage collection settings.