operating system
1 test sites Process Management - deadlock
Test method [analysis]
This test method is a test center substantially the minimum number of exclusive resources when the system does not require operator deadlocks
Points [analysis]
1, concurrent processes requires n exclusive resources to run normally
2, a total of m concurrent process
3, at least m (n-1) +1 disjoint resources, the system will not deadlock
Remarks [coaching]
The third step is to understand the formula
2 test sites Process Management - bankers algorithm
Test method [analysis]
This test method is a test center is given a basic process resource table, and then determines the order of execution of the process
Points [analysis]
1, make sure the total number of available system resources
2, and then confirm the number of system resources allocated each process
3, by subtracting the total number of resources allocated resources to go out and get a few left in the system can allocate resources
4, and then confirm each process, the maximum demand for resources, but also need to see how much resources to make the process of running
5, compared with the number of resources each process is also required by the number of remaining resources in the system. If the number of resources left in the number of resources in the system is greater than the process required, you can allocate resources to the process
6, according to the above process, constant comparison. The final results of the process of the execution order
Remarks [coaching]
By doing title master the method, you do not have to memorize concepts.
3 test sites File Manager - Directory Structure
Test method [analysis]
This test method is basically the test center to test Windows (occasionally Linux) Absolute and relative paths
Points [analysis]
1, in Windows, use the backslash \, under Linux, using the slash /.
2, under Windows
Absolute path:
For example: the root of the E drive of the presence of document1 folder in the user folder has been created document2 folder, the current folder, document1. If the user test.docx document2 file storage folder, then the absolute path to the file as E: \ document1 \ document2
relative path:
For the above example, the relative path was document2 \, since the user at document1 directory, subdirectory document2 is document1
3, under Linux
Absolute path:
Writing path from the root directory / write from, for example: / usr / share / doc directory.
relative path:
Writing path, not by / write from, for example / usr / share / doc be to the / usr / share / man underneath, it can be written as: ../ man, which represents .. parent directory.
Remarks [coaching]
By doing title master the method, you do not have to memorize concepts.
Test center 4 Device Management
Test method [analysis]
This test method is a test center is determined substantially differentiate the data transfer control mode
Points [analysis]
1, the so-called equipment management, hardware device is managed, including the allocation of input and output devices, start and complete recovery
2, the most common test is the program interrupt and DMA mode
3, a CPU interrupt program participation, the external device sends an interrupt request signal to the CPU, the CPU under conditions permitting to suspend currently executing program in response to peripheral interrupt. Data transmission with the peripherals, the transfer is complete, and then return to the interrupted program before execution.
. 4, CPU is not involved in DMA mode, the direct transmission of high-speed peripherals with a special memory interface to the DMA controller.
Remarks [coaching]
Understand and distinguish the difference of several transmission control method