Answer:
Assume that a context switch takes T time. Suggest an upper bound (in terms of T) for holding a spinlock. If the spinlock is held for any longer, a mutex lock (where waiting threads are put to sleep) is a better alternative.
Explanation:
The top limit is to be twice the value of (2xT). Holding the spinlock for a longer time, it will be necessary to put the thread to sleep and get a context switch, so one process awakes the sleeping thread without the need of a second context switch.
In process synchronization, cooperating process can affect or be affected by other processes executing in the system, either directly share a logical address space, both code and data, or be allowed to share data only through files or messages, although concurrent access to shared data may result in data inconsistency. But there are several mechanisms to help the orderly execution of cooperating processes that share a logical address space, so that data consistency is kept.
Answer:
Given that Program instructions consists of:
- 60% floating point multiply
- 20% floating point divide
- 20% other instructions
Amdahl's law states that:
Execution time affected by improvement = (Execution time after improvement/ Amount of improvement) + (Execution time unaffected)
Assuming initially that floating point multiply, divide and other instructions have same clocks per instruction (CPI).
Part (a)
New execution time after improvement with multiply = (60) / 8 + (20 + 20) = 47.5
New execution time after improvement with Divide = (20) / 3 + (60 + 20) = 86.67
New system should be 4x faster which means new execution time should be below = 100/ 4 = 25.
Therefore, Management's goal can NOT be achieved by making the improvement with multiply or divide alone.
Part (b)
New execution time after improvement with multiply and divide = (60 / 8) + (20 / 3) + 20 = 34.17
Speed up = execution time of original machine / Execution time of new machine = (100 / 34.17) = 2.93
Therefore, new machine is 2.93 times faster than original machine.
B- allow the economy fix itself. laissez-faire means to let free or to let be
Rates for corporate outings is NOT an example of an FPRA rate
Explanation:
The FPRA is an agreement between an entrepreneur and a governmental agency in which some indirect charges are determined over a set period of time. All such rates are price forecasts used for cost agreements and contract changes.
By using an FPRA the contracting system can be accelerated by removing the need for audit and analysis of rates. The Contracting Officer (COO) oversees the prices of the contracting party. The ACO should always be asked any questions about the prices. After a FPRA is reached, a copies of the agreement should always be provided for in any ensuing proposal.
Answer:
The amount of dividends paid to common stockholders in 2021 $18000.
Explanation:
The cumulative preferred stock is the stock that accumulates dividends when the dividends are partially or not paid at all in a certain year. The dividends must be paid in the future.
The common stock holders are paid after the preferred stockholders are paid.
The preferred stock dividend per year = 400000 * 0.06 = $24000 per year
As the cash dividends paid in 2019 and 2020 are $20000 each,
The dividend outstanding on preferred stocks for 2019 is = 24000 - 20000 = $4000
Similarly, the dividends outstanding on preferred stocks for 2020 is = 24000 - 20000 = $4000
The total dividends outstanding at start of 2021 = 4000 + 4000 = $8000
Preferred dividend for 2021 = 24000
Total dividend on preferred stock = 24000 + 8000 = $32000
The amount of dividends that common stock holders will receive in 2021 = 50000 - 32000 = $18000
