when reading the book "operating system now" today, there is a sentence in the introduction to threads on page 53:
there are often situations where multiple control threads are running in quasi-parallel in the same address space
I would like to ask you what is the concept of quasi-parallelism and what is the difference between quasi-parallelism and parallelism
this is what the original English text says:
Nevertheless, in many situations, it is desirable to have multiple
threads of control in the same address space running in
quasi-parallel, as though they were (almost) separate processes
(except for the shared address space).
quasi-parallelism, that is, quasi-parallel,
Wikipedia explains ,
almost parallel,
has some of the characteristics of parallel systems or devices
traditional hard drives rely on the mechanical rotation of magnetic heads to read and write data. it is said that solid-state drives have the same principle of reading and writing as memory, so solid-state drives have no heads? then why can t the spee...
1. Main memory includes ROM, RAM, cache 2.Cache is a small capacity memory between CPU and main memory question: 1. In the second point, does main memory mean that RAM, which is commonly known as "br > 2.cache ", only logically belongs to memory, b...
is it faster to cut and paste or copy and paste in Windows? Why? What is the principle of operation? ...
the relationship between bootloader and real mode to protected mode? Recently, I have been studying the operating system, and then I have read several books, 30-day self-made operating system and the implementation of an operating system. In fact, I pref...
** * 32 16 * @param {ByteArray} chunk * static bit32to16(chunk) { const b16 = new Int16Array(chunk.byteLength 4); const dv = new DataView(chunk.buffer); for (let i = 0, offset = 0; offset < chunk.byteLength; iPP, offset...
in the 32-bit case, the Linux kernel virtual address starts from 0xc0000000, and 3GB+896MB belongs to kernel space. 896MB to 4GB is high-end memory, not to mention. The information I found on the Internet shows that kernel image starts from 3GB+16MB. Si...
take a look at the operating system Truth Restoration and find that the logical address used in the real mode above is the physical address, isn t it necessary to add the segment base address? Why does the protection mode avoid this problem? ...
spin locks are easy to understand, which is constantly polling, so what is the mechanism of mutexes? What are the drawbacks of this mechanism that make it better to use spin locks in some situations? ...
Why do pipes have to be half-duplex from a source point of view? ...
is there a special situation that makes memory slower than disk? Like a page break? ...
what are the differences in implementation and functionality between RT, message queues and pipes (including anonymous pipes and FIFO)? ...
win7 system. as shown in the figure, create a bat file in the same directory, and compress the dist folder into dist.zip ....
when any thread X executes the wait () and notify () methods on any thread Y, it needs to acquire the lock first. it is said that the locking mechanism is to solve the critical resource problem, so does it allow threads to start and pause access to any ...
does it seem that kernel cache has been removed from data replication? ...
The thread also does not have a separate address space, and the thread cannot cause the main process to crash through return because the thread is often a separate function? Is there any way for the thread to also recycle the stack of the main process an...
the subject uses Mac. I wonder what kind of process the system background is when a software is opened. In addition, why the window can be opened in the same place on the desktop after some software is closed and restarted, and can retain the window size...
Peterson algorithm implements mutually exclusive access by pure software. But it only illustrates the mutual exclusion between the two processes, as shown below -sharpdefine FALSE 0 -sharpdefine TRUE 1 -sharpdefine N 2 int turn; int interested[N]; vo...
for machines with 32-bit operating system and 4G memory, addressing within the range of 4G is supported at most because of 32-bit systems, and since the actual physical memory size is 4G, in this case, the address of virtual memory must exceed 4G. In tha...
on this question, I understand it like this: 1 to be exact, 32-bit CPU should support up to 4G memory because 32-bit CPU has 32 address buses, each line 0 or 1, a total of 2 ^ 32 possibilities, 2 ^ 32 memory addresses, each memory address corresponds t...
sendfile and mmap are both typical zero-copy technologies, and sendfile is very efficient when files do not need to be modified. It is said that mmap is more suitable for the transfer of small files, while sendfile is more suitable for large files. How s...