why wake up congested

want to buy. So I just took one, and the price was 4 RMB 8, when I was about to reach out and get it, I heard my husband keep shouting: "Four, six, four, six." When I heard this, I suddenly couldn't smile. It seems that he is taking our money-saving plan seriously. One morning, I had a rest. My husband went to work. I sent my husband to the elevator and the elevator door opened. I turned and prepared to go home. I heard my husband call me and turned to see me, I saw my husband standing in front

;} .......... } 15. volatile variable, volatile variable indicates that it must be consistent with the main memory, it is actually "synchronization of variables", that is to say, the volatile variable operation is atomic, for example, it is used before the long or double variable. 16. Using yield () will automatically discard the CPU, sometimes better than sleep. 17. the difference between sleep () and wait () is that the wait () method is unloc

the main memory, it is actually "synchronization of variables", that is to say, the volatile variable operation is atomic, for example, it is used before the long or double variable. 16. Using yield () will automatically discard the CPU, sometimes better than sleep. 17. the difference between sleep () and wait () is that the wait () method is unlocked when it is called, but what we can use is only in a synchronous method or code block. 18. reduce the synchronization scope through manufacturing

service similar to "one question and one answer.Figure 1. Simple Server/client Model We noticed that most of the socket interfaces are blocking. The so-called blocking interface means that a system call (generally an I/O interface) does not return the call result and keeps the current thread congested. It is returned only when the system call gets the result or times out and an error occurs. In fact, almost all I/O interfaces (including socket inter

plug" for the connection so that any part of the frames can be sent out. This is equally important for "congested" network connections.All in all, if you can certainly send multiple data sets together (such as the HTTP response header and body), we recommend that you set the tcp_cork option so that there is no latency between the data. It can greatly benefit the performance of WWW, FTP, and file servers, while also simplifying your work. The sample c

case, the waiting-notification mechanism between threads provided by Java is used. When the conditions required by the thread are not met, the thread enters the waiting state. The other thread is responsible for sending a notification at the right time to wake up the waiting thread. The wait/notify/yyall method group in the Java. Lang. Object Class in Java completes synchronization between threads. When calling the wait method on a Java object, first

First, let's see how the device wakes up the driver when the network receives the frame. 1 round robinThat is, the kernel constantly monitors the corresponding registers to determine whether there are network frames. 2. interruptedWhen there is data, the device executes a hardware interruption and then the kernel calls the corresponding processing function. When the network is under high load, the processing efficiency is very low (the interruption is too frequent ). It will also cause receive-l

headers will be transmitted immediately. In some cases (depending on the internal package counter), this packet is successfully received by the other party and needs to be confirmed by the other party. ThisIn this case, the transmission of a large amount of data will be postponed and unnecessary network traffic exchanges will occur.However, if we set tcp_cork on the socket (it can be equivalent to inserting"Plug-in") option, a packet with a header will fill in a large amount of data, and all da

header is small and TCP_NODELAY is set on the socket. Packets with headers will be transmitted immediately. In some cases (depending on the internal package counter), this packet is successfully received by the other party and needs to be confirmed by the other party. In this way, the transmission of a large amount of data will be postponed and unnecessary network traffic exchange will occur.However, if we set the TCP_CORK option on the socket (which may be equivalent to inserting a "plug-in" o

congested, and there is no concept of first-in-first-out, and all this will happen very fast, because Latch features fast and short-lived. SPIN and sleep: Sleep means temporarily giving up the CPU and performing context switch. In this way, the CPU needs to save some status information during the running of the current process, such as the stack, semaphore, and other data structures, then introduce the status information of subsequent processes, and

depressing. In this case, the responsible department is not responsible, that is, the data center manager, and the hardware service provider, system integrator, or our software developers do not undertake this part of work. As a result, the customer's head is also big, and the cables have not been laid (just like that, messy ~~). Because the cables are not laid, the cables in the cabinet are congested to the backend of the server, causing security ri

to be read, we will obtain the latch of this block. This process is called spin. Another process just needs to modify this block, he also needs the spin block. At this time, he must wait. The current process can only stay in the spin after latch is released, and then modify it. If multiple processes request at the same time, there will be competition between them, there is no queuing mechanism,Once the previous process has been released, the subsequent process will be

interrupted"); } } System.out.println("thread exiting under request.."); } } [Method 3] "brutal" behavior (1) For synchronization, you can enable a "disturbing" thread to throw a runtimeexception. For example, if synchronization is waiting to be done in main thread: A) thread B is enabled in thread A. What we do: Sleep (timeout) time. When we wake up, A runtimeexception is thrown; B) do some things i

only process this page at the next scan, or wait until the cleanup process is activated every 5 seconds. The cleanup process will scan the PFS page and process the ghost page. Skip to the next database if no cleanup is required. If no ghost record is found in this scan, the previous tag will be set and the database will be skipped after the wake-up in the next 5 seconds. Ghost cleanup Redux. When a record in heap is deleted, the record is marked as G

leaving, right? The house money has been paid in advance last night, so you do not need to wake up Liu daxie. Everything was ready. I carried bigpack and took the courtyard of Liu's house. Days have been a little bright, you can see the road. During the journey from chongding village to Bingzhongluo, I walked more than once and each time there were different scenery. At this time, the fog is very low, and the army is under pressure, and the ground is

university, Li Teacher's "Database Principles and Applications" is very important, very miss. Unfortunately can't find the memory of the object-the book lost. Also change the code that was previously written with Oracle proc/c++ to use MySQL. Find your own code to rub it to the point where you can't bear to look straight. yesterday saw a very eye-edge girl, feel very good-looking, dressed and temperament is like the girl next door. There is a kind of impulse to go up, since all use impulse,

The weather was fine(When I got up early in the morning, I found that a heavy snow had been quietly cleared last night, and the weather was fine, As a result, Shi xingfa enjoys his own entertainment, and he is logged on to the crowded bus on the congested road !) The sky is gray "Every day", the magician will show his magic again. He said the performance may take a long night. We recommend that you take a rest first. When I

more screen, can instantly get to two or more camera data stream, you can imagine that there will be more interesting design and implementation 4, GPS location outside the WiFi location, Android p added platform-level support IEEE 802.11 MC Wi-Fi protocol (ie, Wi-Fi round-trip-time,rtt), so that developers can use indoor positioning in the app. On Android P devices with hardware support, your app can use the latest RTT API to measure nearby Wi-Fi APs with RTT capability. Of course, the premise

the size of the sending window is determined by the degree of congestion in the network. slow start and congestion avoidanceThe sender maintains a state variable called the congestion window CWnd (congestion windows) . The size of the congestion window depends on the degree of congestion of the network and is dynamically changing. The sender makes its sending window equal to the Congestion window, and the sending window may be smaller than the congestion window, taking into account the receiv

Psychology of waking upGetting up is not a simple task. At the moment of waking up, our brain needs to complete a series of complex transformations: Environmental security checks, subconscious switching, nervous system startup, and limbs waking. For short, this process is called "switching the startup process ".In this process, when the subconscious receives the "wake up" command, it will first check whether the surrounding environment is safe. If the