CDI (Category Development Index) refers to the category development index. Is the proportion of the total sales of a product in the same region to the total sales of similar products in the country, divided by the ratio of the population of the regional market to the total population, used to assess the relative development of the product category in the Region Market. Evaluate the development status of a category in each region based on 100: when the population share is basically consistent wit
A signal (signal) is a software interrupt that provides a way to handle asynchronous events and is the only asynchronous communication between processes. In a Linux system, the subsequent signaling mechanism is extended according to the POSIX standard, which can be used to inform not only what happened to a program, but also the process of passing data to it.First, the source of the signalThe source of the
I. Signal Set and related operation functions
A signal set is defined as a data type:
Typedef struct {
Unsigned long sig [_ NSIG_WORDS];
} Sigset_t
A signal set is used to describe the set of signals. Each signal occupies one (64-bit ). All signals supported by Linux can appear in the
Signal () function to describe Linux functions in detail
A signal (signal) is a interprocess communication mechanism that provides an application with an asynchronous software interrupt that gives the application the opportunity to accept commands (i.e., signals) sent by other program live terminals. After the application receives a
In the previous section, one of the ways of interprocess communication is the signal generation and capture function in signal communication, this section introduces the signal () function and the SET function group of signal processing functions, and then a section http://blog.csdn.net/mybelief321/article/details/9078
Baseband signalSource (information source, also known as the terminal) emitted by the non-modulated (for spectral removal and transformation) of the original electrical signal, characterized by a low frequency, the signal spectrum from the zero frequency near the beginning, with a low-pass form. According to the characteristics of the original signal, baseband
Lienhua342014-11-031 Signal Transfer processThe signal source generates a signal for the target process, which is then determined by the kernel to pass the signal to the target process. From the signal generation to the flow to the target process, flowchart 1 shows thatFigur
1. sigaction ()
# Include Int sigaction (int signum, const struct sigaction * act, struct sigaction * oldact ));
The sigaction function is used to change the behavior of a process after receiving a specific signal. The first parameter of this function is the signal value, which can be any specific valid signal Except SIGKILL and SIGSTOP (define your own processi
The second parameter of the signal installation function sigaction (int signum, const struct sigaction * Act, struct sigaction * oldact) is a pointer to the sigaction structure (the struct name is the same as the function name, do not confuse it ). In the sigaction structure instance, it specifies the processing of specific signals, the information transmitted by signals, and which functions should be shielded during the execution of
The signal is associated with a certain process. In other words, a process can determine which signals are handled in the process. For example, a process can ignore some signals and handle only some other signals, and a process can also choose how to handle the signal. In short, these are always associated with a particular process. Therefore, the first to establish its
signal is a very important part of Linux programming, this article will detail the basic concept of signal mechanism, the approximate realization method of Linux to signal mechanism, how to use signal, and several system calls about signal.
Http://www.cnblogs.com/taobataoma/archive/2007/08/30/875743.htmlsignal is a very important part of Linux programming, this article will detail the basic concept of signal mechanism, the approximate realization method of Linux to signal mechanism, how to use signal, and several system calls about signal.
Signal is a very important part in Linux programming. This article will introduce in detail the basic concepts of the signal mechanism, the general implementation of the signal mechanism in Linux, and how to use the signal, and several system calls related to signals.The signal
A signal is a software interrupt, an asynchronous communication method that handles an asynchronous event. For example, we run the program in the terminal, by pressing the keyboard "CTRL + C", you can send a SIGINT interrupt signal to stop the program to run.There are 3 ways to handle the signal:1. Ignoring this signal
UNIX advanced environment programming (13) signal, unix programming 13 Signal
The signal is Soft Interrupt.
Signals provide an asynchronous way to process events. For example, you can press the End Process key on the terminal to terminate a process in advance.
1. Concept of Signal
Each
The basic series is better than the subsystem series. Most of these series are excerpted. Many brothers have made a good conclusion before and thank you for choosing them.
I have recently dealt with a debugging problem involving Linux signals. I would like to summarize it here for a memo.
++ ++
Directory:
1. Linux Signal
2. Signal Processing
3. How to process signals in debug
4. How to Write secure
For a complete signal Life Cycle (after the signal is sent to the corresponding processing function for execution), it can be divided into three phases:
Signal Generation
Sign up in process
Logout of signal in process
Signal processing function execution
1.
Linux signal Programming Practice (3) Signal Representation in the kernel (sigaction sigqueue)
Representation of signals in the kernel
The processing action of the actually executed signal is called the Delivery, the State between the signal generation and the Delivery, and the Pending ). A process can Block a
Signal ClassificationUnreliable signalThe Linux signaling mechanism is basically inherited from Unix systems. The signaling mechanism in the early Unix system was relatively simple and primitive, and later exposed some problems in practice, and its main problems were:1. Each time the process processes the signal, the response to the signal is set to the default a
The most commonly used interprocess communication methods today are: signal, semaphore, message queue, shared memory.The so-called process communication, is the different processes to carry out some "contact", this kind of contact is simple, also has the complexity. The mechanism is different and the complexity is not the same. Communication is a generalized meaning, not just a transfer of some massege. Their usage is basically the same, so just have
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