C language Go statement analysis and application
Go statement is a keyword in C language and plays an important role in the program. It can be used in various situations such as loops, conditional statements, function calls, etc. By using Go statements correctly, the logic of the program can be made clearer and more concise. In this article, we will delve into the usage of Go statements in C language and analyze and apply them with specific code examples.
1. The basic syntax of Go statement
In C language, the basic syntax of Go statement is as follows:
go expression;
Among them, expression can be a function call or an assignment statement , a conditional statement, etc. The function of the Go statement is to enable the program to execute the contents of expression concurrently during execution without blocking the current program flow. This allows the program to more efficiently utilize the capabilities of multi-core processors and improve the running efficiency of the program.
2. Use Go statements to achieve concurrent execution
Below we use a simple example to show how to use Go statements to achieve concurrent execution. Suppose we have two functions func1 and func2, which are used to calculate the square of two numbers and print the results:
#include <stdio.h> void func1(int num) { printf("The square of %d is %d ", num, num * num); } void func2(int num) { printf("The square of %d is %d ", num, num * num); } int main() { int num1 = 5; int num2 = 10; go func1(num1); go func2(num2); return 0; }
In the above example, we called the two functions func1 and func2 respectively through the Go statement, so that they can be executed concurrently. In this way, when the program is running, the two functions can be calculated at the same time without waiting for the previous function to complete execution. In this way, the execution efficiency of the program is improved.
3. Use Go statements to implement concurrency control
In addition to achieving concurrent execution, we can also use Go statements to implement concurrency control. For example, we can use Go statements to control certain tasks to be executed simultaneously when certain conditions are reached, or to implement functions such as sequential execution of tasks. Below we use an example to demonstrate how to use Go statements to achieve concurrency control:
#include <stdio.h> #include <pthread.h> pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER; pthread_cond_t cond = PTHREAD_COND_INITIALIZER; int flag = 0; void task1() { pthread_mutex_lock(&mutex); while(flag != 1) { pthread_cond_wait(&cond, &mutex); } pthread_mutex_unlock(&mutex); printf("Task 1 is running "); } void task2() { printf("Task 2 is running "); pthread_mutex_lock(&mutex); flag = 1; pthread_cond_signal(&cond); pthread_mutex_unlock(&mutex); } int main() { pthread_t tid1, tid2; pthread_create(&tid1, NULL, task1, NULL); pthread_create(&tid2, NULL, task2, NULL); pthread_join(tid1, NULL); pthread_join(tid2, NULL); return 0; }
In the above example, we use the mutex lock mutex and the condition variable cond to implement concurrency control of tasks. The task1 function will be executed when the flag variable is 1, and the task2 function will set the flag to 1 after execution, thereby waking up task1's waiting. In this way, we successfully achieved sequential execution of tasks.
4. Summary
This article introduces the basic syntax and usage of Go statements in C language, and shows how to use Go statements to achieve concurrent execution and concurrency control through specific code examples. Correct use of Go statements can make the program more efficient and concise, and give full play to the performance of multi-core processors. I hope this article will help readers understand the concepts and applications of Go statements in C language.
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