Please talk about what memory leaks are, and the causes and troubleshooting methods of common content leaks
foreword
A memory leak means that the dynamically allocated memory space in the program is not released in time, resulting in the memory space being no longer used by the program, and eventually causing the program to consume more and more memory when it is running, until it reaches the upper limit of the system's available memory and crashes. Memory leaks are a common programming error, especially in long-running programs.
1. Common causes of memory leaks include?
The used memory space is not released in time
. Improper use of pointers prevents the memory space from being released
. Circular references prevent the memory space from being reclaimed
. Memory overflow causes the memory space to fail to be released.
Second, the method of troubleshooting memory leaks includes
Static code analysis: Use static code analysis tools to scan program code for potential memory leaks.
Dynamic code analysis: use dynamic code analysis tools to monitor the memory usage of the program during runtime, and find possible memory leaks.
Memory leak detection tool: Use the memory leak detection tool to detect whether there is a memory leak problem when the program is running.
Code review: Code review of the program code to find possible memory leaks.
Memory usage analysis: Analyze the memory usage when the program is running to find possible memory leaks.
Once a memory leak is found, it should be repaired in time. The usual repair method is to release the used memory space in time, avoid circular references, and manage the use of memory space reasonably.
1. Are there any common memory leak cases to share?
Event binding is not unbound: In front-end development, when an event is bound through the addEventListener() method, if the event is not unbound in time, it will cause a memory leak. For example, in a page, if a large number of events are bound and these events are not unbound, it will cause a memory leak.
The timer is not cleared: In front-end development, when creating a timer through setTimeout() or setInterval(), if the timer is not cleared in time, it will cause a memory leak. For example, in a page, if a large number of timers are created and these timers are not cleared, memory leaks will result.
Circular reference: In front-end development, if there is a circular reference between two or more objects, it will cause a memory leak. For example, when using React, memory leaks can result if there are circular references between components.
DOM elements are not removed: In front-end development, if DOM elements are not removed correctly, memory leaks will result. For example, in a page, if a large number of DOM elements are dynamically added and these DOM elements are not removed, memory leaks will result.
The object is not released: In front-end development, if the object is not released in time, it will cause a memory leak. For example, when using JavaScript, if a large number of objects are created and these objects are not released, memory leaks will result.