- Reference
Why understand memory layout?
Imagine that you moved into a new house but don’t know where the bedroom, kitchen, bathroom, and debris room are. If you get up every day and find a toilet, it’s like playing escape room. Isn’t it a big breakdown?
The memory of a computer is like your "digital house". If you don't understand its layout, it is easy to "go into the wrong room" as the code is written. The result is - the program crashes, the computer screens, and the leader rolls his eyes...
What are the "rooms" of memory?
High address +----------------------------
| Environmental variable area | ← Environmental variable (air in room)
+------------------------+
| Command line parameter area | ← Command line parameters (entry door)
+------------------------+
| Stack area | ← Function calls, local variables
| |
+------------------------+
| ↓↓↓ | ← Stack grows downward
| |
+------------------------+
| Free | ← Unused Memory Space
| |
+------------------------+
| ↑↑↑ | ← Heap grows upward
| |
+------------------------+
| Heap area | ← Dynamic allocation of memory
| |
+------------------------+
| Uninitialized data segment | ← Uninitialized global variables
| (BSS segment) |
+------------------------+
| Initialized data segment | ← Initialized global variables
| (Data paragraph) |
+------------------------+
Low address | Code segment | ← Program's instruction code
+------------------------+Let’s simulate a program running. From the visual view of the program, which rooms a program needs to live in and what services do these rooms provide.
When a program can run, the following steps are required:
- Execution package compiled with code;
- When running the execution package, you need to apply for memory storage variables and call calculation instructions from the system.
The system does not pre-allocate fixed memory, but adjusts dynamically according to program requirements.
Each memory room has specific functions, and of course there are limitations.
TODO...
Reference
/xiaokang-coding/p/18799190