不同进程共享同一个堆

Question

Does a parent process share the same heap with its child process? I find something online: "The heap, code and library regions of the parent are shared by the child. A new stack is allocated to the child and the parent's stack is copied into the child's stack."

Does this mean same heap is shared between difference processes?

"Also there might be a global heap (look at Win32 GlobalAlloc() family functions for example) which is shared between processes, persists for the system runtime and indeed can be used for interprocess communications." reference: Is heap memory per-process? (or) Common memory location shared by different processes?

Answer 1

Does a parent process share the same heap with its child process? I find something online: "The heap, code and library regions of the parent are shared by the child. A new stack is allocated to the child and the parent's stack is copied into the child's stack."

Does this mean same heap is shared between difference processes?

The child process gets a copy of parent heap. The page frames can be shared between the processes in copy-on-write mode as an optimization.

man fork :

fork() creates a new process by duplicating the calling process. The new process is referred to as the child process. The calling process is referred to as the parent process.

The child process and the parent process run in separate memory spaces. At the time of fork() both memory spaces have the same content. Memory writes, file mappings (mmap(2)), and unmappings (munmap(2)) performed by one of the processes do not affect the other.