Potential Race Condition in Memory Allocator Initialization

Code:
https://github.com/deepseek-ai/3FS/blob/main/src/memory/common/GlobalMemoryAllocator.cc#L76C2-L76C4

Issue Details:
Instruction reordering: gAllocatorInited = true may execute before std::call_once
Memory visibility: gAllocatorInited is not atomic, causing visibility issues across cores
Race condition: Other threads may see gAllocatorInited = true while the allocator is still uninitialized

May be this is an issue.

Read src/memory/common/GlobalMemoryAllocator.cc around line 76, then trace the initialization path and every use of gAllocatorInited. Check whether std::call_once provides the required ordering and whether other threads can observe the flag before the allocator is ready. Done means confirming the race or showing that initialization and visibility are safe, with a focused regression test if the issue is reproduced.

Written by the indexing model from the issue text.