[GitHub] [incubator-nuttx] xiaoxiang781216 commented on pull request #6083: sched/environ: Refine the environment variables storage layout

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xiaoxiang781216 commented on PR #6083:
URL: https://github.com/apache/incubator-nuttx/pull/6083#issuecomment-1100874550

   > This implementation is already much cleaner than the old one, thanks for fixing it.
   > 
   > My only question is how the string vectors are allocated. IMO the allocation can be done exactly once, but maybe there is some other reason for allocating memory for the vector and the strings separately.
   
   It's more efficient to allocate the array and string in one allocation for read only string(e.g. argv), but since environ string is modifiable:
   
   1. One allocation make the management more hard
   2. More important the follow code is broken:
   ```
   setenv("env1", "Hello");
   const char *env1 = getenv("env1");
   setenv("env2", "World");
   printf("%s\n", evn1);
   ```
   The last statement may access the freed memory because the 3rd statement may reallocate the whole buffer to new location.


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