我需要从ptsname（）中释放结果吗？

Question

当我打电话给ptsname()时，我得到一个char*回来。

联机帮助页未指定其链接，所有权或生命周期，但valgrind显示它正在导致泄漏（与--leak-check=full）。

==46958== 128 bytes in 1 blocks are definitely lost in loss record 41 of 65 
==46958== at 0x10010FEBB: malloc (in /usr/local/Cellar/valgrind/3.11.0/lib/valgrind/vgpreload_memcheck-amd64-darwin.so) 
==46958== by 0x1003F9682: ptsname (in /usr/lib/system/libsystem_c.dylib) 
==46958== by 0x10001BA5F: startJob(childproc*) (unix-base.cc:211) 
==46958== by 0x100019CAB: stepChild(childproc*, std::__1::function<bin::Job* (bin::Job*)>) (unix-base.cc:281) 
==46958== by 0x100018F2C: bin::runJobs(std::__1::function<bin::Job* (bin::Job*)>, int) (unix-base.cc:350) 
==46958== by 0x1000027FC: pmain() (bin.cc:65) 
==46958== by 0x100003787: main (bin.cc:90) 

然而，在free() -ing结果我得到的通常的非malloc倒是错误：

bin(46690,0x7fff76531000) malloc: *** error for object 0x7fb35af00f90: pointer being freed was not allocated 
*** set a breakpoint in malloc_error_break to debug 
./bootstrap.sh: line 41: 46690 Abort trap: 6   bin/bin 

这只是一个在内部实行的ptsname()在这个平台上泄露，还是应该我（以某种方式）释放结果？

Answer 1

库分配该内存，并且文档说该库可能会重用该内存，所以您应该而不是释放它。

On success, ptsname() returns a pointer to a string in static storage which will be overwritten by subsequent calls. This pointer must not be freed. On failure, a NULL pointer is returned.
_{The man page}

您应该忽略此valgrind警告。你可以告诉valgrind为你忽略它。

--ignore-fn=<name>
Any direct heap allocation (i.e. a call to malloc , new , etc, or a call to a function named by an --alloc-fn option) that occurs in a function specified by this option will be ignored. This is mostly useful for testing purposes. This option can be specified multiple times on the command line, to name multiple functions.
_{The man page}