Some epicsThread*() leak when called from a non-EPICS thread

[mdavidsaver]

Several of the epicsThread*() functions will allocate an epicsThreadOSD* the first time one is called from a thread not created with epicsThreadCreate*(). At present, this allocation is not free()'d automatically when the non-EPICS thread exits, causing a memory leak.

Status:

• posix/osdThread.c - Leak observed. Fixed as of 2f8272d
• RTEMS-score/osdThread.c - Believed to be ok
• WIN32/osdThread.c - Candidate fix: Create implicit leak #348
• vxWorks/osdThread.c - Believed to be ok

[mdavidsaver]

wrt. Windows. TlsAlloc() doesn't accept a destructor function like pthread_key_create(). I found a reference to using FlsAlloc() instead, which does. This may have compatibility implications. @FreddieAkeroyd fyi.

[anjohnson]

The RTEMS-score implementation has not been coded to work properly from native threads anyway. It would fault or try to access data at or just above address 0 if some APIs ever get called from a non-EPICS thread. It can't be needed by any of our existing users though since that would have been triggered before now if it was, so we should wait to resolve that issue if it ever comes up (and ask the user if they can upgrade to RTEMS-posix instead).

[anjohnson]

MS blog on Windows Fibers: https://devblogs.microsoft.com/oldnewthing/20191011-00/?p=102989

[mdavidsaver]

I merged a fix for the POSIX targets as of 2f8272d.

[mdavidsaver]

Win32 fix f56412d in #348. All fixed in R7.0.8