pthread动态库命名规则

Library naming
--------------

Because the library is being built using various exception
handling schemes and compilers - and because the library
may not work reliably if these are mixed in an application,
each different version of the library has it's own name.

Note 1: the incompatibility is really between EH implementations
of the different compilers. It should be possible to use the
standard C version from either compiler with C++ applications
built with a different compiler. If you use an EH version of
the library, then you must use the same compiler for the
application. This is another complication and dependency that
can be avoided by using only the standard C library version.

Note 2: if you use a standard C pthread*.dll with a C++
application, then any functions that you define that are
intended to be called via pthread_cleanup_push() must be
__cdecl.

Note 3: the intention was to also name either the VC or GC
version (it should be arbitrary) as pthread.dll, including
pthread.lib and libpthread.a as appropriate. This is no longer
likely to happen.

Note 4: the compatibility number was added so that applications
can differentiate between binary incompatible versions of the
libs and dlls.

In general:
pthread[VG]{SE,CE,C}[c].dll
pthread[VG]{SE,CE,C}[c].lib

where:
[VG] indicates the compiler
V - MS VC, or
G - GNU C

{SE,CE,C} indicates the exception handling scheme
SE - Structured EH, or
CE - C++ EH, or
C - no exceptions - uses setjmp/longjmp

c - DLL compatibility number indicating ABI and API
compatibility with applications built against
a snapshot with the same compatibility number.
See 'Version numbering' below.

The name may also be suffixed by a 'd' to indicate a debugging version
of the library. E.g. pthreadVC2d.lib. Debugging versions contain
additional information for debugging (symbols etc) and are often not
optimised in any way (compiled with optimisation turned off).

Examples:
pthreadVSE.dll (MSVC/SEH)
pthreadGCE.dll (GNUC/C++ EH)
pthreadGC.dll (GNUC/not dependent on exceptions)
pthreadVC1.dll (MSVC/not dependent on exceptions - not binary
compatible with pthreadVC.dll)
pthreadVC2.dll (MSVC/not dependent on exceptions - not binary
compatible with pthreadVC1.dll or pthreadVC.dll)

The GNU library archive file names have correspondingly changed to:

libpthreadGCEc.a
libpthreadGCc.a