diff options
Diffstat (limited to 'INSTALL')
| -rw-r--r-- | INSTALL | 14 |
1 files changed, 14 insertions, 0 deletions
@@ -395,6 +395,20 @@ pngusr.h a system builder may also define equivalent options in pngusr.dfa (or, indeed, any file) and add that to the configuration by setting DFA_XTRA to the file name. The makefiles in contrib/pngminim illustrate how to do this, and a case where pngusr.h is still required. + +Configuring libpng for multiprocessing + +Libpng uses setjmp()/longjmp() for error handling. Unfortunately setjmp() +is known to be not thread-safe on some platforms and we don't know of +any platform where it is guaranteed to be thread-safe. Therefore, if +your application is going to be using multiple threads, you should +configure libpng with PNG_NO_SETJMP in your pngusr.dfa file, with +-DPNG_NO_SETJMP on your compile line, or with + + #undef PNG_SETJMP_SUPPORTED + +in your pnglibconf.h or pngusr.h. + Other sources of information about libpng: Further information can be found in the README and libpng-manual.txt |