Andreas Unterkircher wrote:
Hello Ben,
thank you very much for your response. I tried adding "-D_REENTRANT" and it works fine. Please let me ask some follow up questions for clarification:
On IA32/gcc3.2.3 I tried to compile the below test code both with boost_1_32_0 and boost_1_33_0. The compile comand is constructed by the build system of the project I'm porting but I can influence it by an .m4 file. In both cases it works by using just "-pthread" and it also works with "-pthread -D_REENTRANT". What is the difference between these two (if any) ?
"-pthread" is a gcc-specific option that is meant to support building thread-safe code that may use POSIX threads. On Linux it is generally equivalent to "-lpthread -D_REENTRANT". So on IA32 the addition of "-D_REENTRANT" has no effect.
On IA64/gcc3.2.3 it works only with "-pthread -D_REENTRANT" (having applied your patch). What is the reason for this difference between IA32 and IA64 ? Is it a "bug" ?
On IA64 (and S390), the "-pthread" option is only equivalent to "-lpthread", and "-D_REENTRANT" must be specified explicitly to ensure that thread-safe library functions are used. I consider this inconsistency to be a bug in gcc. (However, it could be that the C library is thread-safe by default on these platforms, and that Boost should not be checking for the _REENTRANT macro. I don't know.)
With a few towards building on IA32 and IA64 using the same Makefile could I just change "-pthread" to "-pthread -D_REENTRANT" and this would produce the same binaries on IA32 as "-pthread" for boost_1_32_0 as well as for boost_1_33_0 ?
It would. Ben.