[#MDEV-9441] Non-blocking API missing on non-x86 platforms

The non-blocking API is missing on non-x86 platforms. This is seen by error
return from mysql_init(MYSQL_OPT_NONBLOCK, 0), and from null-pointer
segfault on all subsequent non-blocking calls.

The problem is that the HAVE_UCONTEXT_H check in CMake is propagated
incorrectly to my_config.h, so my_context.h cannot see the availability of
ucontext. ucontext is used as a fallback for platforms where no
hand-crafted assembler version is available, such as ARM. Without ucontext
fallback, the non-blocking API becomes disabled.

diff --git a/config.h.cmake b/config.h.cmake

index 4030673..70b7518 100644

--- a/config.h.cmake

+++ b/config.h.cmake

@@ -297,7 +297,7 @@

 #cmakedefine HAVE_THR_YIELD 1

 #cmakedefine HAVE_TIME 1

 #cmakedefine HAVE_TIMES 1

-#cmakedefine HAVE_UCONTEXT 1

+#cmakedefine HAVE_UCONTEXT_H 1

 #cmakedefine HAVE_VALLOC 1

 #cmakedefine HAVE_VIDATTR 1

 #define HAVE_VIO_READ_BUFF 1

diff --git a/include/my_context.h b/include/my_context.h

index 1bf13fd..976ed98 100644

--- a/include/my_context.h

+++ b/include/my_context.h

@@ -31,7 +31,7 @@

 #define MY_CONTEXT_USE_X86_64_GCC_ASM

 #elif defined(__GNUC__) && __GNUC__ >= 3 && defined(__i386__)

 #define MY_CONTEXT_USE_I386_GCC_ASM

-#elif defined(HAVE_UCONTEXT)

+#elif defined(HAVE_UCONTEXT_H)

 #define MY_CONTEXT_USE_UCONTEXT

 #else

 #define MY_CONTEXT_DISABLE

[MDEV-9441] Non-blocking API missing on non-x86 platforms Created: 2016-01-21 Updated: 2016-02-01 Resolved: 2016-02-01
Status:	Closed
Project:	MariaDB Server
Component/s:	Scripts & Clients
Affects Version/s:	5.5, 10.0, 10.1
Fix Version/s:	5.5.48, 10.0.24, 10.1.12

[MDEV-9441] Non-blocking API missing on non-x86 platforms Created: 2016-01-21 Updated: 2016-02-01 Resolved: 2016-02-01