swapcontext wrapper can not be implemented in C, the stack pointer saved in
authordavidxu <davidxu@ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f>
Wed, 10 Apr 2013 02:40:03 +0000 (02:40 +0000)
committerdavidxu <davidxu@ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f>
Wed, 10 Apr 2013 02:40:03 +0000 (02:40 +0000)
commit2f603b727eb092555d811fa06f4b75f36ebc4ce2
tree06c13eb76ea94651e8cb651c68dc05bfa1ed83ba
parentd0af1ac676ae80aab1400ae55b24034126fc1ee3
swapcontext wrapper can not be implemented in C, the stack pointer saved in
the context becomes invalid when the function returns, same as setjmp,
it must be implemented in assemble language, see discussions in PR
misc/177624.

git-svn-id: svn://svn.freebsd.org/base/head@249323 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
lib/libthr/thread/thr_sig.c