使用setjump loopjump在线程中跳转的问题

Question

使用setjumploopjump在线程中跳转的问题使用setjump到另一个线程中跳转,跳转成功了,后面的代码不执行了#define_CRT_SECURE_NO_WARNINGS#include#include#include#include#include#include#includejmp_bufbuf;void*print_a(void*);void*print_b(void*);//线程A方法void*print_a(void*a){for(inti=0;i

Answer 1

讲真，我没想到还能这么用....
setjmp/longjmpisimplementedbysavingtheregister(includingstackandcodepointeretc)whenfirstpassed,andrestoringthemjumping.
当线程b通过longjmp跳到print_a时，它的栈帧和线程a的栈帧所在的内存就是一个地方了(原来栈的内存没人管)。当线程a退出时，自然要弹出所有栈帧，那么线程b之后对栈访问就是对非法内存的访问了。
就像你把双胞胎中的弟弟的头嫁接到哥哥身上，哥哥变成了连体婴儿，哥哥挂掉之后，弟弟也活不成了，反之也是
                            

Answer 2

longjmp不能跨线程。
C117.13.2.1/2:
Thelongjmpfunctionrestorestheenvironmentsavedbythemostrecentinvocationofthesetjmpmacrointhesameinvocationoftheprogramwiththecorrespondingjmp_bufargument.Iftherehasbeennosuchinvocation,oriftheinvocationwasfromanotherthreadofexecution,orifthefunctioncontainingtheinvocationofthesetjmpmacrohasterminatedexecutionintheinterim,oriftheinvocationofthesetjmpmacrowaswithinthescopeofanidentifierwithvariablymodifiedtypeandexecutionhasleftthatscopeintheinterim,thebehaviorisundefined