Restores the context, previously saved by setjmp.

#include <setjmp.h>

void longjmp (jmp_buf context, int value);

Parameters

context

Context previously stored by setjmp.

value

Value to be returned to setjmp; must be non-0. If 0, the value 1 is returned to the previous setjmp call.

Remarks

The previous call to setjmp causes the current context to be saved in context. A subsequent call to longjmp restores the context and returns control to the point immediately following the corresponding setjmp call. Execution resumes as if value had just been returned by setjmp.

The values of all local variables (except register variables) that are accessible to the routine receiving control contain the values they had when longjmp was called. The values of register variables are unpredictable.

Observe these restrictions when using longjmp:

• Do not assume that the values of the register variables will remain the same. The values of register variables in the routine calling setjmp may not be restored to the proper values after longjmp is executed.
• Do not use longjmp to transfer control out of an interrupt-handling routine.

Return Values

None.

Requirements

See Also

setjmp