C语言的异常机制--setjump()和longjump()实现

本是古典何须时尚 2022-09-30 00:44 179阅读 0赞

# [/\* ------------------------------------------------------------------------- \*\* File : cexcept.c \* \*\* Coder: Spark Song. \* \*\* Note : Use the example code from 《C Interfaces and Implementations》 \* \*\* ------------------------------------------------------------------------- \*/ \#include <setjmp.h> \#include <stdlib.h> \#include <stdio.h> \#include <assert.h> int Allocation\_handled = 0; jmp\_buf Allocate\_Failed; void \*allocate(unsigned n) \{ void \* new = (void \*)malloc(n); if (new) return new; if (Allocation\_handled) /\* 如果实例化了异常处理程序的话... \*/ longjmp(Allocate\_Failed, 1); /\* 产生异常，并抛出 \*/ assert(0); /\* 如果没有实例化异常处理程序，则此断言会报出运行期的错误 \*/ \} int main(int argc, char \*argv\[\]) \{ char \*buf = 0; int count = 0; Allocation\_handled = 1; /\* 设置实例化异常的标志，设为1表示实例化了异常处理程序 \*/ if (setjmp(Allocate\_Failed)) /\* 实例化异常 \*/ \{ fprintf(stderr, "EXCEPT: Couldn't allocate the buffer/n"); exit(EXIT\_FAILURE); \} while(1) /\* 测试代码：一直分配内存，直到没有内存为止。没有内存时会触发异常 \*/ \{ buf = (char \*)allocate(4096000); printf("Allocate successs, the count is: %d/n", count++); \} Allocation\_handled = 0; return 0;  ][------------------------------------------------------------------------- _ File _ cexcept.c _ _ Coder_ Spark Song. _ _ Note _ Use the example code from _C Interfaces and Implementations_ _ _ ------------------------------------------------------------------------- _ _include _setjmp.h_ _include _stdlib.h_ _include _stdio.h_ _include _assert.h_ int Allocation_handled _ 0_ jmp_buf Allocate_Failed_ void _allocate_unsigned n_ _ void _ new _ _void _malloc_n_ if _new_ return new_ if _Allocation_handled_ _ _... _ longjmp_Allocate_Failed_ 1_ _ _ _ assert_0_ _ _ _ _ int main_int argc_ char _argv_ _ char _buf _ 0_ int count _ 0_ Allocation_handled _ 1_ _ _1_ _ if _setjmp_Allocate_Failed_ _ _ _ _ fprintf_stderr_ _EXCEPT_ Couldn_t allocate the buffer_n_ exit_EXIT_FAILURE_ _ while_1_ _ _ _ _ buf _ _char _allocate_4096000_ printf_Allocate successs_ the count is_ _d_n_ count_ _ Allocation_handled _ 0_ return 0_] #

[------------------------------------------------------------------------- _ File _ cexcept.c _ _ Coder_ Spark Song. _ _ Note _ Use the example code from _C Interfaces and Implementations_ _ _ ------------------------------------------------------------------------- _ _include _setjmp.h_ _include _stdlib.h_ _include _stdio.h_ _include _assert.h_ int Allocation_handled _ 0_ jmp_buf Allocate_Failed_ void _allocate_unsigned n_ _ void _ new _ _void _malloc_n_ if _new_ return new_ if _Allocation_handled_ _ _... _ longjmp_Allocate_Failed_ 1_ _ _ _ assert_0_ _ _ _ _ int main_int argc_ char _argv_ _ char _buf _ 0_ int count _ 0_ Allocation_handled _ 1_ _ _1_ _ if _setjmp_Allocate_Failed_ _ _ _ _ fprintf_stderr_ _EXCEPT_ Couldn_t allocate the buffer_n_ exit_EXIT_FAILURE_ _ while_1_ _ _ _ _ buf _ _char _allocate_4096000_ printf_Allocate successs_ the count is_ _d_n_ count_ _ Allocation_handled _ 0_ return 0_]: http://blog.vckbase.com/smileonce/archive/2005/08/16/11053.html