純c實現異常捕獲try-catch組件教程示例

Posted on 2022-08-07 by WalkonNet

try / catch / finally / throw 介紹

本文用純c的代碼，實現異常捕獲try-catch組件。閱讀本文需要時刻牢記setjmp和longjmp的對應關系。

在java，python，c++裡面都有try catch異常捕獲。在try代碼塊裡面執行的函數，如果出錯有異常瞭，就會throw把異常拋出來，拋出來的異常被catch接收進行處理，而finally意味著無論有沒有異常，都會執行finally代碼塊內的代碼。

try{
    connect_sql();//throw
}catch(){
}finally {
};

如何實現try-catch這一機制？

關於跳轉，有兩個跳轉。那麼在這裡我們必然選用長跳轉。

goto：函數內跳轉，短跳轉
setjmp/longjmp：跨函數跳轉，長跳轉

setjmp/longjmp這兩個函數是不存在壓棧出棧的，也就是說longjmp跳轉到setjmp的地方後，會覆蓋之前的棧。

setjmp/longjmp使用介紹(重點)

setjmp(env)：設置跳轉的位置，第一次返回0，後續返回longjmp的第二個參數
longjmp(env, idx)：跳轉到設置env的位置，第二個參數就是setjmp()的返回值

#include <stdio.h>
#include <setjmp.h>
jmp_buf env;
int count = 0;
void sub_func(int idx) {
    printf("sub_func -->idx : %d\n", idx);
    //第二個參數就是setjmp()的返回值
    longjmp(env, idx);
}
int main() {
    int idx = 0;
    //設置跳轉標簽，第一次返回0
    count = setjmp(env);
    if (count == 0) {
        printf("count : %d\n", count);
        sub_func(++idx);
    }
    else if (count == 1) {
        printf("count : %d\n", count);
        sub_func(++idx);
    }
    else if (count == 2) {
        printf("count : %d\n", count);
        sub_func(++idx);
    }
    else {
        printf("other count \n");
    }
    return 0;
}

count : 0
sub_func -->idx : 1
count : 1
sub_func -->idx : 2
count : 2
sub_func -->idx : 3
other count

try-catch 和 setjmp/longjmp 的關系

try ---&gt; setjmp(env)
throw ---&gt; longjmp(env,Exception)
catch(Exception)

我們其實可以分析出來，setjmp和count==0的地方，相當於try，後面的else if 相當於catch，最後一個else，其實並不是finally，因為finally是不管怎麼樣都會執行，上圖我標註的其實是誤導的。應該是下圖這樣才對。

宏定義實現try-catch Demo

4個關鍵字分析出來它們的關系之後，其實我們就能用宏定義來實現瞭。

#include <stdio.h>
#include <setjmp.h>
typedef struct _Exception {
    jmp_buf env;
    int exceptype;
} Exception;
#define Try(excep) if((excep.exceptype=setjmp(excep.env))==0)
#define Catch(excep, ExcepType) else if(excep.exceptype==ExcepType)
#define Throw(excep, ExcepType) longjmp(excep.env,ExcepType)
#define Finally
void throw_func(Exception ex, int idx) {
    printf("throw_func -->idx : %d\n", idx);
    Throw(ex, idx);
}
int main() {
    int idx = 0;
    Exception ex;
    Try(ex) {
        printf("ex.exceptype : %d\n", ex.exceptype);
        throw_func(ex, ++idx);
    }
    Catch(ex, 1) {
        printf("ex.exceptype : %d\n", ex.exceptype);
    }
    Catch(ex, 2) {
        printf("ex.exceptype : %d\n", ex.exceptype);
    }
    Catch(ex, 3) {
        printf("ex.exceptype : %d\n", ex.exceptype);
    }
    Finally{
        printf("Finally\n");
    };
    return 0;
}

ex.exceptype : 0
throw_func -->idx : 1
ex.exceptype : 1
Finally

實現try-catch的三個問題

雖然現在demo版看起來像這麼回事瞭，但是還是有兩個問題：

在哪個文件哪個函數哪個行拋的異常？
try-catch嵌套怎麼做？
try-catch線程安全怎麼做？

1. 在哪個文件哪個函數哪個行拋的異常

系統提供瞭三個宏可以供我們使用，如果我們沒有catch到異常，我們就可以打印出來

__func__, __FILE__, __LINE__

2. try-catch嵌套怎麼做？

我們知道try-catch是可以嵌套的，那麼這就形成瞭一個棧的數據結構，現在下面有三個try，每個setjmp對應的都是不同的jmp_buf,那麼我們可以定義一個jmp_buf的棧。

try{
    try{
        try{
        }catch(){
        }
    }catch(){
    }
}catch(){
}finally{
};

那麼我們很容易能寫出來，既然是棧，try的時候我們就插入一個結點，catch的時候我們就pop一個出來。

#define EXCEPTION_MESSAGE_LENGTH                512
typedef struct _ntyException {
    const char *name;
} ntyException;
ntyException SQLException = {"SQLException"};
ntyException TimeoutException = {"TimeoutException"};
typedef struct _ntyExceptionFrame {
    jmp_buf env;
    int line;
    const char *func;
    const char *file;
    ntyException *exception;
    struct _ntyExceptionFrame *next;
    char message[EXCEPTION_MESSAGE_LENGTH + 1];
} ntyExceptionFrame;
enum {
    ExceptionEntered = 0,//0
    ExceptionThrown,    //1
    ExceptionHandled, //2
    ExceptionFinalized//3
};

3. try-catch線程安全

每個線程都可以try-catch，但是我們以及知道瞭是個棧結構，既ExceptionStack，那麼每個線程是獨有一個ExceptionStack呢？還是共享同一個ExceptionStack？很明顯，A線程的異常應該有A的處理，而不是由B線程處理。那麼我們就使用Linux線程私有數據Thread-specific Data(TSD)來做。

/* ** **** ******** **************** Thread safety **************** ******** **** ** */
#define ntyThreadLocalData                      pthread_key_t
#define ntyThreadLocalDataSet(key, value)       pthread_setspecific((key), (value))
#define ntyThreadLocalDataGet(key)              pthread_getspecific((key))
#define ntyThreadLocalDataCreate(key)           pthread_key_create(&(key), NULL)
ntyThreadLocalData ExceptionStack;
static void init_once(void) {
    ntyThreadLocalDataCreate(ExceptionStack);
}
static pthread_once_t once_control = PTHREAD_ONCE_INIT;
void ntyExceptionInit(void) {
    pthread_once(&once_control, init_once);
}

代碼實現與解釋

try

首先創建一個新節點入棧，然後setjmp設置一個標記，接下來就是大括號裡面的操作瞭，如果有異常，那麼就會被throw拋出來，為什麼這裡最後一行是if？因為longjmp的時候，返回的地方是setjmp，不要忘瞭！要時刻扣住longjmp和setjmp。

#define Try do {                                                                        \
            volatile int Exception_flag;                                                \
            ntyExceptionFrame frame;                                                    \
            frame.message[0] = 0;                                                       \
            frame.next = (ntyExceptionFrame*)ntyThreadLocalDataGet(ExceptionStack);     \
            ntyThreadLocalDataSet(ExceptionStack, &frame);                              \
            Exception_flag = setjmp(frame.env);                                         \
            if (Exception_flag == ExceptionEntered) {

Try{
	//...
    Throw(A, "A");
}

throw

在這裡，我們不應該把throw定義成宏，而應該定義成函數。這裡分兩類，一類是try裡面的throw，一類是沒有try直接throw。

對於try裡面的異常，我們將其狀態變成ExceptionThrown，然後longjmp到setjmp的地方，由catch處理
對於直接拋的異常，必然沒有catch去捕獲，那麼我們直接打印出來
如果第一種情況的異常，沒有被catch捕獲到怎麼辦呢？後面會被ReThrow出來，對於再次被拋出，我們就直接進行打印異常

這裡的##__VA_ARGS__是可變參數，具體不多介紹瞭，不是本文重點。

#define ReThrow                    ntyExceptionThrow(frame.exception, frame.func, frame.file, frame.line, NULL)
#define Throw(e, cause, ...)    ntyExceptionThrow(&amp;(e), __func__, __FILE__, __LINE__, cause, ##__VA_ARGS__,NULL)

void ntyExceptionThrow(ntyException *excep, const char *func, const char *file, int line, const char *cause, ...) {
    va_list ap;
    ntyExceptionFrame *frame = (ntyExceptionFrame *) ntyThreadLocalDataGet(ExceptionStack);
    if (frame) {
        //異常名
        frame->exception = excep;
        frame->func = func;
        frame->file = file;
        frame->line = line;
        //異常打印的信息
        if (cause) {
            va_start(ap, cause);
            vsnprintf(frame->message, EXCEPTION_MESSAGE_LENGTH, cause, ap);
            va_end(ap);
        }
        ntyExceptionPopStack;
        longjmp(frame->env, ExceptionThrown);
    }
        //沒有被catch,直接throw
    else if (cause) {
        char message[EXCEPTION_MESSAGE_LENGTH + 1];
        va_start(ap, cause);
        vsnprintf(message, EXCEPTION_MESSAGE_LENGTH, cause, ap);
        va_end(ap);
        printf("%s: %s\n raised in %s at %s:%d\n", excep->name, message, func ? func : "?", file ? file : "?", line);
    }
    else {
        printf("%s: %p\n raised in %s at %s:%d\n", excep->name, excep, func ? func : "?", file ? file : "?", line);
    }
}

Catch

如果還是ExceptionEntered狀態，說明沒有異常，沒有throw。如果捕獲到異常瞭，那麼其狀態就是ExceptionHandled。

#define Catch(nty_exception) \
                if (Exception_flag == ExceptionEntered) ntyExceptionPopStack; \
            } else if (frame.exception == &(nty_exception)) { \
                Exception_flag = ExceptionHandled;

Finally

finally也是一樣，如果還是ExceptionEntered狀態，說明沒有異常沒有捕獲，那麼現在狀態是終止階段。

#define Finally \
                if (Exception_flag == ExceptionEntered) ntyExceptionPopStack; \
            } { \
                if (Exception_flag == ExceptionEntered)    \
                    Exception_flag = ExceptionFinalized;

EndTry

有些人看到EndTry可能會有疑問，try-catch一共不就4個關鍵字嗎？怎麼你多瞭一個。我們先來看看EndTry做瞭什麼，首先如果是ExceptionEntered狀態，那意味著什麼？意味著沒有throw，沒有catch，沒有finally，隻有try，我們需要對這種情況進行處理，要出棧。

還有一種情況，如果是ExceptionThrown狀態，說明什麼？沒有被catch捕獲到，那麼我們就再次拋出，進行打印錯誤。至於為什麼多個EndTry，寫起來方便唄~

#define EndTry \
                if (Exception_flag == ExceptionEntered) ntyExceptionPopStack; \
            } if (Exception_flag == ExceptionThrown) {ReThrow;} \
            } while (0)

try-catch代碼

/* ** **** ******** **************** try / catch / finally / throw **************** ******** **** ** */
#define EXCEPTION_MESSAGE_LENGTH                512
typedef struct _ntyException {
    const char *name;
} ntyException;
ntyException SQLException = {"SQLException"};
ntyException TimeoutException = {"TimeoutException"};
typedef struct _ntyExceptionFrame {
    jmp_buf env;
    int line;
    const char *func;
    const char *file;
    ntyException *exception;
    struct _ntyExceptionFrame *next;
    char message[EXCEPTION_MESSAGE_LENGTH + 1];
} ntyExceptionFrame;
enum {
    ExceptionEntered = 0,//0
    ExceptionThrown,    //1
    ExceptionHandled, //2
    ExceptionFinalized//3
};
#define ntyExceptionPopStack    \
    ntyThreadLocalDataSet(ExceptionStack, ((ntyExceptionFrame*)ntyThreadLocalDataGet(ExceptionStack))->next)
#define ReThrow                    ntyExceptionThrow(frame.exception, frame.func, frame.file, frame.line, NULL)
#define Throw(e, cause, ...)    ntyExceptionThrow(&(e), __func__, __FILE__, __LINE__, cause, ##__VA_ARGS__,NULL)
#define Try do {                                                                        \
            volatile int Exception_flag;                                                \
            ntyExceptionFrame frame;                                                    \
            frame.message[0] = 0;                                                       \
            frame.next = (ntyExceptionFrame*)ntyThreadLocalDataGet(ExceptionStack);     \
            ntyThreadLocalDataSet(ExceptionStack, &frame);                              \
            Exception_flag = setjmp(frame.env);                                         \
            if (Exception_flag == ExceptionEntered) {
#define Catch(nty_exception) \
                if (Exception_flag == ExceptionEntered) ntyExceptionPopStack; \
            } else if (frame.exception == &(nty_exception)) { \
                Exception_flag = ExceptionHandled;
#define Finally \
                if (Exception_flag == ExceptionEntered) ntyExceptionPopStack; \
            } { \
                if (Exception_flag == ExceptionEntered)    \
                    Exception_flag = ExceptionFinalized;
#define EndTry \
                if (Exception_flag == ExceptionEntered) ntyExceptionPopStack; \
            } if (Exception_flag == ExceptionThrown) {ReThrow;} \
            } while (0)
void ntyExceptionThrow(ntyException *excep, const char *func, const char *file, int line, const char *cause, ...) {
    va_list ap;
    ntyExceptionFrame *frame = (ntyExceptionFrame *) ntyThreadLocalDataGet(ExceptionStack);
    if (frame) {
        //異常名
        frame->exception = excep;
        frame->func = func;
        frame->file = file;
        frame->line = line;
        //異常打印的信息
        if (cause) {
            va_start(ap, cause);
            vsnprintf(frame->message, EXCEPTION_MESSAGE_LENGTH, cause, ap);
            va_end(ap);
        }
        ntyExceptionPopStack;
        longjmp(frame->env, ExceptionThrown);
    }
        //沒有被catch,直接throw
    else if (cause) {
        char message[EXCEPTION_MESSAGE_LENGTH + 1];
        va_start(ap, cause);
        vsnprintf(message, EXCEPTION_MESSAGE_LENGTH, cause, ap);
        va_end(ap);
        printf("%s: %s\n raised in %s at %s:%d\n", excep->name, message, func ? func : "?", file ? file : "?", line);
    }
    else {
        printf("%s: %p\n raised in %s at %s:%d\n", excep->name, excep, func ? func : "?", file ? file : "?", line);
    }
}

Debug測試代碼

/* ** **** ******** **************** debug **************** ******** **** ** */
ntyException A = {"AException"};
ntyException B = {"BException"};
ntyException C = {"CException"};
ntyException D = {"DException"};
void *thread(void *args) {
    pthread_t selfid = pthread_self();
    Try
            {
                Throw(A, "A");
            }
        Catch (A)
            {
                printf("catch A : %ld\n", selfid);
            }
    EndTry;
    Try
            {
                Throw(B, "B");
            }
        Catch (B)
            {
                printf("catch B : %ld\n", selfid);
            }
    EndTry;
    Try
            {
                Throw(C, "C");
            }
        Catch (C)
            {
                printf("catch C : %ld\n", selfid);
            }
    EndTry;
    Try
            {
                Throw(D, "D");
            }
        Catch (D)
            {
                printf("catch D : %ld\n", selfid);
            }
    EndTry;
    Try
            {
                Throw(A, "A Again");
                Throw(B, "B Again");
                Throw(C, "C Again");
                Throw(D, "D Again");
            }
        Catch (A)
            {
                printf("catch A again : %ld\n", selfid);
            }
        Catch (B)
            {
                printf("catch B again : %ld\n", selfid);
            }
        Catch (C)
            {
                printf("catch C again : %ld\n", selfid);
            }
        Catch (D)
            {
                printf("catch B again : %ld\n", selfid);
            }
    EndTry;
}
#define PTHREAD_NUM        8
int main(void) {
    ntyExceptionInit();
    printf("\n\n=> Test1: Throw\n");
    {
        Throw(D, NULL);     //ntyExceptionThrow(&(D), "_function_name_", "_file_name_", 202, ((void *) 0), ((void *) 0))
        Throw(C, "null C"); //ntyExceptionThrow(&(C), "_function_name_", "_file_name_", 203, "null C", ((void *) 0))
    }
    printf("=> Test1: Ok\n\n");
    printf("\n\n=> Test2: Try-Catch Double Nesting\n");
    {
        Try
                {
                    Try
                            {
                                Throw(B, "call B");
                            }
                        Catch (B)
                            {
                                printf("catch B \n");
                            }
                    EndTry;
                    Throw(A, NULL);
                }
            Catch(A)
                {
                    printf("catch A \n");
                    printf("Result: Ok\n");
                }
        EndTry;
    }
    printf("=> Test2: Ok\n\n");
    printf("\n\n=> Test3: Try-Catch Triple  Nesting\n");
    {
        Try
                {
                    Try
                            {
                                Try
                                        {
                                            Throw(C, "call C");
                                        }
                                    Catch (C)
                                        {
                                            printf("catch C\n");
                                        }
                                EndTry;
                                Throw(B, "call B");
                            }
                        Catch (B)
                            {
                                printf("catch B\n");
                            }
                    EndTry;
                    Throw(A, NULL);
                }
            Catch(A)
                {
                    printf("catch A\n");
                }
        EndTry;
    }
    printf("=> Test3: Ok\n\n");
    printf("=> Test4: Test Thread-safeness\n");
    int i = 0;
    pthread_t th_id[PTHREAD_NUM];
    for (i = 0; i < PTHREAD_NUM; i++) {
        pthread_create(&th_id[i], NULL, thread, NULL);
    }
    for (i = 0; i < PTHREAD_NUM; i++) {
        pthread_join(th_id[i], NULL);
    }
    printf("=> Test4: Ok\n\n");
    printf("\n\n=> Test5: No Success Catch\n");
    {
        Try
                {
                    Throw(A, "no catch A ,should Rethrow");
                }
        EndTry;
    }
    printf("=> Test5: Rethrow Success\n\n");
    printf("\n\n=> Test6: Normal Test\n");
    {
        Try
                {
                    Throw(A, "call A");
                }
            Catch(A)
                {
                    printf("catch A\n");
                }
            Finally
                {
                    printf("wxf nb\n");
                };
        EndTry;
    }
    printf("=> Test6: ok\n\n");
}

線程安全、try-catch、Debug測試代碼匯總

#include <stdio.h>
#include <setjmp.h>
#include <pthread.h>
#include <stdarg.h>
/* ** **** ******** **************** Thread safety **************** ******** **** ** */
#define ntyThreadLocalData                      pthread_key_t
#define ntyThreadLocalDataSet(key, value)       pthread_setspecific((key), (value))
#define ntyThreadLocalDataGet(key)              pthread_getspecific((key))
#define ntyThreadLocalDataCreate(key)           pthread_key_create(&(key), NULL)
ntyThreadLocalData ExceptionStack;
static void init_once(void) {
    ntyThreadLocalDataCreate(ExceptionStack);
}
static pthread_once_t once_control = PTHREAD_ONCE_INIT;
void ntyExceptionInit(void) {
    pthread_once(&once_control, init_once);
}
/* ** **** ******** **************** try / catch / finally / throw **************** ******** **** ** */
#define EXCEPTION_MESSAGE_LENGTH                512
typedef struct _ntyException {
    const char *name;
} ntyException;
ntyException SQLException = {"SQLException"};
ntyException TimeoutException = {"TimeoutException"};
typedef struct _ntyExceptionFrame {
    jmp_buf env;
    int line;
    const char *func;
    const char *file;
    ntyException *exception;
    struct _ntyExceptionFrame *next;
    char message[EXCEPTION_MESSAGE_LENGTH + 1];
} ntyExceptionFrame;
enum {
    ExceptionEntered = 0,//0
    ExceptionThrown,    //1
    ExceptionHandled, //2
    ExceptionFinalized//3
};
#define ntyExceptionPopStack    \
    ntyThreadLocalDataSet(ExceptionStack, ((ntyExceptionFrame*)ntyThreadLocalDataGet(ExceptionStack))->next)
#define ReThrow                    ntyExceptionThrow(frame.exception, frame.func, frame.file, frame.line, NULL)
#define Throw(e, cause, ...)    ntyExceptionThrow(&(e), __func__, __FILE__, __LINE__, cause, ##__VA_ARGS__,NULL)
#define Try do {                                                                        \
            volatile int Exception_flag;                                                \
            ntyExceptionFrame frame;                                                    \
            frame.message[0] = 0;                                                       \
            frame.next = (ntyExceptionFrame*)ntyThreadLocalDataGet(ExceptionStack);     \
            ntyThreadLocalDataSet(ExceptionStack, &frame);                              \
            Exception_flag = setjmp(frame.env);                                         \
            if (Exception_flag == ExceptionEntered) {
#define Catch(nty_exception) \
                if (Exception_flag == ExceptionEntered) ntyExceptionPopStack; \
            } else if (frame.exception == &(nty_exception)) { \
                Exception_flag = ExceptionHandled;
#define Finally \
                if (Exception_flag == ExceptionEntered) ntyExceptionPopStack; \
            } { \
                if (Exception_flag == ExceptionEntered)    \
                    Exception_flag = ExceptionFinalized;
#define EndTry \
                if (Exception_flag == ExceptionEntered) ntyExceptionPopStack; \
            } if (Exception_flag == ExceptionThrown) {ReThrow;} \
            } while (0)
void ntyExceptionThrow(ntyException *excep, const char *func, const char *file, int line, const char *cause, ...) {
    va_list ap;
    ntyExceptionFrame *frame = (ntyExceptionFrame *) ntyThreadLocalDataGet(ExceptionStack);
    if (frame) {
        //異常名
        frame->exception = excep;
        frame->func = func;
        frame->file = file;
        frame->line = line;
        //異常打印的信息
        if (cause) {
            va_start(ap, cause);
            vsnprintf(frame->message, EXCEPTION_MESSAGE_LENGTH, cause, ap);
            va_end(ap);
        }
        ntyExceptionPopStack;
        longjmp(frame->env, ExceptionThrown);
    }
        //沒有被catch,直接throw
    else if (cause) {
        char message[EXCEPTION_MESSAGE_LENGTH + 1];
        va_start(ap, cause);
        vsnprintf(message, EXCEPTION_MESSAGE_LENGTH, cause, ap);
        va_end(ap);
        printf("%s: %s\n raised in %s at %s:%d\n", excep->name, message, func ? func : "?", file ? file : "?", line);
    }
    else {
        printf("%s: %p\n raised in %s at %s:%d\n", excep->name, excep, func ? func : "?", file ? file : "?", line);
    }
}
/* ** **** ******** **************** debug **************** ******** **** ** */
ntyException A = {"AException"};
ntyException B = {"BException"};
ntyException C = {"CException"};
ntyException D = {"DException"};
void *thread(void *args) {
    pthread_t selfid = pthread_self();
    Try
            {
                Throw(A, "A");
            }
        Catch (A)
            {
                printf("catch A : %ld\n", selfid);
            }
    EndTry;
    Try
            {
                Throw(B, "B");
            }
        Catch (B)
            {
                printf("catch B : %ld\n", selfid);
            }
    EndTry;
    Try
            {
                Throw(C, "C");
            }
        Catch (C)
            {
                printf("catch C : %ld\n", selfid);
            }
    EndTry;
    Try
            {
                Throw(D, "D");
            }
        Catch (D)
            {
                printf("catch D : %ld\n", selfid);
            }
    EndTry;
    Try
            {
                Throw(A, "A Again");
                Throw(B, "B Again");
                Throw(C, "C Again");
                Throw(D, "D Again");
            }
        Catch (A)
            {
                printf("catch A again : %ld\n", selfid);
            }
        Catch (B)
            {
                printf("catch B again : %ld\n", selfid);
            }
        Catch (C)
            {
                printf("catch C again : %ld\n", selfid);
            }
        Catch (D)
            {
                printf("catch B again : %ld\n", selfid);
            }
    EndTry;
}
#define PTHREAD_NUM        8
int main(void) {
    ntyExceptionInit();
    printf("\n\n=> Test1: Throw\n");
    {
        Throw(D, NULL);     //ntyExceptionThrow(&(D), "_function_name_", "_file_name_", 202, ((void *) 0), ((void *) 0))
        Throw(C, "null C"); //ntyExceptionThrow(&(C), "_function_name_", "_file_name_", 203, "null C", ((void *) 0))
    }
    printf("=> Test1: Ok\n\n");
    printf("\n\n=> Test2: Try-Catch Double Nesting\n");
    {
        Try
                {
                    Try
                            {
                                Throw(B, "call B");
                            }
                        Catch (B)
                            {
                                printf("catch B \n");
                            }
                    EndTry;
                    Throw(A, NULL);
                }
            Catch(A)
                {
                    printf("catch A \n");
                    printf("Result: Ok\n");
                }
        EndTry;
    }
    printf("=> Test2: Ok\n\n");
    printf("\n\n=> Test3: Try-Catch Triple  Nesting\n");
    {
        Try
                {
                    Try
                            {
                                Try
                                        {
                                            Throw(C, "call C");
                                        }
                                    Catch (C)
                                        {
                                            printf("catch C\n");
                                        }
                                EndTry;
                                Throw(B, "call B");
                            }
                        Catch (B)
                            {
                                printf("catch B\n");
                            }
                    EndTry;
                    Throw(A, NULL);
                }
            Catch(A)
                {
                    printf("catch A\n");
                }
        EndTry;
    }
    printf("=> Test3: Ok\n\n");
    printf("=> Test4: Test Thread-safeness\n");
    int i = 0;
    pthread_t th_id[PTHREAD_NUM];
    for (i = 0; i < PTHREAD_NUM; i++) {
        pthread_create(&th_id[i], NULL, thread, NULL);
    }
    for (i = 0; i < PTHREAD_NUM; i++) {
        pthread_join(th_id[i], NULL);
    }
    printf("=> Test4: Ok\n\n");
    printf("\n\n=> Test5: No Success Catch\n");
    {
        Try
                {
                    Throw(A, "no catch A ,should Rethrow");
                }
        EndTry;
    }
    printf("=> Test5: Rethrow Success\n\n");
    printf("\n\n=> Test6: Normal Test\n");
    {
        Try
                {
                    Throw(A, "call A");
                }
            Catch(A)
                {
                    printf("catch A\n");
                }
            Finally
                {
                    printf("wxf nb\n");
                };
        EndTry;
    }
    printf("=> Test6: ok\n\n");
}
void all() {
    ///////////try
    do {
        volatile int Exception_flag;
        ntyExceptionFrame frame;
        frame.message[0] = 0;
        frame.next = (ntyExceptionFrame *) pthread_getspecific((ExceptionStack));
        pthread_setspecific((ExceptionStack), (&frame));
        Exception_flag = _setjmp(frame.env);
        if (Exception_flag == ExceptionEntered) {
            ///////////
            {
                ///////////try
                do {
                    volatile int Exception_flag;
                    ntyExceptionFrame frame;
                    frame.message[0] = 0;
                    frame.next = (ntyExceptionFrame *) pthread_getspecific((ExceptionStack));
                    pthread_setspecific((ExceptionStack), (&frame));
                    Exception_flag = _setjmp(frame.env);
                    if (Exception_flag == ExceptionEntered) {
                        ///////////
                        {
                            ///////////Throw(B, "recall B"); --->longjmp ExceptionThrown
                            ntyExceptionThrow(&(B), "_function_name_", "_file_name_", 302, "recall B", ((void *) 0));
                            ///////////
                        }
                        ///////////Catch (B)
                        if (Exception_flag == ExceptionEntered)
                            ntyExceptionPopStack;
                    }
                    else if (frame.exception == &(B)) {
                        Exception_flag = ExceptionHandled;
                        ///////////
                        {    ///////////
                            printf("recall B \n");
                            ///////////
                        }
                        ////////fin
                        if (Exception_flag == ExceptionEntered)
                            ntyExceptionPopStack;
                        if (Exception_flag == ExceptionEntered)
                            Exception_flag = ExceptionFinalized;
                        /////////////////{
                        {
                            printf("fin\n");
                        };
                        ////////////////////}
                        ///////////EndTry;
                        if (Exception_flag == ExceptionEntered)
                            ntyExceptionPopStack;
                    }
                    if (Exception_flag == ExceptionThrown)
                        ntyExceptionThrow(frame.exception, frame.func, frame.file, frame.line, ((void *) 0));
                } while (0);
                ///////////Throw(A, NULL); longjmp ExceptionThrown
                ntyExceptionThrow(&(A), "_function_name_", "_file_name_", 329, ((void *) 0), ((void *) 0));
                ///////////
            }
            ///////////Catch(A)
            if (Exception_flag == ExceptionEntered)
                ntyExceptionPopStack;
        }
        else if (frame.exception == &(A)) {
            Exception_flag = ExceptionHandled;
            ///////////
            {
                ///////////
                printf("\tResult: Ok\n");
                ///////////
            }
            /////////// EndTry;
            if (Exception_flag == ExceptionEntered)
                ntyExceptionPopStack;
        }
        if (Exception_flag == ExceptionThrown)
            ntyExceptionThrow(frame.exception, frame.func, frame.file, frame.line, ((void *) 0));
    } while (0);
    ///////////
}

以上就是純c實現異常捕獲try-catch組件教程示例的詳細內容，更多關於c異常捕獲try-catch的資料請關註WalkonNet其它相關文章！

純c實現異常捕獲try-catch組件教程示例

目錄

try / catch / finally / throw 介紹

如何實現try-catch這一機制？

setjmp/longjmp使用介紹(重點)

try-catch 和 setjmp/longjmp 的關系

宏定義實現try-catch Demo

實現try-catch的三個問題

1. 在哪個文件哪個函數哪個行拋的異常

2. try-catch嵌套怎麼做？

3. try-catch線程安全

代碼實現與解釋

try

throw

Catch

Finally

EndTry

try-catch代碼

Debug測試代碼

線程安全、try-catch、Debug測試代碼匯總

推薦閱讀：

發佈留言取消回覆

近期文章

目錄

try / catch / finally / throw 介紹

如何實現try-catch這一機制？

setjmp/longjmp使用介紹(重點)

try-catch 和 setjmp/longjmp 的關系

宏定義實現try-catch Demo

實現try-catch的三個問題

1. 在哪個文件哪個函數哪個行拋的異常

2. try-catch嵌套怎麼做？

3. try-catch線程安全

代碼實現與解釋

try

throw

Catch

Finally

EndTry

try-catch代碼

Debug測試代碼

線程安全、try-catch、Debug測試代碼 匯總

推薦閱讀：

發佈留言 取消回覆

近期文章

標籤

線程安全、try-catch、Debug測試代碼匯總

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