我是 C 的新手,我正在从事一个项目,我一直在努力努力工作好几天,但我无法弄清楚问题出在哪里。
基本上,应用程序应该做的是从数据库中读取数据并将值插入到结构中。有些行是相互关联的,因此在结构中是一个链接列表,它将包含数据库中的其他值。
我不知道要从数据库中取出多少条记录,所以我最初将结构分配为 100 个项目,并且我跟踪一个索引,如果它达到 100,它会重新分配结构以添加另外 100项目。重新分配位似乎有效,但这就是为什么我尝试将一些东西插入到结构中的链表中,我得到一个段错误。
下面是主要结构的定义。
typedef struct CallLogSearchDataStruct
{
char * date;
char * time;
char * bParty;
char * aParty;
float duration;
char * cleardownCause;
struct CallLogSearchOutboundStruct * outboundLegs;
} callLogSearchDataStruct;
下面是链表(CallLogSearchOutboundStruct)的代码
typedef struct CallLogSearchOutboundStruct
{
char * target;
float duration;
char * cleardownCause;
struct CallLogSearchOutboundStruct * nextLeg;
} callLogSearchOutboundStruct;
我使用以下代码初始化结构
callLogSearchData = calloc(INITIAL_CALL_STRUCT_SIZE,sizeof(callLogSearchDataStruct));
callLogSearch = calloc(INITIAL_CALL_STRUCT_SIZE,sizeof(callLogSearchResultStruct));
switches = calloc(INITIAL_CALL_STRUCT_SIZE, sizeof(switchIDStructure));
每次循环数据时,我使用以下代码在结构中分配 outboundLeg 链表
if (dataRow > -1 && callLogSearchData[dataRow].outboundLegs == NULL)
{
//Initialise the outbound struct
callLogSearchData[dataRow].outboundLegs = malloc(sizeof(callLogSearchOutboundStruct));
callLogSearchData[dataRow].outboundLegs->cleardownCause = NULL;
callLogSearchData[dataRow].outboundLegs->duration = 0;
callLogSearchData[dataRow].outboundLegs->target = NULL;
callLogSearchData[dataRow].outboundLegs->nextLeg = NULL;
}
outboundCallLegStartPtr = callLogSearchData[dataRow].outboundLegs;
outboundCallLegStartPtr->nextLeg = NULL;
下面是调用函数将数据插入到结构中的链表中的代码
insertOutboundLegToList(outboundCallLegStartPtr, targetBuffer, durationBuffer, atoi(rowReport[cleardownColIndex]), debugFile);
下面是实际插入函数的代码
void insertOutboundLegToList(callLogSearchOutboundStruct * outboundLeg, char * target, float duration, int cleardown, FILE * debugFile)
{
//fprintf(debugFile, "INSIDE INSERT OUTBOUND LEG FUNCTION\n");
if (outboundLeg->target == NULL)
{
outboundLeg->target = strdup(target);
outboundLeg->duration = duration;
outboundLeg->cleardownCause = strdup(setCallResult(cleardown));
//fprintf(debugFile, "Outbound target is: %s\n", outboundLeg->target);
}
else
{
while (outboundLeg->nextLeg != NULL)
{
outboundLeg = outboundLeg->nextLeg;
}
outboundLeg->nextLeg = (callLogSearchOutboundStruct*)malloc(sizeof(callLogSearchOutboundStruct));
outboundLeg = outboundLeg->nextLeg;
outboundLeg->target = strdup(target);
outboundLeg->duration = duration;
outboundLeg->cleardownCause = strdup(setCallResult(cleardown));
//fprintf(debugFile, "Outbound target is: %s\n", outboundLeg->target);
outboundLeg->nextLeg = NULL;
}
}
下面是我如何调用函数来检查结构是否需要重新分配
if (reallocateStructures(&callLogSearch, &callLogSearchData, &switches, ×StructHasBeenReallocated, currentStructIndexValue, dataRow) == 0)
{
//Structures have been reallocated so reset the index
currentStructIndexValue = -1;
}
下面是结构重新分配的实际功能
int reallocateStructures(callLogSearchResultStruct **callLogSearch, callLogSearchDataStruct ** callLogSearchData,
switchIDStructure ** switches, int *timesStructHasBeenReallocated, int currentStructIndexValue,
int dataRow)
{
int INITIAL_CALL_STRUCT_SIZE = 100;
int currentSize = 0;
int newSize = 0;
int initFromIndex = 0;
callLogSearchResultStruct * callLogSearchTemp;
callLogSearchDataStruct * callLogSearchDataTemp;
switchIDStructure * switchesTemp;
printf("Current Struct Index Value: %i\n", currentStructIndexValue);
if (currentStructIndexValue >= INITIAL_CALL_STRUCT_SIZE) {
printf("REALLOCATING STRUCTURES");
currentSize = currentStructIndexValue * *timesStructHasBeenReallocated;
newSize = currentSize + INITIAL_CALL_STRUCT_SIZE;
*timesStructHasBeenReallocated = *timesStructHasBeenReallocated + 1;
callLogSearchTemp = (callLogSearchResultStruct*)realloc(*callLogSearch, (newSize * sizeof(callLogSearchResultStruct)));
callLogSearchDataTemp = (callLogSearchDataStruct*)realloc(*callLogSearchData, (newSize * sizeof(callLogSearchDataStruct)));
switchesTemp = (switchIDStructure*)realloc(*switches, (newSize * sizeof(switchIDStructure)));
/**callLogSearchData = realloc(*callLogSearchData, newSize * sizeof (callLogSearchDataStruct));
*callLogSearch = realloc(*callLogSearch, newSize * sizeof (callLogSearchResultStruct));
*switches = realloc(*switches, newSize * sizeof (switchIDStructure));
*/
for (initFromIndex = currentSize; initFromIndex < newSize; initFromIndex++) {
callLogSearchDataTemp[initFromIndex].aParty = NULL;
callLogSearchDataTemp[initFromIndex].bParty = NULL;
callLogSearchDataTemp[initFromIndex].cleardownCause = NULL;
callLogSearchDataTemp[initFromIndex].date = NULL;
callLogSearchDataTemp[initFromIndex].duration = 0;
callLogSearchDataTemp[initFromIndex].outboundLegs = NULL;
callLogSearchDataTemp[initFromIndex].time = NULL;
callLogSearchTemp[initFromIndex].date = NULL;
callLogSearchTemp[initFromIndex].dRowIndex = dataRow;
switchesTemp[initFromIndex].switchID = NULL;
}
*callLogSearch = callLogSearchTemp;
*callLogSearchData = callLogSearchDataTemp;
*switches = switchesTemp;
return 0;
}
else
{
return 1;
}
}
我已经尝试通过 Valgrind 运行我的程序,但我不完全确定所有消息的含义并进行谷歌搜索,虽然我找到了一些东西,但并没有帮助我理解问题。
来自 Valgrind 的消息是
==9152== Invalid read of size 4
==9152== at 0x80544EB: GenerateCallLog (performreport.c:3112)
==9152== by 0x804AA49: ProcessReport (performreport.c:344)
==9152== by 0x8056C7E: PerformReportCheck (reportcheck.c:72)
==9152== by 0x80494D0: main (main.c:82)
==9152== Address 0x47b22b0 is not stack'd, malloc'd or (recently) free'd
==9152==
==9152== Invalid read of size 4
==9152== at 0x80545CF: GenerateCallLog (performreport.c:3123)
==9152== by 0x804AA49: ProcessReport (performreport.c:344)
==9152== by 0x8056C7E: PerformReportCheck (reportcheck.c:72)
==9152== by 0x80494D0: main (main.c:82)
==9152== Address 0x47b22b0 is not stack'd, malloc'd or (recently) free'd
==9152==
==9152== Invalid write of size 4
==9152== at 0x80545DF: GenerateCallLog (performreport.c:3124)
==9152== by 0x804AA49: ProcessReport (performreport.c:344)
==9152== by 0x8056C7E: PerformReportCheck (reportcheck.c:72)
==9152== by 0x80494D0: main (main.c:82)
==9152== Address 0x35c is not stack'd, malloc'd or (recently) free'd
行 performreport.c:3112 是
if (dataRow > -1 && callLogSearchData[dataRow].outboundLegs == NULL)
performreport.c:3123 的行是
outboundCallLegStartPtr = callLogSearchData[dataRow].outboundLegs;
performreport.c:3124 的行是outboundCallLegStartPtr->nextLeg = NULL;
,它的这一行也是在重新分配发生后导致核心转储
请求的 setCallResult 函数如下:
char * setCallResult(int callResult)
{
if (callResult == 1)
{
return "Answered";
}
else if (callResult != 3)
{
return "Unanswered";
}
else if (callResult == 3)
{
return "Engaged";
}
else
{
return "N/A";
}
}
抱歉,对于所有代码,但我不知道问题可能出在哪里。在核心转储中看起来好像有什么东西在破坏内存,因为当我检查结构中的一些值时,它只是乱码。
感谢您的任何帮助,您可以提供。