如何用pthread和lpq编译C代码

Question

我一直在试图编译一个包含postgres，pthread和mutexes的非常简单的代码。现在当我单独使用pthread的时候，每件事情都很好，当我单独使用postgress时也是如此！但是当我尝试编译完整的代码时，我正陷入愚蠢的探索之中！

gcc -o pleaseWork uploadData.c -I/usr/include/postgresql -lpthread -lpq 

我得到：

/tmp/ccitU5mG.o: In function `increaseQueryNum': 
uploadData.c:(.text+0x5): relocation truncated to fit: R_X86_64_32 against symbol `counterMutex' defined in COMMON section in /tmp/ccitU5mG.o 
uploadData.c:(.text+0x21): relocation truncated to fit: R_X86_64_32 against symbol `counterMutex' defined in COMMON section in /tmp/ccitU5mG.o 
/tmp/ccitU5mG.o: In function `increaseStackNum': 
uploadData.c:(.text+0x31): relocation truncated to fit: R_X86_64_32 against symbol `stackMutex' defined in COMMON section in /tmp/ccitU5mG.o 
uploadData.c:(.text+0x4a): relocation truncated to fit: R_X86_64_32 against symbol `stackMutex' defined in COMMON section in /tmp/ccitU5mG.o 
/tmp/ccitU5mG.o: In function `decreaseStackNum': 
uploadData.c:(.text+0x5a): relocation truncated to fit: R_X86_64_32 against symbol `stackMutex' defined in COMMON section in /tmp/ccitU5mG.o 
uploadData.c:(.text+0x73): relocation truncated to fit: R_X86_64_32 against symbol `stackMutex' defined in COMMON section in /tmp/ccitU5mG.o 
/tmp/ccitU5mG.o: In function `pop': 
uploadData.c:(.text+0xca): relocation truncated to fit: R_X86_64_32 against symbol `stackPopMutex' defined in COMMON section in /tmp/ccitU5mG.o 
uploadData.c:(.text+0xf7): relocation truncated to fit: R_X86_64_32 against symbol `stackPopMutex' defined in COMMON section in /tmp/ccitU5mG.o 
collect2: error: ld returned 1 exit status 

当我运行：

gcc -o omido -I/usr/include/postgresql -lpq -lpthread uploadData.c 

我得到：

/tmp/ccdXHrz3.o: In function `main': 
uploadData.c:(.text+0x5df): undefined reference to `PQconnectdb' 
uploadData.c:(.text+0x5f5): undefined reference to `PQstatus' 
uploadData.c:(.text+0x613): undefined reference to `PQfinish' 
uploadData.c:(.text+0x68c): undefined reference to `pthread_create' 
uploadData.c:(.text+0x6d5): undefined reference to `pthread_create' 
uploadData.c:(.text+0x6fe): undefined reference to `pthread_join' 
uploadData.c:(.text+0x727): undefined reference to `pthread_join' 
collect2: error: ld returned 1 exit status 

我有一个编译最接近的事情是（以条款错误数）：

gcc -o pleaseWork -I/usr/include/postgresql -pthread -lpthread -lpq uploadData.c 

导致：

/tmp/ccg6RbUk.o: In function `main': 
uploadData.c:(.text+0x5df): undefined reference to `PQconnectdb' 
uploadData.c:(.text+0x5f5): undefined reference to `PQstatus' 
uploadData.c:(.text+0x613): undefined reference to `PQfinish' 
collect2: error: ld returned 1 exit status 

我不知道是否有帮助，但这里是同样的命令与-v：

COLLECT_GCC_OPTIONS='-s' '-o' 'omido' '-I' '/usr/include/postgresql' '-pthread' '-v' '-mtune=generic' '-march=x86-64' 
as -v -I /usr/include/postgresql --64 -o /tmp/ccY3zbjH.o /tmp/ccdK2fuu.s 
GNU assembler version 2.24 (x86_64-linux-gnu) using BFD version (GNU Binutils for Ubuntu) 2.24 
COMPILER_PATH=/usr/lib/gcc/x86_64-linux-gnu/4.8/:/usr/lib/gcc/x86_64-linux-gnu/4.8/:/usr/lib/gcc/x86_64-linux-gnu/:/usr/lib/gcc/x86_64-linux-gnu/4.8/:/usr/lib/gcc/x86_64-linux-gnu/ 
LIBRARY_PATH=/usr/lib/gcc/x86_64-linux-gnu/4.8/:/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../x86_64-linux-gnu/:/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../lib/:/lib/x86_64-linux-gnu/:/lib/../lib/:/usr/lib/x86_64-linux-gnu/:/usr/lib/../lib/:/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../:/lib/:/usr/lib/ 
COLLECT_GCC_OPTIONS='-s' '-o' 'omido' '-I' '/usr/include/postgresql' '-pthread' '-v' '-mtune=generic' '-march=x86-64' 
/usr/lib/gcc/x86_64-linux-gnu/4.8/collect2 --sysroot=/ --build-id --eh-frame-hdr -m elf_x86_64 --hash-style=gnu --as-needed -dynamic-linker /lib64/ld-linux-x86-64.so.2 -z relro -o omido -s /usr/lib/gcc/x86_64-linux-gnu/4.8/../../../x86_64-linux-gnu/crt1.o /usr/lib/gcc/x86_64-linux-gnu/4.8/../../../x86_64-linux-gnu/crti.o /usr/lib/gcc/x86_64-linux-gnu/4.8/crtbegin.o -L/usr/lib/gcc/x86_64-linux-gnu/4.8 -L/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../x86_64-linux-gnu -L/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../lib -L/lib/x86_64-linux-gnu -L/lib/../lib -L/usr/lib/x86_64-linux-gnu -L/usr/lib/../lib -L/usr/lib/gcc/x86_64-linux-gnu/4.8/../../.. -lpq -lpthread /tmp/ccY3zbjH.o -lgcc --as-needed -lgcc_s --no-as-needed -lpthread -lc -lgcc --as-needed -lgcc_s --no-as-needed /usr/lib/gcc/x86_64-linux-gnu/4.8/crtend.o /usr/lib/gcc/x86_64-linux-gnu/4.8/../../../x86_64-linux-gnu/crtn.o 
/tmp/ccY3zbjH.o: In function `main': 
uploadData.c:(.text+0x5df): undefined reference to `PQconnectdb' 
uploadData.c:(.text+0x5f5): undefined reference to `PQstatus' 
uploadData.c:(.text+0x613): undefined reference to `PQfinish' 
collect2: error: ld returned 1 exit status 

至今没有运气:(做任何身体知道这里有什么不对？

这里是我的代码的简化版本：

#include <pthread.h> 
#include <libpq-fe.h> 
#include <time.h> 
#include <stdio.h> 
#include <stdlib.h> 
#include <time.h> 
#include <string.h> 
pthread_mutex_t stackWaitMutex; 
pthread_mutex_t stackMutex; 
pthread_mutex_t counterMutex; 
pthread_mutex_t stackPushMutex; 
pthread_mutex_t stackPopMutex; 

int done=0; 
long queryNum=0; 

char *nameStack[500]; 
char *valueStack[500]; 
char stack[100000][100000]; 

int stackCounter=0; 

void increaseQueryNum(){ 
    pthread_mutex_lock(&counterMutex); 
    queryNum++; 
    pthread_mutex_unlock(&counterMutex); 
} 


void increaseStackNum(){ 
     pthread_mutex_lock(&stackMutex); 
     stackCounter++; 
     pthread_mutex_unlock(&stackMutex); 
} 
void decreaseStackNum(){ 
     pthread_mutex_lock(&stackMutex); 
     stackCounter--; 
     pthread_mutex_unlock(&stackMutex); 
} 


void push(int StackNumber, char* item){ 


    strcpy(stack[stackCounter ], item); 
    increaseStackNum(); 

} 

char* pop (int StackNumber){ 
    char *ret; 
    // while(lock) 
    // usleep(2); 
    pthread_mutex_lock(&stackPopMutex); 

    decreaseStackNum(); 

    ret = stack[stackCounter]; 
    // lock=0; 
    pthread_mutex_unlock(&stackPopMutex); 
    return ret; 
} 

void *doSeperation (void* args){ 

    while(1) 
    { 
     char *p = pop(0); 
     if(p==NULL && done){ 
      return; 
     } 

    } 
} 

void *reader (void *args){ 
    int i; 

    for(i = 0 ; i <12; i++){ 
     push(1, "test!"); 
    } 
    done=1; 
} 

int main(int argC , char** argV ){ 

    int i; 
    PGconn* connection = PQconnectdb("host=XXXXXX dbname=XXXXX user=postgres password=XXXX"); 

    if (PQstatus(connection) == CONNECTION_BAD) { 
     printf("Connection error\n"); 
     PQfinish(connection); 
     return -1; 
    } 
    printf("Connection ok\n"); 

    int maxThread =5; 
    int FilesCount =5; 

    pthread_t threads[1000] ; 

    pthread_t p2; 

    pthread_create(&p2,NULL,reader,&FilesCount); 

    usleep(60); 

    for(i = 0 ; i < maxThread; i++ ){ 
     pthread_create(&threads[i],NULL,doSeperation,NULL); 
    } 

    pthread_join(p2,NULL); 

    for( i = 0 ; i < maxThread; i ++){ 
     pthread_join(threads[i],NULL); 
    } 

    return 0; 
} 

Answer 1

此代码失败的搭建，对我来说，由于错误，如：

uploadData.c:25:(.text+0x5): relocation truncated to fit: R_X86_64_32 against symbol `counterMutex' defined in COMMON section in /tmp/ccfzQ53S.o 
uploadData.c:27:(.text+0x21): relocation truncated to fit: R_X86_64_32 against symbol `counterMutex' defined in COMMON section in /tmp/ccfzQ53S.o 

我解决了通过减少堆栈阵列几个数量级。您的链接器错误可能是相关的，因为在进行更改后链接示例没有问题。

你应该用-Wall编译你的代码。有几个重要的错误，例如一个不返回值的非void函数，被用作pthread_create的输入。