c++ - pthread_join 错误，从线程创建线程

Question

我目前正在尝试从其他线程创建线程。当我的线程试图加入时，出现段错误

这是我的主要功能:

int main( int argc, char *argv[] ) {
    std::cout<< "start" << std::endl;
    init();
    std::cout<<"finished init" << std::endl;
    t1=clock();
    pthread_t threads[THREAD_COUNT];

    for (int i = 0; i < THREAD_COUNT; i++) {
        pthread_create(&threads[i], NULL, &threadMain, (void*)((long)i));
    }

    for (int i = 0; i < THREAD_COUNT; i++) {
        printf("joining %d \n" , i);
        pthread_join(threads[i], NULL);
    }
    timeEnd();


    return(0);
}

还有我的主线:

void *threadMain(void *arg) {
long thread = (long) arg;

volatile int *tix;
tix = (volatile int *)malloc(sizeof(volatile int) * INNER_THREADS);
volatile int *c;
c =  (volatile int *)malloc(sizeof(volatile int) * INNER_THREADS);
volatile int r;

memset((void*)tix, 0, sizeof(tix));
memset((void*)c, 0, sizeof(c));
r = 0;


pthread_t threads[INNER_THREADS];


for (int i = 0; i < INNER_THREADS; ++i) {
    vec[i+thread*2] = new desc();
    vec[i+thread*2]->outterThread = thread;
    vec[i+thread*2]->innerThread = i;
    vec[i+thread*2]->tix = tix;
    vec[i+thread*2]->c = c;
    vec[i+thread*2]->r = &r;
    pthread_create(&threads[i], NULL, &threadBody, (void*) vec[i+thread*2]);


}

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


return 0;
}

运行 valgrind 给我错误:

==820== Thread 288:
==820== Invalid read of size 4
==820==    at 0x387AA08213: pthread_join (in /lib64/libpthread-2.12.so)
==820==    by 0x4019F1: threadMain(void*) (t.c:146)
==820==    by 0x387AA07AA0: start_thread (in /lib64/libpthread-2.12.so)
==820==    by 0x387A2E8AAC: clone (in /lib64/libc-2.12.so)
==820==  Address 0xc29c79d0 is not stack'd, malloc'd or (recently) free'd
==820== 
==820== 
==820== Process terminating with default action of signal 11 (SIGSEGV)
==820==  Access not within mapped region at address 0xC29C79D0
==820==    at 0x387AA08213: pthread_join (in /lib64/libpthread-2.12.so)
==820==    by 0x4019F1: threadMain(void*) (t.c:146)
==820==    by 0x387AA07AA0: start_thread (in /lib64/libpthread-2.12.so)
==820==    by 0x387A2E8AAC: clone (in /lib64/libc-2.12.so)
==820==  If you believe this happened as a result of a stack
==820==  overflow in your program's main thread (unlikely but
==820==  possible), you can try to increase the size of the
==820==  main thread stack using the --main-stacksize= flag.
==820==  The main thread stack size used in this run was 10485760.

每当我在 ubuntu 机器上运行它时，我都会遇到段错误。使用 gdb，在 pthread_join 中放置一个断点并单步执行最终给我一个段错误。

在 mac 上运行它，我得到以下输出:

./a.out

start

finished init

joining 0

a.out(3473,0x10c61e000) malloc: * error for object 0x7f97fa5016f0: pointer being freed was not allocated * set a breakpoint in malloc_error_break to debug

Abort trap: 6

编辑

一些定义:

#define INNER_THREADS 2
#define THREAD_COUNT 10

struct desc{
  long outterThread;
  long innerThread;
  volatile int* tix;
  volatile int* c;
  volatile int* r;
};

struct desc* vec[THREAD_COUNT*2];

Answer 1

请通过添加缺失的细节来完成您的程序:threadBody()、init()、clock() 和 timeEnd()，或者如果它们与所面临的问题无关则将其删除。

我可以通过删除/假定一些缺失的细节来准备代码: http://pastebin.com/j5a9whdR

它工作正常。

$ ./a.out | sort
joining outer thread 0
joining outer thread 1
joining outer thread 2
joining outer thread 3
joining outer thread 4
joining outer thread 5
joining outer thread 6
joining outer thread 7
joining outer thread 8
joining outer thread 9
Outer thread 0 Inner thread 0
Outer thread 0 Inner thread 1
Outer thread 1 Inner thread 0
Outer thread 1 Inner thread 1
Outer thread 2 Inner thread 0
Outer thread 2 Inner thread 1
Outer thread 3 Inner thread 0
Outer thread 3 Inner thread 1
Outer thread 4 Inner thread 0
Outer thread 4 Inner thread 1
Outer thread 5 Inner thread 0
Outer thread 5 Inner thread 1
Outer thread 6 Inner thread 0
Outer thread 6 Inner thread 1
Outer thread 7 Inner thread 0
Outer thread 7 Inner thread 1
Outer thread 8 Inner thread 0
Outer thread 8 Inner thread 1
Outer thread 9 Inner thread 0
Outer thread 9 Inner thread 1
$ 

valgrind 也很高兴，除了一些内存泄漏。

有一件事要提一下:“2”的用法(在 vec[i+thread*2] 和 vec[THREAD_COUNT*2] 中)应该替换为 INNER_THREADS。

主要问题是 threadBody() 函数中有什么？