全局静态布尔指针使用pthread导致分段错误
pthread编程新手，在处理C ++和C混合代码时遇到此错误。
我所做的是在c ++代码创建的线程中调用c代码。在线程中使用了一个静态布尔指针
is_center
static bool *is_center;
// omit other codes in between ...
void streamCluster( PStream* stream)
{
// some code here ...
while(1){
// some code here ...
is_center = (bool*)calloc(points.num,sizeof(bool));
// start the parallel thread here.
// the c code is invoked in this function.
localSearch(&points,kmin, kmax,&kfinal); // parallel
free(is_center);
}
void localSearch( Points* points, long kmin, long kmax, long* kfinal ) {
pthread_barrier_t barrier;
pthread_t* threads = new pthread_t[nproc];
pkmedian_arg_t* arg = new pkmedian_arg_t[nproc];
pthread_barrier_init(&barrier,NULL,nproc);
for( int i = 0; i < nproc; i++ ) {
arg[i].points = points;
arg[i].kmin = kmin;
arg[i].kmax = kmax;
arg[i].pid = i;
arg[i].kfinal = kfinal;
arg[i].barrier = &barrier;
pthread_create(threads+i,NULL,localSearchSub,(void*)&arg[i]);
}
for ( int i = 0; i < nproc; i++) {
pthread_join(threads[i],NULL);
}
delete[] threads;
delete[] arg;
pthread_barrier_destroy(&barrier);
}
void* localSearchSub(void* arg_) {
int eventSet = PAPI_NULL;
begin_papi_thread(&eventSet);
pkmedian_arg_t* arg= (pkmedian_arg_t*)arg_;
pkmedian(arg->points,arg->kmin,arg->kmax,arg->kfinal,arg->pid,arg->barrier);
end_papi_thread(&eventSet);
return NULL;
}
is_center
Breakpoint 2, localSearchSub (arg_=0x600000000000bc40) at streamcluster.cpp:1711
1711 end_papi_thread(&eventSet);
(gdb) s
Hardware watchpoint 1: is_center
Old value = (bool *) 0x600000000000bba0
New value = (bool *) 0xa93f3
0x400000000000d8d1 in localSearchSub (arg_=0x600000000000bc40) at streamcluster.cpp:1711
1711 end_papi_thread(&eventSet);
void begin_papi_thread(int* eventSet)
{
int thread_id = pthread_self();
// Events
if (PAPI_create_eventset(eventSet)) {
PAPI_perror(return_value, error_string, PAPI_MAX_STR_LEN);
printf("*** ERROR *** Failed to create event set for thread %d: %sn.", thread_id, error_string);
}
if((return_value = PAPI_add_events(*eventSet, event_code, event_num)) != PAPI_OK)
{
printf("*** ERROR *** Failed to add event for thread %d: %d.n", thread_id, return_value);
}
// Start counting
if ((return_value = PAPI_start(*eventSet)) != PAPI_OK) {
PAPI_perror(return_value, error_string, PAPI_MAX_STR_LEN);
printf("*** ERROR *** PAPI failed to start the event for thread %d: %s.n", thread_id, error_string);
}
}
void end_papi_thread(int* eventSet)
{
int thread_id = pthread_self();
int i;
long long * count_values = (long long*)malloc(sizeof(long long) * event_num);
if (PAPI_read(*eventSet, count_values) != PAPI_OK)
printf("*** ERROR *** Failed to load count values.n");
if (PAPI_stop(*eventSet, &dummy_values) != PAPI_OK) {
PAPI_perror(return_value, error_string, PAPI_MAX_STR_LEN);
printf("*** ERROR *** PAPI failed to stop the event for thread %d: %s.n", thread_id, error_string);
return;
}
if(PAPI_cleanup_eventset(*eventSet) != PAPI_OK)
printf("*** ERROR *** Clean up failed for the thread %d.n", thread_id);
}
没有找到相关结果
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1 个回复
姬第柔炒
全球性看起来很可疑。我假设你在不止一个地方使用它，可能是多个线程（提到它，这是你的工作线程函数）。 如果多个线程正在读取或写入，您可能希望使用pthread互斥锁来保护它。你说它在线程结束时“被释放”，但是你应该知道有10个线程，看起来他们都在使用一系列布尔。如果，这可能是一件坏事[1]。每个线程应该可以在自己的数组上工作，并且应该聚合结果。功能在谷歌没有任何点击，所以我只能想象它是你自己的...如果问题在那里，我们不太可能帮助你:) [1]：即使，从多个线程（它依赖于编译器和处理器）写入数组的不同元素也不一定好。安全，使用互斥锁。 此外，这是标记为。你能用s替换和动态阵列（使用）吗？它最终可能更容易调试，并且最终更容易维护。你为什么讨厌并想惩罚你的代码的读者？ ;）