首先是scull_pipe的结构体,注意wait_queue_head_t这个队列类型,它就是用来记录等待设备I/O事件的进程的。 structscull_pipe{wait_queue_head_tinq, outq;/* read and write queues */char*buffer, *end;/* begin of buf, end of buf */intbuffersize;/* used in pointer arithmetic */char*rp, *wp;...
/* This is OK as the local fdsets are empty and nready is zero, or we would have returned earlier. */ } else { /* See what's set now after waiting */ nready = lwip_selscan(maxfdp1, readset, writeset, exceptset, &lreadset, &lwriteset, &lexceptset); LWIP_DEBUGF(SOCKETS_DE...
进程queue 1frommultiprocessingimportProcess,Queue2defrun(qq):3qq.put('测试')456if__name__=='__main__':7q =Queue()8#p = threading.Thread(target=run,)9p = Process(target= run,args=(q,))10p.start()11print(q.get())12p.join()13结果:14测试15结论:16#总结:两个进程直接内存空间完全...
RETURN VALUE On success, select() and pselect() return the number of file descriptors contained in the three returned descriptor sets (that is, the total number of bits that are set in readfds, writefds, exceptfds) which may be zero if the timeout expires before anything interesting happens...
The idea is that on submit if the iodev needs to be polled it adds itself to the contexts poll queue. This poll queue is then iterated over at some point in the future. This iteration could be done in a timer ISR, a dedicated thread, a work queue task, or any other sort of delay...
/* This is OK as the local fdsets are empty and nready is zero, or we would have returned earlier. */ } else { /* None ready: add our semaphore to list: We don't actually need any dynamic memory. Our entry on the list is only valid while we are in this function, so it's...
accept queue overflows: two days later,the queue is always full. also,i killed some tcp link manually,but the process didn't consume. top threads is using cpu: accoding to the cpu usage by the threads that appears reactor threads is in the infinite loop(the details can find in the thr...
This parameter is divided into two parts. The first half (the high-order 16 bits) gives the number of pollmsg structures containing message queue identifiers. This number must not exceed the value 32767. The second half (the low-order 16 bits) gives the number of pollfd structures containing...
“As we ramp up supply and as we deal with the affordability issue, we are going to phase that scheme out.” Ms McDonald stressed the need to redirect all efforts of the construction sector into building homes. “The construction workforce is a little bit higher than it was in the Celtic...
The poll() API is part of the Single Unix Specification and the UNIX 95/98 standard. The poll() API performs the same API as the existing select() API. The only difference between these two APIs is the interface provided to the caller.