boost-thread

问题 The boost documentation says: Returns: false if the call is returning because the time specified by abs_time was reached, true otherwise. But what is returned if there is a spurious wakeup? 回答1: If the condition variable could figure that it is a spurious wake-up there would be no need to return, would it? You need to check if the data protected by the mutex and the condition variable has changed to detect a spurious wake-up. The condition variable can not do that for you. 来源： https:/

问题 Is there a way to automatically lock an STL container on access, without having to lock and release around it? 回答1: The currrent C++ standard does not say anything about thread safety for STL containers. Officially it is possible for an STL implementation to be thread safe, but it's very unusual. If your STL implementation is not thread safe, then you will need to "lock and release around it" or find some other way to coordinate access. You may be interested in Intel's Threading Building

问题 I'm using a machine having 8 cores and 32GB ram. In this machine, I'm running a code in c++ using VS2010 on Windows x64 which takes 3 days to complete 8 trees(8 is the number of outer threads). I searched for bottleneck and find out that crossCorrelate method takes around 75-80% of the time. Now, I'm trying to make that method more efficient, code is as follows: int main(){ int numThread = 8; //create threads, run build_tree method for each of them //and join after running all of them } // I

问题 I am running the following chunk of the code. This code is going to create 5 slave threads and 1 main thread. All slave threads are waited for the main thread to make the data ready and when the data gets ready, all slaves will notify to start processing. My question is, it is possible that before the slave threads start waiting for the conditional_variable , the main thread make the data ready and notify the waited threads. In this case, some threads which were waited will get the

问题 currently we are using asynchronous values very heavily. Assume that I have a function which does something like this: int do_something(const boost::posix_time::time_duration& sleep_time) { BOOST_MESSAGE("Sleeping a bit"); boost::this_thread::sleep(sleep_time); BOOST_MESSAGE("Finished taking a nap"); return 42; } At some point in code we create a task which creates a future to such an int value which will be set by a packaged_task - like this (worker_queue is a boost::asio::io_service in this

问题 I am reading these days about memory fences and barriers as a way to synchronize multithreaded code and avoid code reordering. I usually develop in C++ under Linux OS and I use boost libs massively but I am not able to find any class related to it. Do you know if memory barrier of fences are present in boost or if there is a way to achieve the same concept? If not what good library can I have a look to? 回答1: There are no low-level memory barriers in boost yet, but there is a proposed boost

问题 I am using boost threads, and everything works perfectly when compiling with /MD but I really prefer compiling with /MT instead The problem I then get is program.exe: Native' has exited with code 255 (0xff). This happens on this line: thread_1 = thread(testThread,test); after digging down deeper, I realised the problem is the fact that _crtheap equals to 0, ie: it's not initialized. as seen in mlock.c /* * Check if CRT is initialized. The check if _crtheap is initialized * will do the job.

问题 I'm using boost bcp tool to export thread library from boost. The layout of exported library is - Jamroot + libs |----- + thread |----- + build |----- - Jamfile.v2 + boost + doc Now when I run bjam in build library is getting me : boostcpp.jam: No such file or directory ../../../Jamroot:138: in modules.load rule boostcpp.set-version unknown in module Jamfile</Users/miladrezayee/Softwares/developer/boost_1_53_0/tmp1> /Users/miladrezayee/Softwares/developer/boost_1_53_0/tools/build/v2/build

问题 In a single producer / single consumer application using Boost threads, what happens if the producer thread makes more than one call to cond_var.notify_one() before the consumer thread has called cond_var.wait(lock) ? Will the additional calls to notify_one be stacked, such that each call to .wait() will correspond 1:1 with a .notify_one() call? EDIT A commonly quoted example for implementing a concurrent queue has these methods: void push(Data const& data) { boost::mutex::scoped_lock lock

问题 I'm using a common base class has_threads to manage any type that should be allowed to instantiate a boost::thread . Instances of has_threads each own a set of thread s (to support waitAll and interruptAll functions, which I do not include below), and should automatically invoke removeThread when a thread terminates to maintain this set 's integrity. In my program, I have just one of these. Threads are created on an interval every 10s, and each performs a database lookup. When the lookup is