本文介绍了一个非常简单的线程池使用C线程中的pthreads的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我想了解一些使用POSIX pthread的基础知识。我需要做的事情（最终）是并行化一些计算，使用线程池模型。目前，我想确保我对POSIX pthread模型如何工作有一个非常基本的感觉。所以我试图创建最简单的线程池，一般足以做我想做的事情的种类。将有一些共享内存，输入队列和输出队列，并且将有互斥锁保护每个。我写了一些代码，只是这样，但valgrind的helgrind工具不喜欢我做的。我怀疑我缺少一些基本的东西。你有我的代码的见解吗？
I'm trying to understand some of the basics of using POSIX pthreads. The kind of thing I need to do (eventually) is parallelize some computations, using a thread pool model. At present I want to ensure I have a very basic sense for how the POSIX pthread model works. So I'm trying to create the simplest thread pool that's general enough to do the kinds of things I want to do. There will be some shared memory, an input queue, and an output queue, and there will be mutexes protecting each. I've written some code that does just that but valgrind's helgrind tool does not like what I've done. I suspect I'm missing something basic. Do you have insights into my code?
#include <stdlib.h>
#include <string>
#include <sstream>
#include <list>
#include <iostream>
#include <pthread.h>
#include <signal.h>
#include <sys/select.h>
// the muticies, protectors of the shared resources
pthread_mutex_t coutLock;
pthread_mutex_t inQueueLock;
pthread_mutex_t outQueueLock;
// the shared data
std::list< std::string > inQueue;
std::list< std::string > outQueue;
struct thread_detail { // information to pass to worker threads
unsigned long num;
};
extern "C" {
void *workerThread(void *threadarg);
}
void *workerThread(void *threadarg)
{
struct thread_detail *my_data;
my_data = (thread_detail *) threadarg;
int taskid = my_data->num;
std::stringstream ss; ss<<taskid; std::string taskString(ss.str());
bool somethingTodo=true;
while (somethingTodo) // keep on working until inQueue is empty
{
pthread_mutex_lock( &inQueueLock );
std::string workOnMe;
if (inQueue.size()==0) { somethingTodo=false; }
else
{
workOnMe = inQueue.front();
inQueue.pop_front();
}
pthread_mutex_unlock( &inQueueLock );
if (!somethingTodo) break;
workOnMe = "thread " + taskString + " worked on " + workOnMe;
// let's pretend this takes some time, add a delay to the computation
struct timeval timeout;
timeout.tv_sec = 0; timeout.tv_usec = 100000; // 0.1 second delay
select( 0, NULL, NULL, NULL, & timeout );
pthread_mutex_lock( &outQueueLock );
outQueue.push_back( workOnMe );
pthread_mutex_unlock( &outQueueLock );
}
pthread_exit(NULL);
}
int main (int argc, char *argv[])
{
unsigned long comp_DONE=0;
unsigned long comp_START=0;
// set-up the mutexes
pthread_mutex_init( &coutLock, NULL );
pthread_mutex_init( &inQueueLock, NULL );
pthread_mutex_init( &outQueueLock, NULL );
if (argc != 3) { std::cout<<"Program requires two arguments: (1) number of threads to use,"
" and (2) tasks to accomplish.\n"; exit(1); }
unsigned long NUM_THREADS(atoi( argv[1] ));
unsigned long comp_TODO(atoi(argv[2]));
std::cout<<"Program will have "<<NUM_THREADS<<" threads, working on "<<comp_TODO<<" things \n";
for (unsigned long i=0; i<comp_TODO; i++) // fill inQueue will rubbish data since this isn't an actual computation...
{
std::stringstream ss;
ss<<"task "<<i;
inQueue.push_back(ss.str());
}
// start the worker threads
std::list< pthread_t* > threadIdList; // just the thread ids
std::list< thread_detail > thread_table; // for keeping track of information on the various threads we'll create
for (unsigned long i=0; i<NUM_THREADS; i++) // start the threads
{
pthread_t *tId( new pthread_t ); threadIdList.push_back(tId);
thread_detail Y; Y.num=i; thread_table.push_back(Y);
int rc( pthread_create( tId, NULL, workerThread, (void *)(&(thread_table.back() )) ) );
if (rc) { std::cout<<"ERROR; return code from pthread_create() "<<comp_START<<"\n"; std::cout.flush();
exit(-1); }
}
// now we wait for the threads to terminate, perhaps updating the screen with info as we go.
std::string stringOut;
while (comp_DONE != comp_TODO)
{
// poll the queue to get a status update on computation
pthread_mutex_lock(&inQueueLock);
comp_START = comp_TODO - inQueue.size();
pthread_mutex_unlock(&inQueueLock);
pthread_mutex_lock(&outQueueLock);
comp_DONE = outQueue.size();
pthread_mutex_unlock(&outQueueLock);
// update for users
pthread_mutex_lock(&coutLock);
for (unsigned long i=0; i<stringOut.length(); i++) std::cout<<"\b";
std::stringstream ss; ss<<"started "<<comp_START<<" completed "<<comp_DONE<<" of "<<comp_TODO;
stringOut = ss.str(); std::cout<<stringOut; std::cout.flush();
pthread_mutex_unlock(&coutLock);
// wait one second per update
struct timeval timeout;
timeout.tv_sec = 1; timeout.tv_usec = 0;
select( 0, NULL, NULL, NULL, & timeout );
} // big while loop
// call join to kill all worker threads
std::list< pthread_t* >::iterator i(threadIdList.begin());
while (i!=threadIdList.end())
{
if (pthread_join( *(*i), NULL)!=0) { std::cout<<"Thread join error!\n"; exit(1); }
delete (*i);
threadIdList.erase(i++);
}
std::cout<<"\n";
// let the user know what happened
for (std::list< std::string >::iterator i=outQueue.begin(); i!=outQueue.end(); i++)
{
std::cout<<(*i)<<"\n";
}
// clean-up
pthread_mutex_destroy(&coutLock);
pthread_mutex_destroy(&inQueueLock);
pthread_mutex_destroy(&outQueueLock);
// pthread_exit(NULL);
}
这是将参数2 40传递给编译程序时的helgrind输出。
Here is the helgrind output when passing the arguments 2 40 to the compiled program.
valgrind -v --tool=helgrind ./thread1 2 40
==12394== Helgrind, a thread error detector
==12394== Copyright (C) 2007-2009, and GNU GPL'd, by OpenWorks LLP et al.
==12394== Using Valgrind-3.6.0.SVN-Debian and LibVEX; rerun with -h for copyright info
==12394== Command: ./thread1 2 40
==12394==
--12394-- Valgrind options:
--12394-- --suppressions=/usr/lib/valgrind/debian-libc6-dbg.supp
--12394-- -v
--12394-- --tool=helgrind
--12394-- Contents of /proc/version:
--12394-- Linux version 2.6.32-24-generic (buildd@yellow) (gcc version 4.4.3 (Ubuntu 4.4.3-4ubuntu5) ) #38-Ubuntu SMP Mon Jul 5 09:20:59 UTC 2010
--12394-- Arch and hwcaps: AMD64, amd64-sse3-cx16
--12394-- Page sizes: currently 4096, max supported 4096
--12394-- Valgrind library directory: /usr/lib/valgrind
--12394-- Reading syms from /home/rybu/prog/regina/exercise/thread1 (0x400000)
--12394-- Reading syms from /lib/ld-2.11.1.so (0x4000000)
--12394-- Reading debug info from /lib/ld-2.11.1.so ..
--12394-- .. CRC mismatch (computed 99d13f6f wanted 0962e544)
--12394-- Reading debug info from /usr/lib/debug/lib/ld-2.11.1.so ..
--12394-- Reading syms from /usr/lib/valgrind/helgrind-amd64-linux (0x38000000)
--12394-- object doesn't have a dynamic symbol table
--12394-- Reading suppressions file: /usr/lib/valgrind/debian-libc6-dbg.supp
--12394-- Reading suppressions file: /usr/lib/valgrind/default.supp
--12394-- Reading syms from /usr/lib/valgrind/vgpreload_core-amd64-linux.so (0x4a23000)
--12394-- Reading syms from /usr/lib/valgrind/vgpreload_helgrind-amd64-linux.so (0x4c25000)
--12394-- REDIR: 0x4018310 (index) redirected to 0x4c2be59 (index)
--12394-- REDIR: 0x4018390 (strcmp) redirected to 0x4c2bf4b (strcmp)
--12394-- REDIR: 0x40184a0 (strlen) redirected to 0x4c2bec5 (strlen)
--12394-- Reading syms from /usr/lib/libregina-engine-4.6.1.so (0x4e31000)
--12394-- Reading syms from /usr/lib/libgmp.so.3.5.2 (0x52f7000)
--12394-- Reading debug info from /usr/lib/libgmp.so.3.5.2 ..
--12394-- .. CRC mismatch (computed d65050b9 wanted 1e40f6c0)
--12394-- object doesn't have a symbol table
--12394-- Reading syms from /lib/libpthread-2.11.1.so (0x5557000)
--12394-- Reading debug info from /lib/libpthread-2.11.1.so ..
--12394-- .. CRC mismatch (computed 9da7e2f6 wanted 8161fac5)
--12394-- Reading debug info from /usr/lib/debug/lib/libpthread-2.11.1.so ..
--12394-- Reading syms from /lib/librt-2.11.1.so (0x5774000)
--12394-- Reading debug info from /lib/librt-2.11.1.so ..
--12394-- .. CRC mismatch (computed 0e4f4ece wanted 920c9bed)
--12394-- Reading debug info from /usr/lib/debug/lib/librt-2.11.1.so ..
--12394-- Reading syms from /lib/libz.so.1.2.3.3 (0x597c000)
--12394-- Reading debug info from /lib/libz.so.1.2.3.3 ..
--12394-- .. CRC mismatch (computed 86f1fa27 wanted 5f1ca823)
--12394-- object doesn't have a symbol table
--12394-- Reading syms from /usr/lib/libstdc++.so.6.0.13 (0x5b93000)
--12394-- Reading debug info from /usr/lib/libstdc++.so.6.0.13 ..
--12394-- .. CRC mismatch (computed 7b5bd5a5 wanted e2f63673)
--12394-- object doesn't have a symbol table
--12394-- Reading syms from /lib/libm-2.11.1.so (0x5ea7000)
--12394-- Reading debug info from /lib/libm-2.11.1.so ..
--12394-- .. CRC mismatch (computed 043548c3 wanted a081b93d)
--12394-- Reading debug info from /usr/lib/debug/lib/libm-2.11.1.so ..
--12394-- Reading syms from /lib/libgcc_s.so.1 (0x612a000)
--12394-- Reading debug info from /lib/libgcc_s.so.1 ..
--12394-- .. CRC mismatch (computed 7c01dfc9 wanted 9d78e511)
--12394-- object doesn't have a symbol table
--12394-- Reading syms from /lib/libc-2.11.1.so (0x6341000)
--12394-- Reading debug info from /lib/libc-2.11.1.so ..
--12394-- .. CRC mismatch (computed c73d5a83 wanted 02758e3e)
--12394-- Reading debug info from /usr/lib/debug/lib/libc-2.11.1.so ..
--12394-- Reading syms from /usr/lib/libxml2.so.2.7.6 (0x66c4000)
--12394-- Reading debug info from /usr/lib/libxml2.so.2.7.6 ..
--12394-- .. CRC mismatch (computed c2590bed wanted 7aaa27a0)
--12394-- Reading debug info from /usr/lib/debug/usr/lib/libxml2.so.2.7.6 ..
--12394-- Reading syms from /lib/libdl-2.11.1.so (0x6a14000)
--12394-- Reading debug info from /lib/libdl-2.11.1.so ..
--12394-- .. CRC mismatch (computed 4a29f474 wanted e0b8d72c)
--12394-- Reading debug info from /usr/lib/debug/lib/libdl-2.11.1.so ..
--12394-- REDIR: 0x55603c0 (pthread_mutex_lock) redirected to 0x4c299fb (pthread_mutex_lock)
--12394-- REDIR: 0x5561a00 (pthread_mutex_unlock) redirected to 0x4c29e8c (pthread_mutex_unlock)
--12394-- REDIR: 0x63bd520 (malloc) redirected to 0x4c28a06 (malloc)
--12394-- REDIR: 0x63bf360 (calloc) redirected to 0x4c27cc9 (calloc)
--12394-- REDIR: 0x5c5e380 (operator new[](unsigned long)) redirected to 0x4c28e97 (operator new[](unsigned long))
--12394-- REDIR: 0x5c5e250 (operator new(unsigned long)) redirected to 0x4c2921f (operator new(unsigned long))
--12394-- REDIR: 0x5c5c380 (operator delete(void*)) redirected to 0x4c28328 (operator delete(void*))
--12394-- REDIR: 0x5c5c3c0 (operator delete[](void*)) redirected to 0x4c27fa4 (operator delete[](void*))
--12394-- REDIR: 0x63c3fe0 (strlen) redirected to 0x4a235dc (_vgnU_ifunc_wrapper)
--12394-- REDIR: 0x63c4010 (__GI_strlen) redirected to 0x4c2be91 (strlen)
--12394-- REDIR: 0x63c7c60 (memcpy) redirected to 0x4c2bfdb (memcpy)
Program will have 2 threads, working on 40 things
--12394-- REDIR: 0x555dd60 (pthread_create@@GLIBC_2.2.5) redirected to 0x4c2d4c7 (pthread_create@*)
==12394== Thread #2 was created
==12394== at 0x64276BE: clone (clone.S:77)
==12394== by 0x555E172: pthread_create@@GLIBC_2.2.5 (createthread.c:75)
==12394== by 0x4C2D42C: pthread_create_WRK (hg_intercepts.c:230)
==12394== by 0x4C2D4CF: pthread_create@* (hg_intercepts.c:257)
==12394== by 0x401C22: main (in /home/rybu/prog/regina/exercise/thread1)
==12394==
==12394== Thread #1 is the program's root thread
==12394==
==12394== Possible data race during write of size 8 at 0x7fefffcf0 by thread #2
==12394== at 0x4C2D54C: mythread_wrapper (hg_intercepts.c:200)
==12394== This conflicts with a previous read of size 8 by thread #1
==12394== at 0x4C2D440: pthread_create_WRK (hg_intercepts.c:235)
==12394== by 0x4C2D4CF: pthread_create@* (hg_intercepts.c:257)
==12394== by 0x401C22: main (in /home/rybu/prog/regina/exercise/thread1)
==12394==
started 21 completed 19 of 40==12394== Thread #3 was created
==12394== at 0x64276BE: clone (clone.S:77)
==12394== by 0x555E172: pthread_create@@GLIBC_2.2.5 (createthread.c:75)
==12394== by 0x4C2D42C: pthread_create_WRK (hg_intercepts.c:230)
==12394== by 0x4C2D4CF: pthread_create@* (hg_intercepts.c:257)
==12394== by 0x401C22: main (in /home/rybu/prog/regina/exercise/thread1)
==12394==
==12394== Possible data race during read of size 1 at 0x63401a7 by thread #3
==12394== at 0x613A4D7: ??? (in /lib/libgcc_s.so.1)
==12394== by 0x613A947: _Unwind_Resume (in /lib/libgcc_s.so.1)
==12394== by 0x4019C9: workerThread(void*) (in /home/rybu/prog/regina/exercise/thread1)
==12394== by 0x4C2D558: mythread_wrapper (hg_intercepts.c:202)
==12394== by 0x555D9C9: start_thread (pthread_create.c:300)
==12394== by 0x64276FC: clone (clone.S:112)
==12394== This conflicts with a previous write of size 1 by thread #2
==12394== at 0x6138331: ??? (in /lib/libgcc_s.so.1)
==12394== by 0x5563F42: pthread_once (pthread_once.S:104)
==12394== by 0x613A4C9: ??? (in /lib/libgcc_s.so.1)
==12394== by 0x613A7B6: _Unwind_ForcedUnwind (in /lib/libgcc_s.so.1)
==12394== by 0x556508F: __pthread_unwind (unwind.c:130)
==12394== by 0x555EEB4: pthread_exit (pthreadP.h:265)
==12394== by 0x40198E: workerThread(void*) (in /home/rybu/prog/regina/exercise/thread1)
==12394== by 0x4C2D558: mythread_wrapper (hg_intercepts.c:202)
==12394==
==12394== Possible data race during read of size 1 at 0x63401a6 by thread #3
==12394== at 0x6139A12: ??? (in /lib/libgcc_s.so.1)
==12394== by 0x6139AA8: ??? (in /lib/libgcc_s.so.1)
==12394== by 0x613A724: ??? (in /lib/libgcc_s.so.1)
==12394== by 0x613A982: _Unwind_Resume (in /lib/libgcc_s.so.1)
==12394== by 0x4019C9: workerThread(void*) (in /home/rybu/prog/regina/exercise/thread1)
==12394== by 0x4C2D558: mythread_wrapper (hg_intercepts.c:202)
==12394== by 0x555D9C9: start_thread (pthread_create.c:300)
==12394== by 0x64276FC: clone (clone.S:112)
==12394== This conflicts with a previous write of size 1 by thread #2
==12394== at 0x613832A: ??? (in /lib/libgcc_s.so.1)
==12394== by 0x5563F42: pthread_once (pthread_once.S:104)
==12394== by 0x613A4C9: ??? (in /lib/libgcc_s.so.1)
==12394== by 0x613A7B6: _Unwind_ForcedUnwind (in /lib/libgcc_s.so.1)
==12394== by 0x556508F: __pthread_unwind (unwind.c:130)
==12394== by 0x555EEB4: pthread_exit (pthreadP.h:265)
==12394== by 0x40198E: workerThread(void*) (in /home/rybu/prog/regina/exercise/thread1)
==12394== by 0x4C2D558: mythread_wrapper (hg_intercepts.c:202)
==12394==
==12394== Possible data race during read of size 1 at 0x63401b0 by thread #3
==12394== at 0x6139AD7: ??? (in /lib/libgcc_s.so.1)
==12394== by 0x613A724: ??? (in /lib/libgcc_s.so.1)
==12394== by 0x613A982: _Unwind_Resume (in /lib/libgcc_s.so.1)
==12394== by 0x4019C9: workerThread(void*) (in /home/rybu/prog/regina/exercise/thread1)
==12394== by 0x4C2D558: mythread_wrapper (hg_intercepts.c:202)
==12394== by 0x555D9C9: start_thread (pthread_create.c:300)
==12394== by 0x64276FC: clone (clone.S:112)
==12394== This conflicts with a previous write of size 1 by thread #2
==12394== at 0x6138370: ??? (in /lib/libgcc_s.so.1)
==12394== by 0x5563F42: pthread_once (pthread_once.S:104)
==12394== by 0x613A4C9: ??? (in /lib/libgcc_s.so.1)
==12394== by 0x613A7B6: _Unwind_ForcedUnwind (in /lib/libgcc_s.so.1)
==12394== by 0x556508F: __pthread_unwind (unwind.c:130)
==12394== by 0x555EEB4: pthread_exit (pthreadP.h:265)
==12394== by 0x40198E: workerThread(void*) (in /home/rybu/prog/regina/exercise/thread1)
==12394== by 0x4C2D558: mythread_wrapper (hg_intercepts.c:202)
==12394==
--12394-- REDIR: 0x63bede0 (free) redirected to 0x4c28616 (free)
started 40 completed 40 of 40--12394-- REDIR: 0x555ef30 (pthread_join) redirected to 0x4c29796 (pthread_join)
thread 0 worked on task 0
thread 1 worked on task 1
thread 0 worked on task 2
thread 1 worked on task 3
thread 0 worked on task 4
thread 1 worked on task 5
thread 0 worked on task 6
thread 1 worked on task 7
thread 0 worked on task 8
thread 1 worked on task 9
thread 0 worked on task 10
thread 1 worked on task 11
thread 0 worked on task 12
thread 1 worked on task 13
thread 0 worked on task 14
thread 1 worked on task 15
thread 0 worked on task 16
thread 1 worked on task 17
thread 0 worked on task 18
thread 1 worked on task 19
thread 0 worked on task 20
thread 1 worked on task 21
thread 0 worked on task 22
thread 1 worked on task 23
thread 0 worked on task 24
thread 1 worked on task 25
thread 0 worked on task 26
thread 1 worked on task 27
thread 0 worked on task 28
thread 1 worked on task 29
thread 0 worked on task 30
thread 1 worked on task 31
thread 0 worked on task 32
thread 1 worked on task 33
thread 0 worked on task 34
thread 1 worked on task 35
thread 0 worked on task 36
thread 1 worked on task 37
thread 0 worked on task 38
thread 1 worked on task 39
==12394==
==12394== ERROR SUMMARY: 7 errors from 4 contexts (suppressed: 804 from 64)
==12394==
==12394== 1 errors in context 1 of 4:
==12394== Possible data race during read of size 1 at 0x63401a7 by thread #3
==12394== at 0x613A4D7: ??? (in /lib/libgcc_s.so.1)
==12394== by 0x613A947: _Unwind_Resume (in /lib/libgcc_s.so.1)
==12394== by 0x4019C9: workerThread(void*) (in /home/rybu/prog/regina/exercise/thread1)
==12394== by 0x4C2D558: mythread_wrapper (hg_intercepts.c:202)
==12394== by 0x555D9C9: start_thread (pthread_create.c:300)
==12394== by 0x64276FC: clone (clone.S:112)
==12394== This conflicts with a previous write of size 1 by thread #2
==12394== at 0x6138331: ??? (in /lib/libgcc_s.so.1)
==12394== by 0x5563F42: pthread_once (pthread_once.S:104)
==12394== by 0x613A4C9: ??? (in /lib/libgcc_s.so.1)
==12394== by 0x613A7B6: _Unwind_ForcedUnwind (in /lib/libgcc_s.so.1)
==12394== by 0x556508F: __pthread_unwind (unwind.c:130)
==12394== by 0x555EEB4: pthread_exit (pthreadP.h:265)
==12394== by 0x40198E: workerThread(void*) (in /home/rybu/prog/regina/exercise/thread1)
==12394== by 0x4C2D558: mythread_wrapper (hg_intercepts.c:202)
==12394==
==12394==
==12394== 2 errors in context 2 of 4:
==12394== Possible data race during read of size 1 at 0x63401b0 by thread #3
==12394== at 0x6139AD7: ??? (in /lib/libgcc_s.so.1)
==12394== by 0x613A724: ??? (in /lib/libgcc_s.so.1)
==12394== by 0x613A982: _Unwind_Resume (in /lib/libgcc_s.so.1)
==12394== by 0x4019C9: workerThread(void*) (in /home/rybu/prog/regina/exercise/thread1)
==12394== by 0x4C2D558: mythread_wrapper (hg_intercepts.c:202)
==12394== by 0x555D9C9: start_thread (pthread_create.c:300)
==12394== by 0x64276FC: clone (clone.S:112)
==12394== This conflicts with a previous write of size 1 by thread #2
==12394== at 0x6138370: ??? (in /lib/libgcc_s.so.1)
==12394== by 0x5563F42: pthread_once (pthread_once.S:104)
==12394== by 0x613A4C9: ??? (in /lib/libgcc_s.so.1)
==12394== by 0x613A7B6: _Unwind_ForcedUnwind (in /lib/libgcc_s.so.1)
==12394== by 0x556508F: __pthread_unwind (unwind.c:130)
==12394== by 0x555EEB4: pthread_exit (pthreadP.h:265)
==12394== by 0x40198E: workerThread(void*) (in /home/rybu/prog/regina/exercise/thread1)
==12394== by 0x4C2D558: mythread_wrapper (hg_intercepts.c:202)
==12394==
==12394==
==12394== 2 errors in context 3 of 4:
==12394== Possible data race during read of size 1 at 0x63401a6 by thread #3
==12394== at 0x6139A12: ??? (in /lib/libgcc_s.so.1)
==12394== by 0x6139AA8: ??? (in /lib/libgcc_s.so.1)
==12394== by 0x613A724: ??? (in /lib/libgcc_s.so.1)
==12394== by 0x613A982: _Unwind_Resume (in /lib/libgcc_s.so.1)
==12394== by 0x4019C9: workerThread(void*) (in /home/rybu/prog/regina/exercise/thread1)
==12394== by 0x4C2D558: mythread_wrapper (hg_intercepts.c:202)
==12394== by 0x555D9C9: start_thread (pthread_create.c:300)
==12394== by 0x64276FC: clone (clone.S:112)
==12394== This conflicts with a previous write of size 1 by thread #2
==12394== at 0x613832A: ??? (in /lib/libgcc_s.so.1)
==12394== by 0x5563F42: pthread_once (pthread_once.S:104)
==12394== by 0x613A4C9: ??? (in /lib/libgcc_s.so.1)
==12394== by 0x613A7B6: _Unwind_ForcedUnwind (in /lib/libgcc_s.so.1)
==12394== by 0x556508F: __pthread_unwind (unwind.c:130)
==12394== by 0x555EEB4: pthread_exit (pthreadP.h:265)
==12394== by 0x40198E: workerThread(void*) (in /home/rybu/prog/regina/exercise/thread1)
==12394== by 0x4C2D558: mythread_wrapper (hg_intercepts.c:202)
==12394==
==12394==
==12394== 2 errors in context 4 of 4:
==12394== Possible data race during write of size 8 at 0x7fefffcf0 by thread #2
==12394== at 0x4C2D54C: mythread_wrapper (hg_intercepts.c:200)
==12394== This conflicts with a previous read of size 8 by thread #1
==12394== at 0x4C2D440: pthread_create_WRK (hg_intercepts.c:235)
==12394== by 0x4C2D4CF: pthread_create@* (hg_intercepts.c:257)
==12394== by 0x401C22: main (in /home/rybu/prog/regina/exercise/thread1)
==12394==
--12394--
--12394-- used_suppression: 610 helgrind-glibc2X-101
--12394-- used_suppression: 192 helgrind---...-*Unwind*-*pthread_unwind*
--12394-- used_suppression: 2 helgrind-glibc2X-112
==12394==
==12394== ERROR SUMMARY: 7 errors from 4 contexts (suppressed: 804 from 64)
我不太自信，当谈到helgrind输出。
I'm not so confident when it comes to interpreting helgrind output.
感谢您的任何见解。
推荐答案
您的一些错误来自 libgcc_s.so 。
尝试使用 gcc -pthread 以确保编译器知道发生了什么。
Try compiling with gcc -pthread to make sure the compiler knows what's going on.
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