diff options
| -rw-r--r-- | src/threadengines/threadengine_pthread.cpp | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/src/threadengines/threadengine_pthread.cpp b/src/threadengines/threadengine_pthread.cpp index 6a48bd025..2f09cc305 100644 --- a/src/threadengines/threadengine_pthread.cpp +++ b/src/threadengines/threadengine_pthread.cpp @@ -28,6 +28,10 @@ void PThreadEngine::Create(Thread* thread_to_init) pthread_attr_setdetachstate(&attribs, PTHREAD_CREATE_JOINABLE); pthread_t* MyPThread = new pthread_t; + /* Create a thread in a mutex. This prevents whacking the member value NewThread, + * and also prevents recursive creation of threads by mistake (instead, the thread + * will just deadlock itself) + */ Mutex(true); if (pthread_create(MyPThread, &attribs, PThreadEngine::Entry, (void*)this) != 0) @@ -43,8 +47,12 @@ void PThreadEngine::Create(Thread* thread_to_init) NewThread->Creator = this; NewThread->Extend("pthread", MyPThread); + /* Always unset a mutex if you set it */ Mutex(false); + /* Wait for the PThreadEngine::Run method to take a copy of the + * pointer and clear this member value + */ while (NewThread) usleep(1000); } @@ -55,10 +63,15 @@ PThreadEngine::~PThreadEngine() void PThreadEngine::Run() { + /* Take a copy of the member value, then clear it. Do this + * in a mutex so that we can be sure nothing else is looking + * at it. + */ Mutex(true); Thread* nt = NewThread; NewThread = NULL; Mutex(false); + /* Now we have our own safe copy, call the object on it */ nt->Run(); } |