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examples/cpp-multithreaded: fixed locks and timeThread terminate conditions 

C++ unique_lock created through constructor with an argument creates already locked lock. The lock is unlocked with destructor.

condition_variable::wait_for returns true when await at least specified timeout false otherwise. There is no guarantee that it returns false when notified, therefore thread exit is done through extra flag 'running'.
This commit is contained in:
Mariusz Kasolik 2018-10-29 06:48:54 +01:00
parent 1d94e95e83
commit 4b20c5b045
1 changed files with 8 additions and 5 deletions
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13
examples/cpp-multithread/main.cpp
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@ -12,8 +12,8 @@ using namespace std;
uiMultilineEntry *e;
condition_variable cv;
mutex m;
unique_lock<mutex> ourlock(m);
thread *timeThread;
volatile bool running = true;
void sayTime(void *data)
{
@ -25,8 +25,9 @@ void sayTime(void *data)
void threadproc(void)
{
ourlock.lock();
while (cv.wait_for(ourlock, chrono::seconds(1)) == cv_status::timeout) {
unique_lock<mutex> ourlock(m);
while (running) {
cv.wait_for(ourlock, chrono::seconds(1));
time_t t;
char *base;
char *s;
@ -41,6 +42,10 @@ void threadproc(void)
int onClosing(uiWindow *w, void *data)
{
{
unique_lock<mutex> l(m);
running = false;
}
cv.notify_all();
// C++ throws a hissy fit if you don't do this
// we might as well, to ensure no uiQueueMain() gets in after uiQuit()
@ -81,8 +86,6 @@ int main(void)
uiBoxAppend(b, uiControl(e), 1);
// timeThread needs to lock ourlock itself - see http://stackoverflow.com/a/34121629/3408572
ourlock.unlock();
timeThread = new thread(threadproc);
uiWindowOnClosing(w, onClosing, NULL);