TLS ("thread-local storage", "transport layer security")
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, 13 2020 . 17:13
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Qraizer: . static , , . static , thread_local . , .
:
// ------------ thrd.h
#ifdef THREAD_LOCAL
extern thread_local int trdLocalVar;
#else
static int trdLocalVar = -1;
#endif
void g();
// ------------ src1.cpp
#include
#include
#include
#include
#include "thrd.h"
std::mutex out;
void g()
{
std::lock_guard ct(out);
std::cout << std::hex << std::setw(8) << std::this_thread::get_id() << ": the trdLocalVar is "
<< std::dec << trdLocalVar << " now" << std::endl;
}
// ------------ src2.cpp
#include
#include
#include
#include "thrd.h"
#ifdef THREAD_LOCAL
thread_local int trdLocalVar = -1;
#endif
std::mutex mtx;
std::array events;
void thr(int n)
{
trdLocalVar = n;
g();
std::lock_guard ev(events[n-1]);
std::lock_guard ct(mtx);
g();
}
int main()
{
using namespace std::literals;
for (auto &i : events) i.lock();
std::thread trd1(thr, 1);
std::thread trd2(thr, 2);
std::thread trd3(thr, 3);
g();
std::this_thread::sleep_for(2s);
events[1].unlock();
trd2.join();
g();
events[0].unlock();
trd1.join();
g();
events[2].unlock();
trd3.join();
g();
}
THREAD_LOCAL:
bc4: the trdLocalVar is 1 now
f1c: the trdLocalVar is 2 now
198c: the trdLocalVar is 3 now
654: the trdLocalVar is -1 now
f1c: the trdLocalVar is 2 now
654: the trdLocalVar is -1 now
bc4: the trdLocalVar is 1 now
654: the trdLocalVar is -1 now
198c: the trdLocalVar is 3 now
654: the trdLocalVar is -1 now
: "... is -1 now".
P.S. thread_local extern . src1 src2 .
https://forum.sources.ru/index.php?showtopic=419143&view=findpost&p=3834198
