hcq/MaxScale
hcq/MaxScale
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Fix race condition.

Browse Source 
Change a counter (s_next_delayed_call_id) in Worker from class static to
class member to avoid race conditions on the variable.
This commit is contained in:
Niclas Antti 2018-09-25 15:47:41 +03:00
parent 25038432bb
commit 5132339b7b
2 changed files with 23 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

38
maxutils/maxbase/include/maxbase/worker.hh
View File

@ -573,10 +573,9 @@ public:
* case the return value is ignored and the function will not
* be called again.
*/
uint32_t delayed_call(int32_t delay,
bool (* pFunction)(Worker::Call::action_t action))
uint32_t delayed_call(int32_t delay, bool (* pFunction)(Worker::Call::action_t action))
{
return add_delayed_call(new DelayedCallFunctionVoid(delay, pFunction));
return add_delayed_call(new DelayedCallFunctionVoid(delay, next_delayed_call_id(), pFunction));
}
/**
@ -604,7 +603,7 @@ public:
bool (* pFunction)(Worker::Call::action_t action, D data),
D data)
{
return add_delayed_call(new DelayedCallFunction<D>(delay, pFunction, data));
return add_delayed_call(new DelayedCallFunction<D>(delay, next_delayed_call_id(), pFunction, data));
}
/**
@ -631,7 +630,7 @@ public:
bool (T::* pMethod)(Worker::Call::action_t action),
T* pT)
{
return add_delayed_call(new DelayedCallMethodVoid<T>(delay, pMethod, pT));
return add_delayed_call(new DelayedCallMethodVoid<T>(delay, next_delayed_call_id(), pMethod, pT));
}
/**
@ -660,7 +659,11 @@ public:
T* pT,
D data)
{
return add_delayed_call(new DelayedCallMethod<T, D>(delay, pMethod, pT, data));
return add_delayed_call(new DelayedCallMethod<T, D>(delay,
next_delayed_call_id(),
pMethod,
pT,
data));
}
/**
@ -734,12 +737,12 @@ private:
class DelayedCall;
friend class DelayedCall;
static uint32_t next_delayed_call_id()
uint32_t next_delayed_call_id()
{
// Called in single-thread context. Wrapping does not matter
// as it is unlikely there would be 4 billion pending delayed
// calls.
return ++s_next_delayed_call_id;
return ++m_next_delayed_call_id;
}
class DelayedCall
@ -779,8 +782,8 @@ private:
}
protected:
DelayedCall(int32_t delay)
: m_id(Worker::next_delayed_call_id())
DelayedCall(int32_t delay, int32_t id)
: m_id(id)
, m_delay(delay)
, m_at(get_at(delay))
{
@ -815,9 +818,10 @@ private:
public:
DelayedCallFunction(int32_t delay,
int32_t id,
bool (*pFunction)(Worker::Call::action_t action, D data),
D data)
: DelayedCall(delay)
: DelayedCall(delay, id)
, m_pFunction(pFunction)
, m_data(data)
{
@ -842,8 +846,9 @@ private:
public:
DelayedCallFunctionVoid(int32_t delay,
int32_t id,
bool (*pFunction)(Worker::Call::action_t action))
: DelayedCall(delay)
: DelayedCall(delay, id)
, m_pFunction(pFunction)
{
}
@ -866,10 +871,11 @@ private:
public:
DelayedCallMethod(int32_t delay,
int32_t id,
bool (T::* pMethod)(Worker::Call::action_t action, D data),
T* pT,
D data)
: DelayedCall(delay)
: DelayedCall(delay, id)
, m_pMethod(pMethod)
, m_pT(pT)
, m_data(data)
@ -896,9 +902,10 @@ private:
public:
DelayedCallMethodVoid(int32_t delay,
int32_t id,
bool (T::* pMethod)(Worker::Call::action_t),
T* pT)
: DelayedCall(delay)
: DelayedCall(delay, id)
, m_pMethod(pMethod)
, m_pT(pT)
{
@ -925,7 +932,6 @@ private:
void poll_waitevents();
void tick();
private:
class LaterAt : public std::binary_function<const DelayedCall*, const DelayedCall*, bool>
{
@ -956,6 +962,6 @@ private:
DelayedCallsByTime m_sorted_calls; /*< Current delayed calls sorted by time. */
DelayedCallsById m_calls; /*< Current delayed calls indexed by id. */
static uint32_t s_next_delayed_call_id; /*< The next delayed call id. */
int32_t m_next_delayed_call_id; /*< The next delayed call id. */
};
}

4
maxutils/maxbase/src/worker.cc
View File

@ -278,9 +278,6 @@ int create_epoll_instance()
}
}
// static
uint32_t Worker::s_next_delayed_call_id = 1;
Worker::Worker(int max_events)
: m_epoll_fd(create_epoll_instance())
, m_state(STOPPED)
@ -292,6 +289,7 @@ Worker::Worker(int max_events)
, m_nCurrent_descriptors(0)
, m_nTotal_descriptors(0)
, m_pTimer(new PrivateTimer(this, this, &Worker::tick))
, m_next_delayed_call_id{1}
{
mxb_assert(max_events > 0);