Library: Foundation
Package: Threading
Header: Poco/Thread.h
This class implements a platform-independent wrapper to an operating system thread.
Every Thread object gets a unique (within its process) numeric thread ID. Furthermore, a thread can be assigned a name. The name of a thread can be changed at any time.
Direct Base Classes: ThreadImpl
All Base Classes: ThreadImpl
Member Functions: clearTLS, current, currentTid, getMaxOSPriority, getMinOSPriority, getName, getOSPriority, getPriority, getStackSize, id, isRunning, join, makeName, name, setName, setOSPriority, setPriority, setStackSize, sleep, start, tid, tls, tryJoin, trySleep, uniqueId, wakeUp, yield
typedef ThreadImpl::TIDImpl TID;
POLICY_DEFAULT = POLICY_DEFAULT_IMPL
Thread priorities.
PRIO_LOWEST = PRIO_LOWEST_IMPL
The lowest thread priority.
PRIO_LOW = PRIO_LOW_IMPL
A lower than normal thread priority.
PRIO_NORMAL = PRIO_NORMAL_IMPL
The normal thread priority.
PRIO_HIGH = PRIO_HIGH_IMPL
A higher than normal thread priority.
PRIO_HIGHEST = PRIO_HIGHEST_IMPL
The highest thread priority.
Thread();
Creates a thread. Call start() to start it.
Thread(
const std::string & name
);
Creates a named thread. Call start() to start it.
~Thread();
Destroys the thread.
static Thread * current();
Returns the Thread object for the currently active thread. If the current thread is the main thread, 0 is returned.
static TID currentTid();
Returns the native thread ID for the current thread.
static int getMaxOSPriority(
int policy = POLICY_DEFAULT
);
Returns the maximum operating system-specific priority value, which can be passed to setOSPriority() for the given policy.
static int getMinOSPriority(
int policy = POLICY_DEFAULT
);
Returns the mininum operating system-specific priority value, which can be passed to setOSPriority() for the given policy.
std::string getName() const;
Returns the name of the thread.
int getOSPriority() const;
Returns the thread's priority, expressed as an operating system specific priority value.
May return 0 if the priority has not been explicitly set.
Priority getPriority() const;
Returns the thread's priority.
int getStackSize() const;
Returns the thread's stack size in bytes. If the default stack size is used, 0 is returned.
int id() const;
Returns the unique thread ID of the thread.
bool isRunning() const;
Returns true if the thread is running.
void join();
Waits until the thread completes execution. If multiple threads try to join the same thread, the result is undefined.
void join(
long milliseconds
);
Waits for at most the given interval for the thread to complete. Throws a TimeoutException if the thread does not complete within the specified time interval.
std::string name() const;
Returns the name of the thread.
void setName(
const std::string & name
);
Sets the name of the thread.
void setOSPriority(
int prio,
int policy = POLICY_DEFAULT
);
Sets the thread's priority, using an operating system specific priority value. Use getMinOSPriority() and getMaxOSPriority() to obtain mininum and maximum priority values. Additionally, a scheduling policy can be specified. The policy is currently only used on POSIX platforms where the values SCHED_OTHER (default), SCHED_FIFO and SCHED_RR are supported.
void setPriority(
Priority prio
);
Sets the thread's priority.
Some platform only allow changing a thread's priority if the process has certain privileges.
void setStackSize(
int size
);
Sets the thread's stack size in bytes. Setting the stack size to 0 will use the default stack size. Typically, the real stack size is rounded up to the nearest page size multiple.
static void sleep(
long milliseconds
);
Suspends the current thread for the specified amount of time.
void start(
Runnable & target
);
Starts the thread with the given target.
Note that the given Runnable object must remain valid during the entire lifetime of the thread, as only a reference to it is stored internally.
void start(
Callable target,
void * pData = 0
);
Starts the thread with the given target and parameter.
TID tid() const;
Returns the native thread ID of the thread.
bool tryJoin(
long milliseconds
);
Waits for at most the given interval for the thread to complete. Returns true if the thread has finished, false otherwise.
static bool trySleep(
long milliseconds
);
Starts an interruptible sleep. When trySleep() is called, the thread will remain suspended until:
Function returns true if sleep attempt was completed, false if sleep was interrupted by a wakeUp() call. A frequent scenario where trySleep()/wakeUp() pair of functions is useful is with threads spending most of the time idle, with periodic activity between the idle times; trying to sleep (as opposed to sleeping) allows immediate ending of idle thread from the outside.
The trySleep() and wakeUp() calls should be used with understanding that the suspended state is not a true sleep, but rather a state of waiting for an event, with timeout expiration. This makes order of calls significantant; calling wakeUp() before calling trySleep() will prevent the next trySleep() call to actually suspend the thread (which, in some scenarios, may be desirable behavior).
void wakeUp();
Wakes up the thread which is in the state of interruptible sleep. For threads that are not suspended, calling this function has the effect of preventing the subsequent trySleep() call to put thread in a suspended state.
static void yield();
Yields cpu to other threads.
void clearTLS();
Clears the thread's local storage.
std::string makeName();
Creates a unique name for a thread.
ThreadLocalStorage & tls();
Returns a reference to the thread's local storage.
static int uniqueId();
Creates and returns a unique id for a thread.
using ThreadImpl::Callable;