core.thread
The thread module provides support for thread creation and management.License:
BSD Style, see LICENSE
Authors:
Sean Kelly
- Base class for thread exceptions.
- Base class for fiber exceptions.
- This class encapsulates all threading functionality for the D
programming language. As thread manipulation is a required facility
for garbage collection, all user threads should derive from this
class, and instances of this class should never be explicitly deleted.
A new thread may be created using either derivation or composition, as
in the following example.
Example:
class DerivedThread : Thread { this() { super( &run ); } private : void run() { printf( "Derived thread running.\n" ); } } void threadFunc() { printf( "Composed thread running.\n" ); } // create instances of each type Thread derived = new DerivedThread(); Thread composed = new Thread( &threadFunc ); // start both threads derived.start(); composed.start();
- this(void function() fn, size_t sz = 0);
- Initializes a thread object which is associated with a static
D function.
Params:
void function() fn The thread function. size_t sz The stack size for this thread.
In:
fn must not be null.
- this(void delegate() dg, size_t sz = 0);
- Initializes a thread object which is associated with a dynamic
D function.
Params:
void delegate() dg The thread function. size_t sz The stack size for this thread.
In:
dg must not be null.
- Starts the thread and invokes the function or delegate passed upon
construction.
In:
This routine may only be called once per thread instance.
Throws:
ThreadException if the thread fails to start.
- Waits for this thread to complete. If the thread terminated as the
result of an unhandled exception, this exception will be rethrown.
Params:
bool rethrow Rethrow any unhandled exception which may have caused this thread to terminate.
Throws:
ThreadException if the operation fails. Any exception not handled by the joined thread.
Returns:
Any exception not handled by this thread if rethrow = false, null otherwise.
- Gets the user-readable label for this thread.
Returns:
The name of this thread.
- Sets the user-readable label for this thread.
Params:
char[] val The new name of this thread.
- Gets the daemon status for this thread. While the runtime will wait for
all normal threads to complete before tearing down the process, daemon
threads are effectively ignored and thus will not prevent the process
from terminating. In effect, daemon threads will be terminated
automatically by the OS when the process exits.
Returns:
true if this is a daemon thread.
- Sets the daemon status for this thread. While the runtime will wait for
all normal threads to complete before tearing down the process, daemon
threads are effectively ignored and thus will not prevent the process
from terminating. In effect, daemon threads will be terminated
automatically by the OS when the process exits.
Params:
bool val The new daemon status for this thread.
- Tests whether this thread is running.
Returns:
true if the thread is running, false if not.
- The minimum scheduling priority that may be set for a thread. On
systems where multiple scheduling policies are defined, this value
represents the minimum valid priority for the scheduling policy of
the process.
- The maximum scheduling priority that may be set for a thread. On
systems where multiple scheduling policies are defined, this value
represents the minimum valid priority for the scheduling policy of
the process.
- Gets the scheduling priority for the associated thread.
Returns:
The scheduling priority of this thread.
- Sets the scheduling priority for the associated thread.
Params:
int val The new scheduling priority of this thread.
- Suspends the calling thread for at least the supplied period. This may
result in multiple OS calls if period is greater than the maximum sleep
duration supported by the operating system.
Params:
long period The minimum duration the calling thread should be suspended, in 100 nanosecond intervals.
In:
period must be non-negative.
Example:
Thread.sleep( 500 ); // sleep for 50 milliseconds Thread.sleep( 50_000_000 ); // sleep for 5 seconds
- Forces a context switch to occur away from the calling thread.
- Provides a reference to the calling thread.
Returns:
The thread object representing the calling thread. The result of deleting this object is undefined.
- Provides a list of all threads currently being tracked by the system.
Returns:
An array containing references to all threads currently being tracked by the system. The result of deleting any contained objects is undefined.
- Operates on all threads currently being tracked by the system. The
result of deleting any Thread object is undefined.
Params:
int delegate(ref Thread) dg The supplied code as a delegate.
Returns:
Zero if all elemented are visited, nonzero if not.
- Indicates the number of local storage pointers available at program
startup. It is recommended that this number be at least 64.
- Reserves a local storage pointer for use and initializes this location
to null for all running threads.
Returns:
A key representing the array offset of this memory location.
- Marks the supplied key as available and sets the associated location
to null for all running threads. It is assumed that any key passed
to this function is valid. The result of calling this function for
a key which is still in use is undefined.
Params:
uint key The key to delete.
- Loads the value stored at key within a thread-local static array. It is
assumed that any key passed to this function is valid.
Params:
uint key The location which holds the desired data.
Returns:
The data associated with the supplied key.
- Stores the supplied value at key within a thread-local static array. It
is assumed that any key passed to this function is valid.
Params:
uint key The location to store the supplied data. void* val The data to store.
Returns:
A copy of the data which has just been stored.
- Initializes the thread module. This function must be called by the
garbage collector on startup and before any other thread routines
are called.
- Registers the calling thread for use with the D Runtime. If this routine
is called for a thread which is already registered, the result is undefined.
- Deregisters the calling thread from use with the runtime. If this routine
is called for a thread which is already registered, the result is undefined.
- Joins all non-daemon threads that are currently running. This is done by
performing successive scans through the thread list until a scan consists
of only daemon threads.
- This function is used to determine whether the the process is
multi-threaded. Optimizations may only be performed on this
value if the programmer can guarantee that no path from the
enclosed code will start a thread.
Returns:
True if Thread.start() has been called in this process.
- Suspend all threads but the calling thread for "stop the world" garbage
collection runs. This function may be called multiple times, and must
be followed by a matching number of calls to thread_resumeAll before
processing is resumed.
Throws:
ThreadException if the suspend operation fails for a running thread.
- Resume all threads but the calling thread for "stop the world" garbage
collection runs. This function must be called once for each preceding
call to thread_suspendAll before the threads are actually resumed.
In:
This routine must be preceded by a call to thread_suspendAll.
Throws:
ThreadException if the resume operation fails for a running thread.
- The main entry point for garbage collection. The supplied delegate
will be passed ranges representing both stack and register values.
Params:
scanAllThreadsFn scan The scanner function. It should scan from p1 through p2 - 1. void* curStackTop An optional pointer to the top of the calling thread's stack.
In:
This routine must be preceded by a call to thread_suspendAll.
- This class encapsulates the operations required to initialize, access, and
destroy thread local data.
- this(T def = T.init);
- Initializes thread local storage for the indicated value which will be
initialized to def for all threads.
Params:
def The default value to return if no value has been explicitly set.
- Gets the value last set by the calling thread, or def if no such value
has been set.
Returns:
The stored value or def if no value is stored.
- Copies newval to a location specific to the calling thread, and returns
newval.
Params:
T newval The value to set.
Returns:
The value passed to this function.
- This class is intended to simplify certain common programming techniques.
- Creates and starts a new Thread object that executes fn and adds it to
the list of tracked threads.
Params:
void function() fn The thread function.
Returns:
A reference to the newly created thread.
- Creates and starts a new Thread object that executes dg and adds it to
the list of tracked threads.
Params:
void delegate() dg The thread function.
Returns:
A reference to the newly created thread.
- Add t to the list of tracked threads if it is not already being tracked.
Params:
Thread t The thread to add.
In:
t must not be null.
- Removes t from the list of tracked threads. No operation will be
performed if t is not currently being tracked by this object.
Params:
Thread t The thread to remove.
In:
t must not be null.
- Operates on all threads currently tracked by this object.
- Iteratively joins all tracked threads. This function will block add,
remove, and opApply until it completes.
Params:
bool rethrow Rethrow any unhandled exception which may have caused the current thread to terminate.
Throws:
Any exception not handled by the joined threads.
- This class provides a cooperative concurrency mechanism integrated with the
threading and garbage collection functionality. Calling a fiber may be
considered a blocking operation that returns when the fiber yields (via
Fiber.yield()). Execution occurs within the context of the calling thread
so synchronization is not necessary to guarantee memory visibility so long
as the same thread calls the fiber each time. Please note that there is no
requirement that a fiber be bound to one specific thread. Rather, fibers
may be freely passed between threads so long as they are not currently
executing. Like threads, a new fiber thread may be created using either
derivation or composition, as in the following example.
Example:
class DerivedFiber : Fiber { this() { super( &run ); } private : void run() { printf( "Derived fiber running.\n" ); } } void fiberFunc() { printf( "Composed fiber running.\n" ); Fiber.yield(); printf( "Composed fiber running.\n" ); } // create instances of each type Fiber derived = new DerivedFiber(); Fiber composed = new Fiber( &fiberFunc ); // call both fibers once derived.call(); composed.call(); printf( "Execution returned to calling context.\n" ); composed.call(); // since each fiber has run to completion, each should have state TERM assert( derived.state == Fiber.State.TERM ); assert( composed.state == Fiber.State.TERM );
Authors:
Based on a design by Mikola Lysenko.
- this(void function() fn, size_t sz = PAGESIZE);
- Initializes a fiber object which is associated with a static
D function.
Params:
void function() fn The thread function. size_t sz The stack size for this fiber.
In:
fn must not be null.
- this(void delegate() dg, size_t sz = PAGESIZE);
- Initializes a fiber object which is associated with a dynamic
D function.
Params:
void delegate() dg The thread function. size_t sz The stack size for this fiber.
In:
dg must not be null.
- Transfers execution to this fiber object. The calling context will be
suspended until the fiber calls Fiber.yield() or until it terminates
via an unhandled exception.
Params:
bool rethrow Rethrow any unhandled exception which may have caused this fiber to terminate.
In:
This fiber must be in state HOLD.
Throws:
Any exception not handled by the joined thread.
Returns:
Any exception not handled by this fiber if rethrow = false, null otherwise.
- Resets this fiber so that it may be re-used. This routine may only be
called for fibers that have terminated, as doing otherwise could result
in scope-dependent functionality that is not executed. Stack-based
classes, for example, may not be cleaned up properly if a fiber is reset
before it has terminated.
In:
This fiber must be in state TERM.
- A fiber may occupy one of three states: HOLD, EXEC, and TERM. The HOLD
state applies to any fiber that is suspended and ready to be called.
The EXEC state will be set for any fiber that is currently executing.
And the TERM state is set when a fiber terminates. Once a fiber
terminates, it must be reset before it may be called again.
- Gets the current state of this fiber.
Returns:
The state of this fiber as an enumerated value.
- Forces a context switch to occur away from the calling fiber.
- Forces a context switch to occur away from the calling fiber and then
throws obj in the calling fiber.
Params:
Object obj The object to throw.
In:
obj must not be null.
- Provides a reference to the calling fiber or null if no fiber is
currently active.
Returns:
The fiber object representing the calling fiber or null if no fiber is currently active. The result of deleting this object is undefined.