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/* -*- C++ -*- */
// $Id$
// ============================================================================
//
// = LIBRARY
// ace
//
// = FILENAME
// Task.h
//
// = AUTHOR
// Doug Schmidt
//
// ============================================================================
#if !defined (ACE_TASK_H)
#define ACE_TASK_H
#include "ace/Service_Object.h"
#include "ace/Thread_Manager.h"
class ACE_Export ACE_Task_Flags
// = TITLE
// These flags are used within the ACE_Task.
//
// = DESCRIPTION
// These flags should be hidden within ACE_Task. Unfortunately, the
// HP/UX C++ compiler can't grok this... Fortunately, there's no
// code defined here, so we don't have to worry about multiple
// definitions.
{
public:
enum
{
ACE_READER = 01, // Identifies a Task as being the "reader" in a Module.
ACE_FLUSHDATA = 02, // Just flush data messages in the queue.
ACE_FLUSHALL = 04, // Flush all messages in the Queue.
ACE_FLUSHR = 010, // flush read queue
ACE_FLUSHW = 020, // flush write queue
ACE_FLUSHRW = 030 // flush both queues
};
};
class ACE_Export ACE_Task_Base : public ACE_Service_Object
// = TITLE
// Direct base class for the ACE_Task template.
//
// = DESCRIPTION
// This class factors out the non-template code in order to
// reduce template bloat, as well as to make it possible for the
// <ACE_Thread_Manager> to store <ACE_Task_Base> *'s
// polymorphically.
{
public:
// = Initialization method.
ACE_Task_Base (ACE_Thread_Manager *);
// = Initialization and termination hooks (note that these *must* be defined by subclasses).
virtual int open (void *args = 0);
// Hook called to open a Task. <args> can be used to pass arbitrary
// information into <open>.
virtual int close (u_long flags = 0);
// Hook called from <ACE_Task_Exit> when during thread exit and from
// the default implemenation of <module_closed>. In general, this
// method shouldn't be called directly by an application,
// particularly if the <Task> is running as an Active Object.
// Instead, a special message should be passed into the <Task> via
// the <put> method defined below, and the <svc> method should
// interpret this as a flag to shut down the <Task>.
virtual int module_closed (void);
// Hook called during ACE_Module::close(). The default
// implementation calls forwards the call to close(1). Please
// notice the changed value of the default argument of close().
// This allows tasks to differ between the call has been originated
// from <ACE_Task_Exit> or from <module_closed>. Be aware that
// close(0) will be also called when a thread associated with the
// ACE_Task instance exits.
// = Immediate and deferred processing methods, respectively.
virtual int put (ACE_Message_Block *, ACE_Time_Value * = 0);
// Transfer msg into the queue to handle immediate processing.
virtual int svc (void);
// Run by a daemon thread to handle deferred processing.
// = Active object activation method.
virtual int activate (long flags = THR_NEW_LWP,
int n_threads = 1,
int force_active = 0,
long priority = ACE_DEFAULT_THREAD_PRIORITY,
int grp_id = -1,
ACE_Task_Base *task = 0,
ACE_hthread_t thread_handles[] = 0);
// Turn the task into an active object, i.e., having <n_threads> of
// control, all running at the <priority> level (see below) with the same
// <grp_id>, all of which invoke <Task::svc>. Returns -1 if failure
// occurs, returns 1 if Task is already an active object and
// <force_active> is false (doesn't *not* create a new thread in
// this case), and returns 0 if Task was not already an active
// object and a thread is created successfully or thread is an
// active object and <force_active> is true.
//
// The <{flags}> are a bitwise-OR of the following:
// = BEGIN<INDENT>
// THR_CANCEL_DISABLE, THR_CANCEL_ENABLE, THR_CANCEL_DEFERRED,
// THR_CANCEL_ASYNCHRONOUS, THR_BOUND, THR_NEW_LWP, THR_DETACHED,
// THR_SUSPENDED, THR_DAEMON, THR_JOINABLE, THR_SCHED_FIFO,
// THR_SCHED_RR, THR_SCHED_DEFAULT
// = END<INDENT>
//
// By default, or if <{priority}> is set to ACE_DEFAULT_THREAD_PRIORITY,
// an "appropriate"
// priority value for the given scheduling policy (specified in
// <{flags}>, e.g., <THR_SCHED_DEFAULT>) is used. This value is
// calculated dynamically, and is the median value between the
// minimum and maximum priority values for the given policy. If an
// explicit value is given, it is used. Note that actual priority
// values are EXTREMEMLY implementation-dependent, and are probably
// best avoided.
//
// If <thread_handles> != 0 it is assumed to be an array of <n>
// thread_handles that will be assigned the values of the thread
// handles being spawned. Returns -1 on failure (<errno> will
// explain...), otherwise returns the group id of the threads.
virtual int wait (void);
// Wait for all threads running in this task to exit.
// = Suspend/resume a Task
virtual int suspend (void);
// Suspend a task.
virtual int resume (void);
// Resume a suspended task.
int grp_id (void) const;
// Get the current group id.
void grp_id (int);
// Set the current group id.
ACE_Thread_Manager *thr_mgr (void) const;
// Gets the thread manager associated with this Task.
void thr_mgr (ACE_Thread_Manager *);
// Set the thread manager associated with this Task.
int is_reader (void) const;
// True if queue is a reader, else false.
int is_writer (void) const;
// True if queue is a writer, else false.
size_t thr_count (void) const;
// Returns the number of threads currently running within a task.
// If we're a passive object this value is 0, else it's > 0.
void thr_count_dec (void);
// Atomically decrement the thread count by 1. This should only be
// called by the <ACE_Task_Exit> class destructor.
// Routine that runs the service routine as a daemon thread.
static void *svc_run (void *);
static void cleanup (void *object, void *params);
// Cleanup hook that is called when a thread exits to gracefully
// shutdown an <ACE_Task>.
// = Internal data (should be private...).
// private:
size_t thr_count_;
// Count of the number of threads running within the task. If this
// value is > 0 then we're an active object and the value of
// <thr_count_> is the number of active threads at this instant. If
// the value == 0, then we're a passive object.
ACE_Thread_Manager *thr_mgr_;
// Multi-threading manager.
u_long flags_;
// ACE_Task flags.
int grp_id_;
// This maintains the group id of the Task.
#if defined (ACE_MT_SAFE) && (ACE_MT_SAFE != 0)
ACE_Thread_Mutex lock_;
// Protect the state of a Task during concurrent operations, but
// only if we're configured as MT safe...
#endif /* ACE_MT_SAFE */
};
#if defined (__ACE_INLINE__)
#include "ace/Task.i"
#endif /* __ACE_INLINE__ */
// Include the ACE_Task templates classes at this point.
#include "ace/Task_T.h"
#endif /* ACE_TASK_H */
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