diff packages/services/memalloc/common/current/include/mempolt2.inl @ 115:6ed91473a1cd ecos-sw-2000-08-21

Merge from eCos master repository on 2000-08-21-22:40:54-BST
author jlarmour
date Fri, 25 Aug 2000 17:32:38 +0000
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children e0c0827131d1
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+#ifndef CYGONCE_MEMALLOC_MEMPOLT2_INL
+#define CYGONCE_MEMALLOC_MEMPOLT2_INL
+
+//==========================================================================
+//
+//      mempolt2.inl
+//
+//      Mempolt2 (Memory pool template) class declarations
+//
+//==========================================================================
+//####COPYRIGHTBEGIN####
+//                                                                          
+// -------------------------------------------                              
+// The contents of this file are subject to the Red Hat eCos Public License 
+// Version 1.1 (the "License"); you may not use this file except in         
+// compliance with the License.  You may obtain a copy of the License at    
+// http://www.redhat.com/                                                   
+//                                                                          
+// Software distributed under the License is distributed on an "AS IS"      
+// basis, WITHOUT WARRANTY OF ANY KIND, either express or implied.  See the 
+// License for the specific language governing rights and limitations under 
+// the License.                                                             
+//                                                                          
+// The Original Code is eCos - Embedded Configurable Operating System,      
+// released September 30, 1998.                                             
+//                                                                          
+// The Initial Developer of the Original Code is Red Hat.                   
+// Portions created by Red Hat are                                          
+// Copyright (C) 1998, 1999, 2000 Red Hat, Inc.                             
+// All Rights Reserved.                                                     
+// -------------------------------------------                              
+//                                                                          
+//####COPYRIGHTEND####
+//==========================================================================
+//#####DESCRIPTIONBEGIN####
+//
+// Author(s):    hmt
+// Contributors: jlarmour
+// Date:         2000-06-12
+// Purpose:      Define Mempolt2 class interface
+// Description:  The class defined here provides the APIs for thread-safe,
+//               kernel-savvy memory managers; make a class with the
+//               underlying allocator as the template parameter.
+// Usage:        #include <cyg/memalloc/mempolt2.hxx>
+//              
+//
+//####DESCRIPTIONEND####
+//
+//==========================================================================
+
+#include <cyg/infra/cyg_ass.h>    // assertion support
+#include <cyg/infra/cyg_trac.h>   // tracing support
+#include <cyg/kernel/thread.inl>  // implementation eg. Cyg_Thread::self();
+#include <cyg/kernel/sched.inl>   // implementation eg. Cyg_Scheduler::lock();
+
+// -------------------------------------------------------------------------
+// Constructor; we _require_ these arguments and just pass them through to
+// the implementation memory pool in use.
+template <class T>
+Cyg_Mempolt2<T>::Cyg_Mempolt2(
+    cyg_uint8 *base,
+    cyg_int32 size,
+    CYG_ADDRWORD arg_thru)              // Constructor
+    : pool( base, size, arg_thru )
+{
+}
+
+
+template <class T>
+Cyg_Mempolt2<T>::~Cyg_Mempolt2()  // destructor
+{
+    // Prevent preemption
+    Cyg_Scheduler::lock();
+            
+    while ( ! queue.empty() ) {
+        Cyg_Thread *thread = queue.dequeue();
+        thread->set_wake_reason( Cyg_Thread::DESTRUCT );
+        thread->wake();
+    }
+
+    // Unlock the scheduler and maybe switch threads
+    Cyg_Scheduler::unlock();    
+}
+        
+// -------------------------------------------------------------------------
+// get some memory; wait if none available
+template <class T>
+inline cyg_uint8 *
+Cyg_Mempolt2<T>::alloc( cyg_int32 size )
+{
+    CYG_REPORT_FUNCTION();
+        
+    // Prevent preemption
+    Cyg_Scheduler::lock();
+    CYG_ASSERTCLASS( this, "Bad this pointer");
+    
+    cyg_uint8 *ret;
+    ret = pool.try_alloc( size );
+    if ( ret ) {
+        Cyg_Scheduler::unlock();
+        CYG_ASSERTCLASS( this, "Bad this pointer");
+        CYG_REPORT_RETVAL( ret );
+        return ret;
+    }
+
+    Cyg_Thread *self = Cyg_Thread::self();
+
+    Mempolt2WaitInfo waitinfo( size );
+
+    self->set_wait_info( (CYG_ADDRWORD)&waitinfo );
+    self->set_sleep_reason( Cyg_Thread::WAIT );
+    self->sleep();
+    queue.enqueue( self );
+
+    CYG_ASSERT( 1 == Cyg_Scheduler::get_sched_lock(),
+                "Called with non-zero scheduler lock");
+        
+    // Unlock scheduler and allow other threads to run
+    Cyg_Scheduler::unlock();
+
+    cyg_bool result = true; // just used as a flag here
+    switch( self->get_wake_reason() )
+    {
+    case Cyg_Thread::DESTRUCT:
+    case Cyg_Thread::BREAK:
+        result = false;
+        break;
+        
+    case Cyg_Thread::EXIT:            
+        self->exit();
+        break;
+        
+    default:
+        break;
+    }
+
+    if ( ! result )
+        ret = NULL;
+    else
+        ret = waitinfo.addr;
+
+    CYG_ASSERT( (!result) || (NULL != ret), "Good result but no alloc!" );
+    CYG_ASSERTCLASS( this, "Bad this pointer");
+    CYG_REPORT_RETVAL( ret );
+    return ret;
+}
+
+#ifdef CYGFUN_KERNEL_THREADS_TIMER
+// -------------------------------------------------------------------------
+// get some memory with a timeout
+template <class T>
+inline cyg_uint8 *
+Cyg_Mempolt2<T>::alloc( cyg_int32 size, cyg_tick_count abs_timeout )
+{
+    CYG_REPORT_FUNCTION();
+    
+    // Prevent preemption
+    Cyg_Scheduler::lock();
+    CYG_ASSERTCLASS( this, "Bad this pointer");
+    
+    cyg_uint8 *ret;
+    ret = pool.try_alloc( size );
+    if ( ret ) {
+        Cyg_Scheduler::unlock();
+        CYG_ASSERTCLASS( this, "Bad this pointer");
+        CYG_REPORT_RETVAL( ret );
+        return ret;
+    }
+
+    Cyg_Thread *self = Cyg_Thread::self();
+
+    Mempolt2WaitInfo waitinfo( size );
+
+    self->set_timer( abs_timeout, Cyg_Thread::TIMEOUT );
+
+    // If the timeout is in the past, the wake reason will have been set to
+    // something other than NONE already. If so, skip the wait and go
+    // straight to unlock.
+    
+    if( Cyg_Thread::NONE == self->get_wake_reason() ) {
+        self->set_wait_info( (CYG_ADDRWORD)&waitinfo );
+        self->sleep();
+        queue.enqueue( self );
+    }
+
+    CYG_ASSERT( 1 == Cyg_Scheduler::get_sched_lock(),
+                "Called with non-zero scheduler lock");
+        
+    // Unlock scheduler and allow other threads to run
+    Cyg_Scheduler::unlock();
+
+    // clear the timer; if it actually fired, no worries.
+    self->clear_timer();
+
+    cyg_bool result = true; // just used as a flag here
+    switch( self->get_wake_reason() )
+    {
+    case Cyg_Thread::TIMEOUT:
+        result = false;
+        break;
+            
+    case Cyg_Thread::DESTRUCT:
+    case Cyg_Thread::BREAK:
+        result = false;
+        break;
+            
+    case Cyg_Thread::EXIT:            
+        self->exit();
+        break;
+
+    default:
+        break;
+    }
+
+    if ( ! result )
+        ret = NULL;
+    else
+        ret = waitinfo.addr;
+
+    CYG_ASSERT( (!result) || (NULL != ret), "Good result but no alloc!" );
+    CYG_ASSERTCLASS( this, "Bad this pointer");
+    CYG_REPORT_RETVAL( ret );
+    return ret;
+}
+#endif 
+
+// -------------------------------------------------------------------------
+// get some memory, return NULL if none available
+template <class T>
+inline cyg_uint8 *
+Cyg_Mempolt2<T>::try_alloc( cyg_int32 size )
+{
+    CYG_REPORT_FUNCTION();
+        
+    // Prevent preemption
+    Cyg_Scheduler::lock();
+    CYG_ASSERTCLASS( this, "Bad this pointer");
+    
+    cyg_uint8 *ret = pool.try_alloc( size );
+
+    CYG_ASSERTCLASS( this, "Bad this pointer");
+
+    // Unlock the scheduler and maybe switch threads
+    Cyg_Scheduler::unlock();
+    return ret;
+}
+    
+    
+// -------------------------------------------------------------------------
+// resize existing allocation, if oldsize is non-NULL, previous
+// allocation size is placed into it. If previous size not available,
+// it is set to 0. NB previous allocation size may have been rounded up.
+// Occasionally the allocation can be adjusted *backwards* as well as,
+// or instead of forwards, therefore the address of the resized
+// allocation is returned, or NULL if no resizing was possible.
+// Note that this differs from ::realloc() in that no attempt is
+// made to call malloc() if resizing is not possible - that is left
+// to higher layers. The data is copied from old to new though.
+// The effects of alloc_ptr==NULL or newsize==0 are undefined
+template <class T>
+cyg_uint8 *
+Cyg_Mempolt2<T>::resize_alloc( cyg_uint8 *alloc_ptr, cyg_int32 newsize,
+                               cyg_int32 *oldsize )
+{
+    CYG_REPORT_FUNCTION();
+        
+    // Prevent preemption
+    Cyg_Scheduler::lock();
+    CYG_ASSERTCLASS( this, "Bad this pointer");
+    
+    cyg_uint8 *ret = pool.resize_alloc( alloc_ptr, newsize, oldsize );
+
+    CYG_ASSERTCLASS( this, "Bad this pointer");
+
+    // Unlock the scheduler and maybe switch threads
+    Cyg_Scheduler::unlock();
+    return ret;
+}
+    
+    
+// -------------------------------------------------------------------------
+// free the memory back to the pool
+template <class T>
+cyg_bool
+Cyg_Mempolt2<T>::free( cyg_uint8 *p, cyg_int32 size )
+{
+    CYG_REPORT_FUNCTION();
+    // Prevent preemption
+    Cyg_Scheduler::lock();
+    CYG_ASSERTCLASS( this, "Bad this pointer");
+    
+    cyg_int32 ret = pool.free( p, size );
+
+    // anyone waiting?
+    if ( !(queue.empty()) ) {
+        Mempolt2WaitInfo *p;
+        Cyg_Thread     *thread;
+
+#ifdef CYGIMP_MEM_T_ONEFREE_TO_ONEALLOC
+        thread = queue.dequeue();
+        p = (Mempolt2WaitInfo *)(thread->get_wait_info());
+        CYG_ASSERT( NULL == p->addr, "Thread already awoken?" );
+
+        cyg_uint8 *mem;
+        mem = pool.try_alloc( p->size );
+        CYG_ASSERT( NULL != mem, "That should have succeeded" );
+        thread->set_wake_reason( Cyg_Thread::DONE );
+        thread->wake();
+        // return the successful value to it
+        p->addr = mem;
+#else
+        Cyg_ThreadQueue holding;
+        do {
+            thread = queue.dequeue();
+            p = (Mempolt2WaitInfo *)(thread->get_wait_info());
+            CYG_ASSERT( NULL == p->addr, "Thread already awoken?" );
+
+            cyg_uint8 *mem;
+            if ( NULL != (mem = pool.try_alloc( p->size )) ) {
+                // success!  awaken the thread
+                thread->set_wake_reason( Cyg_Thread::DONE );
+                thread->wake();
+                // return the successful value to it
+                p->addr = mem;
+            }
+            else {
+                // preserve the entry on the holding queue
+                holding.enqueue( thread );
+            }
+        } while ( !(queue.empty()) );
+            
+        // Now re-queue the unaffected threads back into the pool queue
+        // (no pun intended)
+        while ( !(holding.empty()) ) {
+            queue.enqueue( holding.dequeue() );
+        }
+#endif // CYGIMP_MEM_T_ONEFREE_TO_ONEALLOC
+    }
+    // Unlock the scheduler and maybe switch threads
+    Cyg_Scheduler::unlock();
+    CYG_REPORT_RETVAL( ret );
+    return ret;
+}
+
+// -------------------------------------------------------------------------
+// Get memory pool status
+// Needs atomicity protection (maybe)
+template <class T>
+inline void
+Cyg_Mempolt2<T>::get_status( cyg_mempool_status_flag_t flags,
+                             Cyg_Mempool_Status &status )
+{
+    // Prevent preemption
+    Cyg_Scheduler::lock();
+    CYG_ASSERTCLASS( this, "Bad this pointer");
+    
+    if (0 != (flags & CYG_MEMPOOL_STAT_WAITING)) {
+        status.waiting = (0 == queue.empty());
+    }
+    pool.get_status(flags, status);
+
+    // Unlock the scheduler and maybe switch threads
+    Cyg_Scheduler::unlock();
+}
+
+// -------------------------------------------------------------------------
+// debugging/assert function
+
+#ifdef CYGDBG_USE_ASSERTS
+
+template <class T>
+inline cyg_bool
+Cyg_Mempolt2<T>::check_this(cyg_assert_class_zeal zeal) const
+{
+    CYG_REPORT_FUNCTION();
+        
+    if ( Cyg_Thread::DESTRUCT == Cyg_Thread::self()->get_wake_reason() )
+        // then the whole thing is invalid, and we know it.
+        // so return OK, since this check should NOT make an error.
+        return true;
+
+    // check that we have a non-NULL pointer first
+    if( this == NULL ) return false;
+
+    return true;
+}
+#endif
+
+// -------------------------------------------------------------------------
+#endif // ifndef CYGONCE_MEMALLOC_MEMPOLT2_INL
+// EOF mempolt2.inl