2 Copyright (C) 1998-99 Paul Barton-Davis
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
28 #include "pbd/error.h"
29 #include "pbd/debug.h"
30 #include "pbd/compose.h"
35 Pool::Pool (string n, unsigned long item_size, unsigned long nitems)
41 /* since some overloaded ::operator new() might use this,
42 its important that we use a "lower level" allocator to
46 block = malloc (nitems * item_size);
48 void **ptrlist = (void **) malloc (sizeof (void *) * nitems);
50 for (unsigned long i = 0; i < nitems; i++) {
51 ptrlist[i] = static_cast<void *> (static_cast<char*>(block) + (i * item_size));
54 free_list.write (ptrlist, nitems);
63 /** Allocate an item's worth of memory in the Pool by taking one from the free list.
64 * @return Pointer to free item.
71 if (free_list.read (&ptr, 1) < 1) {
72 fatal << "CRITICAL: " << _name << " POOL OUT OF MEMORY - RECOMPILE WITH LARGER SIZE!!" << endmsg;
80 /** Release an item's memory by writing its location to the free list */
82 Pool::release (void *ptr)
84 free_list.write (&ptr, 1);
87 /*---------------------------------------------*/
89 MultiAllocSingleReleasePool::MultiAllocSingleReleasePool (string n, unsigned long isize, unsigned long nitems)
90 : Pool (n, isize, nitems)
95 MultiAllocSingleReleasePool::~MultiAllocSingleReleasePool ()
100 SingleAllocMultiReleasePool::SingleAllocMultiReleasePool (string n, unsigned long isize, unsigned long nitems)
101 : Pool (n, isize, nitems)
106 SingleAllocMultiReleasePool::~SingleAllocMultiReleasePool ()
112 MultiAllocSingleReleasePool::alloc ()
116 m_lock = new Glib::Mutex();
117 // umm, I'm not sure that this doesn't also allocate memory.
118 if(!m_lock) error << "cannot create Glib::Mutex in pool.cc" << endmsg;
121 Glib::Mutex::Lock guard(*m_lock);
122 ptr = Pool::alloc ();
127 MultiAllocSingleReleasePool::release (void* ptr)
133 SingleAllocMultiReleasePool::alloc ()
135 return Pool::alloc ();
139 SingleAllocMultiReleasePool::release (void* ptr)
142 m_lock = new Glib::Mutex();
143 // umm, I'm not sure that this doesn't also allocate memory.
144 if(!m_lock) error << "cannot create Glib::Mutex in pool.cc" << endmsg;
146 Glib::Mutex::Lock guard(*m_lock);
150 /*-------------------------------------------------------*/
153 free_per_thread_pool (void* ptr)
155 /* Rather than deleting the CrossThreadPool now, we add it to our trash buffer.
156 * This prevents problems if other threads still require access to this CrossThreadPool.
157 * We assume that some other agent will clean out the trash buffer as required.
159 CrossThreadPool* cp = static_cast<CrossThreadPool*> (ptr);
163 /* This CrossThreadPool is already empty, and the thread is finishing so nothing
164 * more can be added to it. We can just delete the pool.
168 /* This CrossThreadPool is not empty, meaning that there's some Events in it
169 * which another thread may yet read, so we can't delete the pool just yet.
170 * Put it in the trash and hope someone deals with it at some stage.
172 cp->parent()->add_to_trash (cp);
176 PerThreadPool::PerThreadPool ()
180 /* for some reason this appears necessary to get glib's thread private stuff to work */
181 g_private_new (NULL);
184 _key = g_private_new (free_per_thread_pool);
187 /** Create a new CrossThreadPool and set the current thread's private _key to point to it.
189 * @param isize Size of each item in the pool.
190 * @param nitems Number of items in the pool.
193 PerThreadPool::create_per_thread_pool (string n, unsigned long isize, unsigned long nitems)
195 CrossThreadPool* p = new CrossThreadPool (n, isize, nitems, this);
196 g_private_set (_key, p);
199 /** @return CrossThreadPool for the current thread, which must previously have been created by
200 * calling create_per_thread_pool in the current thread.
203 PerThreadPool::per_thread_pool ()
205 CrossThreadPool* p = static_cast<CrossThreadPool*> (g_private_get (_key));
207 fatal << "programming error: no per-thread pool \"" << _name << "\" for thread " << pthread_self() << endmsg;
214 PerThreadPool::set_trash (RingBuffer<CrossThreadPool*>* t)
216 Glib::Mutex::Lock lm (_trash_mutex);
220 /** Add a CrossThreadPool to our trash, if we have one. If not, a warning is emitted. */
222 PerThreadPool::add_to_trash (CrossThreadPool* p)
224 Glib::Mutex::Lock lm (_trash_mutex);
227 warning << "Pool " << p->name() << " has no trash collector; a memory leak has therefore occurred" << endmsg;
231 /* we have a lock here so that multiple threads can safely call add_to_trash (even though there
232 can only be one writer to the _trash RingBuffer)
235 _trash->write (&p, 1);
238 CrossThreadPool::CrossThreadPool (string n, unsigned long isize, unsigned long nitems, PerThreadPool* p)
239 : Pool (n, isize, nitems)
247 CrossThreadPool::alloc ()
251 DEBUG_TRACE (DEBUG::Pool, string_compose ("%1 %2 has %3 pending free entries waiting\n", pthread_self(), name(), pending.read_space()));
252 while (pending.read (&ptr, 1) == 1) {
253 DEBUG_TRACE (DEBUG::Pool, string_compose ("%1 %2 pushes back a pending free list entry before allocating\n", pthread_self(), name()));
254 free_list.write (&ptr, 1);
256 return Pool::alloc ();
260 CrossThreadPool::push (void* t)
262 pending.write (&t, 1);
265 /** @return true if there is nothing in this pool */
267 CrossThreadPool::empty ()
269 return (free_list.write_space() == pending.read_space());