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.
27 #include "pbd/pthread_utils.h"
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)
94 MultiAllocSingleReleasePool::~MultiAllocSingleReleasePool ()
98 SingleAllocMultiReleasePool::SingleAllocMultiReleasePool (string n, unsigned long isize, unsigned long nitems)
99 : Pool (n, isize, nitems)
103 SingleAllocMultiReleasePool::~SingleAllocMultiReleasePool ()
108 MultiAllocSingleReleasePool::alloc ()
111 Glib::Threads::Mutex::Lock guard (m_lock);
112 ptr = Pool::alloc ();
117 MultiAllocSingleReleasePool::release (void* ptr)
123 SingleAllocMultiReleasePool::alloc ()
125 return Pool::alloc ();
129 SingleAllocMultiReleasePool::release (void* ptr)
131 Glib::Threads::Mutex::Lock guard (m_lock);
135 /*-------------------------------------------------------*/
138 free_per_thread_pool (void* ptr)
140 /* Rather than deleting the CrossThreadPool now, we add it to our trash buffer.
141 * This prevents problems if other threads still require access to this CrossThreadPool.
142 * We assume that some other agent will clean out the trash buffer as required.
144 CrossThreadPool* cp = static_cast<CrossThreadPool*> (ptr);
148 /* This CrossThreadPool is already empty, and the thread is finishing so nothing
149 * more can be added to it. We can just delete the pool.
153 /* This CrossThreadPool is not empty, meaning that there's some Events in it
154 * which another thread may yet read, so we can't delete the pool just yet.
155 * Put it in the trash and hope someone deals with it at some stage.
157 cp->parent()->add_to_trash (cp);
161 PerThreadPool::PerThreadPool ()
162 : _key (free_per_thread_pool)
167 /** Create a new CrossThreadPool and set the current thread's private _key to point to it.
169 * @param isize Size of each item in the pool.
170 * @param nitems Number of items in the pool.
173 PerThreadPool::create_per_thread_pool (string n, unsigned long isize, unsigned long nitems)
175 _key.set (new CrossThreadPool (n, isize, nitems, this));
178 /** @return CrossThreadPool for the current thread, which must previously have been created by
179 * calling create_per_thread_pool in the current thread.
182 PerThreadPool::per_thread_pool ()
184 CrossThreadPool* p = _key.get();
186 fatal << "programming error: no per-thread pool \"" << _name << "\" for thread " << pthread_name() << endmsg;
193 PerThreadPool::set_trash (RingBuffer<CrossThreadPool*>* t)
195 Glib::Threads::Mutex::Lock lm (_trash_mutex);
199 /** Add a CrossThreadPool to our trash, if we have one. If not, a warning is emitted. */
201 PerThreadPool::add_to_trash (CrossThreadPool* p)
203 Glib::Threads::Mutex::Lock lm (_trash_mutex);
206 warning << "Pool " << p->name() << " has no trash collector; a memory leak has therefore occurred" << endmsg;
210 /* we have a lock here so that multiple threads can safely call add_to_trash (even though there
211 can only be one writer to the _trash RingBuffer)
214 _trash->write (&p, 1);
217 CrossThreadPool::CrossThreadPool (string n, unsigned long isize, unsigned long nitems, PerThreadPool* p)
218 : Pool (n, isize, nitems)
226 CrossThreadPool::alloc ()
230 DEBUG_TRACE (DEBUG::Pool, string_compose ("%1 %2 has %3 pending free entries waiting\n", pthread_name(), name(), pending.read_space()));
231 while (pending.read (&ptr, 1) == 1) {
232 DEBUG_TRACE (DEBUG::Pool, string_compose ("%1 %2 pushes back a pending free list entry before allocating\n", pthread_name(), name()));
233 free_list.write (&ptr, 1);
235 return Pool::alloc ();
239 CrossThreadPool::push (void* t)
241 pending.write (&t, 1);
244 /** @return true if there is nothing in this pool */
246 CrossThreadPool::empty ()
248 return (free_list.write_space() == pending.read_space());