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/error.h"
28 #include "pbd/debug.h"
29 #include "pbd/compose.h"
34 Pool::Pool (string n, unsigned long item_size, unsigned long nitems)
40 /* since some overloaded ::operator new() might use this,
41 its important that we use a "lower level" allocator to
45 block = malloc (nitems * item_size);
47 void **ptrlist = (void **) malloc (sizeof (void *) * nitems);
49 for (unsigned long i = 0; i < nitems; i++) {
50 ptrlist[i] = static_cast<void *> (static_cast<char*>(block) + (i * item_size));
53 free_list.write (ptrlist, nitems);
62 /** Allocate an item's worth of memory in the Pool by taking one from the free list.
63 * @return Pointer to free item.
70 if (free_list.read (&ptr, 1) < 1) {
71 fatal << "CRITICAL: " << _name << " POOL OUT OF MEMORY - RECOMPILE WITH LARGER SIZE!!" << endmsg;
79 /** Release an item's memory by writing its location to the free list */
81 Pool::release (void *ptr)
83 free_list.write (&ptr, 1);
86 /*---------------------------------------------*/
88 MultiAllocSingleReleasePool::MultiAllocSingleReleasePool (string n, unsigned long isize, unsigned long nitems)
89 : Pool (n, isize, nitems)
93 MultiAllocSingleReleasePool::~MultiAllocSingleReleasePool ()
97 SingleAllocMultiReleasePool::SingleAllocMultiReleasePool (string n, unsigned long isize, unsigned long nitems)
98 : Pool (n, isize, nitems)
102 SingleAllocMultiReleasePool::~SingleAllocMultiReleasePool ()
107 MultiAllocSingleReleasePool::alloc ()
110 Glib::Threads::Mutex::Lock guard (m_lock);
111 ptr = Pool::alloc ();
116 MultiAllocSingleReleasePool::release (void* ptr)
122 SingleAllocMultiReleasePool::alloc ()
124 return Pool::alloc ();
128 SingleAllocMultiReleasePool::release (void* ptr)
130 Glib::Threads::Mutex::Lock guard (m_lock);
134 /*-------------------------------------------------------*/
137 free_per_thread_pool (void* ptr)
139 /* Rather than deleting the CrossThreadPool now, we add it to our trash buffer.
140 * This prevents problems if other threads still require access to this CrossThreadPool.
141 * We assume that some other agent will clean out the trash buffer as required.
143 CrossThreadPool* cp = static_cast<CrossThreadPool*> (ptr);
147 /* This CrossThreadPool is already empty, and the thread is finishing so nothing
148 * more can be added to it. We can just delete the pool.
152 /* This CrossThreadPool is not empty, meaning that there's some Events in it
153 * which another thread may yet read, so we can't delete the pool just yet.
154 * Put it in the trash and hope someone deals with it at some stage.
156 cp->parent()->add_to_trash (cp);
160 PerThreadPool::PerThreadPool ()
161 : _key (free_per_thread_pool)
166 /** Create a new CrossThreadPool and set the current thread's private _key to point to it.
168 * @param isize Size of each item in the pool.
169 * @param nitems Number of items in the pool.
172 PerThreadPool::create_per_thread_pool (string n, unsigned long isize, unsigned long nitems)
174 _key.set (new CrossThreadPool (n, isize, nitems, this));
177 /** @return CrossThreadPool for the current thread, which must previously have been created by
178 * calling create_per_thread_pool in the current thread.
181 PerThreadPool::per_thread_pool ()
183 CrossThreadPool* p = _key.get();
185 fatal << "programming error: no per-thread pool \"" << _name << "\" for thread " << pthread_self() << endmsg;
192 PerThreadPool::set_trash (RingBuffer<CrossThreadPool*>* t)
194 Glib::Threads::Mutex::Lock lm (_trash_mutex);
198 /** Add a CrossThreadPool to our trash, if we have one. If not, a warning is emitted. */
200 PerThreadPool::add_to_trash (CrossThreadPool* p)
202 Glib::Threads::Mutex::Lock lm (_trash_mutex);
205 warning << "Pool " << p->name() << " has no trash collector; a memory leak has therefore occurred" << endmsg;
209 /* we have a lock here so that multiple threads can safely call add_to_trash (even though there
210 can only be one writer to the _trash RingBuffer)
213 _trash->write (&p, 1);
216 CrossThreadPool::CrossThreadPool (string n, unsigned long isize, unsigned long nitems, PerThreadPool* p)
217 : Pool (n, isize, nitems)
225 CrossThreadPool::alloc ()
229 DEBUG_TRACE (DEBUG::Pool, string_compose ("%1 %2 has %3 pending free entries waiting\n", pthread_self(), name(), pending.read_space()));
230 while (pending.read (&ptr, 1) == 1) {
231 DEBUG_TRACE (DEBUG::Pool, string_compose ("%1 %2 pushes back a pending free list entry before allocating\n", pthread_self(), name()));
232 free_list.write (&ptr, 1);
234 return Pool::alloc ();
238 CrossThreadPool::push (void* t)
240 pending.write (&t, 1);
243 /** @return true if there is nothing in this pool */
245 CrossThreadPool::empty ()
247 return (free_list.write_space() == pending.read_space());