/*
Copyright (C) 1998-99 Paul Barton-Davis
-
+
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
*/
#include <cstdlib>
-#include <iostream>
#include <vector>
#include <cstdlib>
+#include <cassert>
#include "pbd/pool.h"
+#include "pbd/pthread_utils.h"
#include "pbd/error.h"
+#include "pbd/debug.h"
+#include "pbd/compose.h"
using namespace std;
using namespace PBD;
Pool::Pool (string n, unsigned long item_size, unsigned long nitems)
: free_list (nitems)
, _name (n)
+#ifndef NDEBUG
+ , max_usage (0)
+#endif
{
_name = n;
/* since some overloaded ::operator new() might use this,
its important that we use a "lower level" allocator to
- get more space.
+ get more space.
*/
block = malloc (nitems * item_size);
Pool::~Pool ()
{
+#ifndef NDEBUG
+ // TODO: after collecting some stats, use DEBUG::PoolStats here
+ cerr << "Pool: '" << _name << "' max: " << max_usage << " / " << total() << endmsg;
+#endif
free (block);
}
+/** Allocate an item's worth of memory in the Pool by taking one from the free list.
+ * @return Pointer to free item.
+ */
void *
Pool::alloc ()
{
void *ptr;
-// cerr << _name << " pool " << " alloc, thread = " << pthread_name() << " space = " << free_list->read_space() << endl;
+#ifndef NDEBUG
+ if (used () > max_usage) {
+ max_usage = used () + 1;
+ }
+#endif
if (free_list.read (&ptr, 1) < 1) {
fatal << "CRITICAL: " << _name << " POOL OUT OF MEMORY - RECOMPILE WITH LARGER SIZE!!" << endmsg;
- /*NOTREACHED*/
+ abort(); /*NOTREACHED*/
return 0;
} else {
return ptr;
}
}
+/** Release an item's memory by writing its location to the free list */
void
Pool::release (void *ptr)
{
free_list.write (&ptr, 1);
-// cerr << _name << ": release, now has " << free_list->read_space() << endl;
}
/*---------------------------------------------*/
-MultiAllocSingleReleasePool::MultiAllocSingleReleasePool (string n, unsigned long isize, unsigned long nitems)
- : Pool (n, isize, nitems),
- m_lock(0)
+MultiAllocSingleReleasePool::MultiAllocSingleReleasePool (string n, unsigned long isize, unsigned long nitems)
+ : Pool (n, isize, nitems)
{
}
MultiAllocSingleReleasePool::~MultiAllocSingleReleasePool ()
{
- delete m_lock;
}
-SingleAllocMultiReleasePool::SingleAllocMultiReleasePool (string n, unsigned long isize, unsigned long nitems)
- : Pool (n, isize, nitems),
- m_lock(0)
+SingleAllocMultiReleasePool::SingleAllocMultiReleasePool (string n, unsigned long isize, unsigned long nitems)
+ : Pool (n, isize, nitems)
{
}
SingleAllocMultiReleasePool::~SingleAllocMultiReleasePool ()
{
- delete m_lock;
}
void*
MultiAllocSingleReleasePool::alloc ()
{
void *ptr;
- if(!m_lock) {
- m_lock = new Glib::Mutex();
- // umm, I'm not sure that this doesn't also allocate memory.
- if(!m_lock) error << "cannot create Glib::Mutex in pool.cc" << endmsg;
- }
-
- Glib::Mutex::Lock guard(*m_lock);
+ Glib::Threads::Mutex::Lock guard (m_lock);
ptr = Pool::alloc ();
return ptr;
}
void
SingleAllocMultiReleasePool::release (void* ptr)
{
- if(!m_lock) {
- m_lock = new Glib::Mutex();
- // umm, I'm not sure that this doesn't also allocate memory.
- if(!m_lock) error << "cannot create Glib::Mutex in pool.cc" << endmsg;
- }
- Glib::Mutex::Lock guard(*m_lock);
+ Glib::Threads::Mutex::Lock guard (m_lock);
Pool::release (ptr);
}
/*-------------------------------------------------------*/
-static void
+static void
free_per_thread_pool (void* ptr)
{
- cerr << "Deleting a per thread pool @ " << ptr << endl;
- Pool* pptr = static_cast<Pool*>(ptr);
- delete pptr;
+ /* Rather than deleting the CrossThreadPool now, we add it to our trash buffer.
+ * This prevents problems if other threads still require access to this CrossThreadPool.
+ * We assume that some other agent will clean out the trash buffer as required.
+ */
+ CrossThreadPool* cp = static_cast<CrossThreadPool*> (ptr);
+ assert (cp);
+
+ if (cp->empty()) {
+ /* This CrossThreadPool is already empty, and the thread is finishing so nothing
+ * more can be added to it. We can just delete the pool.
+ */
+ delete cp;
+ } else {
+ /* This CrossThreadPool is not empty, meaning that there's some Events in it
+ * which another thread may yet read, so we can't delete the pool just yet.
+ * Put it in the trash and hope someone deals with it at some stage.
+ */
+ cp->parent()->add_to_trash (cp);
+ }
}
-
+
PerThreadPool::PerThreadPool ()
+ : _key (free_per_thread_pool)
+ , _trash (0)
{
- {
- /* for some reason this appears necessary to get glib's thread private stuff to work */
- GPrivate* key;
- key = g_private_new (NULL);
- }
-
- _key = g_private_new (free_per_thread_pool);
}
+/** Create a new CrossThreadPool and set the current thread's private _key to point to it.
+ * @param n Name.
+ * @param isize Size of each item in the pool.
+ * @param nitems Number of items in the pool.
+ */
void
PerThreadPool::create_per_thread_pool (string n, unsigned long isize, unsigned long nitems)
{
- Pool* p = new CrossThreadPool (n, isize, nitems);
- g_private_set (_key, p);
+ _key.set (new CrossThreadPool (n, isize, nitems, this));
+}
+
+/** @return True if CrossThreadPool for the current thread exists,
+ * False otherwise
+ */
+bool
+PerThreadPool::has_per_thread_pool ()
+{
+ CrossThreadPool* p = _key.get();
+ if (p) {
+ return true;
+ }
+ return false;
}
+
+/** @return CrossThreadPool for the current thread, which must previously have been created by
+ * calling create_per_thread_pool in the current thread.
+ */
CrossThreadPool*
-PerThreadPool::per_thread_pool ()
+PerThreadPool::per_thread_pool (bool must_exist)
{
- CrossThreadPool* p = static_cast<CrossThreadPool*> (g_private_get (_key));
- if (!p) {
- fatal << "programming error: no per-thread pool \"" << _name << "\" for thread " << pthread_self() << endmsg;
- /*NOTREACHED*/
+ CrossThreadPool* p = _key.get();
+ if (!p && must_exist) {
+ fatal << "programming error: no per-thread pool \"" << _name << "\" for thread " << pthread_name() << endmsg;
+ abort(); /*NOTREACHED*/
}
return p;
}
-CrossThreadPool::CrossThreadPool (string n, unsigned long isize, unsigned long nitems)
+void
+PerThreadPool::set_trash (RingBuffer<CrossThreadPool*>* t)
+{
+ Glib::Threads::Mutex::Lock lm (_trash_mutex);
+ _trash = t;
+}
+
+/** Add a CrossThreadPool to our trash, if we have one. If not, a warning is emitted. */
+void
+PerThreadPool::add_to_trash (CrossThreadPool* p)
+{
+ Glib::Threads::Mutex::Lock lm (_trash_mutex);
+
+ if (!_trash) {
+ warning << "Pool " << p->name() << " has no trash collector; a memory leak has therefore occurred" << endmsg;
+ return;
+ }
+
+ /* we have a lock here so that multiple threads can safely call add_to_trash (even though there
+ can only be one writer to the _trash RingBuffer)
+ */
+
+ _trash->write (&p, 1);
+}
+
+CrossThreadPool::CrossThreadPool (string n, unsigned long isize, unsigned long nitems, PerThreadPool* p)
: Pool (n, isize, nitems)
, pending (nitems)
+ , _parent (p)
{
}
-void*
-CrossThreadPool::alloc ()
+void
+CrossThreadPool::flush_pending_with_ev (void *ptr)
+{
+ push (ptr);
+ flush_pending ();
+}
+
+void
+CrossThreadPool::flush_pending ()
{
void* ptr;
+ bool did_release = false;
+
+ DEBUG_TRACE (DEBUG::Pool, string_compose ("%1 %2 has %3 pending free entries waiting, status size %4 free %5 used %6\n", pthread_name(), name(), pending.read_space(),
+ total(), available(), used()));
+
while (pending.read (&ptr, 1) == 1) {
+ DEBUG_TRACE (DEBUG::Pool, string_compose ("%1 %2 pushes back a pending free list entry before allocating\n", pthread_name(), name()));
free_list.write (&ptr, 1);
+ did_release = true;
+ }
+
+ if (did_release) {
+ DEBUG_TRACE (DEBUG::Pool, string_compose ("Pool size: %1 free %2 used %3 pending now %4\n", total(), available(), used(), pending_size()));
}
+}
+
+void*
+CrossThreadPool::alloc ()
+{
+ /* process anything waiting to be deleted (i.e. moved back to the free list) */
+ flush_pending ();
+ /* now allocate from the potentially larger free list */
return Pool::alloc ();
}
void
-CrossThreadPool::push (void* t)
+CrossThreadPool::push (void* t)
{
pending.write (&t, 1);
}
+
+/** @return true if there is nothing in this pool */
+bool
+CrossThreadPool::empty ()
+{
+ return (free_list.write_space() == pending.read_space());
+}
+
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