add simple ref counting debugging framework

src/pulsecore/memblock.c

@@ -745,8 +745,47 @@ void pa_mempool_free(pa_mempool *p) {
     pa_flist_free(p->free_slots, NULL);
 
     if (pa_atomic_load(&p->stat.n_allocated) > 0) {
-/*         raise(SIGTRAP);  */
-        pa_log_warn("Memory pool destroyed but not all memory blocks freed! %u remain.", pa_atomic_load(&p->stat.n_allocated));
+
+        /* Ouch, somebody is retaining a memory block reference! */
+
+#ifdef DEBUG_REF
+        unsigned i;
+        pa_flist *list;
+
+        /* Let's try to find at least one of those leaked memory blocks */
+
+        list = pa_flist_new(p->n_blocks);
+
+        for (i = 0; i < (unsigned) pa_atomic_load(&p->n_init); i++) {
+            struct mempool_slot *slot;
+            pa_memblock *b, *k;
+
+            slot = (struct mempool_slot*) ((uint8_t*) p->memory.ptr + (p->block_size * (size_t) i));
+            b = mempool_slot_data(slot);
+
+            while ((k = pa_flist_pop(p->free_slots))) {
+                while (pa_flist_push(list, k) < 0)
+                    ;
+
+                if (b == k)
+                    break;
+            }
+
+            if (!k)
+                pa_log("REF: Leaked memory block %p", b);
+
+            while ((k = pa_flist_pop(list)))
+                while (pa_flist_push(p->free_slots, k) < 0)
+                    ;
+        }
+
+        pa_flist_free(list, NULL);
+
+#endif
+
+        pa_log_error("Memory pool destroyed but not all memory blocks freed! %u remain.", pa_atomic_load(&p->stat.n_allocated));
+
+/*         PA_DEBUG_TRAP; */
     }
 
     pa_shm_free(&p->memory);

src/pulsecore/refcnt.h

@@ -23,23 +23,59 @@
 ***/
 
 #include <pulsecore/atomic.h>
+#include <pulsecore/macro.h>
+#include <pulsecore/log.h>
+
+/* #define DEBUG_REF */
 
 #define PA_REFCNT_DECLARE \
     pa_atomic_t _ref
 
-#define PA_REFCNT_INIT(p) \
-    pa_atomic_store(&(p)->_ref, 1)
+#define PA_REFCNT_VALUE(p) \
+    pa_atomic_load(&(p)->_ref)
 
 #define PA_REFCNT_INIT_ZERO(p) \
     pa_atomic_store(&(p)->_ref, 0)
 
+#ifndef DEBUG_REF
+
+#define PA_REFCNT_INIT(p) \
+    pa_atomic_store(&(p)->_ref, 1)
+
 #define PA_REFCNT_INC(p) \
     pa_atomic_inc(&(p)->_ref)
 
 #define PA_REFCNT_DEC(p) \
     (pa_atomic_dec(&(p)->_ref)-1)
 
-#define PA_REFCNT_VALUE(p) \
-    pa_atomic_load(&(p)->_ref)
+#else
+
+/* If you need to debug ref counting problems define DEBUG_REF and
+ * set $PULSE_LOG_BACKTRACE=5 or suchlike in the shell when running
+ * PA */
+
+#define PA_REFCNT_INIT(p)                       \
+    do {                                        \
+        pa_atomic_store(&(p)->_ref, 1);         \
+        pa_log("REF: Init %p", p);              \
+    } while (FALSE)
+
+#define PA_REFCNT_INC(p)                        \
+    do {                                        \
+        pa_atomic_inc(&(p)->_ref);              \
+        pa_log("REF: Inc %p", p);               \
+    } while (FALSE)                             \
+
+#define PA_REFCNT_DEC(p)                        \
+    ({                                          \
+        int _j = (pa_atomic_dec(&(p)->_ref)-1); \
+        if (_j <= 0)                            \
+            pa_log("REF: Done %p", p);          \
+        else                                    \
+            pa_log("REF: Dec %p", p);           \
+        _j;                                     \
+     })
+
+#endif
 
 #endif