/// max(pool.topAddr)
byte *max_addr;
+ /// Total heap memory
+ size_t total_mem;
+ /// Free heap memory
+ size_t free_mem;
+
/// Free list for each size
List*[B_MAX] free_list;
{
assert (gc !is null);
if (gc.inited) {
+ size_t total_mem = 0;
+ size_t free_mem = 0;
for (size_t i = 0; i < gc.pools.length; i++) {
Pool* pool = gc.pools[i];
pool.Invariant();
assert(*pool < *gc.pools[i + 1]);
else if (i + 1 == gc.pools.length)
assert(gc.max_addr == pool.topAddr);
+ total_mem += pool.npages * PAGESIZE;
+ for (size_t pn = 0; pn < pool.npages; ++pn)
+ if (pool.pagetable[pn] == B_FREE)
+ free_mem += PAGESIZE;
}
gc.roots.Invariant();
assert (p >= pool.baseAddr);
assert (p < pool.topAddr);
assert (pool.freebits.test((p - pool.baseAddr) / 16));
+ free_mem += binsize[i];
}
}
+ assert (gc.total_mem == total_mem);
+ assert (gc.free_mem == free_mem);
}
return true;
}
/**
* Minimizes physical memory usage by returning free pools to the OS.
+ *
+ * If full is false, keep some pools alive if the resulting free memory would
+ * be too small.
*/
-void minimize()
+void minimize(bool full = true)
{
// Disabled if a parallel collection is in progress because the shared mark
// bits of the freed pool might be used by the mark process
if (gc.mark_proc_pid != 0)
return;
- size_t n;
- size_t pn;
- Pool* pool;
+ if (gc.pools.length == 0)
+ return;
- for (n = 0; n < gc.pools.length; n++)
+ for (size_t n = 0; n < gc.pools.length; n++)
{
- pool = gc.pools[n];
+ Pool* pool = gc.pools[n];
+ size_t pn;
for (pn = 0; pn < pool.npages; pn++)
{
if (cast(Bins)pool.pagetable[pn] != B_FREE)
}
if (pn < pool.npages)
continue;
+ // Free pool
+ size_t pool_size = pool.npages * PAGESIZE;
+ if (!full) {
+ double percent_free = (gc.free_mem - pool_size) * 100.0 /
+ (gc.total_mem - pool_size);
+ if (percent_free < opts.options.min_free)
+ continue; // not enough free, don't remove this pool
+ }
+ gc.total_mem -= pool_size;
+ gc.free_mem -= pool_size;
pool.Dtor();
cstdlib.free(pool);
gc.pools.remove_at(n);
* Allocate a chunk of memory that is larger than a page.
* Return null if out of memory.
*/
-void* bigAlloc(size_t npages, out Pool* pool, size_t* pn)
+void* bigAlloc(size_t npages, out Pool* pool, size_t* pn, bool* collected)
{
+ *collected = false;
// This code could use some refinement when repeatedly
// allocating very large arrays.
void* alloc_more()
{
- // Release empty pools to prevent bloat
- minimize();
// Allocate new pool
pool = newPool(npages);
if (!pool)
// Try collecting
size_t freedpages = fullcollectshell();
- if (freedpages >= gc.pools.length * ((POOLSIZE / PAGESIZE) / 4)) {
+ *collected = true;
+ if (freedpages >= npages) {
if (void* p = find_block())
return p;
}
assert (inserted_pool is pool);
gc.min_addr = gc.pools[0].baseAddr;
gc.max_addr = gc.pools[gc.pools.length - 1].topAddr;
+ size_t pool_size = pool.topAddr - pool.baseAddr;
+ gc.total_mem += pool_size;
+ gc.free_mem += pool_size;
return pool;
}
debug(COLLECT_PRINTF) printf("\tsweep\n");
gc.p_cache = null;
gc.size_cache = 0;
+ gc.free_mem = 0; // will be recalculated
size_t freedpages = 0;
size_t freed = 0;
for (size_t n = 0; n < gc.pools.length; n++)
pool.pagetable[pn] = B_FREE;
pool.freebits.set_group(bit_i, PAGESIZE / 16);
freedpages++;
+ gc.free_mem += PAGESIZE;
if (opts.options.mem_stomp)
memset(p, 0xF3, PAGESIZE);
while (pn + 1 < pool.npages && pool.pagetable[pn + 1] == B_PAGEPLUS)
bit_i += bit_stride;
pool.freebits.set_group(bit_i, PAGESIZE / 16);
freedpages++;
+ gc.free_mem += PAGESIZE;
if (opts.options.mem_stomp)
{
}
}
}
+ else if (bin == B_FREE) {
+ gc.free_mem += PAGESIZE;
+ }
}
}
pool.pagetable[pn] = B_FREE;
pool.freebits.set_group(bit_base, PAGESIZE / 16);
recoveredpages++;
+ gc.free_mem += PAGESIZE;
continue;
Lnotfree:
if (list.pool != pool)
list.pool = pool;
gc.free_list[bin] = list;
+ gc.free_mem += binsize[bin];
}
}
}
Pool* pool = void;
size_t bit_i = void;
size_t capacity = void; // to figure out where to store the bitmask
+ bool collected = false;
if (bin < B_PAGE)
{
p = gc.free_list[bin];
{
//newPool(1);
}
+ collected = true;
}
if (!gc.free_list[bin] && !allocPage(bin))
{
{
size_t pn;
size_t npages = round_up(size, PAGESIZE);
- p = bigAlloc(npages, pool, &pn);
+ p = bigAlloc(npages, pool, &pn, &collected);
if (!p)
onOutOfMemoryError();
assert (pool !is null);
assert (bin >= B_PAGE || !pool.freebits.test(bit_i));
}
+ gc.free_mem -= capacity;
+ if (collected) {
+ // If there is not enough free memory, allocate a new pool big enough
+ // to have at least the min_free% of the total heap free. If there is
+ // too much free memory, try to free some empty pools.
+ double percent_free = gc.free_mem * 100.0 / gc.total_mem;
+ if (percent_free < opts.options.min_free) {
+ auto pool_size = gc.total_mem * 1.0 / opts.options.min_free
+ - gc.free_mem;
+ newPool(round_up(cast(size_t)pool_size, PAGESIZE));
+ }
+ else
+ minimize(false);
+ }
+
return p;
}
blk_size - size - pm_bitmask_size);
pool.freePages(pagenum + newsz, psz - newsz);
auto new_blk_size = (PAGESIZE * newsz);
+ gc.free_mem += blk_size - new_blk_size;
// update the size cache, assuming that is very likely the
// size of this block will be queried in the near future
pool.update_cache(p, new_blk_size);
memset(pool.pagetable + pagenum +
psz, B_PAGEPLUS, newsz - psz);
auto new_blk_size = (PAGESIZE * newsz);
+ gc.free_mem -= new_blk_size - blk_size;
// update the size cache, assuming that is very
// likely the size of this block will be queried in
// the near future
memset(pool.pagetable + pagenum + psz, B_PAGEPLUS, sz);
gc.p_cache = null;
gc.size_cache = 0;
+ gc.free_mem -= new_size - blk_size;
// update the size cache, assuming that is very likely the size of this
// block will be queried in the near future
pool.update_cache(p, new_size);
pool.freebits.set_group(bit_i, PAGESIZE / 16);
while (++n < pool.npages && pool.pagetable[n] == B_PAGEPLUS)
npages++;
+ size_t size = npages * PAGESIZE;
if (opts.options.mem_stomp)
- memset(p, 0xF2, npages * PAGESIZE);
+ memset(p, 0xF2, size);
pool.freePages(pagenum, npages);
+ gc.free_mem += size;
// just in case we were caching this pointer
pool.clear_cache(p);
}
list.pool = pool;
gc.free_list[bin] = list;
pool.freebits.set(bit_i);
+ gc.free_mem += binsize[bin];
}
+ double percent_free = gc.free_mem * 100.0 / gc.total_mem;
+ if (percent_free > opts.options.min_free)
+ minimize(false);
}
projects / software / dgc / cdgc.git / blobdiff