X-Git-Url: https://git.llucax.com/software/dgc/cdgc.git/blobdiff_plain/8183938bc0141793deae76c17ea182b2774fd0df..7b736090719c6f08e286b246d9b7509413716fcf:/rt/gc/cdgc/gc.d diff --git a/rt/gc/cdgc/gc.d b/rt/gc/cdgc/gc.d index d2f53aa..2ec72c4 100644 --- a/rt/gc/cdgc/gc.d +++ b/rt/gc/cdgc/gc.d @@ -99,6 +99,11 @@ package bool has_pointermap(uint attrs) return !opts.options.conservative && !(attrs & BlkAttr.NO_SCAN); } +private size_t round_up(size_t n, size_t to) +{ + return (n + to - 1) / to; +} + private { alias void delegate(Object) DEvent; @@ -211,6 +216,11 @@ struct GC /// 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; @@ -232,10 +242,19 @@ private T locked(T, alias Code)() private GC* gc; + +bool collect_in_progress() +{ + return gc.mark_proc_pid != 0; +} + + bool Invariant() { 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(); @@ -245,6 +264,10 @@ bool 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(); @@ -264,8 +287,11 @@ bool 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; } @@ -392,7 +418,7 @@ Bins findBin(size_t size) size_t reserve(size_t size) { assert(size != 0); - size_t npages = (size + PAGESIZE - 1) / PAGESIZE; + size_t npages = round_up(size, PAGESIZE); Pool* pool = newPool(npages); if (!pool) @@ -403,21 +429,23 @@ size_t reserve(size_t size) /** * 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) + // The shared mark bits of the freed pool might be used by the mark process + if (collect_in_progress()) 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) @@ -425,6 +453,16 @@ void minimize() } 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); @@ -439,89 +477,50 @@ void minimize() * Allocate a chunk of memory that is larger than a page. * Return null if out of memory. */ -void* bigAlloc(size_t size, out Pool* pool) +void* bigAlloc(size_t npages, out Pool* pool, size_t* pn, bool* collected) { - size_t npages; - size_t n; - size_t pn; - size_t freedpages; - void* p; - int state; - - npages = (size + PAGESIZE - 1) / PAGESIZE; + *collected = false; + // This code could use some refinement when repeatedly + // allocating very large arrays. - for (state = 0; ; ) + void* find_block() { - // This code could use some refinement when repeatedly - // allocating very large arrays. - - for (n = 0; n < gc.pools.length; n++) + for (size_t n = 0; n < gc.pools.length; n++) { pool = gc.pools[n]; - pn = pool.allocPages(npages); - if (pn != OPFAIL) - goto L1; + *pn = pool.allocPages(npages); + if (*pn != OPFAIL) + return pool.baseAddr + *pn * PAGESIZE; } + return null; + } - // Failed - switch (state) - { - case 0: - if (gc.disabled) - { - state = 1; - continue; - } - // Try collecting - freedpages = fullcollectshell(); - if (freedpages >= gc.pools.length * ((POOLSIZE / PAGESIZE) / 4)) - { - state = 1; - continue; - } - // Release empty pools to prevent bloat - minimize(); - // Allocate new pool - pool = newPool(npages); - if (!pool) - { - state = 2; - continue; - } - pn = pool.allocPages(npages); - assert(pn != OPFAIL); - goto L1; - case 1: - // Release empty pools to prevent bloat - minimize(); - // Allocate new pool - pool = newPool(npages); - if (!pool) - goto Lnomemory; - pn = pool.allocPages(npages); - assert(pn != OPFAIL); - goto L1; - case 2: - goto Lnomemory; - default: - assert(false); - } + void* alloc_more() + { + // Allocate new pool + pool = newPool(npages); + if (!pool) + return null; // let malloc handle the error + *pn = pool.allocPages(npages); + assert(*pn != OPFAIL); + return pool.baseAddr + *pn * PAGESIZE; } - L1: - size_t bit_i = pn * (PAGESIZE / 16); - pool.freebits.clear(bit_i); - pool.pagetable[pn] = B_PAGE; - if (npages > 1) - memset(&pool.pagetable[pn + 1], B_PAGEPLUS, npages - 1); - p = pool.baseAddr + pn * PAGESIZE; - memset(cast(char *)p + size, 0, npages * PAGESIZE - size); - if (opts.options.mem_stomp) - memset(p, 0xF1, size); - return p; + if (void* p = find_block()) + return p; - Lnomemory: - return null; // let mallocNoSync handle the error + if (gc.disabled) + return alloc_more(); + + // Try collecting + size_t freedpages = fullcollectshell(); + *collected = true; + if (freedpages >= npages) { + if (void* p = find_block()) + return p; + } + + return alloc_more(); } @@ -572,6 +571,9 @@ Pool *newPool(size_t npages) 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; } @@ -803,7 +805,7 @@ size_t fullcollect(void *stackTop) // memory is freed (if that not the case, the caller will allocate more // memory and the next time it's exhausted it will run a new collection). if (opts.options.eager_alloc) { - if (gc.mark_proc_pid != 0) { // there is a mark process in progress + if (collect_in_progress()) { os.WRes r = os.wait_pid(gc.mark_proc_pid, false); // don't block assert (r != os.WRes.ERROR); switch (r) { @@ -1016,6 +1018,7 @@ size_t sweep() 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++) @@ -1105,6 +1108,7 @@ version(none) // BUG: doesn't work because freebits() must also be cleared 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) @@ -1114,6 +1118,7 @@ version(none) // BUG: doesn't work because freebits() must also be cleared bit_i += bit_stride; pool.freebits.set_group(bit_i, PAGESIZE / 16); freedpages++; + gc.free_mem += PAGESIZE; if (opts.options.mem_stomp) { @@ -1123,6 +1128,9 @@ version(none) // BUG: doesn't work because freebits() must also be cleared } } } + else if (bin == B_FREE) { + gc.free_mem += PAGESIZE; + } } } @@ -1158,6 +1166,7 @@ version(none) // BUG: doesn't work because freebits() must also be cleared pool.pagetable[pn] = B_FREE; pool.freebits.set_group(bit_base, PAGESIZE / 16); recoveredpages++; + gc.free_mem += PAGESIZE; continue; Lnotfree: @@ -1176,6 +1185,7 @@ version(none) // BUG: doesn't work because freebits() must also be cleared if (list.pool != pool) list.pool = pool; gc.free_list[bin] = list; + gc.free_mem += binsize[bin]; } } } @@ -1280,7 +1290,7 @@ void initialize() setStackBottom(rt_stackBottom()); gc.stats = Stats(gc); if (opts.options.prealloc_npools) { - size_t pages = (opts.options.prealloc_psize + PAGESIZE - 1) / PAGESIZE; + size_t pages = round_up(opts.options.prealloc_psize, PAGESIZE); for (size_t i = 0; i < opts.options.prealloc_npools; ++i) newPool(pages); } @@ -1324,6 +1334,7 @@ private void *malloc(size_t size, uint attrs, size_t* pm_bitmask) 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]; @@ -1346,6 +1357,7 @@ private void *malloc(size_t size, uint attrs, size_t* pm_bitmask) { //newPool(1); } + collected = true; } if (!gc.free_list[bin] && !allocPage(bin)) { @@ -1375,14 +1387,24 @@ private void *malloc(size_t size, uint attrs, size_t* pm_bitmask) } else { - p = bigAlloc(size, pool); + size_t pn; + size_t npages = round_up(size, PAGESIZE); + p = bigAlloc(npages, pool, &pn, &collected); if (!p) onOutOfMemoryError(); assert (pool !is null); - // Round the size up to the number of pages needed to store it - size_t npages = (size + PAGESIZE - 1) / PAGESIZE; + capacity = npages * PAGESIZE; - bit_i = (p - pool.baseAddr) / 16; + bit_i = pn * (PAGESIZE / 16); + pool.freebits.clear(bit_i); + pool.pagetable[pn] = B_PAGE; + if (npages > 1) + memset(&pool.pagetable[pn + 1], B_PAGEPLUS, npages - 1); + p = pool.baseAddr + pn * PAGESIZE; + memset(cast(char *)p + size, 0, npages * PAGESIZE - size); + if (opts.options.mem_stomp) + memset(p, 0xF1, size); + } // Store the bit mask AFTER SENTINEL_POST @@ -1404,6 +1426,21 @@ private void *malloc(size_t size, uint attrs, size_t* pm_bitmask) 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; } @@ -1427,139 +1464,125 @@ private void *calloc(size_t size, uint attrs, size_t* pm_bitmask) private void *realloc(void *p, size_t size, uint attrs, size_t* pm_bitmask) { - if (!size) - { + if (!size) { if (p) - { free(p); - p = null; - } + return null; } - else if (!p) - { - p = malloc(size, attrs, pm_bitmask); + + if (p is null) + return malloc(size, attrs, pm_bitmask); + + Pool* pool = findPool(p); + if (pool is null) + return null; + + // Set or retrieve attributes as appropriate + auto bit_i = cast(size_t)(p - pool.baseAddr) / 16; + if (attrs) { + clrAttr(pool, bit_i, BlkAttr.ALL_BITS); + setAttr(pool, bit_i, attrs); } else - { - Pool* pool = findPool(p); - if (pool is null) - return null; + attrs = getAttr(pool, bit_i); - // Set or retrieve attributes as appropriate - auto bit_i = cast(size_t)(p - pool.baseAddr) / 16; - if (attrs) { - clrAttr(pool, bit_i, BlkAttr.ALL_BITS); - setAttr(pool, bit_i, attrs); - } - else - attrs = getAttr(pool, bit_i); - - void* blk_base_addr = pool.findBase(p); - size_t blk_size = pool.findSize(p); - bool has_pm = has_pointermap(attrs); - size_t pm_bitmask_size = 0; - if (has_pm) { - pm_bitmask_size = size_t.sizeof; - // Retrieve pointer map bit mask if appropriate - if (pm_bitmask is null) { - auto end_of_blk = cast(size_t**)(blk_base_addr + - blk_size - size_t.sizeof); - pm_bitmask = *end_of_blk; - } + void* blk_base_addr = pool.findBase(p); + size_t blk_size = pool.findSize(p); + bool has_pm = has_pointermap(attrs); + size_t pm_bitmask_size = 0; + if (has_pm) { + pm_bitmask_size = size_t.sizeof; + // Retrieve pointer map bit mask if appropriate + if (pm_bitmask is null) { + auto end_of_blk = cast(size_t**)( + blk_base_addr + blk_size - size_t.sizeof); + pm_bitmask = *end_of_blk; } + } - if (opts.options.sentinel) - { - sentinel_Invariant(p); - size_t sentinel_stored_size = *sentinel_size(p); - if (sentinel_stored_size != size) - { - void* p2 = malloc(size, attrs, pm_bitmask); - if (sentinel_stored_size < size) - size = sentinel_stored_size; - cstring.memcpy(p2, p, size); - p = p2; + if (opts.options.sentinel) { + sentinel_Invariant(p); + size_t sentinel_stored_size = *sentinel_size(p); + if (sentinel_stored_size != size) { + void* p2 = malloc(size, attrs, pm_bitmask); + if (sentinel_stored_size < size) + size = sentinel_stored_size; + cstring.memcpy(p2, p, size); + p = p2; + } + return p; + } + + size += pm_bitmask_size; + if (blk_size >= PAGESIZE && size >= PAGESIZE) { + auto psz = blk_size / PAGESIZE; + auto newsz = round_up(size, PAGESIZE); + if (newsz == psz) + return p; + + auto pagenum = (p - pool.baseAddr) / PAGESIZE; + + if (newsz < psz) { + // Shrink in place + if (opts.options.mem_stomp) + memset(p + size - pm_bitmask_size, 0xF2, + 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); + if (has_pm) { + auto end_of_blk = cast(size_t**)(blk_base_addr + + new_blk_size - pm_bitmask_size); + *end_of_blk = pm_bitmask; } + return p; } - else - { - size += pm_bitmask_size; - if (blk_size >= PAGESIZE && size >= PAGESIZE) - { - auto psz = blk_size / PAGESIZE; - auto newsz = (size + PAGESIZE - 1) / PAGESIZE; - if (newsz == psz) - return p; - - auto pagenum = (p - pool.baseAddr) / PAGESIZE; - if (newsz < psz) - { - // Shrink in place + if (pagenum + newsz <= pool.npages) { + // Attempt to expand in place + for (size_t i = pagenum + psz; 1;) { + if (i == pagenum + newsz) { if (opts.options.mem_stomp) - memset(p + size - pm_bitmask_size, 0xF2, - blk_size - size - pm_bitmask_size); - pool.freePages(pagenum + newsz, psz - newsz); + memset(p + blk_size - pm_bitmask_size, 0xF0, + size - blk_size - pm_bitmask_size); + memset(pool.pagetable + pagenum + psz, B_PAGEPLUS, + newsz - psz); auto new_blk_size = (PAGESIZE * newsz); - // update the size cache, assuming that is very likely the - // size of this block will be queried in the near future + 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 pool.update_cache(p, new_blk_size); if (has_pm) { - auto end_of_blk = cast(size_t**)(blk_base_addr + - new_blk_size - pm_bitmask_size); + auto end_of_blk = cast(size_t**)( + blk_base_addr + new_blk_size - pm_bitmask_size); *end_of_blk = pm_bitmask; } return p; } - else if (pagenum + newsz <= pool.npages) - { - // Attempt to expand in place - for (size_t i = pagenum + psz; 1;) - { - if (i == pagenum + newsz) - { - if (opts.options.mem_stomp) - memset(p + blk_size - pm_bitmask_size, - 0xF0, size - blk_size - - pm_bitmask_size); - memset(pool.pagetable + pagenum + - psz, B_PAGEPLUS, newsz - psz); - auto new_blk_size = (PAGESIZE * newsz); - // 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); - if (has_pm) { - auto end_of_blk = cast(size_t**)( - blk_base_addr + new_blk_size - - pm_bitmask_size); - *end_of_blk = pm_bitmask; - } - return p; - } - if (i == pool.npages) - { - break; - } - if (pool.pagetable[i] != B_FREE) - break; - i++; - } - } - } - // if new size is bigger or less than half - if (blk_size < size || blk_size > size * 2) - { - size -= pm_bitmask_size; - blk_size -= pm_bitmask_size; - void* p2 = malloc(size, attrs, pm_bitmask); - if (blk_size < size) - size = blk_size; - cstring.memcpy(p2, p, size); - p = p2; + if (i == pool.npages) + break; + if (pool.pagetable[i] != B_FREE) + break; + i++; } } } + + // if new size is bigger or less than half + if (blk_size < size || blk_size > size * 2) { + size -= pm_bitmask_size; + blk_size -= pm_bitmask_size; + void* p2 = malloc(size, attrs, pm_bitmask); + if (blk_size < size) + size = blk_size; + cstring.memcpy(p2, p, size); + p = p2; + } + return p; } @@ -1611,8 +1634,8 @@ body return 0; // cannot extend buckets auto psz = blk_size / PAGESIZE; - auto minsz = (minsize + PAGESIZE - 1) / PAGESIZE; - auto maxsz = (maxsize + PAGESIZE - 1) / PAGESIZE; + auto minsz = round_up(minsize, PAGESIZE); + auto maxsz = round_up(maxsize, PAGESIZE); auto pagenum = (p - pool.baseAddr) / PAGESIZE; @@ -1640,6 +1663,7 @@ body 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); @@ -1686,9 +1710,11 @@ private void free(void *p) 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); } @@ -1704,7 +1730,11 @@ private void free(void *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); } @@ -2017,7 +2047,7 @@ struct Pool freebits.set_all(); // avoid accidental sweeping of new pools while using eager allocation - if (gc.mark_proc_pid) + if (collect_in_progress()) mark.set_all(); pagetable = cast(ubyte*) cstdlib.malloc(npages);