X-Git-Url: https://git.llucax.com/software/dgc/cdgc.git/blobdiff_plain/192f4bfd2ffdaa5e6283bc16e8452fc3c218fb8a..7b736090719c6f08e286b246d9b7509413716fcf:/rt/gc/cdgc/gc.d diff --git a/rt/gc/cdgc/gc.d b/rt/gc/cdgc/gc.d index 432aab9..2ec72c4 100644 --- a/rt/gc/cdgc/gc.d +++ b/rt/gc/cdgc/gc.d @@ -50,6 +50,8 @@ import opts = rt.gc.cdgc.opts; import cstdlib = tango.stdc.stdlib; import cstring = tango.stdc.string; +import cstdio = tango.stdc.stdio; +debug(COLLECT_PRINTF) alias cstdio.printf printf; /* * This is a small optimization that proved it's usefulness. For small chunks @@ -97,6 +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; @@ -201,11 +208,19 @@ struct GC /// Turn off collections if > 0 int disabled; + // PID of the fork()ed process doing the mark() (0 if is not running) + int mark_proc_pid; + /// min(pool.baseAddr) byte *min_addr; /// 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; @@ -227,10 +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(); @@ -240,6 +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(); @@ -253,12 +281,17 @@ bool Invariant() for (size_t i = 0; i < B_PAGE; i++) { for (List *list = gc.free_list[i]; list; list = list.next) { - assert (list.pool !is null); + auto pool = list.pool; + assert (pool !is null); auto p = cast(byte*) list; - assert (p >= list.pool.baseAddr); - assert (p < list.pool.topAddr); + 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; } @@ -307,8 +340,11 @@ BlkInfo getInfo(void* p) return BlkInfo.init; BlkInfo info; info.base = pool.findBase(p); + if (info.base is null) + return BlkInfo.init; info.size = pool.findSize(info.base); - info.attr = getAttr(pool, cast(size_t)(info.base - pool.baseAddr) / 16u); + size_t bit_i = (info.base - pool.baseAddr) / 16; + info.attr = getAttr(pool, bit_i); if (has_pointermap(info.attr)) { info.size -= size_t.sizeof; // PointerMap bitmask // Points to the PointerMap bitmask pointer, not user data @@ -382,7 +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) @@ -393,16 +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) { - size_t n; - size_t pn; - Pool* pool; + // The shared mark bits of the freed pool might be used by the mark process + if (collect_in_progress()) + return; - for (n = 0; n < gc.pools.length; n++) + if (gc.pools.length == 0) + return; + + 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) @@ -410,6 +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); @@ -424,87 +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; + *collected = false; + // This code could use some refinement when repeatedly + // allocating very large arrays. - npages = (size + PAGESIZE - 1) / PAGESIZE; - - 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: - 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(); } @@ -555,6 +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; } @@ -567,12 +586,9 @@ Pool *newPool(size_t npages) int allocPage(Bins bin) { Pool* pool; - size_t n; size_t pn; - byte* p; - byte* ptop; - 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(1); @@ -588,8 +604,10 @@ int allocPage(Bins bin) size_t size = binsize[bin]; auto list_head = &gc.free_list[bin]; - p = pool.baseAddr + pn * PAGESIZE; - ptop = p + PAGESIZE; + byte* p = pool.baseAddr + pn * PAGESIZE; + byte* ptop = p + PAGESIZE; + size_t bit_i = pn * (PAGESIZE / 16); + pool.freebits.set_group(bit_i, PAGESIZE / 16); for (; p < ptop; p += size) { List* l = cast(List *) p; @@ -778,17 +796,56 @@ size_t fullcollect(void *stackTop) { debug(COLLECT_PRINTF) printf("Gcx.fullcollect()\n"); - // we always need to stop the world to make threads save the CPU registers + // If eager allocation is used, we need to check first if there is a mark + // process running. If there isn't, we start a new one (see the next code + // block). If there is, we check if it's still running or already finished. + // If it's still running, we tell the caller process no memory has been + // recovered (it will allocated more to fulfill the current request). If + // the mark process is done, we lunch the sweep phase and hope enough + // 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 (collect_in_progress()) { + os.WRes r = os.wait_pid(gc.mark_proc_pid, false); // don't block + assert (r != os.WRes.ERROR); + switch (r) { + case os.WRes.DONE: + debug(COLLECT_PRINTF) printf("\t\tmark proc DONE\n"); + gc.mark_proc_pid = 0; + return sweep(); + case os.WRes.RUNNING: + debug(COLLECT_PRINTF) printf("\t\tmark proc RUNNING\n"); + return 0; + case os.WRes.ERROR: + debug(COLLECT_PRINTF) printf("\t\tmark proc ERROR\n"); + disable_fork(); // Try to keep going without forking + break; + } + } + } + + // We always need to stop the world to make threads save the CPU registers // in the stack and prepare themselves for thread_scanAll() thread_suspendAll(); gc.stats.world_stopped(); + // If forking is enabled, we fork() and start a new mark phase in the + // child. The parent process will tell the caller that no memory could be + // recycled if eager allocation is used, allowing the mutator to keep going + // almost instantly (at the expense of more memory consumption because + // a new allocation will be triggered to fulfill the current request). If + // no eager allocation is used, the parent will wait for the mark phase to + // finish before returning control to the mutator, but other threads are + // restarted and may run in parallel with the mark phase (unless they + // allocate or use the GC themselves, in which case the global GC lock will + // stop them). if (opts.options.fork) { + cstdio.fflush(null); // avoid duplicated FILE* output os.pid_t child_pid = os.fork(); assert (child_pid != -1); // don't accept errors in non-release mode switch (child_pid) { - case -1: // if fork() fails, fallback to stop-the-world - opts.options.fork = false; + case -1: // if fork() fails, fall-back to stop-the-world + disable_fork(); break; case 0: // child process (i.e. the collectors mark phase) mark(stackTop); @@ -798,15 +855,28 @@ size_t fullcollect(void *stackTop) // start the world again and wait for the mark phase to finish thread_resumeAll(); gc.stats.world_started(); - int status = void; - os.pid_t wait_pid = os.waitpid(child_pid, &status, 0); - assert (wait_pid == child_pid); - return sweep(); + if (opts.options.eager_alloc) { + gc.mark_proc_pid = child_pid; + return 0; + } + os.WRes r = os.wait_pid(child_pid); // block until it finishes + assert (r == os.WRes.DONE); + debug(COLLECT_PRINTF) printf("\t\tmark proc DONE (block)\n"); + if (r == os.WRes.DONE) + return sweep(); + debug(COLLECT_PRINTF) printf("\tmark() proc ERROR\n"); + // If there was some error, try to keep going without forking + disable_fork(); + // Re-suspend the threads to do the marking in this process + thread_suspendAll(); + gc.stats.world_stopped(); } } - // if we reach here, we are using the standard stop-the-world collection + // If we reach here, we are using the standard stop-the-world collection, + // either because fork was disabled in the first place, or because it was + // disabled because of some error. mark(stackTop); thread_resumeAll(); gc.stats.world_started(); @@ -822,37 +892,13 @@ void mark(void *stackTop) { debug(COLLECT_PRINTF) printf("\tmark()\n"); - gc.p_cache = null; - gc.size_cache = 0; - gc.any_changes = false; - for (size_t n = 0; n < gc.pools.length; n++) - { - Pool* pool = gc.pools[n]; - pool.mark.zero(); - pool.scan.zero(); - pool.freebits.zero(); - } - - // Mark each free entry, so it doesn't get scanned - for (size_t n = 0; n < B_PAGE; n++) - { - for (List *list = gc.free_list[n]; list; list = list.next) - { - Pool* pool = list.pool; - auto ptr = cast(byte*) list; - assert (pool); - assert (pool.baseAddr <= ptr); - assert (ptr < pool.topAddr); - size_t bit_i = cast(size_t)(ptr - pool.baseAddr) / 16; - pool.freebits.set(bit_i); - } - } for (size_t n = 0; n < gc.pools.length; n++) { Pool* pool = gc.pools[n]; pool.mark.copy(&pool.freebits); + pool.scan.zero(); } /// Marks a range of memory in conservative mode. @@ -970,6 +1016,9 @@ size_t sweep() { // Free up everything not marked 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++) @@ -999,7 +1048,7 @@ version(none) // BUG: doesn't work because freebits() must also be cleared { for (; p < ptop; p += size, bit_i += bit_stride) { - if (pool.finals.nbits && pool.finals.testClear(bit_i)) { + if (pool.finals.testClear(bit_i)) { if (opts.options.sentinel) rt_finalize(sentinel_add(p), false/*gc.no_stack > 0*/); else @@ -1023,7 +1072,7 @@ version(none) // BUG: doesn't work because freebits() must also be cleared sentinel_Invariant(sentinel_add(p)); pool.freebits.set(bit_i); - if (pool.finals.nbits && pool.finals.testClear(bit_i)) { + if (pool.finals.testClear(bit_i)) { if (opts.options.sentinel) rt_finalize(sentinel_add(p), false/*gc.no_stack > 0*/); else @@ -1040,13 +1089,14 @@ version(none) // BUG: doesn't work because freebits() must also be cleared } else if (bin == B_PAGE) { - size_t bit_i = pn * (PAGESIZE / 16); + size_t bit_stride = PAGESIZE / 16; + size_t bit_i = pn * bit_stride; if (!pool.mark.test(bit_i)) { byte *p = pool.baseAddr + pn * PAGESIZE; if (opts.options.sentinel) sentinel_Invariant(sentinel_add(p)); - if (pool.finals.nbits && pool.finals.testClear(bit_i)) { + if (pool.finals.testClear(bit_i)) { if (opts.options.sentinel) rt_finalize(sentinel_add(p), false/*gc.no_stack > 0*/); else @@ -1054,16 +1104,21 @@ version(none) // BUG: doesn't work because freebits() must also be cleared } clrAttr(pool, bit_i, BlkAttr.ALL_BITS); - debug(COLLECT_PRINTF) printf("\tcollecting big %x\n", p); + debug(COLLECT_PRINTF) printf("\tcollecting big %p\n", p); 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) { pn++; pool.pagetable[pn] = B_FREE; + bit_i += bit_stride; + pool.freebits.set_group(bit_i, PAGESIZE / 16); freedpages++; + gc.free_mem += PAGESIZE; if (opts.options.mem_stomp) { @@ -1073,6 +1128,9 @@ version(none) // BUG: doesn't work because freebits() must also be cleared } } } + else if (bin == B_FREE) { + gc.free_mem += PAGESIZE; + } } } @@ -1106,7 +1164,9 @@ version(none) // BUG: doesn't work because freebits() must also be cleared goto Lnotfree; } pool.pagetable[pn] = B_FREE; + pool.freebits.set_group(bit_base, PAGESIZE / 16); recoveredpages++; + gc.free_mem += PAGESIZE; continue; Lnotfree: @@ -1125,6 +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]; } } } @@ -1149,14 +1210,11 @@ in body { uint attrs; - - if (pool.finals.nbits && - pool.finals.test(bit_i)) + if (pool.finals.test(bit_i)) attrs |= BlkAttr.FINALIZE; if (pool.noscan.test(bit_i)) attrs |= BlkAttr.NO_SCAN; -// if (pool.nomove.nbits && -// pool.nomove.test(bit_i)) +// if (pool.nomove.test(bit_i)) // attrs |= BlkAttr.NO_MOVE; return attrs; } @@ -1174,8 +1232,6 @@ body { if (mask & BlkAttr.FINALIZE) { - if (!pool.finals.nbits) - pool.finals.alloc(pool.mark.nbits); pool.finals.set(bit_i); } if (mask & BlkAttr.NO_SCAN) @@ -1201,7 +1257,7 @@ in } body { - if (mask & BlkAttr.FINALIZE && pool.finals.nbits) + if (mask & BlkAttr.FINALIZE) pool.finals.clear(bit_i); if (mask & BlkAttr.NO_SCAN) pool.noscan.clear(bit_i); @@ -1210,6 +1266,13 @@ body } +void disable_fork() +{ + // we have to disable both options, as eager_alloc assumes fork is enabled + opts.options.fork = false; + opts.options.eager_alloc = false; +} + void initialize() { @@ -1219,10 +1282,18 @@ void initialize() // If we are going to fork, make sure we have the needed OS support if (opts.options.fork) opts.options.fork = os.HAVE_SHARED && os.HAVE_FORK; + // Eager allocation is only possible when forking + if (!opts.options.fork) + opts.options.eager_alloc = false; gc.lock = GCLock.classinfo; gc.inited = 1; setStackBottom(rt_stackBottom()); gc.stats = Stats(gc); + if (opts.options.prealloc_npools) { + size_t pages = round_up(opts.options.prealloc_psize, PAGESIZE); + for (size_t i = 0; i < opts.options.prealloc_npools; ++i) + newPool(pages); + } } @@ -1261,7 +1332,9 @@ 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]; @@ -1284,6 +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)) { @@ -1303,6 +1377,9 @@ private void *malloc(size_t size, uint attrs, size_t* pm_bitmask) assert ((cast(byte*)list) < list.pool.topAddr); gc.free_list[bin] = list.next; pool = list.pool; + bit_i = (p - pool.baseAddr) / 16; + assert (pool.freebits.test(bit_i)); + pool.freebits.clear(bit_i); if (!(attrs & BlkAttr.NO_SCAN)) memset(p + size, 0, capacity - size); if (opts.options.mem_stomp) @@ -1310,13 +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 = 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 @@ -1333,8 +1421,25 @@ private void *malloc(size_t size, uint attrs, size_t* pm_bitmask) sentinel_init(p, size); } - if (attrs) - setAttr(pool, cast(size_t)(p - pool.baseAddr) / 16, attrs); + if (attrs) { + setAttr(pool, bit_i, attrs); + 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; } @@ -1359,132 +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); + 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 + (PAGESIZE * newsz) - - pm_bitmask_size); + 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); - if (has_pm) { - auto end_of_blk = cast(size_t**)( - blk_base_addr + - (PAGESIZE * newsz) - - 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; } @@ -1536,8 +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; @@ -1565,6 +1663,10 @@ 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); if (has_pm) { new_size -= size_t.sizeof; @@ -1605,11 +1707,16 @@ private void free(void *p) // Free pages size_t npages = 1; size_t n = pagenum; + 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); } else { @@ -1622,7 +1729,12 @@ private void free(void *p) list.next = gc.free_list[bin]; 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); } @@ -1888,10 +2000,18 @@ struct Pool size_t cached_size; void* cached_ptr; - void clear_cache() + void clear_cache(void* ptr = null) { - this.cached_ptr = null; - this.cached_size = 0; + if (ptr is null || ptr is this.cached_ptr) { + this.cached_ptr = null; + this.cached_size = 0; + } + } + + void update_cache(void* ptr, size_t size) + { + this.cached_ptr = ptr; + this.cached_size = size; } void initialize(size_t npages) @@ -1918,10 +2038,17 @@ struct Pool if (opts.options.fork) vis = os.Vis.SHARED; mark.alloc(nbits, vis); // shared between mark and sweep - freebits.alloc(nbits, vis); // ditto + freebits.alloc(nbits); // not used by the mark phase scan.alloc(nbits); // only used in the mark phase - finals.alloc(nbits); // mark phase *MUST* have a snapshot - noscan.alloc(nbits); // ditto + finals.alloc(nbits); // not used by the mark phase + noscan.alloc(nbits); // mark phase *MUST* have a snapshot + + // all is free when we start + freebits.set_all(); + + // avoid accidental sweeping of new pools while using eager allocation + if (collect_in_progress()) + mark.set_all(); pagetable = cast(ubyte*) cstdlib.malloc(npages); if (!pagetable) @@ -1956,7 +2083,7 @@ struct Pool if (opts.options.fork) vis = os.Vis.SHARED; mark.Dtor(vis); - freebits.Dtor(vis); + freebits.Dtor(); scan.Dtor(); finals.Dtor(); noscan.Dtor();