projects/ldc: druntime/src/gc/basic/gcx.d comparison

comparison druntime/src/gc/basic/gcx.d @ 759:d3eb054172f9

Added copy of druntime from DMD 2.020 modified for LDC.

author	Tomas Lindquist Olsen <tomas.l.olsen@gmail.com>
date	Tue, 11 Nov 2008 01:52:37 +0100
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-:f04dde6e882c
+:d3eb054172f9
+/**
+* This module contains the garbage collector implementation.
+*
+* Copyright: Copyright (C) 2001-2007 Digital Mars, www.digitalmars.com.
+*            All rights reserved.
+* License:
+*  This software is provided 'as-is', without any express or implied
+*  warranty. In no event will the authors be held liable for any damages
+*  arising from the use of this software.
+*
+*  Permission is granted to anyone to use this software for any purpose,
+*  including commercial applications, and to alter it and redistribute it
+*  freely, in both source and binary form, subject to the following
+*  restrictions:
+*
+*  o  The origin of this software must not be misrepresented; you must not
+*     claim that you wrote the original software. If you use this software
+*     in a product, an acknowledgment in the product documentation would be
+*     appreciated but is not required.
+*  o  Altered source versions must be plainly marked as such, and must not
+*     be misrepresented as being the original software.
+*  o  This notice may not be removed or altered from any source
+*     distribution.
+* Authors:   Walter Bright, David Friedman, Sean Kelly
+*/
+module gc.gcx;
+// D Programming Language Garbage Collector implementation
+/************** Debugging ***************************/
+//debug = PRINTF;               // turn on printf's
+//debug = COLLECT_PRINTF;       // turn on printf's
+//debug = THREADINVARIANT;      // check thread integrity
+//debug = LOGGING;              // log allocations / frees
+//debug = MEMSTOMP;             // stomp on memory
+//debug = SENTINEL;             // add underrun/overrrun protection
+//debug = PTRCHECK;             // more pointer checking
+//debug = PTRCHECK2;            // thorough but slow pointer checking
+/*************** Configuration *********************/
+version = STACKGROWSDOWN;       // growing the stack means subtracting from the stack pointer
+// (use for Intel X86 CPUs)
+// else growing the stack means adding to the stack pointer
+version = MULTI_THREADED;       // produce multithreaded version
+/***************************************************/
+private import gcbits;
+private import gcstats;
+private import gcalloc;
+private import cstdlib = stdc.stdlib : calloc, free, malloc, realloc;
+private import stdc.string;
+debug private import stdc.stdio;
+version (GNU)
+{
+// BUG: The following import will likely not work, since the gcc
+//      subdirectory is elsewhere.  Instead, perhaps the functions
+//      could be declared directly or some other resolution could
+//      be found.
+private import gcc.builtins; // for __builtin_unwind_init
+}
+struct BlkInfo
+{
+void*  base;
+size_t size;
+uint   attr;
+}
+private
+{
+enum BlkAttr : uint
+{
+FINALIZE = 0b0000_0001,
+NO_SCAN  = 0b0000_0010,
+NO_MOVE  = 0b0000_0100,
+ALL_BITS = 0b1111_1111
+}
+extern (C) void* rt_stackBottom();
+extern (C) void* rt_stackTop();
+extern (C) void* rt_staticDataBottom();
+extern (C) void* rt_staticDataTop();
+extern (C) void rt_finalize( void* p, bool det = true );
+alias void delegate( void*, void* ) scanFn;
+extern (C) void rt_scanStaticData( scanFn scan );
+version (MULTI_THREADED)
+{
+extern (C) bool thread_needLock();
+extern (C) void thread_suspendAll();
+extern (C) void thread_resumeAll();
+extern (C) void thread_scanAll( scanFn fn, void* curStackTop = null );
+}
+extern (C) void onOutOfMemoryError();
+enum
+{
+OPFAIL = ~cast(size_t)0
+}
+}
+alias GC gc_t;
+/* ======================= Leak Detector =========================== */
+debug (LOGGING)
+{
+struct Log
+{
+void*  p;
+size_t size;
+size_t line;
+char*  file;
+void*  parent;
+void print()
+{
+printf("    p = %x, size = %d, parent = %x ", p, size, parent);
+if (file)
+{
+printf("%s(%u)", file, line);
+}
+printf("\n");
+}
+}
+struct LogArray
+{
+size_t dim;
+size_t allocdim;
+Log *data;
+void Dtor()
+{
+if (data)
+cstdlib.free(data);
+data = null;
+}
+void reserve(size_t nentries)
+{
+assert(dim <= allocdim);
+if (allocdim - dim < nentries)
+{
+allocdim = (dim + nentries) * 2;
+assert(dim + nentries <= allocdim);
+if (!data)
+{
+data = cast(Log*)cstdlib.malloc(allocdim * Log.sizeof);
+if (!data && allocdim)
+onOutOfMemoryError();
+}
+else
+{   Log *newdata;
+newdata = cast(Log*)cstdlib.malloc(allocdim * Log.sizeof);
+if (!newdata && allocdim)
+onOutOfMemoryError();
+memcpy(newdata, data, dim * Log.sizeof);
+cstdlib.free(data);
+data = newdata;
+}
+}
+}
+void push(Log log)
+{
+reserve(1);
+data[dim++] = log;
+}
+void remove(size_t i)
+{
+memmove(data + i, data + i + 1, (dim - i) * Log.sizeof);
+dim--;
+}
+size_t find(void *p)
+{
+for (size_t i = 0; i < dim; i++)
+{
+if (data[i].p == p)
+return i;
+}
+return OPFAIL; // not found
+}
+void copy(LogArray *from)
+{
+reserve(from.dim - dim);
+assert(from.dim <= allocdim);
+memcpy(data, from.data, from.dim * Log.sizeof);
+dim = from.dim;
+}
+}
+}
+/* ============================ GC =============================== */
+class GCLock { }                // just a dummy so we can get a global lock
+const uint GCVERSION = 1;       // increment every time we change interface
+// to GC.
+class GC
+{
+// For passing to debug code
+static size_t line;
+static char*  file;
+uint gcversion = GCVERSION;
+Gcx *gcx;                   // implementation
+static ClassInfo gcLock;    // global lock
+void initialize()
+{
+gcLock = GCLock.classinfo;
+gcx = cast(Gcx*)cstdlib.calloc(1, Gcx.sizeof);
+if (!gcx)
+onOutOfMemoryError();
+gcx.initialize();
+setStackBottom(rt_stackBottom());
+}
+void Dtor()
+{
+version (linux)
+{
+//debug(PRINTF) printf("Thread %x ", pthread_self());
+//debug(PRINTF) printf("GC.Dtor()\n");
+}
+if (gcx)
+{
+gcx.Dtor();
+cstdlib.free(gcx);
+gcx = null;
+}
+}
+invariant()
+{
+if (gcx)
+{
+gcx.thread_Invariant();
+}
+}
+/**
+*
+*/
+void enable()
+{
+if (!thread_needLock())
+{
+assert(gcx.disabled > 0);
+gcx.disabled--;
+}
+else synchronized (gcLock)
+{
+assert(gcx.disabled > 0);
+gcx.disabled--;
+}
+}
+/**
+*
+*/
+void disable()
+{
+if (!thread_needLock())
+{
+gcx.disabled++;
+}
+else synchronized (gcLock)
+{
+gcx.disabled++;
+}
+}
+/**
+*
+*/
+uint getAttr(void* p)
+{
+if (!p)
+{
+return 0;
+}
+uint go()
+{
+Pool* pool = gcx.findPool(p);
+uint  oldb = 0;
+if (pool)
+{
+auto biti = cast(size_t)(p - pool.baseAddr) / 16;
+oldb = gcx.getBits(pool, biti);
+}
+return oldb;
+}
+if (!thread_needLock())
+{
+return go();
+}
+else synchronized (gcLock)
+{
+return go();
+}
+}
+/**
+*
+*/
+uint setAttr(void* p, uint mask)
+{
+if (!p)
+{
+return 0;
+}
+uint go()
+{
+Pool* pool = gcx.findPool(p);
+uint  oldb = 0;
+if (pool)
+{
+auto biti = cast(size_t)(p - pool.baseAddr) / 16;
+oldb = gcx.getBits(pool, biti);
+gcx.setBits(pool, biti, mask);
+}
+return oldb;
+}
+if (!thread_needLock())
+{
+return go();
+}
+else synchronized (gcLock)
+{
+return go();
+}
+}
+/**
+*
+*/
+uint clrAttr(void* p, uint mask)
+{
+if (!p)
+{
+return 0;
+}
+uint go()
+{
+Pool* pool = gcx.findPool(p);
+uint  oldb = 0;
+if (pool)
+{
+auto biti = cast(size_t)(p - pool.baseAddr) / 16;
+oldb = gcx.getBits(pool, biti);
+gcx.clrBits(pool, biti, mask);
+}
+return oldb;
+}
+if (!thread_needLock())
+{
+return go();
+}
+else synchronized (gcLock)
+{
+return go();
+}
+}
+/**
+*
+*/
+void *malloc(size_t size, uint bits = 0)
+{
+if (!size)
+{
+return null;
+}
+if (!thread_needLock())
+{
+return mallocNoSync(size, bits);
+}
+else synchronized (gcLock)
+{
+return mallocNoSync(size, bits);
+}
+}
+//
+//
+//
+private void *mallocNoSync(size_t size, uint bits = 0)
+{
+assert(size != 0);
+void *p = null;
+Bins bin;
+//debug(PRINTF) printf("GC::malloc(size = %d, gcx = %p)\n", size, gcx);
+assert(gcx);
+//debug(PRINTF) printf("gcx.self = %x, pthread_self() = %x\n", gcx.self, pthread_self());
+size += SENTINEL_EXTRA;
+// Compute size bin
+// Cache previous binsize lookup - Dave Fladebo.
+static size_t lastsize = -1;
+static Bins lastbin;
+if (size == lastsize)
+bin = lastbin;
+else
+{
+bin = gcx.findBin(size);
+lastsize = size;
+lastbin = bin;
+}
+if (bin < B_PAGE)
+{
+p = gcx.bucket[bin];
+if (p is null)
+{
+if (!gcx.allocPage(bin) && !gcx.disabled)   // try to find a new page
+{
+if (!thread_needLock())
+{
+/* Then we haven't locked it yet. Be sure
+* and lock for a collection, since a finalizer
+* may start a new thread.
+*/
+synchronized (gcLock)
+{
+gcx.fullcollectshell();
+}
+}
+else if (!gcx.fullcollectshell())       // collect to find a new page
+{
+//gcx.newPool(1);
+}
+}
+if (!gcx.bucket[bin] && !gcx.allocPage(bin))
+{   int result;
+gcx.newPool(1);         // allocate new pool to find a new page
+result = gcx.allocPage(bin);
+if (!result)
+onOutOfMemoryError();
+}
+p = gcx.bucket[bin];
+}
+// Return next item from free list
+gcx.bucket[bin] = (cast(List*)p).next;
+if( !(bits & BlkAttr.NO_SCAN) )
+memset(p + size, 0, binsize[bin] - size);
+//debug(PRINTF) printf("\tmalloc => %x\n", p);
+debug (MEMSTOMP) memset(p, 0xF0, size);
+}
+else
+{
+p = gcx.bigAlloc(size);
+if (!p)
+onOutOfMemoryError();
+}
+size -= SENTINEL_EXTRA;
+p = sentinel_add(p);
+sentinel_init(p, size);
+gcx.log_malloc(p, size);
+if (bits)
+{
+Pool *pool = gcx.findPool(p);
+assert(pool);
+gcx.setBits(pool, cast(size_t)(p - pool.baseAddr) / 16, bits);
+}
+return p;
+}
+/**
+*
+*/
+void *calloc(size_t size, uint bits = 0)
+{
+if (!size)
+{
+return null;
+}
+if (!thread_needLock())
+{
+return callocNoSync(size, bits);
+}
+else synchronized (gcLock)
+{
+return callocNoSync(size, bits);
+}
+}
+//
+//
+//
+private void *callocNoSync(size_t size, uint bits = 0)
+{
+assert(size != 0);
+//debug(PRINTF) printf("calloc: %x len %d\n", p, len);
+void *p = mallocNoSync(size, bits);
+memset(p, 0, size);
+return p;
+}
+/**
+*
+*/
+void *realloc(void *p, size_t size, uint bits = 0)
+{
+if (!thread_needLock())
+{
+return reallocNoSync(p, size, bits);
+}
+else synchronized (gcLock)
+{
+return reallocNoSync(p, size, bits);
+}
+}
+//
+//
+//
+private void *reallocNoSync(void *p, size_t size, uint bits = 0)
+{
+if (!size)
+{   if (p)
+{   freeNoSync(p);
+p = null;
+}
+}
+else if (!p)
+{
+p = mallocNoSync(size, bits);
+}
+else
+{   void *p2;
+size_t psize;
+//debug(PRINTF) printf("GC::realloc(p = %x, size = %u)\n", p, size);
+version (SENTINEL)
+{
+sentinel_Invariant(p);
+psize = *sentinel_size(p);
+if (psize != size)
+{
+if (psize)
+{
+Pool *pool = gcx.findPool(p);
+if (pool)
+{
+auto biti = cast(size_t)(p - pool.baseAddr) / 16;
+if (bits)
+{
+gcx.clrBits(pool, biti, BlkAttr.ALL_BITS);
+gcx.setBits(pool, biti, bits);
+}
+else
+{
+bits = gcx.getBits(pool, biti);
+}
+}
+}
+p2 = mallocNoSync(size, bits);
+if (psize < size)
+size = psize;
+//debug(PRINTF) printf("\tcopying %d bytes\n",size);
+memcpy(p2, p, size);
+p = p2;
+}
+}
+else
+{
+psize = gcx.findSize(p);        // find allocated size
+if (psize >= PAGESIZE && size >= PAGESIZE)
+{
+auto psz = psize / PAGESIZE;
+auto newsz = (size + PAGESIZE - 1) / PAGESIZE;
+if (newsz == psz)
+return p;
+auto pool = gcx.findPool(p);
+auto pagenum = (p - pool.baseAddr) / PAGESIZE;
+if (newsz < psz)
+{   // Shrink in place
+synchronized (gcLock)
+{
+debug (MEMSTOMP) memset(p + size, 0xF2, psize - size);
+pool.freePages(pagenum + newsz, psz - newsz);
+}
+return p;
+}
+else if (pagenum + newsz <= pool.npages)
+{
+// Attempt to expand in place
+synchronized (gcLock)
+{
+for (size_t i = pagenum + psz; 1;)
+{
+if (i == pagenum + newsz)
+{
+debug (MEMSTOMP) memset(p + psize, 0xF0, size - psize);
+memset(&pool.pagetable[pagenum + psz], B_PAGEPLUS, newsz - psz);
+return p;
+}
+if (i == pool.ncommitted)
+{
+auto u = pool.extendPages(pagenum + newsz - pool.ncommitted);
+if (u == OPFAIL)
+break;
+i = pagenum + newsz;
+continue;
+}
+if (pool.pagetable[i] != B_FREE)
+break;
+i++;
+}
+}
+}
+}
+if (psize < size ||             // if new size is bigger
+psize > size * 2)           // or less than half
+{
+if (psize)
+{
+Pool *pool = gcx.findPool(p);
+if (pool)
+{
+auto biti = cast(size_t)(p - pool.baseAddr) / 16;
+if (bits)
+{
+gcx.clrBits(pool, biti, BlkAttr.ALL_BITS);
+gcx.setBits(pool, biti, bits);
+}
+else
+{
+bits = gcx.getBits(pool, biti);
+}
+}
+}
+p2 = mallocNoSync(size, bits);
+if (psize < size)
+size = psize;
+//debug(PRINTF) printf("\tcopying %d bytes\n",size);
+memcpy(p2, p, size);
+p = p2;
+}
+}
+}
+return p;
+}
+/**
+* Attempt to in-place enlarge the memory block pointed to by p by at least
+* minbytes beyond its current capacity, up to a maximum of maxsize.  This
+* does not attempt to move the memory block (like realloc() does).
+*
+* Returns:
+*  0 if could not extend p,
+*  total size of entire memory block if successful.
+*/
+size_t extend(void* p, size_t minsize, size_t maxsize)
+{
+if (!thread_needLock())
+{
+return extendNoSync(p, minsize, maxsize);
+}
+else synchronized (gcLock)
+{
+return extendNoSync(p, minsize, maxsize);
+}
+}
+//
+//
+//
+private size_t extendNoSync(void* p, size_t minsize, size_t maxsize)
+in
+{
+assert( minsize <= maxsize );
+}
+body
+{
+//debug(PRINTF) printf("GC::extend(p = %x, minsize = %u, maxsize = %u)\n", p, minsize, maxsize);
+version (SENTINEL)
+{
+return 0;
+}
+auto psize = gcx.findSize(p);   // find allocated size
+if (psize < PAGESIZE)
+return 0;                   // cannot extend buckets
+auto psz = psize / PAGESIZE;
+auto minsz = (minsize + PAGESIZE - 1) / PAGESIZE;
+auto maxsz = (maxsize + PAGESIZE - 1) / PAGESIZE;
+auto pool = gcx.findPool(p);
+auto pagenum = (p - pool.baseAddr) / PAGESIZE;
+size_t sz;
+for (sz = 0; sz < maxsz; sz++)
+{
+auto i = pagenum + psz + sz;
+if (i == pool.ncommitted)
+break;
+if (pool.pagetable[i] != B_FREE)
+{   if (sz < minsz)
+return 0;
+break;
+}
+}
+if (sz >= minsz)
+{
+}
+else if (pagenum + psz + sz == pool.ncommitted)
+{
+auto u = pool.extendPages(minsz - sz);
+if (u == OPFAIL)
+return 0;
+sz = minsz;
+}
+else
+return 0;
+debug (MEMSTOMP) memset(p + psize, 0xF0, (psz + sz) * PAGESIZE - psize);
+memset(pool.pagetable + pagenum + psz, B_PAGEPLUS, sz);
+gcx.p_cache = null;
+gcx.size_cache = 0;
+return (psz + sz) * PAGESIZE;
+}
+/**
+*
+*/
+size_t reserve(size_t size)
+{
+if (!size)
+{
+return 0;
+}
+if (!thread_needLock())
+{
+return reserveNoSync(size);
+}
+else synchronized (gcLock)
+{
+return reserveNoSync(size);
+}
+}
+//
+//
+//
+private size_t reserveNoSync(size_t size)
+{
+assert(size != 0);
+assert(gcx);
+return gcx.reserve(size);
+}
+/**
+*
+*/
+void free(void *p)
+{
+if (!p)
+{
+return;
+}
+if (!thread_needLock())
+{
+return freeNoSync(p);
+}
+else synchronized (gcLock)
+{
+return freeNoSync(p);
+}
+}
+//
+//
+//
+private void freeNoSync(void *p)
+{
+assert (p);
+Pool*  pool;
+size_t pagenum;
+Bins   bin;
+size_t biti;
+// Find which page it is in
+pool = gcx.findPool(p);
+if (!pool)                              // if not one of ours
+return;                             // ignore
+sentinel_Invariant(p);
+p = sentinel_sub(p);
+pagenum = cast(size_t)(p - pool.baseAddr) / PAGESIZE;
+biti = cast(size_t)(p - pool.baseAddr) / 16;
+gcx.clrBits(pool, biti, BlkAttr.ALL_BITS);
+bin = cast(Bins)pool.pagetable[pagenum];
+if (bin == B_PAGE)              // if large alloc
+{   size_t npages;
+size_t n;
+// Free pages
+npages = 1;
+n = pagenum;
+while (++n < pool.ncommitted && pool.pagetable[n] == B_PAGEPLUS)
+npages++;
+debug (MEMSTOMP) memset(p, 0xF2, npages * PAGESIZE);
+pool.freePages(pagenum, npages);
+}
+else
+{   // Add to free list
+List *list = cast(List*)p;
+debug (MEMSTOMP) memset(p, 0xF2, binsize[bin]);
+list.next = gcx.bucket[bin];
+gcx.bucket[bin] = list;
+}
+gcx.log_free(sentinel_add(p));
+}
+/**
+* Determine the base address of the block containing p.  If p is not a gc
+* allocated pointer, return null.
+*/
+void* addrOf(void *p)
+{
+if (!p)
+{
+return null;
+}
+if (!thread_needLock())
+{
+return addrOfNoSync(p);
+}
+else synchronized (gcLock)
+{
+return addrOfNoSync(p);
+}
+}
+//
+//
+//
+void* addrOfNoSync(void *p)
+{
+if (!p)
+{
+return null;
+}
+return gcx.findBase(p);
+}
+/**
+* Determine the allocated size of pointer p.  If p is an interior pointer
+* or not a gc allocated pointer, return 0.
+*/
+size_t sizeOf(void *p)
+{
+if (!p)
+{
+return 0;
+}
+if (!thread_needLock())
+{
+return sizeOfNoSync(p);
+}
+else synchronized (gcLock)
+{
+return sizeOfNoSync(p);
+}
+}
+//
+//
+//
+private size_t sizeOfNoSync(void *p)
+{
+assert (p);
+version (SENTINEL)
+{
+p = sentinel_sub(p);
+size_t size = gcx.findSize(p);
+// Check for interior pointer
+// This depends on:
+// 1) size is a power of 2 for less than PAGESIZE values
+// 2) base of memory pool is aligned on PAGESIZE boundary
+if (cast(size_t)p & (size - 1) & (PAGESIZE - 1))
+size = 0;
+return size ? size - SENTINEL_EXTRA : 0;
+}
+else
+{
+if (p == gcx.p_cache)
+return gcx.size_cache;
+size_t size = gcx.findSize(p);
+// Check for interior pointer
+// This depends on:
+// 1) size is a power of 2 for less than PAGESIZE values
+// 2) base of memory pool is aligned on PAGESIZE boundary
+if (cast(size_t)p & (size - 1) & (PAGESIZE - 1))
+size = 0;
+else
+{
+gcx.p_cache = p;
+gcx.size_cache = size;
+}
+return size;
+}
+}
+/**
+* Determine the base address of the block containing p.  If p is not a gc
+* allocated pointer, return null.
+*/
+BlkInfo query(void *p)
+{
+if (!p)
+{
+BlkInfo i;
+return  i;
+}
+if (!thread_needLock())
+{
+return queryNoSync(p);
+}
+else synchronized (gcLock)
+{
+return queryNoSync(p);
+}
+}
+//
+//
+//
+BlkInfo queryNoSync(void *p)
+{
+assert(p);
+return gcx.getInfo(p);
+}
+/**
+* Verify that pointer p:
+*  1) belongs to this memory pool
+*  2) points to the start of an allocated piece of memory
+*  3) is not on a free list
+*/
+void check(void *p)
+{
+if (!p)
+{
+return;
+}
+if (!thread_needLock())
+{
+checkNoSync(p);
+}
+else synchronized (gcLock)
+{
+checkNoSync(p);
+}
+}
+//
+//
+//
+private void checkNoSync(void *p)
+{
+assert(p);
+sentinel_Invariant(p);
+debug (PTRCHECK)
+{
+Pool*  pool;
+size_t pagenum;
+Bins   bin;
+size_t size;
+p = sentinel_sub(p);
+pool = gcx.findPool(p);
+assert(pool);
+pagenum = cast(size_t)(p - pool.baseAddr) / PAGESIZE;
+bin = cast(Bins)pool.pagetable[pagenum];
+assert(bin <= B_PAGE);
+size = binsize[bin];
+assert((cast(size_t)p & (size - 1)) == 0);
+debug (PTRCHECK2)
+{
+if (bin < B_PAGE)
+{
+// Check that p is not on a free list
+List *list;
+for (list = gcx.bucket[bin]; list; list = list.next)
+{
+assert(cast(void*)list != p);
+}
+}
+}
+}
+}
+//
+//
+//
+private void setStackBottom(void *p)
+{
+version (STACKGROWSDOWN)
+{
+//p = (void *)((uint *)p + 4);
+if (p > gcx.stackBottom)
+{
+//debug(PRINTF) printf("setStackBottom(%x)\n", p);
+gcx.stackBottom = p;
+}
+}
+else
+{
+//p = (void *)((uint *)p - 4);
+if (p < gcx.stackBottom)
+{
+//debug(PRINTF) printf("setStackBottom(%x)\n", p);
+gcx.stackBottom = cast(char*)p;
+}
+}
+}
+static void scanStaticData(gc_t g)
+{
+//debug(PRINTF) printf("+GC.scanStaticData()\n");
+auto pbot = rt_staticDataBottom();
+auto ptop = rt_staticDataTop();
+g.addRange(pbot, ptop - pbot);
+//debug(PRINTF) printf("-GC.scanStaticData()\n");
+}
+static void unscanStaticData(gc_t g)
+{
+auto pbot = rt_staticDataBottom();
+g.removeRange(pbot);
+}
+/**
+* add p to list of roots
+*/
+void addRoot(void *p)
+{
+if (!p)
+{
+return;
+}
+if (!thread_needLock())
+{
+gcx.addRoot(p);
+}
+else synchronized (gcLock)
+{
+gcx.addRoot(p);
+}
+}
+/**
+* remove p from list of roots
+*/
+void removeRoot(void *p)
+{
+if (!p)
+{
+return;
+}
+if (!thread_needLock())
+{
+gcx.removeRoot(p);
+}
+else synchronized (gcLock)
+{
+gcx.removeRoot(p);
+}
+}
+/**
+* add range to scan for roots
+*/
+void addRange(void *p, size_t sz)
+{
+if (!p || !sz)
+{
+return;
+}
+//debug(PRINTF) printf("+GC.addRange(pbot = x%x, ptop = x%x)\n", pbot, ptop);
+if (!thread_needLock())
+{
+gcx.addRange(p, p + sz);
+}
+else synchronized (gcLock)
+{
+gcx.addRange(p, p + sz);
+}
+//debug(PRINTF) printf("-GC.addRange()\n");
+}
+/**
+* remove range
+*/
+void removeRange(void *p)
+{
+if (!p)
+{
+return;
+}
+if (!thread_needLock())
+{
+gcx.removeRange(p);
+}
+else synchronized (gcLock)
+{
+gcx.removeRange(p);
+}
+}
+/**
+* do full garbage collection
+*/
+void fullCollect()
+{
+debug(PRINTF) printf("GC.fullCollect()\n");
+if (!thread_needLock())
+{
+gcx.fullcollectshell();
+}
+else synchronized (gcLock)
+{
+gcx.fullcollectshell();
+}
+version (none)
+{
+GCStats stats;
+getStats(stats);
+debug(PRINTF) printf("poolsize = %x, usedsize = %x, freelistsize = %x\n",
+stats.poolsize, stats.usedsize, stats.freelistsize);
+}
+gcx.log_collect();
+}
+/**
+* do full garbage collection ignoring roots
+*/
+void fullCollectNoStack()
+{
+if (!thread_needLock())
+{
+gcx.noStack++;
+gcx.fullcollectshell();
+gcx.noStack--;
+}
+else synchronized (gcLock)
+{
+gcx.noStack++;
+gcx.fullcollectshell();
+gcx.noStack--;
+}
+}
+/**
+* minimize free space usage
+*/
+void minimize()
+{
+if (!thread_needLock())
+{
+gcx.minimize();
+}
+else synchronized (gcLock)
+{
+gcx.minimize();
+}
+}
+/**
+* Retrieve statistics about garbage collection.
+* Useful for debugging and tuning.
+*/
+void getStats(out GCStats stats)
+{
+if (!thread_needLock())
+{
+getStatsNoSync(stats);
+}
+else synchronized (gcLock)
+{
+getStatsNoSync(stats);
+}
+}
+//
+//
+//
+private void getStatsNoSync(out GCStats stats)
+{
+size_t psize = 0;
+size_t usize = 0;
+size_t flsize = 0;
+size_t n;
+size_t bsize = 0;
+//debug(PRINTF) printf("getStats()\n");
+memset(&stats, 0, GCStats.sizeof);
+for (n = 0; n < gcx.npools; n++)
+{   Pool *pool = gcx.pooltable[n];
+psize += pool.ncommitted * PAGESIZE;
+for (size_t j = 0; j < pool.ncommitted; j++)
+{
+Bins bin = cast(Bins)pool.pagetable[j];
+if (bin == B_FREE)
+stats.freeblocks++;
+else if (bin == B_PAGE)
+stats.pageblocks++;
+else if (bin < B_PAGE)
+bsize += PAGESIZE;
+}
+}
+for (n = 0; n < B_PAGE; n++)
+{
+//debug(PRINTF) printf("bin %d\n", n);
+for (List *list = gcx.bucket[n]; list; list = list.next)
+{
+//debug(PRINTF) printf("\tlist %x\n", list);
+flsize += binsize[n];
+}
+}
+usize = bsize - flsize;
+stats.poolsize = psize;
+stats.usedsize = bsize - flsize;
+stats.freelistsize = flsize;
+}
+}
+/* ============================ Gcx =============================== */
+enum
+{   PAGESIZE =    4096,
+COMMITSIZE = (4096*16),
+POOLSIZE =   (4096*256),
+}
+enum
+{
+B_16,
+B_32,
+B_64,
+B_128,
+B_256,
+B_512,
+B_1024,
+B_2048,
+B_PAGE,             // start of large alloc
+B_PAGEPLUS,         // continuation of large alloc
+B_FREE,             // free page
+B_UNCOMMITTED,      // memory not committed for this page
+B_MAX
+}
+alias ubyte Bins;
+struct List
+{
+List *next;
+}
+struct Range
+{
+void *pbot;
+void *ptop;
+}
+const uint binsize[B_MAX] = [ 16,32,64,128,256,512,1024,2048,4096 ];
+const uint notbinsize[B_MAX] = [ ~(16u-1),~(32u-1),~(64u-1),~(128u-1),~(256u-1),
+~(512u-1),~(1024u-1),~(2048u-1),~(4096u-1) ];
+/* ============================ Gcx =============================== */
+struct Gcx
+{
+debug (THREADINVARIANT)
+{
+pthread_t self;
+void thread_Invariant()
+{
+if (self != pthread_self())
+printf("thread_Invariant(): gcx = %x, self = %x, pthread_self() = %x\n", this, self, pthread_self());
+assert(self == pthread_self());
+}
+}
+else
+{
+void thread_Invariant() { }
+}
+void *p_cache;
+size_t size_cache;
+size_t nroots;
+size_t rootdim;
+void **roots;
+size_t nranges;
+size_t rangedim;
+Range *ranges;
+uint noStack;       // !=0 means don't scan stack
+uint log;           // turn on logging
+uint anychanges;
+void *stackBottom;
+uint inited;
+int disabled;       // turn off collections if >0
+byte *minAddr;      // min(baseAddr)
+byte *maxAddr;      // max(topAddr)
+size_t npools;
+Pool **pooltable;
+List *bucket[B_MAX];        // free list for each size
+void initialize()
+{   int dummy;
+(cast(byte*)this)[0 .. Gcx.sizeof] = 0;
+stackBottom = cast(char*)&dummy;
+log_init();
+debug (THREADINVARIANT)
+self = pthread_self();
+//printf("gcx = %p, self = %x\n", this, self);
+inited = 1;
+}
+void Dtor()
+{
+inited = 0;
+for (size_t i = 0; i < npools; i++)
+{   Pool *pool = pooltable[i];
+pool.Dtor();
+cstdlib.free(pool);
+}
+if (pooltable)
+cstdlib.free(pooltable);
+if (roots)
+cstdlib.free(roots);
+if (ranges)
+cstdlib.free(ranges);
+}
+void Invariant() { }
+invariant()
+{
+if (inited)
+{
+//printf("Gcx.invariant(): this = %p\n", this);
+size_t i;
+// Assure we're called on the right thread
+debug (THREADINVARIANT) assert(self == pthread_self());
+for (i = 0; i < npools; i++)
+{   Pool *pool = pooltable[i];
+pool.Invariant();
+if (i == 0)
+{
+assert(minAddr == pool.baseAddr);
+}
+if (i + 1 < npools)
+{
+assert(pool.opCmp(pooltable[i + 1]) < 0);
+}
+else if (i + 1 == npools)
+{
+assert(maxAddr == pool.topAddr);
+}
+}
+if (roots)
+{
+assert(rootdim != 0);
+assert(nroots <= rootdim);
+}
+if (ranges)
+{
+assert(rangedim != 0);
+assert(nranges <= rangedim);
+for (i = 0; i < nranges; i++)
+{
+assert(ranges[i].pbot);
+assert(ranges[i].ptop);
+assert(ranges[i].pbot <= ranges[i].ptop);
+}
+}
+for (i = 0; i < B_PAGE; i++)
+{
+for (List *list = bucket[i]; list; list = list.next)
+{
+}
+}
+}
+}
+/**
+*
+*/
+void addRoot(void *p)
+{
+if (nroots == rootdim)
+{
+size_t newdim = rootdim * 2 + 16;
+void** newroots;
+newroots = cast(void**)cstdlib.malloc(newdim * newroots[0].sizeof);
+if (!newroots)
+onOutOfMemoryError();
+if (roots)
+{   memcpy(newroots, roots, nroots * newroots[0].sizeof);
+cstdlib.free(roots);
+}
+roots = newroots;
+rootdim = newdim;
+}
+roots[nroots] = p;
+nroots++;
+}
+/**
+*
+*/
+void removeRoot(void *p)
+{
+for (size_t i = nroots; i--;)
+{
+if (roots[i] == p)
+{
+nroots--;
+memmove(roots + i, roots + i + 1, (nroots - i) * roots[0].sizeof);
+return;
+}
+}
+assert(0);
+}
+/**
+*
+*/
+void addRange(void *pbot, void *ptop)
+{
+debug(PRINTF) printf("Thread %x ", pthread_self());
+debug(PRINTF) printf("%x.Gcx::addRange(%x, %x), nranges = %d\n", this, pbot, ptop, nranges);
+if (nranges == rangedim)
+{
+size_t newdim = rangedim * 2 + 16;
+Range *newranges;
+newranges = cast(Range*)cstdlib.malloc(newdim * newranges[0].sizeof);
+if (!newranges)
+onOutOfMemoryError();
+if (ranges)
+{   memcpy(newranges, ranges, nranges * newranges[0].sizeof);
+cstdlib.free(ranges);
+}
+ranges = newranges;
+rangedim = newdim;
+}
+ranges[nranges].pbot = pbot;
+ranges[nranges].ptop = ptop;
+nranges++;
+}
+/**
+*
+*/
+void removeRange(void *pbot)
+{
+debug(PRINTF) printf("Thread %x ", pthread_self());
+debug(PRINTF) printf("%x.Gcx.removeRange(%x), nranges = %d\n", this, pbot, nranges);
+for (size_t i = nranges; i--;)
+{
+if (ranges[i].pbot == pbot)
+{
+nranges--;
+memmove(ranges + i, ranges + i + 1, (nranges - i) * ranges[0].sizeof);
+return;
+}
+}
+debug(PRINTF) printf("Wrong thread\n");
+// This is a fatal error, but ignore it.
+// The problem is that we can get a Close() call on a thread
+// other than the one the range was allocated on.
+//assert(zero);
+}
+/**
+* Find Pool that pointer is in.
+* Return null if not in a Pool.
+* Assume pooltable[] is sorted.
+*/
+Pool *findPool(void *p)
+{
+if (p >= minAddr && p < maxAddr)
+{
+if (npools == 1)
+{
+return pooltable[0];
+}
+for (size_t i = 0; i < npools; i++)
+{   Pool *pool;
+pool = pooltable[i];
+if (p < pool.topAddr)
+{   if (pool.baseAddr <= p)
+return pool;
+break;
+}
+}
+}
+return null;
+}
+/**
+* Find base address of block containing pointer p.
+* Returns null if not a gc'd pointer
+*/
+void* findBase(void *p)
+{
+Pool *pool;
+pool = findPool(p);
+if (pool)
+{
+size_t offset = cast(size_t)(p - pool.baseAddr);
+size_t pn = offset / PAGESIZE;
+Bins   bin = cast(Bins)pool.pagetable[pn];
+// Adjust bit to be at start of allocated memory block
+if (bin <= B_PAGE)
+{
+return pool.baseAddr + (offset & notbinsize[bin]);
+}
+else if (bin == B_PAGEPLUS)
+{
+do
+{   --pn, offset -= PAGESIZE;
+} while (cast(Bins)pool.pagetable[pn] == B_PAGEPLUS);
+return pool.baseAddr + (offset & (offset.max ^ (PAGESIZE-1)));
+}
+else
+{
+// we are in a B_FREE or B_UNCOMMITTED page
+return null;
+}
+}
+return null;
+}
+/**
+* Find size of pointer p.
+* Returns 0 if not a gc'd pointer
+*/
+size_t findSize(void *p)
+{
+Pool*  pool;
+size_t size = 0;
+pool = findPool(p);
+if (pool)
+{
+size_t pagenum;
+Bins   bin;
+pagenum = cast(size_t)(p - pool.baseAddr) / PAGESIZE;
+bin = cast(Bins)pool.pagetable[pagenum];
+size = binsize[bin];
+if (bin == B_PAGE)
+{   size_t npages = pool.ncommitted;
+ubyte* pt;
+size_t i;
+pt = &pool.pagetable[0];
+for (i = pagenum + 1; i < npages; i++)
+{
+if (pt[i] != B_PAGEPLUS)
+break;
+}
+size = (i - pagenum) * PAGESIZE;
+}
+}
+return size;
+}
+/**
+*
+*/
+BlkInfo getInfo(void* p)
+{
+Pool*   pool;
+BlkInfo info;
+pool = findPool(p);
+if (pool)
+{
+size_t offset = cast(size_t)(p - pool.baseAddr);
+size_t pn = offset / PAGESIZE;
+Bins   bin = cast(Bins)pool.pagetable[pn];
+////////////////////////////////////////////////////////////////////
+// findAddr
+////////////////////////////////////////////////////////////////////
+if (bin <= B_PAGE)
+{
+info.base = pool.baseAddr + (offset & notbinsize[bin]);
+}
+else if (bin == B_PAGEPLUS)
+{
+do
+{   --pn, offset -= PAGESIZE;
+} while (cast(Bins)pool.pagetable[pn] == B_PAGEPLUS);
+info.base = pool.baseAddr + (offset & (offset.max ^ (PAGESIZE-1)));
+// fix bin for use by size calc below
+bin = cast(Bins)pool.pagetable[pn];
+}
+////////////////////////////////////////////////////////////////////
+// findSize
+////////////////////////////////////////////////////////////////////
+info.size = binsize[bin];
+if (bin == B_PAGE)
+{   size_t npages = pool.ncommitted;
+ubyte* pt;
+size_t i;
+pt = &pool.pagetable[0];
+for (i = pn + 1; i < npages; i++)
+{
+if (pt[i] != B_PAGEPLUS)
+break;
+}
+info.size = (i - pn) * PAGESIZE;
+}
+////////////////////////////////////////////////////////////////////
+// getBits
+////////////////////////////////////////////////////////////////////
+info.attr = getBits(pool, cast(size_t)(offset / 16));
+}
+return info;
+}
+/**
+* Compute bin for size.
+*/
+static Bins findBin(size_t size)
+{   Bins bin;
+if (size <= 256)
+{
+if (size <= 64)
+{
+if (size <= 16)
+bin = B_16;
+else if (size <= 32)
+bin = B_32;
+else
+bin = B_64;
+}
+else
+{
+if (size <= 128)
+bin = B_128;
+else
+bin = B_256;
+}
+}
+else
+{
+if (size <= 1024)
+{
+if (size <= 512)
+bin = B_512;
+else
+bin = B_1024;
+}
+else
+{
+if (size <= 2048)
+bin = B_2048;
+else
+bin = B_PAGE;
+}
+}
+return bin;
+}
+/**
+* Allocate a new pool of at least size bytes.
+* Sort it into pooltable[].
+* Mark all memory in the pool as B_FREE.
+* Return the actual number of bytes reserved or 0 on error.
+*/
+size_t reserve(size_t size)
+{
+size_t npages = (size + PAGESIZE - 1) / PAGESIZE;
+Pool*  pool = newPool(npages);
+if (!pool || pool.extendPages(npages) == OPFAIL)
+return 0;
+return pool.ncommitted * PAGESIZE;
+}
+/**
+* Minimizes physical memory usage by returning free pools to the OS.
+*/
+void minimize()
+{
+size_t n;
+size_t pn;
+Pool*  pool;
+size_t ncommitted;
+for (n = 0; n < npools; n++)
+{
+pool = pooltable[n];
+ncommitted = pool.ncommitted;
+for (pn = 0; pn < ncommitted; pn++)
+{
+if (cast(Bins)pool.pagetable[pn] != B_FREE)
+break;
+}
+if (pn < ncommitted)
+{
+n++;
+continue;
+}
+pool.Dtor();
+cstdlib.free(pool);
+memmove(pooltable + n,
+pooltable + n + 1,
+(--npools - n) * (Pool*).sizeof);
+minAddr = pooltable[0].baseAddr;
+maxAddr = pooltable[npools - 1].topAddr;
+}
+}
+/**
+* Allocate a chunk of memory that is larger than a page.
+* Return null if out of memory.
+*/
+void *bigAlloc(size_t size)
+{
+Pool*  pool;
+size_t npages;
+size_t n;
+size_t pn;
+size_t freedpages;
+void*  p;
+int    state;
+npages = (size + PAGESIZE - 1) / PAGESIZE;
+for (state = 0; ; )
+{
+// This code could use some refinement when repeatedly
+// allocating very large arrays.
+for (n = 0; n < npools; n++)
+{
+pool = pooltable[n];
+pn = pool.allocPages(npages);
+if (pn != OPFAIL)
+goto L1;
+}
+// Failed
+switch (state)
+{
+case 0:
+if (disabled)
+{   state = 1;
+continue;
+}
+// Try collecting
+freedpages = fullcollectshell();
+if (freedpages >= npools * ((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);
+}
+}
+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);
+debug (MEMSTOMP) memset(p, 0xF1, size);
+//debug(PRINTF) printf("\tp = %x\n", p);
+return p;
+Lnomemory:
+return null; // let mallocNoSync handle the error
+}
+/**
+* Allocate a new pool with at least npages in it.
+* Sort it into pooltable[].
+* Return null if failed.
+*/
+Pool *newPool(size_t npages)
+{
+Pool*  pool;
+Pool** newpooltable;
+size_t newnpools;
+size_t i;
+//debug(PRINTF) printf("************Gcx::newPool(npages = %d)****************\n", npages);
+// Round up to COMMITSIZE pages
+npages = (npages + (COMMITSIZE/PAGESIZE) - 1) & ~(COMMITSIZE/PAGESIZE - 1);
+// Minimum of POOLSIZE
+if (npages < POOLSIZE/PAGESIZE)
+npages = POOLSIZE/PAGESIZE;
+else if (npages > POOLSIZE/PAGESIZE)
+{   // Give us 150% of requested size, so there's room to extend
+auto n = npages + (npages >> 1);
+if (n < size_t.max/PAGESIZE)
+npages = n;
+}
+// Allocate successively larger pools up to 8 megs
+if (npools)
+{   size_t n;
+n = npools;
+if (n > 8)
+n = 8;                  // cap pool size at 8 megs
+n *= (POOLSIZE / PAGESIZE);
+if (npages < n)
+npages = n;
+}
+pool = cast(Pool *)cstdlib.calloc(1, Pool.sizeof);
+if (pool)
+{
+pool.initialize(npages);
+if (!pool.baseAddr)
+goto Lerr;
+newnpools = npools + 1;
+newpooltable = cast(Pool **)cstdlib.realloc(pooltable, newnpools * (Pool *).sizeof);
+if (!newpooltable)
+goto Lerr;
+// Sort pool into newpooltable[]
+for (i = 0; i < npools; i++)
+{
+if (pool.opCmp(newpooltable[i]) < 0)
+break;
+}
+memmove(newpooltable + i + 1, newpooltable + i, (npools - i) * (Pool *).sizeof);
+newpooltable[i] = pool;
+pooltable = newpooltable;
+npools = newnpools;
+minAddr = pooltable[0].baseAddr;
+maxAddr = pooltable[npools - 1].topAddr;
+}
+return pool;
+Lerr:
+pool.Dtor();
+cstdlib.free(pool);
+return null;
+}
+/**
+* Allocate a page of bin's.
+* Returns:
+*  0       failed
+*/
+int allocPage(Bins bin)
+{
+Pool*  pool;
+size_t n;
+size_t pn;
+byte*  p;
+byte*  ptop;
+//debug(PRINTF) printf("Gcx::allocPage(bin = %d)\n", bin);
+for (n = 0; n < npools; n++)
+{
+pool = pooltable[n];
+pn = pool.allocPages(1);
+if (pn != OPFAIL)
+goto L1;
+}
+return 0;               // failed
+L1:
+pool.pagetable[pn] = cast(ubyte)bin;
+// Convert page to free list
+size_t size = binsize[bin];
+List **b = &bucket[bin];
+p = pool.baseAddr + pn * PAGESIZE;
+ptop = p + PAGESIZE;
+for (; p < ptop; p += size)
+{
+(cast(List *)p).next = *b;
+*b = cast(List *)p;
+}
+return 1;
+}
+/**
+* Search a range of memory values and mark any pointers into the GC pool.
+*/
+void mark(void *pbot, void *ptop)
+{
+void **p1 = cast(void **)pbot;
+void **p2 = cast(void **)ptop;
+size_t pcache = 0;
+uint changes = 0;
+//printf("marking range: %p -> %p\n", pbot, ptop);
+for (; p1 < p2; p1++)
+{
+Pool *pool;
+byte *p = cast(byte *)(*p1);
+//if (log) debug(PRINTF) printf("\tmark %x\n", p);
+if (p >= minAddr && p < maxAddr)
+{
+if ((cast(size_t)p & ~(PAGESIZE-1)) == pcache)
+continue;
+pool = findPool(p);
+if (pool)
+{
+size_t offset = cast(size_t)(p - pool.baseAddr);
+size_t biti;
+size_t pn = offset / PAGESIZE;
+Bins   bin = cast(Bins)pool.pagetable[pn];
+//debug(PRINTF) printf("\t\tfound pool %x, base=%x, pn = %d, bin = %d, biti = x%x\n", pool, pool.baseAddr, pn, bin, biti);
+// Adjust bit to be at start of allocated memory block
+if (bin <= B_PAGE)
+{
+biti = (offset & notbinsize[bin]) >> 4;
+//debug(PRINTF) printf("\t\tbiti = x%x\n", biti);
+}
+else if (bin == B_PAGEPLUS)
+{
+do
+{   --pn;
+} while (cast(Bins)pool.pagetable[pn] == B_PAGEPLUS);
+biti = pn * (PAGESIZE / 16);
+}
+else
+{
+// Don't mark bits in B_FREE or B_UNCOMMITTED pages
+continue;
+}
+if (bin >= B_PAGE) // Cache B_PAGE and B_PAGEPLUS lookups
+pcache = cast(size_t)p & ~(PAGESIZE-1);
+//debug(PRINTF) printf("\t\tmark(x%x) = %d\n", biti, pool.mark.test(biti));
+if (!pool.mark.test(biti))
+{
+//if (log) debug(PRINTF) printf("\t\tmarking %x\n", p);
+pool.mark.set(biti);
+if (!pool.noscan.test(biti))
+{
+pool.scan.set(biti);
+changes = 1;
+}
+log_parent(sentinel_add(pool.baseAddr + biti * 16), sentinel_add(pbot));
+}
+}
+}
+}
+anychanges |= changes;
+}
+/**
+* Return number of full pages free'd.
+*/
+size_t fullcollectshell()
+{
+// The purpose of the 'shell' is to ensure all the registers
+// get put on the stack so they'll be scanned
+void *sp;
+size_t result;
+version (GNU)
+{
+__builtin_unwind_init();
+sp = & sp;
+}
+else
+{
+asm
+{
+pushad              ;
+mov sp[EBP],ESP     ;
+}
+}
+result = fullcollect(sp);
+version (GNU)
+{
+// nothing to do
+}
+else
+{
+asm
+{
+popad               ;
+}
+}
+return result;
+}
+/**
+*
+*/
+size_t fullcollect(void *stackTop)
+{
+size_t n;
+Pool*  pool;
+debug(COLLECT_PRINTF) printf("Gcx.fullcollect()\n");
+thread_suspendAll();
+p_cache = null;
+size_cache = 0;
+anychanges = 0;
+for (n = 0; n < npools; n++)
+{
+pool = pooltable[n];
+pool.mark.zero();
+pool.scan.zero();
+pool.freebits.zero();
+}
+// Mark each free entry, so it doesn't get scanned
+for (n = 0; n < B_PAGE; n++)
+{
+for (List *list = bucket[n]; list; list = list.next)
+{
+pool = findPool(list);
+assert(pool);
+pool.freebits.set(cast(size_t)(cast(byte*)list - pool.baseAddr) / 16);
+}
+}
+for (n = 0; n < npools; n++)
+{
+pool = pooltable[n];
+pool.mark.copy(&pool.freebits);
+}
+rt_scanStaticData( &mark );
+version (MULTI_THREADED)
+{
+if (!noStack)
+{
+// Scan stacks and registers for each paused thread
+thread_scanAll( &mark, stackTop );
+}
+}
+else
+{
+if (!noStack)
+{
+// Scan stack for main thread
+debug(PRINTF) printf(" scan stack bot = %x, top = %x\n", stackTop, stackBottom);
+version (STACKGROWSDOWN)
+mark(stackTop, stackBottom);
+else
+mark(stackBottom, stackTop);
+}
+}
+// Scan roots[]
+debug(COLLECT_PRINTF) printf("scan roots[]\n");
+mark(roots, roots + nroots);
+// Scan ranges[]
+debug(COLLECT_PRINTF) printf("scan ranges[]\n");
+//log++;
+for (n = 0; n < nranges; n++)
+{
+debug(COLLECT_PRINTF) printf("\t%x .. %x\n", ranges[n].pbot, ranges[n].ptop);
+mark(ranges[n].pbot, ranges[n].ptop);
+}
+//log--;
+debug(COLLECT_PRINTF) printf("\tscan heap\n");
+while (anychanges)
+{
+anychanges = 0;
+for (n = 0; n < npools; n++)
+{
+uint *bbase;
+uint *b;
+uint *btop;
+pool = pooltable[n];
+bbase = pool.scan.base();
+btop = bbase + pool.scan.nwords;
+for (b = bbase; b < btop;)
+{   Bins   bin;
+size_t pn;
+size_t u;
+size_t bitm;
+byte*  o;
+bitm = *b;
+if (!bitm)
+{   b++;
+continue;
+}
+*b = 0;
+o = pool.baseAddr + (b - bbase) * 32 * 16;
+if (!(bitm & 0xFFFF))
+{
+bitm >>= 16;
+o += 16 * 16;
+}
+for (; bitm; o += 16, bitm >>= 1)
+{
+if (!(bitm & 1))
+continue;
+pn = cast(size_t)(o - pool.baseAddr) / PAGESIZE;
+bin = cast(Bins)pool.pagetable[pn];
+if (bin < B_PAGE)
+{
+mark(o, o + binsize[bin]);
+}
+else if (bin == B_PAGE || bin == B_PAGEPLUS)
+{
+if (bin == B_PAGEPLUS)
+{
+while (pool.pagetable[pn - 1] != B_PAGE)
+pn--;
+}
+u = 1;
+while (pn + u < pool.ncommitted && pool.pagetable[pn + u] == B_PAGEPLUS)
+u++;
+mark(o, o + u * PAGESIZE);
+}
+}
+}
+}
+}
+thread_resumeAll();
+// Free up everything not marked
+debug(COLLECT_PRINTF) printf("\tfree'ing\n");
+size_t freedpages = 0;
+size_t freed = 0;
+for (n = 0; n < npools; n++)
+{   size_t pn;
+size_t ncommitted;
+uint*  bbase;
+pool = pooltable[n];
+bbase = pool.mark.base();
+ncommitted = pool.ncommitted;
+for (pn = 0; pn < ncommitted; pn++, bbase += PAGESIZE / (32 * 16))
+{
+Bins bin = cast(Bins)pool.pagetable[pn];
+if (bin < B_PAGE)
+{   byte* p;
+byte* ptop;
+size_t biti;
+size_t bitstride;
+auto   size = binsize[bin];
+p = pool.baseAddr + pn * PAGESIZE;
+ptop = p + PAGESIZE;
+biti = pn * (PAGESIZE/16);
+bitstride = size / 16;
+version(none) // BUG: doesn't work because freebits() must also be cleared
+{
+// If free'd entire page
+if (bbase[0] == 0 && bbase[1] == 0 && bbase[2] == 0 && bbase[3] == 0 &&
+bbase[4] == 0 && bbase[5] == 0 && bbase[6] == 0 && bbase[7] == 0)
+{
+for (; p < ptop; p += size, biti += bitstride)
+{
+if (pool.finals.nbits && pool.finals.testClear(biti))
+rt_finalize(cast(List *)sentinel_add(p), false/*noStack > 0*/);
+gcx.clrBits(pool, biti, BlkAttr.ALL_BITS);
+List *list = cast(List *)p;
+//debug(PRINTF) printf("\tcollecting %x\n", list);
+log_free(sentinel_add(list));
+debug (MEMSTOMP) memset(p, 0xF3, size);
+}
+pool.pagetable[pn] = B_FREE;
+freed += PAGESIZE;
+//debug(PRINTF) printf("freeing entire page %d\n", pn);
+continue;
+}
+}
+for (; p < ptop; p += size, biti += bitstride)
+{
+if (!pool.mark.test(biti))
+{
+sentinel_Invariant(sentinel_add(p));
+pool.freebits.set(biti);
+if (pool.finals.nbits && pool.finals.testClear(biti))
+rt_finalize(cast(List *)sentinel_add(p), false/*noStack > 0*/);
+clrBits(pool, biti, BlkAttr.ALL_BITS);
+List *list = cast(List *)p;
+debug(PRINTF) printf("\tcollecting %x\n", list);
+log_free(sentinel_add(list));
+debug (MEMSTOMP) memset(p, 0xF3, size);
+freed += size;
+}
+}
+}
+else if (bin == B_PAGE)
+{   size_t biti = pn * (PAGESIZE / 16);
+if (!pool.mark.test(biti))
+{   byte *p = pool.baseAddr + pn * PAGESIZE;
+sentinel_Invariant(sentinel_add(p));
+if (pool.finals.nbits && pool.finals.testClear(biti))
+rt_finalize(sentinel_add(p), false/*noStack > 0*/);
+clrBits(pool, biti, BlkAttr.ALL_BITS);
+debug(COLLECT_PRINTF) printf("\tcollecting big %x\n", p);
+log_free(sentinel_add(p));
+pool.pagetable[pn] = B_FREE;
+freedpages++;
+debug (MEMSTOMP) memset(p, 0xF3, PAGESIZE);
+while (pn + 1 < ncommitted && pool.pagetable[pn + 1] == B_PAGEPLUS)
+{
+pn++;
+pool.pagetable[pn] = B_FREE;
+freedpages++;
+debug (MEMSTOMP)
+{   p += PAGESIZE;
+memset(p, 0xF3, PAGESIZE);
+}
+}
+}
+}
+}
+}
+// Zero buckets
+bucket[] = null;
+// Free complete pages, rebuild free list
+debug(COLLECT_PRINTF) printf("\tfree complete pages\n");
+size_t recoveredpages = 0;
+for (n = 0; n < npools; n++)
+{   size_t pn;
+size_t ncommitted;
+pool = pooltable[n];
+ncommitted = pool.ncommitted;
+for (pn = 0; pn < ncommitted; pn++)
+{
+Bins   bin = cast(Bins)pool.pagetable[pn];
+size_t biti;
+size_t u;
+if (bin < B_PAGE)
+{
+size_t size = binsize[bin];
+size_t bitstride = size / 16;
+size_t bitbase = pn * (PAGESIZE / 16);
+size_t bittop = bitbase + (PAGESIZE / 16);
+byte*  p;
+biti = bitbase;
+for (biti = bitbase; biti < bittop; biti += bitstride)
+{   if (!pool.freebits.test(biti))
+goto Lnotfree;
+}
+pool.pagetable[pn] = B_FREE;
+recoveredpages++;
+continue;
+Lnotfree:
+p = pool.baseAddr + pn * PAGESIZE;
+for (u = 0; u < PAGESIZE; u += size)
+{   biti = bitbase + u / 16;
+if (pool.freebits.test(biti))
+{   List *list;
+list = cast(List *)(p + u);
+if (list.next != bucket[bin])       // avoid unnecessary writes
+list.next = bucket[bin];
+bucket[bin] = list;
+}
+}
+}
+}
+}
+debug(COLLECT_PRINTF) printf("recovered pages = %d\n", recoveredpages);
+debug(COLLECT_PRINTF) printf("\tfree'd %u bytes, %u pages from %u pools\n", freed, freedpages, npools);
+return freedpages + recoveredpages;
+}
+/**
+*
+*/
+uint getBits(Pool* pool, size_t biti)
+in
+{
+assert( pool );
+}
+body
+{
+uint bits;
+if (pool.finals.nbits &&
+pool.finals.test(biti))
+bits |= BlkAttr.FINALIZE;
+if (pool.noscan.test(biti))
+bits |= BlkAttr.NO_SCAN;
+//        if (pool.nomove.nbits &&
+//            pool.nomove.test(biti))
+//            bits |= BlkAttr.NO_MOVE;
+return bits;
+}
+/**
+*
+*/
+void setBits(Pool* pool, size_t biti, uint mask)
+in
+{
+assert( pool );
+}
+body
+{
+if (mask & BlkAttr.FINALIZE)
+{
+if (!pool.finals.nbits)
+pool.finals.alloc(pool.mark.nbits);
+pool.finals.set(biti);
+}
+if (mask & BlkAttr.NO_SCAN)
+{
+pool.noscan.set(biti);
+}
+//        if (mask & BlkAttr.NO_MOVE)
+//        {
+//            if (!pool.nomove.nbits)
+//                pool.nomove.alloc(pool.mark.nbits);
+//            pool.nomove.set(biti);
+//        }
+}
+/**
+*
+*/
+void clrBits(Pool* pool, size_t biti, uint mask)
+in
+{
+assert( pool );
+}
+body
+{
+if (mask & BlkAttr.FINALIZE && pool.finals.nbits)
+pool.finals.clear(biti);
+if (mask & BlkAttr.NO_SCAN)
+pool.noscan.clear(biti);
+//        if (mask & BlkAttr.NO_MOVE && pool.nomove.nbits)
+//            pool.nomove.clear(biti);
+}
+/***** Leak Detector ******/
+debug (LOGGING)
+{
+LogArray current;
+LogArray prev;
+void log_init()
+{
+//debug(PRINTF) printf("+log_init()\n");
+current.reserve(1000);
+prev.reserve(1000);
+//debug(PRINTF) printf("-log_init()\n");
+}
+void log_malloc(void *p, size_t size)
+{
+//debug(PRINTF) printf("+log_malloc(p = %x, size = %d)\n", p, size);
+Log log;
+log.p = p;
+log.size = size;
+log.line = GC.line;
+log.file = GC.file;
+log.parent = null;
+GC.line = 0;
+GC.file = null;
+current.push(log);
+//debug(PRINTF) printf("-log_malloc()\n");
+}
+void log_free(void *p)
+{
+//debug(PRINTF) printf("+log_free(%x)\n", p);
+size_t i;
+i = current.find(p);
+if (i == OPFAIL)
+{
+debug(PRINTF) printf("free'ing unallocated memory %x\n", p);
+}
+else
+current.remove(i);
+//debug(PRINTF) printf("-log_free()\n");
+}
+void log_collect()
+{
+//debug(PRINTF) printf("+log_collect()\n");
+// Print everything in current that is not in prev
+debug(PRINTF) printf("New pointers this cycle: --------------------------------\n");
+size_t used = 0;
+for (size_t i = 0; i < current.dim; i++)
+{
+size_t j;
+j = prev.find(current.data[i].p);
+if (j == OPFAIL)
+current.data[i].print();
+else
+used++;
+}
+debug(PRINTF) printf("All roots this cycle: --------------------------------\n");
+for (size_t i = 0; i < current.dim; i++)
+{
+void *p;
+size_t j;
+p = current.data[i].p;
+if (!findPool(current.data[i].parent))
+{
+j = prev.find(current.data[i].p);
+if (j == OPFAIL)
+debug(PRINTF) printf("N");
+else
+debug(PRINTF) printf(" ");;
+current.data[i].print();
+}
+}
+debug(PRINTF) printf("Used = %d-------------------------------------------------\n", used);
+prev.copy(&current);
+debug(PRINTF) printf("-log_collect()\n");
+}
+void log_parent(void *p, void *parent)
+{
+//debug(PRINTF) printf("+log_parent()\n");
+size_t i;
+i = current.find(p);
+if (i == OPFAIL)
+{
+debug(PRINTF) printf("parent'ing unallocated memory %x, parent = %x\n", p, parent);
+Pool *pool;
+pool = findPool(p);
+assert(pool);
+size_t offset = cast(size_t)(p - pool.baseAddr);
+size_t biti;
+size_t pn = offset / PAGESIZE;
+Bins bin = cast(Bins)pool.pagetable[pn];
+biti = (offset & notbinsize[bin]);
+debug(PRINTF) printf("\tbin = %d, offset = x%x, biti = x%x\n", bin, offset, biti);
+}
+else
+{
+current.data[i].parent = parent;
+}
+//debug(PRINTF) printf("-log_parent()\n");
+}
+}
+else
+{
+void log_init() { }
+void log_malloc(void *p, size_t size) { }
+void log_free(void *p) { }
+void log_collect() { }
+void log_parent(void *p, void *parent) { }
+}
+}
+/* ============================ Pool  =============================== */
+struct Pool
+{
+byte* baseAddr;
+byte* topAddr;
+GCBits mark;        // entries already scanned, or should not be scanned
+GCBits scan;        // entries that need to be scanned
+GCBits freebits;    // entries that are on the free list
+GCBits finals;      // entries that need finalizer run on them
+GCBits noscan;      // entries that should not be scanned
+size_t npages;
+size_t ncommitted;    // ncommitted <= npages
+ubyte* pagetable;
+void initialize(size_t npages)
+{
+size_t poolsize;
+//debug(PRINTF) printf("Pool::Pool(%u)\n", npages);
+poolsize = npages * PAGESIZE;
+assert(poolsize >= POOLSIZE);
+baseAddr = cast(byte *)os_mem_map(poolsize);
+// Some of the code depends on page alignment of memory pools
+assert((cast(size_t)baseAddr & (PAGESIZE - 1)) == 0);
+if (!baseAddr)
+{
+//debug(PRINTF) printf("GC fail: poolsize = x%x, errno = %d\n", poolsize, errno);
+//debug(PRINTF) printf("message = '%s'\n", sys_errlist[errno]);
+npages = 0;
+poolsize = 0;
+}
+//assert(baseAddr);
+topAddr = baseAddr + poolsize;
+mark.alloc(cast(size_t)poolsize / 16);
+scan.alloc(cast(size_t)poolsize / 16);
+freebits.alloc(cast(size_t)poolsize / 16);
+noscan.alloc(cast(size_t)poolsize / 16);
+pagetable = cast(ubyte*)cstdlib.malloc(npages);
+if (!pagetable)
+onOutOfMemoryError();
+memset(pagetable, B_UNCOMMITTED, npages);
+this.npages = npages;
+ncommitted = 0;
+}
+void Dtor()
+{
+if (baseAddr)
+{
+int result;
+if (ncommitted)
+{
+result = os_mem_decommit(baseAddr, 0, ncommitted * PAGESIZE);
+assert(result == 0);
+ncommitted = 0;
+}
+if (npages)
+{
+result = os_mem_unmap(baseAddr, npages * PAGESIZE);
+assert(result == 0);
+npages = 0;
+}
+baseAddr = null;
+topAddr = null;
+}
+if (pagetable)
+cstdlib.free(pagetable);
+mark.Dtor();
+scan.Dtor();
+freebits.Dtor();
+finals.Dtor();
+noscan.Dtor();
+}
+void Invariant() { }
+invariant()
+{
+//mark.Invariant();
+//scan.Invariant();
+//freebits.Invariant();
+//finals.Invariant();
+//noscan.Invariant();
+if (baseAddr)
+{
+//if (baseAddr + npages * PAGESIZE != topAddr)
+//printf("baseAddr = %p, npages = %d, topAddr = %p\n", baseAddr, npages, topAddr);
+assert(baseAddr + npages * PAGESIZE == topAddr);
+assert(ncommitted <= npages);
+}
+for (size_t i = 0; i < npages; i++)
+{   Bins bin = cast(Bins)pagetable[i];
+assert(bin < B_MAX);
+}
+}
+/**
+* Allocate n pages from Pool.
+* Returns OPFAIL on failure.
+*/
+size_t allocPages(size_t n)
+{
+size_t i;
+size_t n2;
+//debug(PRINTF) printf("Pool::allocPages(n = %d)\n", n);
+n2 = n;
+for (i = 0; i < ncommitted; i++)
+{
+if (pagetable[i] == B_FREE)
+{
+if (--n2 == 0)
+{   //debug(PRINTF) printf("\texisting pn = %d\n", i - n + 1);
+return i - n + 1;
+}
+}
+else
+n2 = n;
+}
+return extendPages(n);
+}
+/**
+* Extend Pool by n pages.
+* Returns OPFAIL on failure.
+*/
+size_t extendPages(size_t n)
+{
+//debug(PRINTF) printf("Pool::extendPages(n = %d)\n", n);
+if (ncommitted + n <= npages)
+{
+size_t tocommit;
+tocommit = (n + (COMMITSIZE/PAGESIZE) - 1) & ~(COMMITSIZE/PAGESIZE - 1);
+if (ncommitted + tocommit > npages)
+tocommit = npages - ncommitted;
+//debug(PRINTF) printf("\tlooking to commit %d more pages\n", tocommit);
+//fflush(stdout);
+if (os_mem_commit(baseAddr, ncommitted * PAGESIZE, tocommit * PAGESIZE) == 0)
+{
+memset(pagetable + ncommitted, B_FREE, tocommit);
+auto i = ncommitted;
+ncommitted += tocommit;
+while (i && pagetable[i - 1] == B_FREE)
+i--;
+return i;
+}
+//debug(PRINTF) printf("\tfailed to commit %d pages\n", tocommit);
+}
+return OPFAIL;
+}
+/**
+* Free npages pages starting with pagenum.
+*/
+void freePages(size_t pagenum, size_t npages)
+{
+memset(&pagetable[pagenum], B_FREE, npages);
+}
+/**
+* Used for sorting pooltable[]
+*/
+int opCmp(Pool *p2)
+{
+if (baseAddr < p2.baseAddr)
+return -1;
+else
+return cast(int)(baseAddr > p2.baseAddr);
+}
+}
+/* ============================ SENTINEL =============================== */
+version (SENTINEL)
+{
+const size_t SENTINEL_PRE = cast(size_t) 0xF4F4F4F4F4F4F4F4UL; // 32 or 64 bits
+const ubyte SENTINEL_POST = 0xF5;           // 8 bits
+const uint SENTINEL_EXTRA = 2 * size_t.sizeof + 1;
+size_t* sentinel_size(void *p)  { return &(cast(size_t *)p)[-2]; }
+size_t* sentinel_pre(void *p)   { return &(cast(size_t *)p)[-1]; }
+ubyte* sentinel_post(void *p) { return &(cast(ubyte *)p)[*sentinel_size(p)]; }
+void sentinel_init(void *p, size_t size)
+{
+*sentinel_size(p) = size;
+*sentinel_pre(p) = SENTINEL_PRE;
+*sentinel_post(p) = SENTINEL_POST;
+}
+void sentinel_Invariant(void *p)
+{
+assert(*sentinel_pre(p) == SENTINEL_PRE);
+assert(*sentinel_post(p) == SENTINEL_POST);
+}
+void *sentinel_add(void *p)
+{
+return p + 2 * size_t.sizeof;
+}
+void *sentinel_sub(void *p)
+{
+return p - 2 * size_t.sizeof;
+}
+}
+else
+{
+const uint SENTINEL_EXTRA = 0;
+void sentinel_init(void *p, size_t size)
+{
+}
+void sentinel_Invariant(void *p)
+{
+}
+void *sentinel_add(void *p)
+{
+return p;
+}
+void *sentinel_sub(void *p)
+{
+return p;
+}
+}

Mercurial > projects > ldc

comparison druntime/src/gc/basic/gcx.d @ 759:d3eb054172f9