/src/gcstub/gc.d
http://github.com/AlexeyProkhin/druntime · D · 379 lines · 299 code · 52 blank · 28 comment · 34 complexity · 8c887d83f8251a5d45464fb8272cf11e MD5 · raw file
- /**
- * This module contains a minimal garbage collector implementation according to
- * published requirements. This library is mostly intended to serve as an
- * example, but it is usable in applications which do not rely on a garbage
- * collector to clean up memory (ie. when dynamic array resizing is not used,
- * and all memory allocated with 'new' is freed deterministically with
- * 'delete').
- *
- * Please note that block attribute data must be tracked, or at a minimum, the
- * FINALIZE bit must be tracked for any allocated memory block because calling
- * rt_finalize on a non-object block can result in an access violation. In the
- * allocator below, this tracking is done via a leading uint bitmask. A real
- * allocator may do better to store this data separately, similar to the basic
- * GC.
- *
- * Copyright: Copyright Sean Kelly 2005 - 2009.
- * License: <a href="http://www.boost.org/LICENSE_1_0.txt">Boost License 1.0</a>.
- * Authors: Sean Kelly
- */
- /* Copyright Sean Kelly 2005 - 2009.
- * Distributed under the Boost Software License, Version 1.0.
- * (See accompanying file LICENSE or copy at
- * http://www.boost.org/LICENSE_1_0.txt)
- */
- module gc.gc;
- private
- {
- import core.stdc.stdlib;
- import core.stdc.stdio;
- enum BlkAttr : uint
- {
- FINALIZE = 0b0000_0001,
- NO_SCAN = 0b0000_0010,
- NO_MOVE = 0b0000_0100,
- APPENDABLE = 0b0000_1000,
- ALL_BITS = 0b1111_1111
- }
- struct BlkInfo
- {
- void* base;
- size_t size;
- uint attr;
- }
- extern (C) void thread_init();
- extern (C) void onOutOfMemoryError();
- struct Proxy
- {
- extern (C) void function() gc_enable;
- extern (C) void function() gc_disable;
- extern (C) void function() gc_collect;
- extern (C) void function() gc_minimize;
- extern (C) uint function(void*) gc_getAttr;
- extern (C) uint function(void*, uint) gc_setAttr;
- extern (C) uint function(void*, uint) gc_clrAttr;
- extern (C) void* function(size_t, uint) gc_malloc;
- extern (C) BlkInfo function(size_t, uint) gc_qalloc;
- extern (C) void* function(size_t, uint) gc_calloc;
- extern (C) void* function(void*, size_t, uint ba) gc_realloc;
- extern (C) size_t function(void*, size_t, size_t) gc_extend;
- extern (C) size_t function(size_t) gc_reserve;
- extern (C) void function(void*) gc_free;
- extern (C) void* function(void*) gc_addrOf;
- extern (C) size_t function(void*) gc_sizeOf;
- extern (C) BlkInfo function(void*) gc_query;
- extern (C) void function(void*) gc_addRoot;
- extern (C) void function(void*, size_t) gc_addRange;
- extern (C) void function(void*) gc_removeRoot;
- extern (C) void function(void*) gc_removeRange;
- }
- __gshared Proxy pthis;
- __gshared Proxy* proxy;
- void initProxy()
- {
- pthis.gc_enable = &gc_enable;
- pthis.gc_disable = &gc_disable;
- pthis.gc_collect = &gc_collect;
- pthis.gc_minimize = &gc_minimize;
- pthis.gc_getAttr = &gc_getAttr;
- pthis.gc_setAttr = &gc_setAttr;
- pthis.gc_clrAttr = &gc_clrAttr;
- pthis.gc_malloc = &gc_malloc;
- pthis.gc_qalloc = &gc_qalloc;
- pthis.gc_calloc = &gc_calloc;
- pthis.gc_realloc = &gc_realloc;
- pthis.gc_extend = &gc_extend;
- pthis.gc_reserve = &gc_reserve;
- pthis.gc_free = &gc_free;
- pthis.gc_addrOf = &gc_addrOf;
- pthis.gc_sizeOf = &gc_sizeOf;
- pthis.gc_query = &gc_query;
- pthis.gc_addRoot = &gc_addRoot;
- pthis.gc_addRange = &gc_addRange;
- pthis.gc_removeRoot = &gc_removeRoot;
- pthis.gc_removeRange = &gc_removeRange;
- }
- __gshared void** roots = null;
- __gshared size_t nroots = 0;
- struct Range
- {
- void* pos;
- size_t len;
- }
- __gshared Range* ranges = null;
- __gshared size_t nranges = 0;
- }
- extern (C) void gc_init()
- {
- // NOTE: The GC must initialize the thread library before its first
- // collection, and always before returning from gc_init().
- thread_init();
- initProxy();
- }
- extern (C) void gc_term()
- {
- free( roots );
- free( ranges );
- }
- extern (C) void gc_enable()
- {
- if( proxy is null )
- return;
- return proxy.gc_enable();
- }
- extern (C) void gc_disable()
- {
- if( proxy is null )
- return;
- return proxy.gc_disable();
- }
- extern (C) void gc_collect()
- {
- if( proxy is null )
- return;
- return proxy.gc_collect();
- }
- extern (C) void gc_minimize()
- {
- if( proxy is null )
- return;
- return proxy.gc_minimize();
- }
- extern (C) uint gc_getAttr( void* p )
- {
- if( proxy is null )
- return 0;
- return proxy.gc_getAttr( p );
- }
- extern (C) uint gc_setAttr( void* p, uint a )
- {
- if( proxy is null )
- return 0;
- return proxy.gc_setAttr( p, a );
- }
- extern (C) uint gc_clrAttr( void* p, uint a )
- {
- if( proxy is null )
- return 0;
- return proxy.gc_clrAttr( p, a );
- }
- extern (C) void* gc_malloc( size_t sz, uint ba = 0 )
- {
- if( proxy is null )
- {
- void* p = malloc( sz );
- if( sz && p is null )
- onOutOfMemoryError();
- return p;
- }
- return proxy.gc_malloc( sz, ba );
- }
- extern (C) BlkInfo gc_qalloc( size_t sz, uint ba = 0 )
- {
- if( proxy is null )
- {
- BlkInfo retval;
- retval.base = gc_malloc(sz, ba);
- retval.size = sz;
- retval.attr = ba;
- return retval;
- }
- return proxy.gc_qalloc( sz, ba );
- }
- extern (C) void* gc_calloc( size_t sz, uint ba = 0 )
- {
- if( proxy is null )
- {
- void* p = calloc( 1, sz );
- if( sz && p is null )
- onOutOfMemoryError();
- return p;
- }
- return proxy.gc_calloc( sz, ba );
- }
- extern (C) void* gc_realloc( void* p, size_t sz, uint ba = 0 )
- {
- if( proxy is null )
- {
- p = realloc( p, sz );
- if( sz && p is null )
- onOutOfMemoryError();
- return p;
- }
- return proxy.gc_realloc( p, sz, ba );
- }
- extern (C) size_t gc_extend( void* p, size_t mx, size_t sz )
- {
- if( proxy is null )
- return 0;
- return proxy.gc_extend( p, mx, sz );
- }
- extern (C) size_t gc_reserve( size_t sz )
- {
- if( proxy is null )
- return 0;
- return proxy.gc_reserve( sz );
- }
- extern (C) void gc_free( void* p )
- {
- if( proxy is null )
- return free( p );
- return proxy.gc_free( p );
- }
- extern (C) void* gc_addrOf( void* p )
- {
- if( proxy is null )
- return null;
- return proxy.gc_addrOf( p );
- }
- extern (C) size_t gc_sizeOf( void* p )
- {
- if( proxy is null )
- return 0;
- return proxy.gc_sizeOf( p );
- }
- extern (C) BlkInfo gc_query( void* p )
- {
- if( proxy is null )
- return BlkInfo.init;
- return proxy.gc_query( p );
- }
- extern (C) void gc_addRoot( void* p )
- {
- if( proxy is null )
- {
- void** r = cast(void**) realloc( roots,
- (nroots+1) * roots[0].sizeof );
- if( r is null )
- onOutOfMemoryError();
- r[nroots++] = p;
- roots = r;
- return;
- }
- return proxy.gc_addRoot( p );
- }
- extern (C) void gc_addRange( void* p, size_t sz )
- {
- //printf("gcstub::gc_addRange() proxy = %p\n", proxy);
- if( proxy is null )
- {
- Range* r = cast(Range*) realloc( ranges,
- (nranges+1) * ranges[0].sizeof );
- if( r is null )
- onOutOfMemoryError();
- r[nranges].pos = p;
- r[nranges].len = sz;
- ranges = r;
- ++nranges;
- return;
- }
- return proxy.gc_addRange( p, sz );
- }
- extern (C) void gc_removeRoot( void *p )
- {
- if( proxy is null )
- {
- for( size_t i = 0; i < nroots; ++i )
- {
- if( roots[i] is p )
- {
- roots[i] = roots[--nroots];
- return;
- }
- }
- assert( false );
- }
- return proxy.gc_removeRoot( p );
- }
- extern (C) void gc_removeRange( void *p )
- {
- if( proxy is null )
- {
- for( size_t i = 0; i < nranges; ++i )
- {
- if( ranges[i].pos is p )
- {
- ranges[i] = ranges[--nranges];
- return;
- }
- }
- assert( false );
- }
- return proxy.gc_removeRange( p );
- }
- extern (C) Proxy* gc_getProxy()
- {
- return &pthis;
- }
- export extern (C) void gc_setProxy( Proxy* p )
- {
- if( proxy !is null )
- {
- // TODO: Decide if this is an error condition.
- }
- proxy = p;
- foreach( r; roots[0 .. nroots] )
- proxy.gc_addRoot( r );
- foreach( r; ranges[0 .. nranges] )
- proxy.gc_addRange( r.pos, r.len );
- }
- export extern (C) void gc_clrProxy()
- {
- foreach( r; ranges[0 .. nranges] )
- proxy.gc_removeRange( r.pos );
- foreach( r; roots[0 .. nroots] )
- proxy.gc_removeRoot( r );
- proxy = null;
- }