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Merge pull request #2057 from somzzz/moving_gc_init
GC Initialized on First Alloc merged-on-behalf-of: unknown
2 parents dd5fe6f + c025466 commit fb17fe9

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7 files changed

+303
-19
lines changed

7 files changed

+303
-19
lines changed

‎changelog/lazy-gc-init.dd‎

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the garbage collector is now lazily initialized on first use
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The runtime now lazily initializes the GC on first use, thus allowing applications that do not use the GC to skip its initialization.

‎mak/SRCS‎

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@@ -298,6 +298,7 @@ SRCS=\
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src\gc\proxy.d \
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src\gc\impl\conservative\gc.d \
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src\gc\impl\manual\gc.d \
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src\gc\impl\proto\gc.d \
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\
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src\rt\aApply.d \
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src\rt\aApplyR.d \

‎src/gc/impl/proto/gc.d‎

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module gc.impl.proto.gc;
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import gc.config;
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import gc.gcinterface;
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import rt.util.container.array;
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import cstdlib = core.stdc.stdlib : calloc, free, malloc, realloc;
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static import core.memory;
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extern (C) void onOutOfMemoryError(void* pretend_sideffect = null) @trusted pure nothrow @nogc; /* dmd @@@BUG11461@@@ */
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private
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{
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extern (C) void gc_init_nothrow() nothrow @nogc;
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extern (C) void gc_term();
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extern (C) void gc_enable() nothrow;
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extern (C) void gc_disable() nothrow;
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extern (C) void* gc_malloc( size_t sz, uint ba = 0, const TypeInfo = null ) pure nothrow;
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extern (C) void* gc_calloc( size_t sz, uint ba = 0, const TypeInfo = null ) pure nothrow;
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extern (C) BlkInfo gc_qalloc( size_t sz, uint ba = 0, const TypeInfo = null ) pure nothrow;
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extern (C) void* gc_realloc( void* p, size_t sz, uint ba = 0, const TypeInfo = null ) pure nothrow;
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extern (C) size_t gc_reserve( size_t sz ) nothrow;
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extern (C) void gc_addRange( void* p, size_t sz, const TypeInfo ti = null ) nothrow @nogc;
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extern (C) void gc_addRoot( void* p ) nothrow @nogc;
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}
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class ProtoGC : GC
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{
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Array!Root roots;
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Array!Range ranges;
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// Call this function when initializing the real GC
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// upon ProtoGC term. This function should be called
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// after the real GC is in place.
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void term()
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{
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// Transfer all ranges
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foreach (ref r; ranges)
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{
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// Range(p, p + sz, cast() ti)
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gc_addRange(r.pbot, r.ptop - r.pbot, r.ti);
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}
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// Transfer all roots
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foreach (ref r; roots)
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{
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gc_addRoot(r.proot);
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}
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}
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this()
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{
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}
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void Dtor()
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{
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}
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void enable()
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{
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gc_init_nothrow();
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gc_enable();
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}
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void disable()
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{
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gc_init_nothrow();
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gc_disable();
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}
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void collect() nothrow
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{
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}
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void collectNoStack() nothrow
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{
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}
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void minimize() nothrow
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{
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}
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uint getAttr(void* p) nothrow
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{
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return 0;
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}
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uint setAttr(void* p, uint mask) nothrow
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{
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return 0;
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}
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uint clrAttr(void* p, uint mask) nothrow
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{
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return 0;
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}
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void* malloc(size_t size, uint bits, const TypeInfo ti) nothrow
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{
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gc_init_nothrow();
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return gc_malloc(size, bits, ti);
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}
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BlkInfo qalloc(size_t size, uint bits, const TypeInfo ti) nothrow
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{
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gc_init_nothrow();
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return gc_qalloc(size, bits, ti);
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}
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void* calloc(size_t size, uint bits, const TypeInfo ti) nothrow
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{
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gc_init_nothrow();
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return gc_calloc(size, bits, ti);
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}
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void* realloc(void* p, size_t size, uint bits, const TypeInfo ti) nothrow
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{
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gc_init_nothrow();
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return gc_realloc(p, size, bits, ti);
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}
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size_t extend(void* p, size_t minsize, size_t maxsize, const TypeInfo ti) nothrow
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{
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return 0;
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}
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size_t reserve(size_t size) nothrow
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{
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gc_init_nothrow();
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return reserve(size);
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}
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void free(void* p) nothrow @nogc
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{
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if (p) assert(false, "Invalid memory deallocation");
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}
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void* addrOf(void* p) nothrow @nogc
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{
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return null;
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}
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size_t sizeOf(void* p) nothrow @nogc
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{
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return 0;
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}
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BlkInfo query(void* p) nothrow
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{
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return BlkInfo.init;
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}
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core.memory.GC.Stats stats() nothrow
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{
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return typeof(return).init;
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}
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void addRoot(void* p) nothrow @nogc
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{
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roots.insertBack(Root(p));
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}
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void removeRoot(void* p) nothrow @nogc
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{
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foreach (ref r; roots)
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{
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if (r is p)
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{
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r = roots.back;
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roots.popBack();
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return;
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}
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}
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assert(false);
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}
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@property RootIterator rootIter() return @nogc
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{
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return &rootsApply;
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}
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private int rootsApply(scope int delegate(ref Root) nothrow dg)
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{
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foreach (ref r; roots)
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{
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if (auto result = dg(r))
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return result;
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}
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return 0;
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}
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void addRange(void* p, size_t sz, const TypeInfo ti = null) nothrow @nogc
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{
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ranges.insertBack(Range(p, p + sz, cast() ti));
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}
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void removeRange(void* p) nothrow @nogc
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{
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foreach (ref r; ranges)
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{
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if (r.pbot is p)
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{
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r = ranges.back;
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ranges.popBack();
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return;
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}
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}
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assert(false);
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}
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@property RangeIterator rangeIter() return @nogc
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{
219+
return &rangesApply;
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}
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private int rangesApply(scope int delegate(ref Range) nothrow dg)
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{
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foreach (ref r; ranges)
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{
226+
if (auto result = dg(r))
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return result;
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}
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return 0;
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}
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void runFinalizers(in void[] segment) nothrow
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{
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}
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bool inFinalizer() nothrow
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{
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return false;
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}
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}

‎src/gc/proxy.d‎

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Original file line numberDiff line numberDiff line change
@@ -15,6 +15,7 @@ module gc.proxy;
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import gc.impl.conservative.gc;
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import gc.impl.manual.gc;
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import gc.impl.proto.gc;
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import gc.config;
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import gc.gcinterface;
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@@ -25,28 +26,55 @@ private
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static import core.memory;
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alias BlkInfo = core.memory.GC.BlkInfo;
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28-
__gshared GC instance;
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__gshared GC proxiedGC; // used to iterate roots of Windows DLLs
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import core.internal.spinlock;
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static SpinLock instanceLock;
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32+
__gshared bool isInstanceInit = false;
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__gshared GC instance = new ProtoGC();
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__gshared GC proxiedGC; // used to iterate roots of Windows DLLs
3135
}
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extern (C)
3538
{
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void gc_init()
3840
{
39-
config.initialize();
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ManualGC.initialize(instance);
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ConservativeGC.initialize(instance);
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if (instance is null)
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instanceLock.lock();
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if (!isInstanceInit)
4343
{
44-
import core.stdc.stdio : fprintf, stderr;
45-
import core.stdc.stdlib : exit;
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auto protoInstance = instance;
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config.initialize();
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ManualGC.initialize(instance);
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ConservativeGC.initialize(instance);
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if (instance is protoInstance)
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{
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import core.stdc.stdio : fprintf, stderr;
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import core.stdc.stdlib : exit;
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fprintf(stderr, "No GC was initialized, please recheck the name of the selected GC ('%.*s').\n", cast(int)config.gc.length, config.gc.ptr);
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instanceLock.unlock();
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exit(1);
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// Shouldn't get here.
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assert(0);
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}
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// Transfer all ranges and roots to the real GC.
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(cast(ProtoGC) protoInstance).term();
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isInstanceInit = true;
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}
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instanceLock.unlock();
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}
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47-
fprintf(stderr, "No GC was initialized, please recheck the name of the selected GC ('%.*s').\n", cast(int)config.gc.length, config.gc.ptr);
48-
exit(1);
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void gc_init_nothrow() nothrow
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{
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scope(failure)
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{
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import core.internal.abort;
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abort("Cannot initialize the garbage collector.\n");
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assert(0);
4976
}
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gc_init();
5078
}
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5280
void gc_term()
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// NOTE: Due to popular demand, this has been re-enabled. It still has
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// the problems mentioned above though, so I guess we'll see.
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instance.collectNoStack(); // not really a 'collect all' -- still scans
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// static data area, roots, and ranges.
92+
if (isInstanceInit)
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{
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instance.collectNoStack(); // not really a 'collect all' -- still scans
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// static data area, roots, and ranges.
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67-
ManualGC.finalize(instance);
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ConservativeGC.finalize(instance);
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ManualGC.finalize(instance);
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ConservativeGC.finalize(instance);
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}
69100
}
70101

71102
void gc_enable()
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158189
return instance.stats();
159190
}
160191

161-
void gc_addRoot( void* p ) nothrow
192+
void gc_addRoot( void* p ) nothrow @nogc
162193
{
163194
return instance.addRoot( p );
164195
}
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166-
void gc_addRange( void* p, size_t sz, const TypeInfo ti = null ) nothrow
197+
void gc_addRange( void* p, size_t sz, const TypeInfo ti = null ) nothrow @nogc
167198
{
168199
return instance.addRange( p, sz, ti );
169200
}

‎src/rt/dmain2.d‎

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// in other druntime systems.
198198
_d_initMonoTime();
199199
thread_init();
200-
gc_init();
200+
// TODO: fixme - calls GC.addRange -> Initializes GC
201201
initStaticDataGC();
202202
lifetime_init();
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rt_moduleCtor();

‎test/exceptions/src/unknown_gc.d‎

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import core.memory;
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extern(C) __gshared string[] rt_options = [ "gcopt=gc:unknowngc" ];
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void main()
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{
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// GC initialized upon first call -> Unknown GC error is thrown
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GC.enable();
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}

‎test/nogc.d‎

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extern(C) __gshared string[] rt_options = [ "gcopt=gc:non-existing" ];
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void main() @nogc
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{
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}

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