addRange/addRoot lazy init

Author: somzzz

src/gc/impl/proto/gc.d

@@ -31,8 +31,27 @@ private
 
 class ProtoGC : GC
 {
-    __gshared Array!Root roots;
-    __gshared Array!Range ranges;
+    Array!Root roots;
+    Array!Range ranges;
+
+    // Call this function when initializing the real GC
+    // upon ProtoGC term. This function should be called
+    // after the real GC is in place.
+    void term()
+    {
+        // Transfer all ranges
+        foreach (ref r; ranges)
+        {
+            // Range(p, p + sz, cast() ti)
+            gc_addRange(r.pbot, r.ptop - r.pbot, r.ti);
+        }
+
+        // Transfer all roots
+        foreach (ref r; roots)
+        {
+            gc_addRoot(r.proot);
+        }
+    }
 
     this()
     {
@@ -141,14 +160,24 @@ class ProtoGC : GC
         return typeof(return).init;
     }
 
+
     void addRoot(void* p) nothrow @nogc
     {
-        gc_init_nothrow();
-        gc_addRoot(p);
+        roots.insertBack(Root(p));
     }
 
     void removeRoot(void* p) nothrow @nogc
     {
+        foreach (ref r; roots)
+        {
+            if (r is p)
+            {
+                r = roots.back;
+                roots.popBack();
+                return;
+            }
+        }
+        assert(false);
     }
 
     @property RootIterator rootIter() return @nogc
@@ -158,17 +187,31 @@ class ProtoGC : GC
 
     private int rootsApply(scope int delegate(ref Root) nothrow dg)
     {
+        foreach (ref r; roots)
+        {
+            if (auto result = dg(r))
+                return result;
+        }
         return 0;
     }
 
     void addRange(void* p, size_t sz, const TypeInfo ti = null) nothrow @nogc
     {
-        gc_init_nothrow();
-        gc_addRange(p, sz, ti);
+        ranges.insertBack(Range(p, p + sz, cast() ti));
     }
 
     void removeRange(void* p) nothrow @nogc
     {
+        foreach (ref r; ranges)
+        {
+            if (r.pbot is p)
+            {
+                r = ranges.back;
+                ranges.popBack();
+                return;
+            }
+        }
+        assert(false);
     }
 
     @property RangeIterator rangeIter() return @nogc
@@ -178,6 +221,11 @@ class ProtoGC : GC
 
     private int rangesApply(scope int delegate(ref Range) nothrow dg)
     {
+        foreach (ref r; ranges)
+        {
+            if (auto result = dg(r))
+                return result;
+        }
         return 0;
     }
 

src/gc/proxy.d

@@ -38,8 +38,6 @@ extern (C)
 {
     void gc_init()
     {
-        import core.atomic : atomicLoad, atomicStore, MemoryOrder;
-
         instanceLock.lock();
         if (!isInstanceInit)
         {
@@ -48,7 +46,7 @@ extern (C)
             ManualGC.initialize(instance);
             ConservativeGC.initialize(instance);
 
-            if (instance == protoInstance)
+            if (instance is protoInstance)
             {
                 import core.stdc.stdio : fprintf, stderr;
                 import core.stdc.stdlib : exit;
@@ -61,6 +59,8 @@ extern (C)
                 assert(0);
             }
 
+            // Transfer all ranges and roots to the real GC.
+            (cast(ProtoGC) protoInstance).term();
             isInstanceInit = true;
         }
         instanceLock.unlock();
@@ -89,11 +89,14 @@ extern (C)
         // NOTE: Due to popular demand, this has been re-enabled.  It still has
         //       the problems mentioned above though, so I guess we'll see.
 
-        instance.collectNoStack();  // not really a 'collect all' -- still scans
-                                    // static data area, roots, and ranges.
+        if (isInstanceInit)
+        {
+            instance.collectNoStack();  // not really a 'collect all' -- still scans
+                                        // static data area, roots, and ranges.
 
-        ManualGC.finalize(instance);
-        ConservativeGC.finalize(instance);
+            ManualGC.finalize(instance);
+            ConservativeGC.finalize(instance);
+        }
     }
 
     void gc_enable()

src/rt/dmain2.d

@@ -58,7 +58,6 @@ extern (C) void _d_monitor_staticctor();
 extern (C) void _d_monitor_staticdtor();
 extern (C) void _d_critical_init();
 extern (C) void _d_critical_term();
-extern (C) void protogc_init();
 extern (C) void gc_init();
 extern (C) void gc_term();
 extern (C) void thread_init() @nogc;

test/exceptions/src/unknown_gc.d

@@ -1,5 +1,9 @@
+import core.memory;
+
 extern(C) __gshared string[] rt_options = [ "gcopt=gc:unknowngc" ];
 
 void main()
 {
+	// GC initialized upon first call -> Unknown GC error is thrown
+	GC.enable();
 }

test/nogc.d

@@ -1,4 +1,4 @@
-extern(C) __gshared string[] rt_options = [ "gcopt=gc:conservative" ];
+extern(C) __gshared string[] rt_options = [ "gcopt=gc:non-existing" ];
 
 void main() @nogc
 {