Merge pull request #75 from CyberShadow/add-invalidmemoryoperation

Add InvalidMemoryOperationError to indicate garbage collector errors

src/core/exception.d

@@ -260,6 +260,47 @@ unittest
 }
 
 
+/**
+ * Thrown on an invalid memory operation.
+ *
+ * An invalid memory operation error occurs in circumstances when the garbage
+ * collector has detected an operation it cannot reliably handle. The default
+ * D GC is not re-entrant, so this can happen due to allocations done from
+ * within finalizers called during a garbage collection cycle.
+ */
+class InvalidMemoryOperationError : Error
+{
+    this(string file = __FILE__, size_t line = __LINE__, Throwable next = null )
+    {
+        super( "Invalid memory operation", file, line, next );
+    }
+
+    override string toString()
+    {
+        return msg ? super.toString() : "Invalid memory operation";
+    }
+}
+
+unittest
+{
+    {
+        auto oome = new InvalidMemoryOperationError();
+        assert(oome.file == __FILE__);
+        assert(oome.line == __LINE__ - 2);
+        assert(oome.next is null);
+        assert(oome.msg == "Invalid memory operation");
+    }
+
+    {
+        auto oome = new InvalidMemoryOperationError("hello", 42, new Exception("It's an Exception!"));
+        assert(oome.file == "hello");
+        assert(oome.line == 42);
+        assert(oome.next !is null);
+        assert(oome.msg == "Invalid memory operation");
+    }
+}
+
+
 /**
  * Thrown on a switch error.
  */
@@ -462,6 +503,22 @@ extern (C) void onOutOfMemoryError()
 }
 
 
+/**
+ * A callback for invalid memory operations in D.  An
+ * InvalidMemoryOperationError will be thrown.
+ *
+ * Throws:
+ *  InvalidMemoryOperationError.
+ */
+extern (C) void onInvalidMemoryOperationError()
+{
+    // The same restriction applies as for onOutOfMemoryError. The GC is in an
+    // undefined state, thus no allocation must occur while generating this object.
+    throw cast(InvalidMemoryOperationError)
+        cast(void*) InvalidMemoryOperationError.classinfo.init;
+}
+
+
 /**
  * A callback for switch errors in D.  A SwitchError will be thrown.
  *

src/gc/gcx.d

@@ -109,6 +109,7 @@ private
     }
 
     extern (C) void onOutOfMemoryError();
+    extern (C) void onInvalidMemoryOperationError();
 
     enum
     {
@@ -456,7 +457,7 @@ class GC
         //debug(PRINTF) printf("gcx.self = %x, pthread_self() = %x\n", gcx.self, pthread_self());
 
         if (gcx.running)
-            onOutOfMemoryError();
+            onInvalidMemoryOperationError();
 
         size += SENTINEL_EXTRA;
         bin = gcx.findBin(size);
@@ -587,7 +588,7 @@ class GC
     private void *reallocNoSync(void *p, size_t size, uint bits = 0, size_t *alloc_size = null)
     {
         if (gcx.running)
-            onOutOfMemoryError();
+            onInvalidMemoryOperationError();
 
         if (!size)
         {   if (p)
@@ -768,7 +769,7 @@ class GC
     body
     {
         if (gcx.running)
-            onOutOfMemoryError();
+            onInvalidMemoryOperationError();
 
         //debug(PRINTF) printf("GC::extend(p = %p, minsize = %zu, maxsize = %zu)\n", p, minsize, maxsize);
         version (SENTINEL)
@@ -859,7 +860,7 @@ class GC
         assert(gcx);
 
         if (gcx.running)
-            onOutOfMemoryError();
+            onInvalidMemoryOperationError();
 
         return gcx.reserve(size);
     }
@@ -895,7 +896,7 @@ class GC
         assert (p);
 
         if (gcx.running)
-            onOutOfMemoryError();
+            onInvalidMemoryOperationError();
 
         Pool*  pool;
         size_t pagenum;
@@ -2465,7 +2466,7 @@ struct Gcx
         //printf("\tpool address range = %p .. %p\n", minAddr, maxAddr);
 
         if (running)
-            onOutOfMemoryError();
+            onInvalidMemoryOperationError();
         running = 1;
 
         thread_suspendAll();