Add method to disown blocks

Intended for use in cases where the memory block deallocation is expected to be out of the plugin's control.
nosoop · Jan 21, 2020 · 53de1fd · 53de1fd
1 parent 8905e1a
commit 53de1fd
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Showing 4 changed files with 34 additions and 9 deletions.
diff --git a/scripting/include/sourcescramble.inc b/scripting/include/sourcescramble.inc
@@ -48,6 +48,15 @@ methodmap MemoryBlock < Handle {
 	 */
 	public native MemoryBlock(int size);
 
+	/**
+	 * Disowns the associated memory block, allowing it to remain allocated even when the handle
+	 * is deleted.  Disowning the memory does not invalidate the handle.
+	 * 
+	 * Only use this if you are certain that something else will free (or has freed) the memory
+	 * block.
+	 */
+	public native void Disown();
+
 	/**
 	 * Returns the address of the allocated memory block.
 	 */
@@ -94,7 +103,7 @@ static stock int GetNumberTypeByteSize(NumberType size) {
 		case NumberType_Int32: return 4;
 	}
 	ThrowError("Unknown NumberType %d.  Did the SourceMod developers add some new ones?", size);
-	return 1;
+	return 1; // maybe `return (1 << size);` ?
 }
 
 public Extension __ext_sourcescramble = {

diff --git a/smsdk_config.h b/smsdk_config.h
@@ -39,8 +39,8 @@
 
 /* Basic information exposed publicly */
 #define SMEXT_CONF_NAME			"Source Scramble"
-#define SMEXT_CONF_DESCRIPTION	"Convenience functions to perform memory patching."
-#define SMEXT_CONF_VERSION		"0.3.4"
+#define SMEXT_CONF_DESCRIPTION	"Tools for working with memory."
+#define SMEXT_CONF_VERSION		"0.4.0"
 #define SMEXT_CONF_AUTHOR		"nosoop"
 #define SMEXT_CONF_URL			"https://github.com/nosoop/SMExt-SourceScramble"
 #define SMEXT_CONF_LOGTAG		"sscramble"

diff --git a/types/memblock.cpp b/types/memblock.cpp
@@ -5,18 +5,19 @@
 
 HandleType_t g_MemoryBlockType = 0;
 
-class MemoryBlock {
-public:
-	MemoryBlock(size_t size) {
+struct MemoryBlock {
+	MemoryBlock(size_t size) : size{size}, disowned{false} {
 		this->block = calloc(size, 1);
-		this->size = size;
 	}
 
 	~MemoryBlock() {
-		free(this->block);
+		if (!disowned) {
+			free(this->block);
+		}
 	}
 
 	size_t size;
+	bool disowned;
 	void* block;
 };
 
@@ -61,7 +62,7 @@ cell_t sm_MemoryBlockPropAddressGet(IPluginContext *pContext, const cell_t *para
 		return pContext->ThrowNativeError("Invalid MemoryBlock handle %x (error %d)", hndl, err);
 	}
 
-	return (uint32_t) pMemoryBlock->block;
+	return (uintptr_t) pMemoryBlock->block;
 }
 
 cell_t sm_MemoryBlockPropSizeGet(IPluginContext *pContext, const cell_t *params) {
@@ -75,3 +76,16 @@ cell_t sm_MemoryBlockPropSizeGet(IPluginContext *pContext, const cell_t *params)
 
 	return pMemoryBlock->size;
 }
+
+cell_t sm_MemoryBlockDisown(IPluginContext *pContext, const cell_t *params) {
+	Handle_t hndl = static_cast<Handle_t>(params[1]);
+
+	MemoryBlock *pMemoryBlock;
+	HandleError err;
+	if ((err = ReadMemoryBlockHandle(hndl, &pMemoryBlock)) != HandleError_None) {
+		return pContext->ThrowNativeError("Invalid MemoryBlock handle %x (error %d)", hndl, err);
+	}
+
+	pMemoryBlock->disowned = true;
+	return 0;
+}
diff --git a/types/memblock.h b/types/memblock.h
@@ -11,12 +11,14 @@ cell_t sm_MemoryBlockCreate(IPluginContext *pContext, const cell_t *params);
 
 cell_t sm_MemoryBlockPropAddressGet(IPluginContext *pContext, const cell_t *params);
 cell_t sm_MemoryBlockPropSizeGet(IPluginContext *pContext, const cell_t *params);
+cell_t sm_MemoryBlockDisown(IPluginContext *pContext, const cell_t *params);
 
 const sp_nativeinfo_t g_MemoryBlockNatives[] = {
 	{ "MemoryBlock.MemoryBlock", sm_MemoryBlockCreate },
 
 	{ "MemoryBlock.Address.get", sm_MemoryBlockPropAddressGet },
 	{ "MemoryBlock.Size.get", sm_MemoryBlockPropSizeGet },
+	{ "MemoryBlock.Disown", sm_MemoryBlockDisown },
 
 	{NULL, NULL},
 };