Insights-compatible memory tracking (#214)

This change introduces support for tracing of memory allocation activity. The code is ported from UE5, and Unreal Insights can be used to analyze the output. This is currently only fully supported on Windows, but will be extended to Mac/Linux in the near future.

To activate full memory tracking, pass `--trace=memory` on the commandline alongside `--tracehost=<ip>` or `-tracefile=<path>`. For more control over how much detail is traced you can instead pass some combination of `callstack`, `memtag`, `memalloc` instead. In practice, `--trace=memory` is an alias for `--trace=callstack,memtag,memalloc`). For convenience we also support `--trace=memory_light` which omits call stacks.

This change also introduces multiple memory allocators, which may be selected via command-line option `--malloc=<allocator>`:

* `mimalloc` - mimalloc (default, same as before)
* `rpmalloc` - rpmalloc is another high performance allocator for multithreaded applications which may be a better option than mimalloc (to be evaluated). Due to toolchain limitations this is currently only supported on Windows.
* `stomp` - an allocator intended to be used during development/debugging to help track down memory issues such as use-after-free or out-of-bounds access. Currently only supported on Windows.
* `ansi` - fallback to default system allocator

1 files changed, 107 insertions, 0 deletions

diff --git a/src/zencore/memtrack/platformtls.h b/src/zencore/memtrack/platformtls.h
new file mode 100644
index 000000000..f134e68a8
--- /dev/null
+++ b/src/zencore/memtrack/platformtls.h
@@ -0,0 +1,107 @@
+// Copyright Epic Games, Inc. All Rights Reserved.
+
+#pragma once
+
+#include <zenbase/zenbase.h>
+
+/**
+ * It should be possible to provide a generic implementation as long as a threadID is provided. We don't do that yet.
+ */
+struct FGenericPlatformTLS
+{
+	static const uint32_t InvalidTlsSlot = 0xFFFFFFFF;
+
+	/**
+	 * Return false if this is an invalid TLS slot
+	 * @param SlotIndex the TLS index to check
+	 * @return true if this looks like a valid slot
+	 */
+	static bool IsValidTlsSlot(uint32_t SlotIndex) { return SlotIndex != InvalidTlsSlot; }
+};
+
+#if ZEN_PLATFORM_WINDOWS
+
+#	include <zencore/windows.h>
+
+class FWindowsPlatformTLS : public FGenericPlatformTLS
+{
+public:
+	static uint32_t AllocTlsSlot() { return ::TlsAlloc(); }
+
+	static void FreeTlsSlot(uint32_t SlotIndex) { ::TlsFree(SlotIndex); }
+
+	static void SetTlsValue(uint32_t SlotIndex, void* Value) { ::TlsSetValue(SlotIndex, Value); }
+
+	/**
+	 * Reads the value stored at the specified TLS slot
+	 *
+	 * @return the value stored in the slot
+	 */
+	static void* GetTlsValue(uint32_t SlotIndex) { return ::TlsGetValue(SlotIndex); }
+
+	/**
+	 * Return false if this is an invalid TLS slot
+	 * @param SlotIndex the TLS index to check
+	 * @return true if this looks like a valid slot
+	 */
+	static bool IsValidTlsSlot(uint32_t SlotIndex) { return SlotIndex != InvalidTlsSlot; }
+};
+
+typedef FWindowsPlatformTLS FPlatformTLS;
+
+#elif ZEN_PLATFORM_MAC
+
+#	include <pthread.h
+
+/**
+ * Apple implementation of the TLS OS functions
+ **/
+struct FApplePlatformTLS : public FGenericPlatformTLS
+{
+	/**
+	 * Returns the currently executing thread's id
+	 */
+	static uint32_t GetCurrentThreadId(void) { return (uint32_t)pthread_mach_thread_np(pthread_self()); }
+
+	/**
+	 * Allocates a thread local store slot
+	 */
+	static uint32_t AllocTlsSlot(void)
+	{
+		// allocate a per-thread mem slot
+		pthread_key_t SlotKey = 0;
+		if (pthread_key_create(&SlotKey, NULL) != 0)
+		{
+			SlotKey = InvalidTlsSlot;  // matches the Windows TlsAlloc() retval.
+		}
+		return SlotKey;
+	}
+
+	/**
+	 * Sets a value in the specified TLS slot
+	 *
+	 * @param SlotIndex the TLS index to store it in
+	 * @param Value the value to store in the slot
+	 */
+	static void SetTlsValue(uint32_t SlotIndex, void* Value) { pthread_setspecific((pthread_key_t)SlotIndex, Value); }
+
+	/**
+	 * Reads the value stored at the specified TLS slot
+	 *
+	 * @return the value stored in the slot
+	 */
+	static void* GetTlsValue(uint32_t SlotIndex) { return pthread_getspecific((pthread_key_t)SlotIndex); }
+
+	/**
+	 * Frees a previously allocated TLS slot
+	 *
+	 * @param SlotIndex the TLS index to store it in
+	 */
+	static void FreeTlsSlot(uint32_t SlotIndex) { pthread_key_delete((pthread_key_t)SlotIndex); }
+};
+
+typedef FApplePlatformTLS FPlatformTLS;
+
+#else
+#	error Platform not yet supported
+#endif