From 2d49ac78b804031942a294b1e0225aeae0e01cdc Mon Sep 17 00:00:00 2001
From: Jordan Bancino <jordan@bancino.net>
Date: Wed, 12 Oct 2022 21:29:05 -0400
Subject: [PATCH] Add custom memory management code.

This will be helpful in detecting leaks among other things, and may help
with controlling the cache size as well.
---
 src/Memory.c         | 272 +++++++++++++++++++++++++++++++++++++++++++
 src/include/Memory.h |  29 +++++
 2 files changed, 301 insertions(+)
 create mode 100644 src/Memory.c
 create mode 100644 src/include/Memory.h

diff --git a/src/Memory.c b/src/Memory.c
new file mode 100644
index 0000000..ca3bea9
--- /dev/null
+++ b/src/Memory.c
@@ -0,0 +1,272 @@
+#include <Memory.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <pthread.h>
+
+struct MemoryInfo
+{
+	size_t size;
+	const char *file;
+	const char *func;
+	int line;
+	void *pointer;
+
+	MemoryInfo *next;
+	MemoryInfo *prev;
+};
+
+static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
+static MemoryInfo *lastAllocation = NULL;
+
+void *
+MemoryAllocate(size_t size, const char *file, int line, const char *func)
+{
+	void *p;
+	MemoryInfo *a;
+
+	pthread_mutex_lock(&lock);
+
+	p = malloc(size);
+	if (!p)
+	{
+		pthread_mutex_unlock(&lock);
+		return NULL;
+	}
+
+	a = malloc(sizeof(MemoryInfo));
+	if (!a)
+	{
+		free(p);
+		pthread_mutex_unlock(&lock);
+		return NULL;
+	}
+
+	a->size = size;
+	a->file = file;
+	a->line = line;
+	a->func = func;
+	a->pointer = p;
+	a->next = NULL;
+	a->prev = lastAllocation;
+
+	if (lastAllocation)
+	{
+		lastAllocation->next = a;
+	}
+
+	lastAllocation = a;
+
+	pthread_mutex_unlock(&lock);
+	return p;
+}
+
+void *
+MemoryReallocate(void *p, size_t size)
+{
+	MemoryInfo *a;
+	void *new = NULL;
+
+	pthread_mutex_lock(&lock);
+
+	a = lastAllocation;
+	while (a)
+	{
+		if (a->pointer == p)
+		{
+			new = realloc(p, size);
+			if (new)
+			{
+				a->pointer = new;
+				a->size = size;
+			}
+
+			break;
+		}
+
+		a = a->prev;
+	}
+
+	pthread_mutex_unlock(&lock);
+
+	return new;
+}
+
+void
+MemoryFree(void *p)
+{
+	MemoryInfo *a;
+
+	pthread_mutex_lock(&lock);
+
+	a = lastAllocation;
+
+	while (a)
+	{
+		if (a->pointer == p)
+		{
+			if (a->prev)
+			{
+				a->prev->next = a->next;
+			}
+			else
+			{
+				lastAllocation = a->next;
+			}
+
+			if (a->next)
+			{
+				a->next->prev = a->prev;
+			}
+			else
+			{
+				lastAllocation = a->prev;
+			}
+
+			free(a);
+			free(p);
+
+			break;
+		}
+			
+		a = a->prev;
+	}
+
+	pthread_mutex_unlock(&lock);
+}
+
+size_t
+MemoryAllocated(void)
+{
+	MemoryInfo *a;
+	size_t total = 0;
+
+	pthread_mutex_lock(&lock);
+
+	a = lastAllocation;
+	while (a)
+	{
+		total += a->size;
+		a = a->prev;
+	}
+
+	pthread_mutex_unlock(&lock);
+
+	return total;
+}
+
+void
+MemoryFreeAll(void)
+{
+	MemoryInfo *a;
+
+	pthread_mutex_lock(&lock);
+
+	a = lastAllocation;
+	while (a)
+	{
+		MemoryInfo *prev = a->prev;
+
+		free(a->pointer);
+		free(a);
+
+		a = prev;
+	}
+
+	lastAllocation = NULL;
+
+	pthread_mutex_unlock(&lock);
+}
+
+MemoryInfo *
+MemoryInfoGet(void *p)
+{
+	MemoryInfo *a;
+
+	pthread_mutex_lock(&lock);
+
+	a = lastAllocation;
+	while (a)
+	{
+		if (a->pointer == p)
+		{
+			break;
+		}
+
+		a = a->prev;
+	}
+
+	return a;
+}
+
+size_t
+MemoryInfoGetSize(MemoryInfo *a)
+{
+	if (!a)
+	{
+		return 0;
+	}
+
+	return a->size;
+}
+
+const char *
+MemoryInfoGetFile(MemoryInfo *a)
+{
+	if (!a)
+	{
+		return NULL;
+	}
+
+	return a->file;
+}
+
+const char *
+MemoryInfoGetFunc(MemoryInfo *a)
+{
+	if (!a)
+	{
+		return NULL;
+	}
+
+	return a->func;
+}
+
+int
+MemoryInfoGetLine(MemoryInfo *a)
+{
+	if (!a)
+	{
+		return -1;
+	}
+
+	return a->line;
+}
+
+void *
+MemoryInfoGetPointer(MemoryInfo *a)
+{
+	if (!a)
+	{
+		return NULL;
+	}
+
+	return a->pointer;
+}
+
+void
+MemoryIterate(void (*iterFunc)(MemoryInfo *, void *), void *args)
+{
+	MemoryInfo *a;
+
+	pthread_mutex_lock(&lock);
+
+	a = lastAllocation;
+	while (a)
+	{
+		iterFunc(a, args);
+		a = a->prev;
+	}
+
+	pthread_mutex_unlock(&lock);
+}
diff --git a/src/include/Memory.h b/src/include/Memory.h
new file mode 100644
index 0000000..800b7f3
--- /dev/null
+++ b/src/include/Memory.h
@@ -0,0 +1,29 @@
+#ifndef TELODENDRIA_MEMORY_H
+#define TELODENDRIA_MEMORY_H
+
+#include <stddef.h>
+
+#define Malloc(x) MemoryAllocate(x, __FILE__, __LINE__, __FUNCTION__)
+#define Realloc(x, s) MemoryReallocate(x, s)
+#define Free(x) MemoryFree(x)
+
+typedef struct MemoryInfo MemoryInfo;
+
+extern void *MemoryAllocate(size_t, const char *, int, const char *);
+extern void *MemoryReallocate(void *, size_t);
+extern void MemoryFree(void *);
+
+extern size_t MemoryAllocated(void);
+extern void MemoryFreeAll(void);
+
+extern MemoryInfo * MemoryInfoGet(void *);
+
+extern size_t MemoryInfoGetSize(MemoryInfo *);
+extern const char * MemoryInfoGetFile(MemoryInfo *);
+extern const char * MemoryInfoGetFunc(MemoryInfo *);
+extern int MemoryInfoGetLine(MemoryInfo *);
+extern void * MemoryInfoGetPointer(MemoryInfo *);
+
+extern void MemoryIterate(void (*)(MemoryInfo *, void *), void *);
+
+#endif