/*************************************************************************/
/*  memory_pool_static_malloc.cpp                                        */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
/*                    http://www.godotengine.org                         */
/*************************************************************************/
/* Copyright (c) 2007-2016 Juan Linietsky, Ariel Manzur.                 */
/*                                                                       */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the       */
/* "Software"), to deal in the Software without restriction, including   */
/* without limitation the rights to use, copy, modify, merge, publish,   */
/* distribute, sublicense, and/or sell copies of the Software, and to    */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions:                                             */
/*                                                                       */
/* The above copyright notice and this permission notice shall be        */
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/*                                                                       */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
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/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
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/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
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/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
/*************************************************************************/
#include "memory_pool_static_malloc.h"
#include "error_macros.h"
#include "os/memory.h"
#include <stdlib.h>
#include <stdio.h>
#include "os/copymem.h"
#include "os/os.h"

/**
 * NOTE NOTE NOTE NOTE
 * in debug mode, this prepends the memory size to the allocated block
 * so BE CAREFUL!
 */

void* MemoryPoolStaticMalloc::alloc(size_t p_bytes,const char *p_description) {

	#if DEFAULT_ALIGNMENT == 1

		return _alloc(p_bytes, p_description);

	#else

		int total = p_bytes + DEFAULT_ALIGNMENT;
		uint8_t* ptr = (uint8_t*)_alloc(total, p_description);
		ERR_FAIL_COND_V( !ptr, ptr );
		int ofs = (DEFAULT_ALIGNMENT - ((uintptr_t)ptr & (DEFAULT_ALIGNMENT - 1)));
		ptr[ofs-1] = ofs;
		return (void*)(ptr + ofs);
	#endif
};
 
void* MemoryPoolStaticMalloc::_alloc(size_t p_bytes,const char *p_description) {
 
 	ERR_FAIL_COND_V(p_bytes==0,0);
	
	MutexLock lock(mutex);
	
#ifdef DEBUG_MEMORY_ENABLED
	void *mem=malloc(p_bytes+sizeof(RingPtr)); /// add for size and ringlist

	if (!mem) {
		printf("**ERROR: out of memory while allocating %i bytes by %s?\n",(int) p_bytes, p_description);
		printf("**ERROR: memory usage is %i\n", (int)get_total_usage());
	};
	
	ERR_FAIL_COND_V(!mem,0); //out of memory, or unreasonable request
		
	/* setup the ringlist element */
	
	RingPtr *ringptr = (RingPtr*)mem;
	
	/* setup the ringlist element data (description and size ) */
	
	ringptr->size = p_bytes;
	ringptr->descr=p_description;
	
	if (ringlist) { /* existing ringlist */
		
		/* assign next */
		ringptr->next = ringlist->next;
		ringlist->next = ringptr;
		/* assign prev */
		ringptr->prev = ringlist;
		ringptr->next->prev = ringptr;
	} else { /* non existing ringlist */
		
		ringptr->next=ringptr;
		ringptr->prev=ringptr;
		ringlist=ringptr;
		
	}
	
	total_mem+=p_bytes;
	
	/* update statistics */
	if (total_mem > max_mem )
		max_mem = total_mem;
	
	total_pointers++;
	
	if (total_pointers > max_pointers)
		max_pointers=total_pointers;
	
	return ringptr + 1; /* return memory after ringptr */
		
#else		
	void *mem=malloc(p_bytes);

	ERR_FAIL_COND_V(!mem,0); //out of memory, or unreasonable request
	return mem;			
#endif	
}


void* MemoryPoolStaticMalloc::realloc(void *p_memory,size_t p_bytes) {

	#if DEFAULT_ALIGNMENT == 1

		return _realloc(p_memory,p_bytes);
	#else
		if (!p_memory)
			return alloc(p_bytes);

		int total = p_bytes + DEFAULT_ALIGNMENT;
		uint8_t* mem = (uint8_t*)p_memory;
		int ofs = *(mem-1);
		mem = mem - ofs;
		uint8_t* ptr = (uint8_t*)_realloc(mem, total);
		ERR_FAIL_COND_V(ptr == NULL, NULL);
		int new_ofs = (DEFAULT_ALIGNMENT - ((uintptr_t)ptr & (DEFAULT_ALIGNMENT - 1)));
		if (new_ofs != ofs) {

			//printf("realloc moving %i bytes\n", p_bytes);
			movemem((ptr + new_ofs), (ptr + ofs), p_bytes);
			ptr[new_ofs-1] = new_ofs;
		};
		return ptr + new_ofs;
	#endif
};

void* MemoryPoolStaticMalloc::_realloc(void *p_memory,size_t p_bytes) {
	
	if (p_memory==NULL) {
		
		return alloc( p_bytes );
	}
		
	if (p_bytes==0) {
		
		this->free(p_memory);
		ERR_FAIL_COND_V( p_bytes < 0 , NULL );
		return NULL;
	}
	
	MutexLock lock(mutex);
	
#ifdef DEBUG_MEMORY_ENABLED
	
	
	RingPtr *ringptr = (RingPtr*)p_memory;
	ringptr--; /* go back an element to find the tingptr */
	
	bool single_element = (ringptr->next == ringptr) && (ringptr->prev == ringptr);
	bool is_list = ( ringlist == ringptr );
	
	RingPtr *new_ringptr=(RingPtr*)::realloc(ringptr, p_bytes+sizeof(RingPtr));
	
	ERR_FAIL_COND_V( new_ringptr == 0, NULL ); /// reallocation failed 
		
	/* actualize mem used */
	total_mem -= new_ringptr->size;
	new_ringptr->size = p_bytes;
	total_mem +=  new_ringptr->size;
	
	if (total_mem > max_mem ) //update statistics
		max_mem = total_mem;
	
	if (new_ringptr == ringptr )
		return ringptr + 1; // block didn't move, don't do anything
	
	if (single_element) {
		
		new_ringptr->next=new_ringptr;
		new_ringptr->prev=new_ringptr;
	} else {
		
		new_ringptr->next->prev=new_ringptr;
		new_ringptr->prev->next=new_ringptr;		
	}
	
	if (is_list)
		ringlist=new_ringptr;
	
	
	return new_ringptr + 1;
		
#else
	return ::realloc( p_memory, p_bytes );
#endif
}

void MemoryPoolStaticMalloc::free(void *p_ptr) {

	ERR_FAIL_COND( !MemoryPoolStatic::get_singleton());

	#if DEFAULT_ALIGNMENT == 1

		_free(p_ptr);
	#else

		uint8_t* mem = (uint8_t*)p_ptr;
		int ofs = *(mem-1);
		mem = mem - ofs;

		_free(mem);
	#endif
};


void MemoryPoolStaticMalloc::_free(void *p_ptr) {
	
	MutexLock lock(mutex);
	
#ifdef DEBUG_MEMORY_ENABLED
		
	if (p_ptr==0) {
		printf("**ERROR: STATIC ALLOC: Attempted free of NULL pointer.\n");
		return;
	};
	
	RingPtr *ringptr = (RingPtr*)p_ptr;
	
	ringptr--; /* go back an element to find the ringptr */
	
	
#if 0	
	{ // check for existing memory on free.
		RingPtr *p = ringlist;
		
		bool found=false;
		
		if (ringlist) {
			do {
				if (p==ringptr) {
					found=true;
					break;
				}
						
				p=p->next;
			} while (p!=ringlist);
		}
		
		if (!found) {
			printf("**ERROR: STATIC ALLOC: Attempted free of unknown pointer at %p\n",(ringptr+1));
			return;
		}
		
	}		
#endif	
	/* proceed to erase */
	
	bool single_element = (ringptr->next == ringptr) && (ringptr->prev == ringptr);
	bool is_list = ( ringlist == ringptr );
	
	if (single_element) {
		/* just get rid of it */
		ringlist=0;
			
	} else {
		/* auto-remove from ringlist */
		if (is_list)
			ringlist=ringptr->next;
			
		ringptr->prev->next = ringptr->next;
		ringptr->next->prev = ringptr->prev;
	}
	
	total_mem -= ringptr->size;
	total_pointers--;
	// catch more errors
	zeromem(ringptr,sizeof(RingPtr)+ringptr->size);
	::free(ringptr); //just free that pointer
		
#else
	ERR_FAIL_COND(p_ptr==0);
		
	::free(p_ptr);
#endif
}


size_t MemoryPoolStaticMalloc::get_available_mem() const {

	return 0xffffffff;
}

size_t MemoryPoolStaticMalloc::get_total_usage() {
	
#ifdef DEBUG_MEMORY_ENABLED
		
	return total_mem;
#else	
	return 0;
#endif

}

size_t MemoryPoolStaticMalloc::get_max_usage() {

	return max_mem;
}
			
/* Most likely available only if memory debugger was compiled in */
int MemoryPoolStaticMalloc::get_alloc_count() {
	
	return 0;
}
void * MemoryPoolStaticMalloc::get_alloc_ptr(int p_alloc_idx) {
	
	return 0;
}
const char* MemoryPoolStaticMalloc::get_alloc_description(int p_alloc_idx) {
	
	
	return "";
}
size_t MemoryPoolStaticMalloc::get_alloc_size(int p_alloc_idx) {
	
	return 0;
}

void MemoryPoolStaticMalloc::dump_mem_to_file(const char* p_file) {

#ifdef DEBUG_MEMORY_ENABLED
	
	ERR_FAIL_COND( !ringlist ); /** WTF BUG !? */
	RingPtr *p = ringlist;
	FILE *f = fopen(p_file,"wb");
	
	do {
		fprintf(f,"%p-%i-%s\n", p+1, (int)p->size, (p->descr?p->descr:"") );
		p=p->next;
	} while (p!=ringlist);

	fclose(f);
#endif 

}

MemoryPoolStaticMalloc::MemoryPoolStaticMalloc() {
	
#ifdef DEBUG_MEMORY_ENABLED
	total_mem=0;
	total_pointers=0;
	ringlist=0;
	max_mem=0;
	max_pointers=0;


#endif
		
	mutex=NULL;
#ifndef NO_THREADS

	mutex=Mutex::create(); // at this point, this should work
#endif

}


MemoryPoolStaticMalloc::~MemoryPoolStaticMalloc() {
	
	Mutex *old_mutex=mutex;
	mutex=NULL;
	if (old_mutex)
		memdelete(old_mutex);
	
#ifdef DEBUG_MEMORY_ENABLED

	if (OS::get_singleton()->is_stdout_verbose()) {
		if (total_mem > 0 ) {
			printf("**ERROR: STATIC ALLOC: ** MEMORY LEAKS DETECTED **\n");
			printf("**ERROR: STATIC ALLOC: %i bytes of memory in use at exit.\n",(int)total_mem);

			if (1){
				printf("**ERROR: STATIC ALLOC: Following is the list of leaked allocations: \n");

				ERR_FAIL_COND( !ringlist ); /** WTF BUG !? */
				RingPtr *p = ringlist;

				do {
					printf("\t%p - %i bytes - %s\n", (RingPtr*)(p+1), (int)p->size, (p->descr?p->descr:"") );
					p=p->next;
				} while (p!=ringlist);

				printf("**ERROR: STATIC ALLOC: End of Report.\n");
			};

			printf("mem - max %i, pointers %i, leaks %i.\n",(int)max_mem,max_pointers,(int)total_mem);
		} else {

			printf("INFO: mem - max %i, pointers %i, no leaks.\n",(int)max_mem,max_pointers);
		}
	}
	
#endif
}