--- /dev/null
+/**
+ * @file
+ * Dynamic memory manager
+ *
+ * This is a lightweight replacement for the standard C library malloc().
+ *
+ * If you want to use the standard C library malloc() instead, define
+ * MEM_LIBC_MALLOC to 1 in your lwipopts.h
+ *
+ * To let mem_malloc() use pools (prevents fragmentation and is much faster than
+ * a heap but might waste some memory), define MEM_USE_POOLS to 1, define
+ * MEM_USE_CUSTOM_POOLS to 1 and create a file "lwippools.h" that includes a list
+ * of pools like this (more pools can be added between _START and _END):
+ *
+ * Define three pools with sizes 256, 512, and 1512 bytes
+ * LWIP_MALLOC_MEMPOOL_START
+ * LWIP_MALLOC_MEMPOOL(20, 256)
+ * LWIP_MALLOC_MEMPOOL(10, 512)
+ * LWIP_MALLOC_MEMPOOL(5, 1512)
+ * LWIP_MALLOC_MEMPOOL_END
+ */
+
+/*
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Adam Dunkels <adam@sics.se>
+ * Simon Goldschmidt
+ *
+ */
+
+#include "lwip/opt.h"
+
+#if !MEM_LIBC_MALLOC /* don't build if not configured for use in lwipopts.h */
+
+#include "lwip/def.h"
+#include "lwip/mem.h"
+#include "lwip/sys.h"
+#include "lwip/stats.h"
+
+#include <string.h>
+
+#if MEM_USE_POOLS
+/* lwIP head implemented with different sized pools */
+
+/**
+ * This structure is used to save the pool one element came from.
+ */
+struct mem_helper
+{
+ memp_t poolnr;
+};
+
+/**
+ * Allocate memory: determine the smallest pool that is big enough
+ * to contain an element of 'size' and get an element from that pool.
+ *
+ * @param size the size in bytes of the memory needed
+ * @return a pointer to the allocated memory or NULL if the pool is empty
+ */
+void *
+mem_malloc(mem_size_t size)
+{
+ struct mem_helper *element;
+ memp_t poolnr;
+
+ for (poolnr = MEMP_POOL_FIRST; poolnr <= MEMP_POOL_LAST; poolnr++) {
+ /* is this pool big enough to hold an element of the required size
+ plus a struct mem_helper that saves the pool this element came from? */
+ if ((size + sizeof(struct mem_helper)) <= memp_sizes[poolnr]) {
+ break;
+ }
+ }
+ if (poolnr > MEMP_POOL_LAST) {
+ LWIP_ASSERT("mem_malloc(): no pool is that big!", 0);
+ return NULL;
+ }
+ element = (struct mem_helper*)memp_malloc(poolnr);
+ if (element == NULL) {
+ /* No need to DEBUGF or ASSERT: This error is already
+ taken care of in memp.c */
+ /** @todo: we could try a bigger pool if this one is empty! */
+ return NULL;
+ }
+
+ /* save the pool number this element came from */
+ element->poolnr = poolnr;
+ /* and return a pointer to the memory directly after the struct mem_helper */
+ element++;
+
+ return element;
+}
+
+/**
+ * Free memory previously allocated by mem_malloc. Loads the pool number
+ * and calls memp_free with that pool number to put the element back into
+ * its pool
+ *
+ * @param rmem the memory element to free
+ */
+void
+mem_free(void *rmem)
+{
+ struct mem_helper *hmem = (struct mem_helper*)rmem;
+
+ LWIP_ASSERT("rmem != NULL", (rmem != NULL));
+ LWIP_ASSERT("rmem == MEM_ALIGN(rmem)", (rmem == LWIP_MEM_ALIGN(rmem)));
+
+ /* get the original struct mem_helper */
+ hmem--;
+
+ LWIP_ASSERT("hmem != NULL", (hmem != NULL));
+ LWIP_ASSERT("hmem == MEM_ALIGN(hmem)", (hmem == LWIP_MEM_ALIGN(hmem)));
+ LWIP_ASSERT("hmem->poolnr < MEMP_MAX", (hmem->poolnr < MEMP_MAX));
+
+ /* and put it in the pool we saved earlier */
+ memp_free(hmem->poolnr, hmem);
+}
+
+#else /* MEM_USE_POOLS */
+/* lwIP replacement for your libc malloc() */
+
+/**
+ * The heap is made up as a list of structs of this type.
+ * This does not have to be aligned since for getting its size,
+ * we only use the macro SIZEOF_STRUCT_MEM, which automatically alignes.
+ */
+struct mem {
+ /** index (-> ram[next]) of the next struct */
+ mem_size_t next;
+ /** index (-> ram[next]) of the next struct */
+ mem_size_t prev;
+ /** 1: this area is used; 0: this area is unused */
+ u8_t used;
+};
+
+/** All allocated blocks will be MIN_SIZE bytes big, at least!
+ * MIN_SIZE can be overridden to suit your needs. Smaller values save space,
+ * larger values could prevent too small blocks to fragment the RAM too much. */
+#ifndef MIN_SIZE
+#define MIN_SIZE 12
+#endif /* MIN_SIZE */
+/* some alignment macros: we define them here for better source code layout */
+#define MIN_SIZE_ALIGNED LWIP_MEM_ALIGN_SIZE(MIN_SIZE)
+#define SIZEOF_STRUCT_MEM LWIP_MEM_ALIGN_SIZE(sizeof(struct mem))
+#define MEM_SIZE_ALIGNED LWIP_MEM_ALIGN_SIZE(MEM_SIZE)
+
+/** the heap. we need one struct mem at the end and some room for alignment */
+static u8_t ram_heap[MEM_SIZE_ALIGNED + (2*SIZEOF_STRUCT_MEM) + MEM_ALIGNMENT];
+/** pointer to the heap (ram_heap): for alignment, ram is now a pointer instead of an array */
+static u8_t *ram;
+/** the last entry, always unused! */
+static struct mem *ram_end;
+/** pointer to the lowest free block, this is used for faster search */
+static struct mem *lfree;
+/** concurrent access protection */
+static sys_sem_t mem_sem;
+
+/**
+ * "Plug holes" by combining adjacent empty struct mems.
+ * After this function is through, there should not exist
+ * one empty struct mem pointing to another empty struct mem.
+ *
+ * @param mem this points to a struct mem which just has been freed
+ * @internal this function is only called by mem_free() and mem_realloc()
+ *
+ * This assumes access to the heap is protected by the calling function
+ * already.
+ */
+static void
+plug_holes(struct mem *mem)
+{
+ struct mem *nmem;
+ struct mem *pmem;
+
+ LWIP_ASSERT("plug_holes: mem >= ram", (u8_t *)mem >= ram);
+ LWIP_ASSERT("plug_holes: mem < ram_end", (u8_t *)mem < (u8_t *)ram_end);
+ LWIP_ASSERT("plug_holes: mem->used == 0", mem->used == 0);
+
+ /* plug hole forward */
+ LWIP_ASSERT("plug_holes: mem->next <= MEM_SIZE_ALIGNED", mem->next <= MEM_SIZE_ALIGNED);
+
+ nmem = (struct mem *)&ram[mem->next];
+ if (mem != nmem && nmem->used == 0 && (u8_t *)nmem != (u8_t *)ram_end) {
+ /* if mem->next is unused and not end of ram, combine mem and mem->next */
+ if (lfree == nmem) {
+ lfree = mem;
+ }
+ mem->next = nmem->next;
+ ((struct mem *)&ram[nmem->next])->prev = (u8_t *)mem - ram;
+ }
+
+ /* plug hole backward */
+ pmem = (struct mem *)&ram[mem->prev];
+ if (pmem != mem && pmem->used == 0) {
+ /* if mem->prev is unused, combine mem and mem->prev */
+ if (lfree == mem) {
+ lfree = pmem;
+ }
+ pmem->next = mem->next;
+ ((struct mem *)&ram[mem->next])->prev = (u8_t *)pmem - ram;
+ }
+}
+
+/**
+ * Zero the heap and initialize start, end and lowest-free
+ */
+void
+mem_init(void)
+{
+ struct mem *mem;
+
+ LWIP_ASSERT("Sanity check alignment",
+ (SIZEOF_STRUCT_MEM & (MEM_ALIGNMENT-1)) == 0);
+
+ /* align the heap */
+ ram = LWIP_MEM_ALIGN(ram_heap);
+ /* initialize the start of the heap */
+ mem = (struct mem *)ram;
+ mem->next = MEM_SIZE_ALIGNED;
+ mem->prev = 0;
+ mem->used = 0;
+ /* initialize the end of the heap */
+ ram_end = (struct mem *)&ram[MEM_SIZE_ALIGNED];
+ ram_end->used = 1;
+ ram_end->next = MEM_SIZE_ALIGNED;
+ ram_end->prev = MEM_SIZE_ALIGNED;
+
+ mem_sem = sys_sem_new(1);
+
+ /* initialize the lowest-free pointer to the start of the heap */
+ lfree = (struct mem *)ram;
+
+#if MEM_STATS
+ lwip_stats.mem.avail = MEM_SIZE_ALIGNED;
+#endif /* MEM_STATS */
+}
+
+/**
+ * Put a struct mem back on the heap
+ *
+ * @param rmem is the data portion of a struct mem as returned by a previous
+ * call to mem_malloc()
+ */
+void
+mem_free(void *rmem)
+{
+ struct mem *mem;
+
+ if (rmem == NULL) {
+ LWIP_DEBUGF(MEM_DEBUG | LWIP_DBG_TRACE | 2, ("mem_free(p == NULL) was called.\n"));
+ return;
+ }
+ LWIP_ASSERT("mem_free: sanity check alignment", (((mem_ptr_t)rmem) & (MEM_ALIGNMENT-1)) == 0);
+
+ /* protect the heap from concurrent access */
+ sys_arch_sem_wait(mem_sem, 0);
+
+ LWIP_ASSERT("mem_free: legal memory", (u8_t *)rmem >= (u8_t *)ram &&
+ (u8_t *)rmem < (u8_t *)ram_end);
+
+ if ((u8_t *)rmem < (u8_t *)ram || (u8_t *)rmem >= (u8_t *)ram_end) {
+ LWIP_DEBUGF(MEM_DEBUG | 3, ("mem_free: illegal memory\n"));
+#if MEM_STATS
+ ++lwip_stats.mem.err;
+#endif /* MEM_STATS */
+ sys_sem_signal(mem_sem);
+ return;
+ }
+ /* Get the corresponding struct mem ... */
+ mem = (struct mem *)((u8_t *)rmem - SIZEOF_STRUCT_MEM);
+ /* ... which has to be in a used state ... */
+ LWIP_ASSERT("mem_free: mem->used", mem->used);
+ /* ... and is now unused. */
+ mem->used = 0;
+
+ if (mem < lfree) {
+ /* the newly freed struct is now the lowest */
+ lfree = mem;
+ }
+
+#if MEM_STATS
+ lwip_stats.mem.used -= mem->next - ((u8_t *)mem - ram);
+#endif /* MEM_STATS */
+
+ /* finally, see if prev or next are free also */
+ plug_holes(mem);
+ sys_sem_signal(mem_sem);
+}
+
+/**
+ * In contrast to its name, mem_realloc can only shrink memory, not expand it.
+ * Since the only use (for now) is in pbuf_realloc (which also can only shrink),
+ * this shouldn't be a problem!
+ *
+ * @param rmem pointer to memory allocated by mem_malloc the is to be shrinked
+ * @param newsize required size after shrinking (needs to be smaller than or
+ * equal to the previous size)
+ * @return for compatibility reasons: is always == rmem, at the moment
+ */
+void *
+mem_realloc(void *rmem, mem_size_t newsize)
+{
+ mem_size_t size;
+ mem_size_t ptr, ptr2;
+ struct mem *mem, *mem2;
+
+ /* Expand the size of the allocated memory region so that we can
+ adjust for alignment. */
+ newsize = LWIP_MEM_ALIGN_SIZE(newsize);
+
+ if(newsize < MIN_SIZE_ALIGNED) {
+ /* every data block must be at least MIN_SIZE_ALIGNED long */
+ newsize = MIN_SIZE_ALIGNED;
+ }
+
+ if (newsize > MEM_SIZE_ALIGNED) {
+ return NULL;
+ }
+
+ LWIP_ASSERT("mem_realloc: legal memory", (u8_t *)rmem >= (u8_t *)ram &&
+ (u8_t *)rmem < (u8_t *)ram_end);
+
+ if ((u8_t *)rmem < (u8_t *)ram || (u8_t *)rmem >= (u8_t *)ram_end) {
+ LWIP_DEBUGF(MEM_DEBUG | 3, ("mem_realloc: illegal memory\n"));
+ return rmem;
+ }
+ /* Get the corresponding struct mem ... */
+ mem = (struct mem *)((u8_t *)rmem - SIZEOF_STRUCT_MEM);
+ /* ... and its offset pointer */
+ ptr = (u8_t *)mem - ram;
+
+ size = mem->next - ptr - SIZEOF_STRUCT_MEM;
+ LWIP_ASSERT("mem_realloc can only shrink memory", newsize <= size);
+ if (newsize > size) {
+ /* not supported */
+ return NULL;
+ }
+ if (newsize == size) {
+ /* No change in size, simply return */
+ return rmem;
+ }
+
+ /* protect the heap from concurrent access */
+ sys_arch_sem_wait(mem_sem, 0);
+
+#if MEM_STATS
+ lwip_stats.mem.used -= (size - newsize);
+#endif /* MEM_STATS */
+
+ mem2 = (struct mem *)&ram[mem->next];
+ if(mem2->used == 0) {
+ /* The next struct is unused, we can simply move it at little */
+ mem_size_t next;
+ /* remember the old next pointer */
+ next = mem2->next;
+ /* create new struct mem which is moved directly after the shrinked mem */
+ ptr2 = ptr + SIZEOF_STRUCT_MEM + newsize;
+ if (lfree == mem2) {
+ lfree = (struct mem *)&ram[ptr2];
+ }
+ mem2 = (struct mem *)&ram[ptr2];
+ mem2->used = 0;
+ /* restore the next pointer */
+ mem2->next = next;
+ /* link it back to mem */
+ mem2->prev = ptr;
+ /* link mem to it */
+ mem->next = ptr2;
+ /* last thing to restore linked list: as we have moved mem2,
+ * let 'mem2->next->prev' point to mem2 again. but only if mem2->next is not
+ * the end of the heap */
+ if (mem2->next != MEM_SIZE_ALIGNED) {
+ ((struct mem *)&ram[mem2->next])->prev = ptr2;
+ }
+ /* no need to plug holes, we've already done that */
+ } else if (newsize + SIZEOF_STRUCT_MEM + MIN_SIZE_ALIGNED <= size) {
+ /* Next struct is used but there's room for another struct mem with
+ * at least MIN_SIZE_ALIGNED of data.
+ * Old size ('size') must be big enough to contain at least 'newsize' plus a struct mem
+ * ('SIZEOF_STRUCT_MEM') with some data ('MIN_SIZE_ALIGNED').
+ * @todo we could leave out MIN_SIZE_ALIGNED. We would create an empty
+ * region that couldn't hold data, but when mem->next gets freed,
+ * the 2 regions would be combined, resulting in more free memory */
+ ptr2 = ptr + SIZEOF_STRUCT_MEM + newsize;
+ mem2 = (struct mem *)&ram[ptr2];
+ if (mem2 < lfree) {
+ lfree = mem2;
+ }
+ mem2->used = 0;
+ mem2->next = mem->next;
+ mem2->prev = ptr;
+ mem->next = ptr2;
+ if (mem2->next != MEM_SIZE_ALIGNED) {
+ ((struct mem *)&ram[mem2->next])->prev = ptr2;
+ }
+ /* the original mem->next is used, so no need to plug holes! */
+ }
+ /* else {
+ next struct mem is used but size between mem and mem2 is not big enough
+ to create another struct mem
+ -> don't do anyhting.
+ -> the remaining space stays unused since it is too small
+ } */
+ sys_sem_signal(mem_sem);
+ return rmem;
+}
+
+/**
+ * Adam's mem_malloc() plus solution for bug #17922
+ * Allocate a block of memory with a minimum of 'size' bytes.
+ *
+ * @param size is the minimum size of the requested block in bytes.
+ * @return pointer to allocated memory or NULL if no free memory was found.
+ *
+ * Note that the returned value will always be aligned (as defined by MEM_ALIGNMENT).
+ */
+void *
+mem_malloc(mem_size_t size)
+{
+ mem_size_t ptr, ptr2;
+ struct mem *mem, *mem2;
+
+ if (size == 0) {
+ return NULL;
+ }
+
+ /* Expand the size of the allocated memory region so that we can
+ adjust for alignment. */
+ size = LWIP_MEM_ALIGN_SIZE(size);
+
+ if(size < MIN_SIZE_ALIGNED) {
+ /* every data block must be at least MIN_SIZE_ALIGNED long */
+ size = MIN_SIZE_ALIGNED;
+ }
+
+ if (size > MEM_SIZE_ALIGNED) {
+ return NULL;
+ }
+
+ /* protect the heap from concurrent access */
+ sys_arch_sem_wait(mem_sem, 0);
+
+ /* Scan through the heap searching for a free block that is big enough,
+ * beginning with the lowest free block.
+ */
+ for (ptr = (u8_t *)lfree - ram; ptr < MEM_SIZE_ALIGNED - size;
+ ptr = ((struct mem *)&ram[ptr])->next) {
+ mem = (struct mem *)&ram[ptr];
+
+ if ((!mem->used) &&
+ (mem->next - (ptr + SIZEOF_STRUCT_MEM)) >= size) {
+ /* mem is not used and at least perfect fit is possible:
+ * mem->next - (ptr + SIZEOF_STRUCT_MEM) gives us the 'user data size' of mem */
+
+ if (mem->next - (ptr + SIZEOF_STRUCT_MEM) >= (size + SIZEOF_STRUCT_MEM + MIN_SIZE_ALIGNED)) {
+ /* (in addition to the above, we test if another struct mem (SIZEOF_STRUCT_MEM) containing
+ * at least MIN_SIZE_ALIGNED of data also fits in the 'user data space' of 'mem')
+ * -> split large block, create empty remainder,
+ * remainder must be large enough to contain MIN_SIZE_ALIGNED data: if
+ * mem->next - (ptr + (2*SIZEOF_STRUCT_MEM)) == size,
+ * struct mem would fit in but no data between mem2 and mem2->next
+ * @todo we could leave out MIN_SIZE_ALIGNED. We would create an empty
+ * region that couldn't hold data, but when mem->next gets freed,
+ * the 2 regions would be combined, resulting in more free memory
+ */
+ ptr2 = ptr + SIZEOF_STRUCT_MEM + size;
+ /* create mem2 struct */
+ mem2 = (struct mem *)&ram[ptr2];
+ mem2->used = 0;
+ mem2->next = mem->next;
+ mem2->prev = ptr;
+ /* and insert it between mem and mem->next */
+ mem->next = ptr2;
+ mem->used = 1;
+
+ if (mem2->next != MEM_SIZE_ALIGNED) {
+ ((struct mem *)&ram[mem2->next])->prev = ptr2;
+ }
+#if MEM_STATS
+ lwip_stats.mem.used += (size + SIZEOF_STRUCT_MEM);
+ if (lwip_stats.mem.max < lwip_stats.mem.used) {
+ lwip_stats.mem.max = lwip_stats.mem.used;
+ }
+#endif /* MEM_STATS */
+ } else {
+ /* (a mem2 struct does no fit into the user data space of mem and mem->next will always
+ * be used at this point: if not we have 2 unused structs in a row, plug_holes should have
+ * take care of this).
+ * -> near fit or excact fit: do not split, no mem2 creation
+ * also can't move mem->next directly behind mem, since mem->next
+ * will always be used at this point!
+ */
+ mem->used = 1;
+#if MEM_STATS
+ lwip_stats.mem.used += mem->next - ((u8_t *)mem - ram);
+ if (lwip_stats.mem.max < lwip_stats.mem.used) {
+ lwip_stats.mem.max = lwip_stats.mem.used;
+ }
+#endif /* MEM_STATS */
+ }
+
+ if (mem == lfree) {
+ /* Find next free block after mem and update lowest free pointer */
+ while (lfree->used && lfree != ram_end) {
+ lfree = (struct mem *)&ram[lfree->next];
+ }
+ LWIP_ASSERT("mem_malloc: !lfree->used", ((lfree == ram_end) || (!lfree->used)));
+ }
+ sys_sem_signal(mem_sem);
+ LWIP_ASSERT("mem_malloc: allocated memory not above ram_end.",
+ (mem_ptr_t)mem + SIZEOF_STRUCT_MEM + size <= (mem_ptr_t)ram_end);
+ LWIP_ASSERT("mem_malloc: allocated memory properly aligned.",
+ (unsigned long)((u8_t *)mem + SIZEOF_STRUCT_MEM) % MEM_ALIGNMENT == 0);
+ LWIP_ASSERT("mem_malloc: sanity check alignment",
+ (((mem_ptr_t)mem) & (MEM_ALIGNMENT-1)) == 0);
+
+ return (u8_t *)mem + SIZEOF_STRUCT_MEM;
+ }
+ }
+ LWIP_DEBUGF(MEM_DEBUG | 2, ("mem_malloc: could not allocate %"S16_F" bytes\n", (s16_t)size));
+#if MEM_STATS
+ ++lwip_stats.mem.err;
+#endif /* MEM_STATS */
+ sys_sem_signal(mem_sem);
+ return NULL;
+}
+
+#endif /* MEM_USE_POOLS */
+/**
+ * Contiguously allocates enough space for count objects that are size bytes
+ * of memory each and returns a pointer to the allocated memory.
+ *
+ * The allocated memory is filled with bytes of value zero.
+ *
+ * @param count number of objects to allocate
+ * @param size size of the objects to allocate
+ * @return pointer to allocated memory / NULL pointer if there is an error
+ */
+void *mem_calloc(mem_size_t count, mem_size_t size)
+{
+ void *p;
+
+ /* allocate 'count' objects of size 'size' */
+ p = mem_malloc(count * size);
+ if (p) {
+ /* zero the memory */
+ memset(p, 0, count * size);
+ }
+ return p;
+}
+
+#endif /* !MEM_LIBC_MALLOC */
git.joshuawise.com / netwatch.git / blobdiff