/**
* @brief Allocates a block of memory from the heap by using the first-fit
* algorithm.
* @details The allocated block is guaranteed to be properly aligned for a
* pointer data type (@p stkalign_t).
*
* @param[in] heapp pointer to a heap descriptor or @p NULL in order to
* access the default heap.
* @param[in] size the size of the block to be allocated. Note that the
* allocated block may be a bit bigger than the requested
* size for alignment and fragmentation reasons.
* @return A pointer to the allocated block.
* @retval NULL if the block cannot be allocated.
*
* @api
*/
void *chHeapAlloc(memory_heap_t *heapp, size_t size) {
union heap_header *qp, *hp, *fp;
if (heapp == NULL) {
heapp = &default_heap;
}
size = MEM_ALIGN_NEXT(size);
qp = &heapp->h_free;
H_LOCK(heapp);
while (qp->h.u.next != NULL) {
hp = qp->h.u.next;
if (hp->h.size >= size) {
if (hp->h.size < (size + sizeof(union heap_header))) {
/* Gets the whole block even if it is slightly bigger than the
requested size because the fragment would be too small to be
useful.*/
qp->h.u.next = hp->h.u.next;
}
else {
/* Block bigger enough, must split it.*/
/*lint -save -e9087 [11.3] Safe cast.*/
fp = (void *)((uint8_t *)(hp) + sizeof(union heap_header) + size);
/*lint -restore*/
fp->h.u.next = hp->h.u.next;
fp->h.size = (hp->h.size - sizeof(union heap_header)) - size;
qp->h.u.next = fp;
hp->h.size = size;
}
hp->h.u.heap = heapp;
H_UNLOCK(heapp);
/*lint -save -e9087 [11.3] Safe cast.*/
return (void *)(hp + 1);
/*lint -restore*/
}
qp = hp;
}
H_UNLOCK(heapp);
/* More memory is required, tries to get it from the associated provider
else fails.*/
if (heapp->h_provider != NULL) {
hp = heapp->h_provider(size + sizeof(union heap_header));
if (hp != NULL) {
hp->h.u.heap = heapp;
hp->h.size = size;
hp++;
/*lint -save -e9087 [11.3] Safe cast.*/
return (void *)hp;
/*lint -restore*/
}
}
return NULL;
}
void chHeapFree(void *p) {
chDbgCheck(p != NULL, "chHeapFree");
H_LOCK();
free(p);
H_UNLOCK();
}
void *chHeapAlloc(MemoryHeap *heapp, size_t size) {
void *p;
chDbgCheck(heapp == NULL, "chHeapAlloc");
H_LOCK();
p = malloc(size);
H_UNLOCK();
return p;
}
/**
* @brief Reports the heap status.
* @note This function is meant to be used in the test suite, it should
* not be really useful for the application code.
* @note This function is not implemented when the @p CH_USE_MALLOC_HEAP
* configuration option is used (it always returns zero).
*
* @param[in] heapp pointer to a heap descriptor or @p NULL in order to
* access the default heap.
* @param[in] sizep pointer to a variable that will receive the total
* fragmented free space
* @return The number of fragments in the heap.
*
* @api
*/
size_t chHeapStatus(MemoryHeap *heapp, size_t *sizep) {
union heap_header *qp;
size_t n, sz;
if (heapp == NULL)
heapp = &default_heap;
H_LOCK(heapp);
sz = 0;
for (n = 0, qp = &heapp->h_free; qp->h.u.next; n++, qp = qp->h.u.next)
sz += qp->h.u.next->h.size;
if (sizep)
*sizep = sz;
H_UNLOCK(heapp);
return n;
}
/**
* @brief Frees a previously allocated memory block.
*
* @param[in] p pointer to the memory block to be freed
*
* @api
*/
void chHeapFree(void *p) {
union heap_header *qp, *hp;
MemoryHeap *heapp;
chDbgCheck(p != NULL, "chHeapFree");
hp = (union heap_header *)p - 1;
heapp = hp->h.u.heap;
qp = &heapp->h_free;
H_LOCK(heapp);
while (TRUE) {
chDbgAssert((hp < qp) || (hp >= LIMIT(qp)),
"chHeapFree(), #1",
"within free block");
if (((qp == &heapp->h_free) || (hp > qp)) &&
((qp->h.u.next == NULL) || (hp < qp->h.u.next))) {
/* Insertion after qp.*/
hp->h.u.next = qp->h.u.next;
qp->h.u.next = hp;
/* Verifies if the newly inserted block should be merged.*/
if (LIMIT(hp) == hp->h.u.next) {
/* Merge with the next block.*/
hp->h.size += hp->h.u.next->h.size + sizeof(union heap_header);
hp->h.u.next = hp->h.u.next->h.u.next;
}
if ((LIMIT(qp) == hp)) {
/* Merge with the previous block.*/
qp->h.size += hp->h.size + sizeof(union heap_header);
qp->h.u.next = hp->h.u.next;
}
break;
}
qp = qp->h.u.next;
}
H_UNLOCK(heapp);
return;
}
/**
* @brief Frees a previously allocated memory block.
*
* @param[in] p pointer to the memory block to be freed
*
* @api
*/
void chHeapFree(void *p) {
union heap_header *qp, *hp;
memory_heap_t *heapp;
chDbgCheck(p != NULL);
/*lint -save -e9087 [11.3] Safe cast.*/
hp = (union heap_header *)p - 1;
/*lint -restore*/
heapp = hp->h.u.heap;
qp = &heapp->h_free;
H_LOCK(heapp);
while (true) {
chDbgAssert((hp < qp) || (hp >= LIMIT(qp)), "within free block");
if (((qp == &heapp->h_free) || (hp > qp)) &&
((qp->h.u.next == NULL) || (hp < qp->h.u.next))) {
/* Insertion after qp.*/
hp->h.u.next = qp->h.u.next;
qp->h.u.next = hp;
/* Verifies if the newly inserted block should be merged.*/
if (LIMIT(hp) == hp->h.u.next) {
/* Merge with the next block.*/
hp->h.size += hp->h.u.next->h.size + sizeof(union heap_header);
hp->h.u.next = hp->h.u.next->h.u.next;
}
if ((LIMIT(qp) == hp)) {
/* Merge with the previous block.*/
qp->h.size += hp->h.size + sizeof(union heap_header);
qp->h.u.next = hp->h.u.next;
}
break;
}
qp = qp->h.u.next;
}
H_UNLOCK(heapp);
return;
}
/**
* @brief Reports the heap status.
* @note This function is meant to be used in the test suite, it should
* not be really useful for the application code.
*
* @param[in] heapp pointer to a heap descriptor or @p NULL in order to
* access the default heap.
* @param[in] sizep pointer to a variable that will receive the total
* fragmented free space
* @return The number of fragments in the heap.
*
* @api
*/
size_t chHeapStatus(memory_heap_t *heapp, size_t *sizep) {
union heap_header *qp;
size_t n, sz;
if (heapp == NULL) {
heapp = &default_heap;
}
H_LOCK(heapp);
sz = 0;
n = 0;
qp = &heapp->h_free;
while (qp->h.u.next != NULL) {
sz += qp->h.u.next->h.size;
n++;
qp = qp->h.u.next;
}
if (sizep != NULL) {
*sizep = sz;
}
H_UNLOCK(heapp);
return n;
}