예제 #1
0
파일: gc.c 프로젝트: AvdN/micropython
// force the freeing of a piece of memory
// TODO: freeing here does not call finaliser
void gc_free(void *ptr) {
    if (MP_STATE_MEM(gc_lock_depth) > 0) {
        // TODO how to deal with this error?
        return;
    }

    DEBUG_printf("gc_free(%p)\n", ptr);

    if (VERIFY_PTR(ptr)) {
        size_t block = BLOCK_FROM_PTR(ptr);
        if (ATB_GET_KIND(block) == AT_HEAD) {
            #if MICROPY_ENABLE_FINALISER
            FTB_CLEAR(block);
            #endif
            // set the last_free pointer to this block if it's earlier in the heap
            if (block / BLOCKS_PER_ATB < MP_STATE_MEM(gc_last_free_atb_index)) {
                MP_STATE_MEM(gc_last_free_atb_index) = block / BLOCKS_PER_ATB;
            }

            // free head and all of its tail blocks
            do {
                ATB_ANY_TO_FREE(block);
                block += 1;
            } while (ATB_GET_KIND(block) == AT_TAIL);

            #if EXTENSIVE_HEAP_PROFILING
            gc_dump_alloc_table();
            #endif
        } else {
            assert(!"bad free");
        }
    } else if (ptr != NULL) {
        assert(!"bad free");
    }
}
예제 #2
0
파일: gc.c 프로젝트: evanhunter/micropython
// force the freeing of a piece of memory
void gc_free(void *ptr_in) {
    if (gc_lock_depth > 0) {
        // TODO how to deal with this error?
        return;
    }

    mp_uint_t ptr = (mp_uint_t)ptr_in;
    DEBUG_printf("gc_free(%p)\n", ptr);

    if (VERIFY_PTR(ptr)) {
        mp_uint_t block = BLOCK_FROM_PTR(ptr);
        if (ATB_GET_KIND(block) == AT_HEAD) {
            // set the last_free pointer to this block if it's earlier in the heap
            if (block / BLOCKS_PER_ATB < gc_last_free_atb_index) {
                gc_last_free_atb_index = block / BLOCKS_PER_ATB;
            }

            // free head and all of its tail blocks
            do {
                ATB_ANY_TO_FREE(block);
                block += 1;
            } while (ATB_GET_KIND(block) == AT_TAIL);

            #if EXTENSIVE_HEAP_PROFILING
            gc_dump_alloc_table();
            #endif
        }
    }
}
예제 #3
0
// force the freeing of a piece of memory
void gc_free(void *ptr_in) {
    machine_uint_t ptr = (machine_uint_t)ptr_in;

    if (VERIFY_PTR(ptr)) {
        machine_uint_t block = BLOCK_FROM_PTR(ptr);
        if (ATB_GET_KIND(block) == AT_HEAD) {
            // free head and all of its tail blocks
            do {
                ATB_ANY_TO_FREE(block);
                block += 1;
            } while (ATB_GET_KIND(block) == AT_TAIL);
        }
    }
}
예제 #4
0
void gc_collect_root(void **ptrs, size_t len) {
    for (size_t i = 0; i < len; i++) {
        void *ptr = ptrs[i];
        if (VERIFY_PTR(ptr)) {
            size_t block = BLOCK_FROM_PTR(ptr);
            if (ATB_GET_KIND(block) == AT_HEAD) {
                // An unmarked head: mark it, and mark all its children
                TRACE_MARK(block, ptr);
                ATB_HEAD_TO_MARK(block);
                gc_mark_subtree(block);
            }
        }
    }
}
예제 #5
0
파일: gc.c 프로젝트: AvdN/micropython
size_t gc_nbytes(const void *ptr) {
    if (VERIFY_PTR(ptr)) {
        size_t block = BLOCK_FROM_PTR(ptr);
        if (ATB_GET_KIND(block) == AT_HEAD) {
            // work out number of consecutive blocks in the chain starting with this on
            size_t n_blocks = 0;
            do {
                n_blocks += 1;
            } while (ATB_GET_KIND(block + n_blocks) == AT_TAIL);
            return n_blocks * BYTES_PER_BLOCK;
        }
    }

    // invalid pointer
    return 0;
}
예제 #6
0
파일: gc.c 프로젝트: CarterTsai/micropython
// force the freeing of a piece of memory
void gc_free(void *ptr_in) {
    if (gc_lock_depth > 0) {
        // TODO how to deal with this error?
        return;
    }

    machine_uint_t ptr = (machine_uint_t)ptr_in;

    if (VERIFY_PTR(ptr)) {
        machine_uint_t block = BLOCK_FROM_PTR(ptr);
        if (ATB_GET_KIND(block) == AT_HEAD) {
            // free head and all of its tail blocks
            do {
                ATB_ANY_TO_FREE(block);
                block += 1;
            } while (ATB_GET_KIND(block) == AT_TAIL);
        }
    }
}
예제 #7
0
// Take the given block as the topmost block on the stack. Check all it's
// children: mark the unmarked child blocks and put those newly marked
// blocks on the stack. When all children have been checked, pop off the
// topmost block on the stack and repeat with that one.
STATIC void gc_mark_subtree(size_t block) {
    // Start with the block passed in the argument.
    size_t sp = 0;
    for (;;) {
        // work out number of consecutive blocks in the chain starting with this one
        size_t n_blocks = 0;
        do {
            n_blocks += 1;
        } while (ATB_GET_KIND(block + n_blocks) == AT_TAIL);

        // check this block's children
        void **ptrs = (void**)PTR_FROM_BLOCK(block);
        for (size_t i = n_blocks * BYTES_PER_BLOCK / sizeof(void*); i > 0; i--, ptrs++) {
            void *ptr = *ptrs;
            if (VERIFY_PTR(ptr)) {
                // Mark and push this pointer
                size_t childblock = BLOCK_FROM_PTR(ptr);
                if (ATB_GET_KIND(childblock) == AT_HEAD) {
                    // an unmarked head, mark it, and push it on gc stack
                    TRACE_MARK(childblock, ptr);
                    ATB_HEAD_TO_MARK(childblock);
                    if (sp < MICROPY_ALLOC_GC_STACK_SIZE) {
                        MP_STATE_MEM(gc_stack)[sp++] = childblock;
                    } else {
                        MP_STATE_MEM(gc_stack_overflow) = 1;
                    }
                }
            }
        }

        // Are there any blocks on the stack?
        if (sp == 0) {
            break; // No, stack is empty, we're done.
        }

        // pop the next block off the stack
        block = MP_STATE_MEM(gc_stack)[--sp];
    }
}
예제 #8
0
파일: gc.c 프로젝트: un33k/micropython
// old, simple realloc that didn't expand memory in place
void *gc_realloc(void *ptr, machine_uint_t n_bytes) {
    machine_uint_t n_existing = gc_nbytes(ptr);
    if (n_bytes <= n_existing) {
        return ptr;
    } else {
        bool has_finaliser;
        if (ptr == NULL) {
            has_finaliser = false;
        } else {
#if MICROPY_ENABLE_FINALISER
            has_finaliser = FTB_GET(BLOCK_FROM_PTR((machine_uint_t)ptr));
#else
            has_finaliser = false;
#endif
        }
        void *ptr2 = gc_alloc(n_bytes, has_finaliser);
        if (ptr2 == NULL) {
            return ptr2;
        }
        memcpy(ptr2, ptr, n_existing);
        gc_free(ptr);
        return ptr2;
    }
}
예제 #9
0
파일: gc.c 프로젝트: un33k/micropython
void *gc_realloc(void *ptr_in, machine_uint_t n_bytes) {
    if (gc_lock_depth > 0) {
        return NULL;
    }

    // check for pure allocation
    if (ptr_in == NULL) {
        return gc_alloc(n_bytes, false);
    }

    machine_uint_t ptr = (machine_uint_t)ptr_in;

    // sanity check the ptr
    if (!VERIFY_PTR(ptr)) {
        return NULL;
    }

    // get first block
    machine_uint_t block = BLOCK_FROM_PTR(ptr);

    // sanity check the ptr is pointing to the head of a block
    if (ATB_GET_KIND(block) != AT_HEAD) {
        return NULL;
    }

    // compute number of new blocks that are requested
    machine_uint_t new_blocks = (n_bytes + BYTES_PER_BLOCK - 1) / BYTES_PER_BLOCK;

    // get the number of consecutive tail blocks and
    // the number of free blocks after last tail block
    // stop if we reach (or are at) end of heap
    machine_uint_t n_free   = 0;
    machine_uint_t n_blocks = 1; // counting HEAD block
    machine_uint_t max_block = gc_alloc_table_byte_len * BLOCKS_PER_ATB;
    while (block + n_blocks + n_free < max_block) {
        if (n_blocks + n_free >= new_blocks) {
            // stop as soon as we find enough blocks for n_bytes
            break;
        }
        byte block_type = ATB_GET_KIND(block + n_blocks + n_free);
        switch (block_type) {
            case AT_FREE: n_free++; continue;
            case AT_TAIL: n_blocks++; continue;
            case AT_MARK: assert(0);
        }
        break;
    }

    // return original ptr if it already has the requested number of blocks
    if (new_blocks == n_blocks) {
        return ptr_in;
    }

    // check if we can shrink the allocated area
    if (new_blocks < n_blocks) {
        // free unneeded tail blocks
        for (machine_uint_t bl = block + new_blocks; ATB_GET_KIND(bl) == AT_TAIL; bl++) {
            ATB_ANY_TO_FREE(bl);
        }
        return ptr_in;
    }

    // check if we can expand in place
    if (new_blocks <= n_blocks + n_free) {
        // mark few more blocks as used tail
        for (machine_uint_t bl = block + n_blocks; bl < block + new_blocks; bl++) {
            assert(ATB_GET_KIND(bl) == AT_FREE);
            ATB_FREE_TO_TAIL(bl);
        }

        // zero out the additional bytes of the newly allocated blocks (see comment above in gc_alloc)
        memset((byte*)ptr_in + n_bytes, 0, new_blocks * BYTES_PER_BLOCK - n_bytes);

        return ptr_in;
    }

    // can't resize inplace; try to find a new contiguous chain
    void *ptr_out = gc_alloc(n_bytes,
#if MICROPY_ENABLE_FINALISER
        FTB_GET(block)
#else
        false
#endif
    );

    // check that the alloc succeeded
    if (ptr_out == NULL) {
        return NULL;
    }

    DEBUG_printf("gc_realloc(%p -> %p)\n", ptr_in, ptr_out);
    memcpy(ptr_out, ptr_in, n_blocks * BYTES_PER_BLOCK);
    gc_free(ptr_in);
    return ptr_out;
}
예제 #10
0
파일: gc.c 프로젝트: AvdN/micropython
void *gc_realloc(void *ptr_in, size_t n_bytes, bool allow_move) {
    if (MP_STATE_MEM(gc_lock_depth) > 0) {
        return NULL;
    }

    // check for pure allocation
    if (ptr_in == NULL) {
        return gc_alloc(n_bytes, false);
    }

    // check for pure free
    if (n_bytes == 0) {
        gc_free(ptr_in);
        return NULL;
    }

    void *ptr = ptr_in;

    // sanity check the ptr
    if (!VERIFY_PTR(ptr)) {
        return NULL;
    }

    // get first block
    size_t block = BLOCK_FROM_PTR(ptr);

    // sanity check the ptr is pointing to the head of a block
    if (ATB_GET_KIND(block) != AT_HEAD) {
        return NULL;
    }

    // compute number of new blocks that are requested
    size_t new_blocks = (n_bytes + BYTES_PER_BLOCK - 1) / BYTES_PER_BLOCK;

    // Get the total number of consecutive blocks that are already allocated to
    // this chunk of memory, and then count the number of free blocks following
    // it.  Stop if we reach the end of the heap, or if we find enough extra
    // free blocks to satisfy the realloc.  Note that we need to compute the
    // total size of the existing memory chunk so we can correctly and
    // efficiently shrink it (see below for shrinking code).
    size_t n_free   = 0;
    size_t n_blocks = 1; // counting HEAD block
    size_t max_block = MP_STATE_MEM(gc_alloc_table_byte_len) * BLOCKS_PER_ATB;
    for (size_t bl = block + n_blocks; bl < max_block; bl++) {
        byte block_type = ATB_GET_KIND(bl);
        if (block_type == AT_TAIL) {
            n_blocks++;
            continue;
        }
        if (block_type == AT_FREE) {
            n_free++;
            if (n_blocks + n_free >= new_blocks) {
                // stop as soon as we find enough blocks for n_bytes
                break;
            }
            continue;
        }
        break;
    }

    // return original ptr if it already has the requested number of blocks
    if (new_blocks == n_blocks) {
        return ptr_in;
    }

    // check if we can shrink the allocated area
    if (new_blocks < n_blocks) {
        // free unneeded tail blocks
        for (size_t bl = block + new_blocks, count = n_blocks - new_blocks; count > 0; bl++, count--) {
            ATB_ANY_TO_FREE(bl);
        }

        // set the last_free pointer to end of this block if it's earlier in the heap
        if ((block + new_blocks) / BLOCKS_PER_ATB < MP_STATE_MEM(gc_last_free_atb_index)) {
            MP_STATE_MEM(gc_last_free_atb_index) = (block + new_blocks) / BLOCKS_PER_ATB;
        }

        #if EXTENSIVE_HEAP_PROFILING
        gc_dump_alloc_table();
        #endif

        return ptr_in;
    }

    // check if we can expand in place
    if (new_blocks <= n_blocks + n_free) {
        // mark few more blocks as used tail
        for (size_t bl = block + n_blocks; bl < block + new_blocks; bl++) {
            assert(ATB_GET_KIND(bl) == AT_FREE);
            ATB_FREE_TO_TAIL(bl);
        }

        // zero out the bytes of the newly allocated blocks (see comment above in gc_alloc)
        memset((byte*)ptr_in + n_blocks * BYTES_PER_BLOCK, 0, (new_blocks - n_blocks) * BYTES_PER_BLOCK);

        #if EXTENSIVE_HEAP_PROFILING
        gc_dump_alloc_table();
        #endif

        return ptr_in;
    }

    if (!allow_move) {
        // not allowed to move memory block so return failure
        return NULL;
    }

    // can't resize inplace; try to find a new contiguous chain
    void *ptr_out = gc_alloc(n_bytes,
#if MICROPY_ENABLE_FINALISER
        FTB_GET(block)
#else
        false
#endif
    );

    // check that the alloc succeeded
    if (ptr_out == NULL) {
        return NULL;
    }

    DEBUG_printf("gc_realloc(%p -> %p)\n", ptr_in, ptr_out);
    memcpy(ptr_out, ptr_in, n_blocks * BYTES_PER_BLOCK);
    gc_free(ptr_in);
    return ptr_out;
}