user
1140 lines
40 KiB
JSON
1140 lines
40 KiB
JSON
{
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"card": {
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"number": "01",
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"slug": "heap4-mechanics",
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"title": "heap_4: From Linear Cursor to Reusable Blocks",
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"topic": "headers, address-ordered free list, first-fit, split, coalescing and heap statistics",
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"status": "Gotowa",
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"version": "v00.01",
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"revision_date": "2026-07-20T00:00:00+02:00"
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},
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"front": {
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"goal": "Uczeń przechodzi od liniowego kursora z K\\&R 5.4 do wielokrotnego użycia tej samej areny: rozpoznaje nagłówek bloku, first-fit, split oraz dwustronne scalanie wolnych bloków w heap\\_4.",
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"scope": "Dwa małe modele C przygotowują przewidywanie. Główny replay uruchamia prawdziwe FreeRTOS-Kernel V11.3.0 heap\\_4 na RV32I/Hazard3 i dowodzi fragmentacji, pełnego scalenia, minimum-ever oraz kontrolowanego OOM."
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},
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"viewpoints": [
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{
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"id": "A1",
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"label": "CONTEXT",
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"subtitle": "from cursor to reusable heap",
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"status": "enabled"
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},
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{
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"id": "A2",
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"label": "STRUCTURE",
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"subtitle": "RV32 header, split and address order",
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"status": "enabled"
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},
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{
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"id": "A3",
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"label": "DISPATCH",
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"subtitle": "not used by the allocator",
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"status": "unavailable",
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"reason": "heap_4 is called directly through pvPortMalloc and vPortFree; there is no callback or dispatch mechanism to explain."
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},
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{
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"id": "A4",
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"label": "APPLICATION",
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"subtitle": "experiment is already explicit",
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"status": "unavailable",
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"reason": "The concrete A/B/C allocation experiment is completely represented by the eight-state replay in A5."
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},
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{
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"id": "A5",
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"label": "FLOW",
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"subtitle": "allocate, fragment, coalesce",
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"status": "enabled"
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},
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{
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"id": "A6",
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"label": "STATE",
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"subtitle": "block list and statistics",
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"status": "enabled"
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},
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{
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"id": "A7",
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"label": "RUNTIME",
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"subtitle": "Hazard3 evidence",
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"status": "enabled"
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},
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{
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"id": "A8",
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"label": "PATTERNS",
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"subtitle": "mechanism, not a separate page",
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"status": "unavailable",
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"reason": "First-fit and the intrusive address-ordered free list are already proved in A2 and A5; a separate pattern page would duplicate them."
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}
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],
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"artifact": {
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"source": "src/tasks/task03_freertos_heap4.c",
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"elf": "build/task03_freertos_heap4/prog.elf",
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"image": "build/task03_freertos_heap4/prog.bin"
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},
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"strategies": [
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{
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"id": "code.boundary",
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"kind": "code",
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"expected_observations": [
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"application code calls only the public FreeRTOS allocation API",
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"the selected heap implementation is linked below that API"
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],
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"assertions": [
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"the application never edits allocator metadata",
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"Hazard3 observes the same ucHeap object named by the ELF"
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],
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"evidence_fields": [
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"code_ref",
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"public symbol",
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"arena symbol",
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"target profile"
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],
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"prerequisites": [
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"K&R 5.4 linear allocator complete"
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],
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"layout": [
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"application",
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"FreeRTOS API",
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"heap_4",
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"ucHeap",
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"Hazard3"
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],
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"commands": [
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"rg -n 'pvPortMalloc|vPortFree|vPortGetHeapStats|ucHeap' src/tasks/task03_freertos_heap4.c",
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"rg -n 'TASK03_KERNEL_SOURCES|HEAP4_SOURCE' Makefile"
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]
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},
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{
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"id": "code.heap4",
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"kind": "code",
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"expected_observations": [
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"heap_4 keeps metadata inside the arena",
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"free blocks form one address-ordered intrusive list"
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],
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"assertions": [
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"allocated bit is stored in the size field",
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"xStart and pxEnd are sentinels"
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],
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"evidence_fields": [
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"symbol",
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"list link",
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"block size",
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"arena address"
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],
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"prerequisites": [
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"FreeRTOS-Kernel V11.3.0 available"
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],
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"layout": [
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"ucHeap",
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"BlockLink_t",
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"xStart",
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"pxEnd"
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],
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"commands": [
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"rg -n 'BlockLink_t|prvHeapInit|prvInsertBlockIntoFreeList|pvPortMalloc|vPortFree' ${FREERTOS_KERNEL_PATH:-/opt/FreeRTOS-Kernel}/portable/MemMang/heap_4.c"
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]
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},
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{
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"id": "run.timeline",
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"kind": "run",
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"expected_observations": [
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"every checkpoint is reached from a clean reset with the same ELF",
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"free bytes change by the aligned whole-block size, not by payload alone"
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],
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"assertions": [
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"A, B and C are aligned",
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"the free-byte sequence is strictly decreasing during allocation"
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],
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"evidence_fields": [
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"payload pointer",
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"consumed bytes",
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"available bytes",
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"free-list statistics"
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],
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"prerequisites": [
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"clean Hazard3 RAM",
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"task03 image loaded"
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],
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"layout": [
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"current checkpoint",
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"source call",
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"heap statistics",
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"ucHeap memory"
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],
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"commands": [
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"print g_initial_free",
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"print g_after_a_free",
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"print g_after_b_free",
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"print g_after_allocations",
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"print g_a_consumed",
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"print g_b_consumed",
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"print g_c_consumed"
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]
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},
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{
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"id": "run.fragmented",
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"kind": "run",
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"expected_observations": [
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"A and C are free while B remains allocated",
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"the free list contains two blocks"
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],
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"assertions": [
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"xNumberOfFreeBlocks equals 2",
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"current free bytes exceed the largest free block"
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],
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"evidence_fields": [
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"free blocks",
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"largest block",
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"free bytes",
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"heap bytes"
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],
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"prerequisites": [
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"clean Hazard3 RAM",
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"task03 image loaded"
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],
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"layout": [
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"source",
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"free-list stats",
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"ucHeap memory",
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"registers"
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],
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"commands": [
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"break heap4_fragmented_checkpoint",
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"print g_fragmented_stats",
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"print g_fragmented_free",
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"x/96bx ucHeap"
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]
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},
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{
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"id": "run.coalescing",
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"kind": "run",
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"expected_observations": [
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"the replay stops after free(C), immediately before free(B)",
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"inside prvInsertBlockIntoFreeList the previous block is merged before the next block"
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],
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"assertions": [
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"pxIterator < pxBlockToInsert < pxIterator->pxNextFreeBlock",
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"the left adjacency test is evaluated before the right adjacency test"
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],
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"evidence_fields": [
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"pxIterator",
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"pxBlockToInsert",
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"left end address",
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"right start address"
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],
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"prerequisites": [
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"task01.fragmented replay ready"
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],
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"layout": [
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"application call vPortFree(g_b)",
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"prvInsertBlockIntoFreeList",
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"free-list links",
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"ucHeap addresses"
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],
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"commands": [
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"tbreak prvInsertBlockIntoFreeList",
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"continue",
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"print pxIterator",
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"print pxBlockToInsert",
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"next"
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]
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},
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{
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"id": "run.coalesced",
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"kind": "run",
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"expected_observations": [
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"freeing B joins both neighbours",
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"the arena returns to one reusable block"
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],
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"assertions": [
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"final free equals initial free",
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"one free block is also the largest block",
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"minimum-ever does not rise after free"
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],
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"evidence_fields": [
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"final free",
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"largest block",
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"minimum-ever",
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"free blocks"
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],
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"prerequisites": [
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"fragmented checkpoint reached"
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],
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"layout": [
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"final stats",
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"minimum-ever",
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"OOM hook",
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"PASS"
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],
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"commands": [
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"break heap4_coalesced_checkpoint",
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"print g_final_stats",
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"print g_final_free",
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"print g_minimum_ever_free"
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]
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},
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{
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"id": "run.verified",
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"kind": "run",
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"expected_observations": [
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"the oversized request returns NULL",
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"the malloc-failed hook runs once without corrupting the recovered arena"
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],
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"assertions": [
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"g_oom_is_null equals 1",
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"g_malloc_failed_hooks equals 1",
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"g_assert_failures equals 0",
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"g_task03_pass equals 1"
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],
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"evidence_fields": [
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"OOM result",
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"hook count",
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"assert count",
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"PASS"
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],
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"prerequisites": [
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"coalesced checkpoint reproducible"
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],
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"layout": [
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"final stats",
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"OOM result",
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"hook",
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"PASS"
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],
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"commands": [
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"break task03_debug_checkpoint",
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"print g_too_large",
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"print g_malloc_failed_hooks",
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"print g_assert_failures",
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"print g_task03_pass"
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]
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},
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{
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"id": "code.identity",
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"kind": "code",
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"expected_observations": [
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"upstream heap_4 symbols are linked",
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"checkpoint and ucHeap symbols remain observable"
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],
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"assertions": [
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"pvPortMalloc and vPortFree are present",
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"prvInsertBlockIntoFreeList is present",
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"all eight replay checkpoint symbols are present"
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],
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"evidence_fields": [
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"source blob",
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"ELF SHA256",
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"image SHA256",
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"symbol"
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],
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"prerequisites": [
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"built ELF"
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],
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"layout": [
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"symbols",
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"sections",
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"artifact hashes"
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],
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"commands": [
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"tests/check_task03_elf.sh build/task03_freertos_heap4/prog.elf"
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]
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}
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],
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"checkpoints": {
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"task01.reset": {
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"event_id": "E01",
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"stop": {
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"symbol": "heap4_reset_checkpoint",
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"offset": 0
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},
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"verify": {
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"expressions": [
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{
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"expr": "g_initial_stats.xNumberOfFreeBlocks",
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"equals": 1
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},
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{
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"expr": "g_initial_stats.xSizeOfLargestFreeBlockInBytes == g_initial_free",
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"equals": 1
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},
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{
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"expr": "g_initial_free",
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"equals": 4080
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}
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]
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}
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},
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"task01.alloc-a": {
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"event_id": "E02",
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"stop": {
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"symbol": "heap4_alloc_a_checkpoint",
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"offset": 0
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},
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"verify": {
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"expressions": [
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{
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"expr": "g_a != 0",
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"equals": 1
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},
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{
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"expr": "g_a_aligned",
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"equals": 1
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},
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{
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"expr": "g_a_consumed",
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"equals": 48
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},
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{
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"expr": "g_after_a_stats.xNumberOfFreeBlocks",
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"equals": 1
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},
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{
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"expr": "g_after_a_free",
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"equals": 4032
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}
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]
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}
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},
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"task01.alloc-b": {
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"event_id": "E03",
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"stop": {
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"symbol": "heap4_alloc_b_checkpoint",
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"offset": 0
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},
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"verify": {
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"expressions": [
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{
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"expr": "g_b != 0",
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"equals": 1
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},
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{
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"expr": "g_b_aligned",
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"equals": 1
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},
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{
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"expr": "g_b_consumed",
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"equals": 64
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},
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{
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"expr": "g_after_b_free < g_after_a_free",
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"equals": 1
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},
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{
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"expr": "g_after_b_free",
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"equals": 3968
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}
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]
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}
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},
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"task01.alloc-c": {
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"event_id": "E04",
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"stop": {
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"symbol": "heap4_alloc_c_checkpoint",
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"offset": 0
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},
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"verify": {
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"expressions": [
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{
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"expr": "g_c != 0",
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"equals": 1
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},
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{
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"expr": "g_c_aligned",
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"equals": 1
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},
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{
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"expr": "g_c_consumed",
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"equals": 32
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},
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{
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"expr": "g_allocations_aligned",
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"equals": 1
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},
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{
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"expr": "g_after_allocations",
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"equals": 3936
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}
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]
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}
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},
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"task01.free-a": {
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"event_id": "E05",
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"stop": {
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"symbol": "heap4_free_a_checkpoint",
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"offset": 0
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},
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"verify": {
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"expressions": [
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{
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"expr": "g_after_free_a_stats.xNumberOfFreeBlocks",
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"equals": 2
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},
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{
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"expr": "g_after_free_a == g_after_allocations + g_a_consumed",
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"equals": 1
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},
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{
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"expr": "g_after_free_a_stats.xAvailableHeapSpaceInBytes > g_after_free_a_stats.xSizeOfLargestFreeBlockInBytes",
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"equals": 1
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},
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{
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"expr": "g_after_free_a",
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"equals": 3984
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}
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]
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}
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},
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"task01.fragmented": {
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"event_id": "E06",
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"stop": {
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"symbol": "heap4_fragmented_checkpoint",
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"offset": 0
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},
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"verify": {
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"expressions": [
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{
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"expr": "g_fragmented_stats.xNumberOfFreeBlocks",
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"equals": 2
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},
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{
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"expr": "g_fragmented_free == g_after_free_a + g_c_consumed",
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"equals": 1
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},
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{
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"expr": "g_fragmented_stats.xAvailableHeapSpaceInBytes > g_fragmented_stats.xSizeOfLargestFreeBlockInBytes",
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"equals": 1
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},
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{
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"expr": "g_fragmented_free",
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"equals": 4016
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}
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]
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}
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},
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"task01.coalesced": {
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"event_id": "E07",
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"stop": {
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"symbol": "heap4_coalesced_checkpoint",
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"offset": 0
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},
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"verify": {
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"expressions": [
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{
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"expr": "g_final_stats.xNumberOfFreeBlocks",
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"equals": 1
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},
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{
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"expr": "g_final_free == g_initial_free",
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"equals": 1
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},
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{
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"expr": "g_final_stats.xSizeOfLargestFreeBlockInBytes == g_initial_free",
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"equals": 1
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},
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{
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"expr": "g_minimum_ever_free <= g_after_allocations",
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"equals": 1
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},
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{
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"expr": "g_final_free",
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"equals": 4080
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}
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]
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}
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},
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"task01.verified": {
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"event_id": "E08",
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"stop": {
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"symbol": "task03_debug_checkpoint",
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"offset": 0
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},
|
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"verify": {
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"expressions": [
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{
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"expr": "g_oom_is_null",
|
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"equals": 1
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},
|
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{
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"expr": "g_malloc_failed_hooks",
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"equals": 1
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},
|
|
{
|
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"expr": "g_assert_failures",
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"equals": 0
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},
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{
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"expr": "g_task03_pass",
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"equals": 1
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|
},
|
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{
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"expr": "g_rv32_layout_expected",
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"equals": 1
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}
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]
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}
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}
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},
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"sections": [
|
|
{
|
|
"id": "A1",
|
|
"label": "CONTEXT",
|
|
"title": "Od liniowego kursora do odzyskiwalnej areny",
|
|
"order": 10,
|
|
"orientation": "portrait",
|
|
"description": "Aplikacja korzysta z publicznego API, heap_4 zarządza jedną areną, a Hazard3 pokazuje jej rzeczywisty stan.",
|
|
"content_tex": "Kursor liniowy potrafi tylko rosnąć. heap_4 dodaje metadane i listę wolnych bloków, dzięki czemu zwolniona pamięć wraca do ponownego użycia.",
|
|
"assets": [
|
|
{
|
|
"stem": "a1-context",
|
|
"title": "A1 · granice odpowiedzialności heap_4",
|
|
"caption": "A1 CONTEXT — od żądania aplikacji do rzeczywistych bajtów ucHeap.",
|
|
"label": "fig:a1-context",
|
|
"alt": "A1 · granice odpowiedzialności heap_4",
|
|
"phases": [
|
|
{
|
|
"id": "boundary",
|
|
"label": "APPLICATION / API / ALLOCATOR / TARGET",
|
|
"steps": [
|
|
{
|
|
"id": "application",
|
|
"number": 1,
|
|
"label": "aplikacja żąda i zwalnia bajty",
|
|
"mode": "CODE",
|
|
"strategy_ref": "code.boundary",
|
|
"svg_label": "01",
|
|
"code_ref": "src/tasks/task03_freertos_heap4.c:127",
|
|
"description": "Aplikacja zna wyłącznie publiczne API i wskaźniki payloadu.",
|
|
"evidence": "trzy żądania 24, 40 i 16 bajtów"
|
|
},
|
|
{
|
|
"id": "api",
|
|
"number": 2,
|
|
"label": "FreeRTOS wystawia malloc, free i statystyki",
|
|
"mode": "CODE",
|
|
"strategy_ref": "code.boundary",
|
|
"svg_label": "02",
|
|
"code_ref": "src/tasks/task03_freertos_heap4.c:127",
|
|
"description": "API oddziela eksperyment od prywatnej listy bloków.",
|
|
"evidence": "pvPortMalloc, vPortFree, vPortGetHeapStats"
|
|
},
|
|
{
|
|
"id": "allocator",
|
|
"number": 3,
|
|
"label": "heap_4 zarządza blokami i kolejnością adresów",
|
|
"mode": "CODE",
|
|
"strategy_ref": "code.heap4",
|
|
"svg_label": "03",
|
|
"code_ref": "UPSTREAM.md:1",
|
|
"description": "Prywatny mechanizm wybiera, dzieli i scala wolne bloki; strategia otwiera prawdziwy heap_4.c.",
|
|
"evidence": "prvHeapInit i prvInsertBlockIntoFreeList"
|
|
},
|
|
{
|
|
"id": "arena",
|
|
"number": 4,
|
|
"label": "ucHeap jest jedną ograniczoną areną",
|
|
"mode": "CODE",
|
|
"strategy_ref": "code.boundary",
|
|
"svg_label": "04",
|
|
"code_ref": "src/tasks/task03_freertos_heap4.c:11",
|
|
"description": "Metadane i payload znajdują się w tej samej statycznej tablicy.",
|
|
"evidence": "4096 bajtów, wyrównanie portu"
|
|
},
|
|
{
|
|
"id": "target",
|
|
"number": 5,
|
|
"label": "Hazard3 ujawnia adresy i bajty",
|
|
"mode": "CODE",
|
|
"strategy_ref": "code.identity",
|
|
"svg_label": "05",
|
|
"code_ref": "tests/check_task03_elf.sh:8",
|
|
"description": "ELF łączy kod, symbole i pamięć obserwowaną przez GDB.",
|
|
"evidence": "ucHeap i checkpointy w symbolach ELF"
|
|
}
|
|
]
|
|
}
|
|
]
|
|
}
|
|
]
|
|
},
|
|
{
|
|
"id": "A2",
|
|
"label": "STRUCTURE",
|
|
"title": "Nagłówek, payload i lista wolnych bloków",
|
|
"order": 20,
|
|
"orientation": "portrait",
|
|
"description": "Każdy blok ma nagłówek, a tylko wolne bloki wykorzystują wskaźnik next do budowy listy uporządkowanej adresami.",
|
|
"content_tex": "Rozmiar żądania rośnie o nagłówek i wyrównanie. Duży wolny blok może zostać rozdzielony na blok przydzielony i użyteczną resztę.",
|
|
"assets": [
|
|
{
|
|
"stem": "a2-structure",
|
|
"title": "A2 · struktura bloku i listy",
|
|
"caption": "A2 STRUCTURE — metadane wewnątrz areny i adresowo uporządkowana lista.",
|
|
"label": "fig:a2-structure",
|
|
"alt": "A2 · struktura bloku i listy",
|
|
"phases": [
|
|
{
|
|
"id": "blocks",
|
|
"label": "HEADER / PAYLOAD / FREE LIST",
|
|
"steps": [
|
|
{
|
|
"id": "header",
|
|
"number": 1,
|
|
"label": "nagłówek RV32 przechowuje next i size",
|
|
"mode": "CODE",
|
|
"strategy_ref": "code.heap4",
|
|
"svg_label": "01",
|
|
"code_ref": "UPSTREAM.md:1",
|
|
"description": "Prawdziwy BlockLink_t zawiera wskaźnik i size_t, po 4 bajty na RV32; port wyrównuje nagłówek do 16 bajtów.",
|
|
"evidence": "sizeof(BlockLink_t)=8; portBYTE_ALIGNMENT=16; xHeapStructSize=16"
|
|
},
|
|
{
|
|
"id": "alignment",
|
|
"number": 2,
|
|
"label": "A(24) obejmuje nagłówek i wyrównanie",
|
|
"mode": "RUN",
|
|
"event_id": "E02",
|
|
"strategy_ref": "run.timeline",
|
|
"svg_label": "02",
|
|
"code_ref": "src/tasks/task03_freertos_heap4.c:137",
|
|
"snapshot_ref": "task01.alloc-a",
|
|
"description": "Różnica licznika wolnych bajtów mierzy cały blok, nie sam payload.",
|
|
"evidence": "g_a_consumed = 48; g_a_aligned = 1"
|
|
},
|
|
{
|
|
"id": "split",
|
|
"number": 3,
|
|
"label": "split pozostawia osobny wolny blok",
|
|
"mode": "RUN",
|
|
"event_id": "E02",
|
|
"strategy_ref": "run.timeline",
|
|
"svg_label": "03",
|
|
"code_ref": "src/tasks/task03_freertos_heap4.c:137",
|
|
"snapshot_ref": "task01.alloc-a",
|
|
"description": "Po pierwszym first-fit pozostała część areny nadal jest jednym wolnym blokiem.",
|
|
"evidence": "free = 4032; free blocks = 1"
|
|
},
|
|
{
|
|
"id": "address-order",
|
|
"number": 4,
|
|
"label": "lista jest uporządkowana rosnącymi adresami",
|
|
"mode": "RUN",
|
|
"event_id": "E06",
|
|
"strategy_ref": "run.fragmented",
|
|
"svg_label": "04",
|
|
"code_ref": "src/tasks/task03_freertos_heap4.c:168",
|
|
"snapshot_ref": "task01.fragmented",
|
|
"description": "Pozycja w liście ujawnia bezpośredniego poprzednika i następnika.",
|
|
"evidence": "g_a < g_b < g_c; dwa wolne obszary"
|
|
},
|
|
{
|
|
"id": "left-join",
|
|
"number": 5,
|
|
"label": "heap_4 scala najpierw poprzedni blok",
|
|
"mode": "RUN",
|
|
"event_id": "E06",
|
|
"strategy_ref": "run.coalescing",
|
|
"svg_label": "05",
|
|
"code_ref": "src/tasks/task03_freertos_heap4.c:173",
|
|
"snapshot_ref": "task01.fragmented",
|
|
"description": "Replay E06, tymczasowy breakpoint i step w prywatnej funkcji pokazują pierwszy test ciągłości.",
|
|
"evidence": "previous + previous.size == inserted"
|
|
},
|
|
{
|
|
"id": "right-join",
|
|
"number": 6,
|
|
"label": "następnie scala prawy blok",
|
|
"mode": "RUN",
|
|
"event_id": "E06",
|
|
"strategy_ref": "run.coalescing",
|
|
"svg_label": "06",
|
|
"code_ref": "src/tasks/task03_freertos_heap4.c:173",
|
|
"snapshot_ref": "task01.fragmented",
|
|
"description": "Drugi test wykorzystuje już powiększony lewy blok i domyka scalenie areny.",
|
|
"evidence": "merged + merged.size == current"
|
|
}
|
|
]
|
|
}
|
|
]
|
|
}
|
|
]
|
|
},
|
|
{
|
|
"id": "A5",
|
|
"label": "FLOW",
|
|
"title": "First-fit, fragmentacja i pełne scalenie",
|
|
"order": 50,
|
|
"orientation": "landscape",
|
|
"description": "Jeden przebieg A/B/C przechodzi od pustej areny przez trzy przydziały i dwa wolne obszary do ponownie scalonego bloku.",
|
|
"content_tex": "Uczeń przewiduje układ bloków, a następnie odtwarza osiem deterministycznych stanów tego samego przebiegu Hazard3.",
|
|
"assets": [
|
|
{
|
|
"stem": "a5-flow",
|
|
"title": "A5 · pełny przebieg heap_4",
|
|
"caption": "A5 FLOW — inicjalizacja, A/B/C, fragmentacja, dwustronne scalenie i OOM.",
|
|
"label": "fig:a5-flow",
|
|
"alt": "A5 · pełny przebieg heap_4",
|
|
"phases": [
|
|
{
|
|
"id": "replay",
|
|
"label": "ALLOCATE / FRAGMENT / COALESCE",
|
|
"steps": [
|
|
{
|
|
"id": "reset",
|
|
"number": 1,
|
|
"label": "reset i inicjalizacja areny",
|
|
"mode": "RUN",
|
|
"event_id": "E01",
|
|
"strategy_ref": "run.timeline",
|
|
"svg_label": "01",
|
|
"code_ref": "src/tasks/task03_freertos_heap4.c:127",
|
|
"snapshot_ref": "task01.reset",
|
|
"description": "Próbne żądanie inicjalizuje sentinele; po jego zwolnieniu arena ma jeden blok.",
|
|
"evidence": "free = largest = 4080; blocks = 1"
|
|
},
|
|
{
|
|
"id": "alloc-a",
|
|
"number": 2,
|
|
"label": "first-fit przydziela A",
|
|
"mode": "RUN",
|
|
"event_id": "E02",
|
|
"strategy_ref": "run.timeline",
|
|
"svg_label": "02",
|
|
"code_ref": "src/tasks/task03_freertos_heap4.c:137",
|
|
"snapshot_ref": "task01.alloc-a",
|
|
"description": "Pierwszy wystarczający blok zostaje rozdzielony.",
|
|
"evidence": "A=24; consumed=48; free=4032"
|
|
},
|
|
{
|
|
"id": "alloc-b",
|
|
"number": 3,
|
|
"label": "kolejny split tworzy B",
|
|
"mode": "RUN",
|
|
"event_id": "E03",
|
|
"strategy_ref": "run.timeline",
|
|
"svg_label": "03",
|
|
"code_ref": "src/tasks/task03_freertos_heap4.c:145",
|
|
"snapshot_ref": "task01.alloc-b",
|
|
"description": "B zajmuje następny fragment tej samej reszty.",
|
|
"evidence": "B=40; consumed=64; free=3968"
|
|
},
|
|
{
|
|
"id": "alloc-c",
|
|
"number": 4,
|
|
"label": "trzeci split tworzy C",
|
|
"mode": "RUN",
|
|
"event_id": "E04",
|
|
"strategy_ref": "run.timeline",
|
|
"svg_label": "04",
|
|
"code_ref": "src/tasks/task03_freertos_heap4.c:153",
|
|
"snapshot_ref": "task01.alloc-c",
|
|
"description": "A, B i C są wyrównane, a za nimi pozostaje jedna wolna reszta.",
|
|
"evidence": "C=16; consumed=32; free=3936"
|
|
},
|
|
{
|
|
"id": "free-a",
|
|
"number": 5,
|
|
"label": "zwolnij A, pozostaw B i C",
|
|
"mode": "RUN",
|
|
"event_id": "E05",
|
|
"strategy_ref": "run.timeline",
|
|
"svg_label": "05",
|
|
"code_ref": "src/tasks/task03_freertos_heap4.c:163",
|
|
"snapshot_ref": "task01.free-a",
|
|
"description": "Wolny A i końcowa reszta są rozdzielone przez B i C.",
|
|
"evidence": "blocks=2; free=3984"
|
|
},
|
|
{
|
|
"id": "fragmented",
|
|
"number": 6,
|
|
"label": "zwolnij C, pozostaw B",
|
|
"mode": "RUN",
|
|
"event_id": "E06",
|
|
"strategy_ref": "run.fragmented",
|
|
"svg_label": "06",
|
|
"code_ref": "src/tasks/task03_freertos_heap4.c:168",
|
|
"snapshot_ref": "task01.fragmented",
|
|
"description": "C scala się z prawą resztą, ale B nadal rozdziela dwa wolne obszary.",
|
|
"evidence": "blocks=2; free=4016; free>largest"
|
|
},
|
|
{
|
|
"id": "coalesced",
|
|
"number": 7,
|
|
"label": "zwolnij B i scal oba sąsiednie bloki",
|
|
"mode": "RUN",
|
|
"event_id": "E07",
|
|
"strategy_ref": "run.coalesced",
|
|
"svg_label": "07",
|
|
"code_ref": "src/tasks/task03_freertos_heap4.c:173",
|
|
"snapshot_ref": "task01.coalesced",
|
|
"description": "Scalenie lewego, a potem prawego sąsiada przywraca jeden blok.",
|
|
"evidence": "free=largest=initial=4080; blocks=1"
|
|
},
|
|
{
|
|
"id": "oom",
|
|
"number": 8,
|
|
"label": "zbyt duże żądanie kończy się NULL",
|
|
"mode": "RUN",
|
|
"event_id": "E08",
|
|
"strategy_ref": "run.verified",
|
|
"svg_label": "08",
|
|
"code_ref": "src/tasks/task03_freertos_heap4.c:179",
|
|
"snapshot_ref": "task01.verified",
|
|
"description": "Kontrolowany OOM nie narusza listy i wywołuje hook dokładnie raz.",
|
|
"evidence": "NULL; hooks=1; asserts=0; PASS=1"
|
|
}
|
|
]
|
|
}
|
|
],
|
|
"diagram_kind": "sequence"
|
|
}
|
|
]
|
|
},
|
|
{
|
|
"id": "A6",
|
|
"label": "STATE",
|
|
"title": "Stan bloku a stan statystyk",
|
|
"order": 60,
|
|
"orientation": "portrait",
|
|
"description": "Bieżąca liczba wolnych bajtów może rosnąć po free, ale minimum-ever pozostaje historycznym minimum.",
|
|
"content_tex": "Fragmentacja to nie tylko suma wolnych bajtów. O możliwości przydziału decyduje także największy pojedynczy blok.",
|
|
"assets": [
|
|
{
|
|
"stem": "a6-state",
|
|
"title": "A6 · stany bloków i liczników",
|
|
"caption": "A6 STATE — wolny, przydzielony, rozdzielony, scalony oraz minimum-ever.",
|
|
"label": "fig:a6-state",
|
|
"alt": "A6 · stany bloków i liczników",
|
|
"phases": [
|
|
{
|
|
"id": "state",
|
|
"label": "BLOCK STATE / HEAP STATS",
|
|
"steps": [
|
|
{
|
|
"id": "free",
|
|
"number": 1,
|
|
"label": "wolny blok należy do listy",
|
|
"mode": "RUN",
|
|
"event_id": "E01",
|
|
"strategy_ref": "run.timeline",
|
|
"svg_label": "01",
|
|
"code_ref": "src/tasks/task03_freertos_heap4.c:127",
|
|
"snapshot_ref": "task01.reset",
|
|
"description": "Stan początkowy zawiera jeden największy wolny blok.",
|
|
"evidence": "initial free = largest free = 4080"
|
|
},
|
|
{
|
|
"id": "allocated",
|
|
"number": 2,
|
|
"label": "przydzielony blok znika z listy wolnych",
|
|
"mode": "RUN",
|
|
"event_id": "E04",
|
|
"strategy_ref": "run.timeline",
|
|
"svg_label": "02",
|
|
"code_ref": "src/tasks/task03_freertos_heap4.c:153",
|
|
"snapshot_ref": "task01.alloc-c",
|
|
"description": "Payload jest wyrównany, a bieżąca wolna pamięć maleje.",
|
|
"evidence": "all payload pointers aligned; free=3936"
|
|
},
|
|
{
|
|
"id": "fragmented-state",
|
|
"number": 3,
|
|
"label": "dwa wolne bloki nie są jednym dużym blokiem",
|
|
"mode": "RUN",
|
|
"event_id": "E06",
|
|
"strategy_ref": "run.fragmented",
|
|
"svg_label": "03",
|
|
"code_ref": "src/tasks/task03_freertos_heap4.c:168",
|
|
"snapshot_ref": "task01.fragmented",
|
|
"description": "Suma wolnego miejsca nie gwarantuje jednego dużego przydziału.",
|
|
"evidence": "free blocks = 2"
|
|
},
|
|
{
|
|
"id": "coalesced-state",
|
|
"number": 4,
|
|
"label": "scalenie przywraca jeden największy blok",
|
|
"mode": "RUN",
|
|
"event_id": "E07",
|
|
"strategy_ref": "run.coalesced",
|
|
"svg_label": "04",
|
|
"code_ref": "src/tasks/task03_freertos_heap4.c:173",
|
|
"snapshot_ref": "task01.coalesced",
|
|
"description": "Current free i largest wracają do wartości początkowej.",
|
|
"evidence": "free blocks = 1"
|
|
},
|
|
{
|
|
"id": "minimum-ever",
|
|
"number": 5,
|
|
"label": "minimum-ever zachowuje najniższy poziom",
|
|
"mode": "RUN",
|
|
"event_id": "E08",
|
|
"strategy_ref": "run.verified",
|
|
"svg_label": "05",
|
|
"code_ref": "src/tasks/task03_freertos_heap4.c:179",
|
|
"snapshot_ref": "task01.verified",
|
|
"description": "Historyczne minimum nie zwiększa się po odzyskaniu pamięci.",
|
|
"evidence": "minimum-ever <= after allocations"
|
|
}
|
|
]
|
|
}
|
|
]
|
|
}
|
|
]
|
|
},
|
|
{
|
|
"id": "A7",
|
|
"label": "RUNTIME",
|
|
"title": "Dowód w Hazard3 i ELF",
|
|
"order": 70,
|
|
"orientation": "landscape",
|
|
"description": "Ten sam artefakt łączy źródło, symbole ELF, osiem checkpointów, pamięć ucHeap i końcowe asercje.",
|
|
"content_tex": "Snapshot jest dowodem tylko wtedy, gdy zawiera tożsamość artefaktu, pozycję programu i wartości, które rozstrzygają hipotezę.",
|
|
"assets": [
|
|
{
|
|
"stem": "a7-runtime",
|
|
"title": "A7 · dowód runtime heap_4",
|
|
"caption": "A7 RUNTIME — kod, ELF, checkpoint, pamięć i statystyki jednego przebiegu.",
|
|
"label": "fig:a7-runtime",
|
|
"alt": "A7 · dowód runtime heap_4",
|
|
"phases": [
|
|
{
|
|
"id": "evidence",
|
|
"label": "ARTIFACT / CHECKPOINT / MEMORY / ASSERTION",
|
|
"steps": [
|
|
{
|
|
"id": "source",
|
|
"number": 1,
|
|
"label": "źródło wskazuje eksperyment A/B/C",
|
|
"mode": "CODE",
|
|
"strategy_ref": "code.identity",
|
|
"svg_label": "01",
|
|
"code_ref": "src/tasks/task03_freertos_heap4.c:127",
|
|
"description": "Blob źródła jest częścią tożsamości karty.",
|
|
"evidence": "source git blob"
|
|
},
|
|
{
|
|
"id": "elf",
|
|
"number": 2,
|
|
"label": "ELF zawiera prawdziwe symbole heap_4",
|
|
"mode": "CODE",
|
|
"strategy_ref": "code.identity",
|
|
"svg_label": "02",
|
|
"code_ref": "tests/check_task03_elf.sh:8",
|
|
"description": "Test ABI odrzuca atrapę bez pvPortMalloc, vPortFree i ucHeap.",
|
|
"evidence": "upstream symbols present"
|
|
},
|
|
{
|
|
"id": "fragmented-runtime",
|
|
"number": 3,
|
|
"label": "checkpoint pokazuje dwa wolne bloki",
|
|
"mode": "RUN",
|
|
"event_id": "E06",
|
|
"strategy_ref": "run.fragmented",
|
|
"svg_label": "03",
|
|
"code_ref": "src/tasks/task03_freertos_heap4.c:168",
|
|
"snapshot_ref": "task01.fragmented",
|
|
"description": "Neovim, GDB i pamięć zatrzymują się na tym samym stanie.",
|
|
"evidence": "blocks=2 and free>largest"
|
|
},
|
|
{
|
|
"id": "memory",
|
|
"number": 4,
|
|
"label": "ucHeap ujawnia nagłówki i payload",
|
|
"mode": "RUN",
|
|
"event_id": "E06",
|
|
"strategy_ref": "run.fragmented",
|
|
"svg_label": "04",
|
|
"code_ref": "src/tasks/task03_freertos_heap4.c:11",
|
|
"snapshot_ref": "task01.fragmented",
|
|
"description": "Widok bajtów łączy diagram z realnym układem areny.",
|
|
"evidence": "aligned arena and in-band metadata"
|
|
},
|
|
{
|
|
"id": "final-runtime",
|
|
"number": 5,
|
|
"label": "checkpoint końcowy dowodzi odzyskania",
|
|
"mode": "RUN",
|
|
"event_id": "E08",
|
|
"strategy_ref": "run.verified",
|
|
"svg_label": "05",
|
|
"code_ref": "src/tasks/task03_freertos_heap4.c:179",
|
|
"snapshot_ref": "task01.verified",
|
|
"description": "Jedna ramka łączy stats, OOM, hook i PASS.",
|
|
"evidence": "final=initial, blocks=1, pass=1"
|
|
}
|
|
]
|
|
}
|
|
]
|
|
}
|
|
]
|
|
}
|
|
],
|
|
"learning": {
|
|
"model_label": "Model bloków heap_4",
|
|
"model": "Uczeń wyjaśnia nagłówek, wyrównanie, first-fit, split, adresową listę wolnych bloków i dwustronne coalescing.",
|
|
"replay_label": "Fragmentacja i odzyskanie areny",
|
|
"replay": "Uczeń odtwarza osiem checkpointów Hazard3 i odróżnia current free, largest free block oraz minimum-ever.",
|
|
"criterion": "Na RV32 BlockLink_t ma 8 bajtów, lecz 16-bajtowe wyrównanie portu daje xHeapStructSize=16; A/B/C zużywają 48/64/32 bajty; po free(A,C) są dwa wolne bloki, po free(B) jeden; final free = initial free; minimum-ever nie rośnie; OOM zwraca NULL; PASS=1.",
|
|
"requirement": "Analiza i weryfikacja mechaniki dynamicznej alokacji heap_4 w FreeRTOS C na RV32I/Hazard3."
|
|
},
|
|
"task": {
|
|
"short_label": "mechanika heap_4",
|
|
"title": "Predict and prove reusable heap_4 blocks",
|
|
"prompt_tex": "Przewidź układ bloków po alloc A/B/C, następnie po free(A), free(C) i free(B). Odtwórz checkpointy E01--E08 i udowodnij, że arena została scalona bez utraty minimum-ever.",
|
|
"conclusion_tex": "heap\\_4 odzyskuje pamięć dzięki metadanym w arenie, adresowo uporządkowanej liście i scalaniu sąsiadów. Suma wolnych bajtów nie zastępuje informacji o największym bloku, a minimum-ever jest historią, nie bieżącym stanem.",
|
|
"flow": [
|
|
{
|
|
"kind": "block",
|
|
"id": "predict",
|
|
"title": "A — przewidywanie",
|
|
"content_tex": "Przejdź przez model nagłówka, split i porządek adresowy przed uruchomieniem prawdziwego heap\\_4.",
|
|
"steps": [
|
|
{
|
|
"id": "size",
|
|
"title": "Policz rozmiary całych bloków.",
|
|
"content_tex": "Rozróżnij surowy BlockLink\\_t (8 bajtów) od xHeapStructSize (16 bajtów), dodaj nagłówek do żądań 24, 40 i 16 bajtów, a następnie wyrównaj wynik do 16."
|
|
},
|
|
{
|
|
"id": "list",
|
|
"title": "Narysuj listę po free(A,C).",
|
|
"content_tex": "Zaznacz, dlaczego przydzielony B rozdziela dwa wolne obszary."
|
|
}
|
|
]
|
|
},
|
|
{
|
|
"kind": "block",
|
|
"id": "replay",
|
|
"title": "B — replay Hazard3",
|
|
"content_tex": "Powiąż każdy stan diagramu z deterministycznym checkpointem E01--E08.",
|
|
"steps": [
|
|
{
|
|
"id": "allocate",
|
|
"title": "Sprawdź E01--E04.",
|
|
"content_tex": "Potwierdź wartości 4080, 4032, 3968 i 3936 oraz zużycie 48/64/32 bajtów."
|
|
},
|
|
{
|
|
"id": "release",
|
|
"title": "Sprawdź E05--E07.",
|
|
"content_tex": "Porównaj liczbę wolnych bloków i udowodnij scalenie poprzedniego, a potem następnego sąsiada."
|
|
},
|
|
{
|
|
"id": "verify",
|
|
"title": "Sprawdź E08.",
|
|
"content_tex": "Udowodnij zachowanie minimum-ever, kontrolowany OOM, brak asercji i PASS=1."
|
|
}
|
|
]
|
|
},
|
|
{
|
|
"kind": "exercise",
|
|
"id": "fragmentation",
|
|
"title": "Ćwiczenie — ta sama suma, inna użyteczność",
|
|
"prompt_tex": "Zaproponuj dwa układy wolnych bloków o tej samej sumie bajtów, ale tylko jeden zdolny obsłużyć wskazane duże żądanie. Uzasadnij odpowiedź przez largest-free-block.",
|
|
"evidence_tex": "Dwa diagramy listy, suma wolnych bajtów, rozmiar największego bloku i wynik pvPortMalloc.",
|
|
"criterion": "Uczeń nie utożsamia sumy wolnej pamięci z możliwością pojedynczego dużego przydziału.",
|
|
"based_on": [
|
|
"predict",
|
|
"replay"
|
|
]
|
|
}
|
|
]
|
|
}
|
|
}
|