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Diffstat (limited to 'archive/2.vm/034address.cc')
| -rw-r--r-- | archive/2.vm/034address.cc | 514 |
1 files changed, 0 insertions, 514 deletions
diff --git a/archive/2.vm/034address.cc b/archive/2.vm/034address.cc deleted file mode 100644 index bafde7b4..00000000 --- a/archive/2.vm/034address.cc +++ /dev/null @@ -1,514 +0,0 @@ -//: Addresses help us spend less time copying data around. - -//: So far we've been operating on primitives like numbers and characters, and -//: we've started combining these primitives together into larger logical -//: units (containers or arrays) that may contain many different primitives at -//: once. Containers and arrays can grow quite large in complex programs, and -//: we'd like some way to efficiently share them between recipes without -//: constantly having to make copies. Right now 'next-ingredient' and 'return' -//: copy data across recipe boundaries. To avoid copying large quantities of -//: data around, we'll use *addresses*. An address is a bookmark to some -//: arbitrary quantity of data (the *payload*). It's a primitive, so it's as -//: efficient to copy as a number. To read or modify the payload 'pointed to' -//: by an address, we'll perform a *lookup*. -//: -//: The notion of 'lookup' isn't an instruction like 'add' or 'subtract'. -//: Instead it's an operation that can be performed when reading any of the -//: ingredients of an instruction, and when writing to any of the products. To -//: write to the payload of an ingredient rather than its value, simply add -//: the /lookup property to it. Modern computers provide efficient support for -//: addresses and lookups, making this a realistic feature. -//: -//: To create addresses and allocate memory exclusively for their use, use -//: 'new'. Memory is a finite resource so if the computer can't satisfy your -//: request, 'new' may return a 0 (null) address. -//: -//: Computers these days have lots of memory so in practice we can often -//: assume we'll never run out. If you start running out however, say in a -//: long-running program, you'll need to switch mental gears and start -//: husbanding our memory more carefully. The most important tool to avoid -//: wasting memory is to 'abandon' an address when you don't need it anymore. -//: That frees up the memory allocated to it to be reused in future calls to -//: 'new'. - -//: Since memory can be reused multiple times, it can happen that you have a -//: stale copy to an address that has since been abandoned and reused. Using -//: the stale address is almost never safe, but it can be very hard to track -//: down such copies because any errors caused by them may occur even millions -//: of instructions after the copy or abandon instruction. To help track down -//: such issues, Mu tracks an 'alloc id' for each allocation it makes. The -//: first call to 'new' has an alloc id of 1, the second gets 2, and so on. -//: The alloc id is never reused. -:(before "End Globals") -long long Next_alloc_id = 0; -:(before "End Reset") -Next_alloc_id = 0; - -//: The 'new' instruction records alloc ids both in the memory being allocated -//: and *also* in the address. The 'abandon' instruction clears alloc ids in -//: both places as well. Tracking alloc ids in this manner allows us to raise -//: errors about stale addresses much earlier: 'lookup' operations always -//: compare alloc ids between the address and its payload. - -//: todo: give 'new' a custodian ingredient. Following malloc/free is a temporary hack. - -:(code) -void test_new() { - run( - // call 'new' two times with identical types without modifying the - // results; you should get back different results - "def main [\n" - " 10:&:num <- new num:type\n" - " 12:&:num <- new num:type\n" - " 20:bool <- equal 10:&:num, 12:&:num\n" - "]\n" - ); - CHECK_TRACE_CONTENTS( - "mem: storing 1000 in location 11\n" - "mem: storing 0 in location 20\n" - ); -} - -void test_new_array() { - run( - // call 'new' with a second ingredient to allocate an array of some type - // rather than a single copy - "def main [\n" - " 10:&:@:num <- new num:type, 5\n" - " 12:&:num <- new num:type\n" - " 20:num/alloc2, 21:num/alloc1 <- deaddress 10:&:@:num, 12:&:num\n" - " 30:num <- subtract 21:num/alloc2, 20:num/alloc1\n" - "]\n" - ); - CHECK_TRACE_CONTENTS( - "run: {10: (\"address\" \"array\" \"number\")} <- new {num: \"type\"}, {5: \"literal\"}\n" - "mem: array length is 5\n" - // skip alloc id in allocation - "mem: storing 1000 in location 11\n" - // don't forget the extra locations for alloc id and array length - "mem: storing 7 in location 30\n" - ); -} - -void test_dilated_reagent_with_new() { - run( - "def main [\n" - " 10:&:&:num <- new {(& num): type}\n" - "]\n" - ); - CHECK_TRACE_CONTENTS( - "new: size of '(& num)' is 2\n" - ); -} - -//: 'new' takes a weird 'type' as its first ingredient; don't error on it -:(before "End Mu Types Initialization") -put(Type_ordinal, "type", 0); -:(code) -bool is_mu_type_literal(const reagent& r) { - return is_literal(r) && r.type && r.type->name == "type"; -} - -:(before "End Primitive Recipe Declarations") -NEW, -:(before "End Primitive Recipe Numbers") -put(Recipe_ordinal, "new", NEW); -:(before "End Primitive Recipe Checks") -case NEW: { - const recipe& caller = get(Recipe, r); - if (inst.ingredients.empty() || SIZE(inst.ingredients) > 2) { - raise << maybe(caller.name) << "'new' requires one or two ingredients, but got '" << to_original_string(inst) << "'\n" << end(); - break; - } - // End NEW Check Special-cases - const reagent& type = inst.ingredients.at(0); - if (!is_mu_type_literal(type)) { - raise << maybe(caller.name) << "first ingredient of 'new' should be a type, but got '" << type.original_string << "'\n" << end(); - break; - } - if (SIZE(inst.ingredients) > 1 && !is_mu_number(inst.ingredients.at(1))) { - raise << maybe(caller.name) << "second ingredient of 'new' should be a number (array length), but got '" << type.original_string << "'\n" << end(); - break; - } - if (inst.products.empty()) { - raise << maybe(caller.name) << "result of 'new' should never be ignored\n" << end(); - break; - } - if (!product_of_new_is_valid(inst)) { - raise << maybe(caller.name) << "product of 'new' has incorrect type: '" << to_original_string(inst) << "'\n" << end(); - break; - } - break; -} - -:(code) -bool product_of_new_is_valid(const instruction& inst) { - reagent/*copy*/ product = inst.products.at(0); - // Update NEW product in Check - if (!product.type || product.type->atom || product.type->left->value != Address_type_ordinal) - return false; - drop_from_type(product, "address"); - if (SIZE(inst.ingredients) > 1) { - // array allocation - if (!product.type || product.type->atom || product.type->left->value != Array_type_ordinal) - return false; - drop_from_type(product, "array"); - } - reagent/*local*/ expected_product(new_type_tree(inst.ingredients.at(0).name)); - return types_strictly_match(product, expected_product); -} - -void drop_from_type(reagent& r, string expected_type) { - assert(!r.type->atom); - if (r.type->left->name != expected_type) { - raise << "can't drop2 " << expected_type << " from '" << to_string(r) << "'\n" << end(); - return; - } - // r.type = r.type->right - type_tree* tmp = r.type; - r.type = tmp->right; - tmp->right = NULL; - delete tmp; - // if (!r.type->right) r.type = r.type->left - assert(!r.type->atom); - if (r.type->right) return; - tmp = r.type; - r.type = tmp->left; - tmp->left = NULL; - delete tmp; -} - -void test_new_returns_incorrect_type() { - Hide_errors = true; - run( - "def main [\n" - " 1:bool <- new num:type\n" - "]\n" - ); - CHECK_TRACE_CONTENTS( - "error: main: product of 'new' has incorrect type: '1:bool <- new num:type'\n" - ); -} - -void test_new_discerns_singleton_list_from_atom_container() { - Hide_errors = true; - run( - "def main [\n" - " 1:&:num <- new {(num): type}\n" // should be '{num: type}' - "]\n" - ); - CHECK_TRACE_CONTENTS( - "error: main: product of 'new' has incorrect type: '1:&:num <- new {(num): type}'\n" - ); -} - -void test_new_with_type_abbreviation() { - run( - "def main [\n" - " 1:&:num <- new num:type\n" - "]\n" - ); - CHECK_TRACE_COUNT("error", 0); -} - -void test_new_with_type_abbreviation_inside_compound() { - run( - "def main [\n" - " {1: (address address number), raw: ()} <- new {(& num): type}\n" - "]\n" - ); - CHECK_TRACE_COUNT("error", 0); -} - -void test_equal_result_of_new_with_null() { - run( - "def main [\n" - " 1:&:num <- new num:type\n" - " 10:bool <- equal 1:&:num, null\n" - "]\n" - ); - CHECK_TRACE_CONTENTS( - "mem: storing 0 in location 10\n" - ); -} - -//: To implement 'new', a Mu transform turns all 'new' instructions into -//: 'allocate' instructions that precompute the amount of memory they want to -//: allocate. - -//: Ensure that we never call 'allocate' directly, and that there's no 'new' -//: instructions left after the transforms have run. -:(before "End Primitive Recipe Checks") -case ALLOCATE: { - raise << "never call 'allocate' directly'; always use 'new'\n" << end(); - break; -} -:(before "End Primitive Recipe Implementations") -case NEW: { - raise << "no implementation for 'new'; why wasn't it translated to 'allocate'? Please save a copy of your program and send it to Kartik.\n" << end(); - break; -} - -:(after "Transform.push_back(check_instruction)") // check_instruction will guard against direct 'allocate' instructions below -Transform.push_back(transform_new_to_allocate); // idempotent - -:(code) -void transform_new_to_allocate(const recipe_ordinal r) { - trace(101, "transform") << "--- convert 'new' to 'allocate' for recipe " << get(Recipe, r).name << end(); - for (int i = 0; i < SIZE(get(Recipe, r).steps); ++i) { - instruction& inst = get(Recipe, r).steps.at(i); - // Convert 'new' To 'allocate' - if (inst.name == "new") { - if (inst.ingredients.empty()) return; // error raised elsewhere - inst.operation = ALLOCATE; - type_tree* type = new_type_tree(inst.ingredients.at(0).name); - inst.ingredients.at(0).set_value(size_of(type)); - trace(102, "new") << "size of '" << inst.ingredients.at(0).name << "' is " << inst.ingredients.at(0).value << end(); - delete type; - } - } -} - -//: implement 'allocate' based on size - -:(before "End Globals") -extern const int Reserved_for_tests = 1000; -int Memory_allocated_until = Reserved_for_tests; -int Initial_memory_per_routine = 100000; -:(before "End Reset") -Memory_allocated_until = Reserved_for_tests; -Initial_memory_per_routine = 100000; -:(before "End routine Fields") -int alloc, alloc_max; -:(before "End routine Constructor") -alloc = Memory_allocated_until; -Memory_allocated_until += Initial_memory_per_routine; -alloc_max = Memory_allocated_until; -trace(Callstack_depth+1, "new") << "routine allocated memory from " << alloc << " to " << alloc_max << end(); - -:(before "End Primitive Recipe Declarations") -ALLOCATE, -:(before "End Primitive Recipe Numbers") -put(Recipe_ordinal, "allocate", ALLOCATE); -:(before "End Primitive Recipe Implementations") -case ALLOCATE: { - // compute the space we need - int size = ingredients.at(0).at(0); - int alloc_id = Next_alloc_id; - Next_alloc_id++; - if (SIZE(ingredients) > 1) { - // array allocation - trace(Callstack_depth+1, "mem") << "array length is " << ingredients.at(1).at(0) << end(); - size = /*space for length*/1 + size*ingredients.at(1).at(0); - } - int result = allocate(size); - // initialize alloc-id in payload - trace(Callstack_depth+1, "mem") << "storing alloc-id " << alloc_id << " in location " << result << end(); - put(Memory, result, alloc_id); - if (SIZE(current_instruction().ingredients) > 1) { - // initialize array length - trace(Callstack_depth+1, "mem") << "storing array length " << ingredients.at(1).at(0) << " in location " << result+/*skip alloc id*/1 << end(); - put(Memory, result+/*skip alloc id*/1, ingredients.at(1).at(0)); - } - products.resize(1); - products.at(0).push_back(alloc_id); - products.at(0).push_back(result); - break; -} -:(code) -int allocate(int size) { - // include space for alloc id - ++size; - trace(Callstack_depth+1, "mem") << "allocating size " << size << end(); -//? Total_alloc += size; -//? ++Num_alloc; - // Allocate Special-cases - // compute the region of memory to return - // really crappy at the moment - ensure_space(size); - const int result = Current_routine->alloc; - trace(Callstack_depth+1, "mem") << "new alloc: " << result << end(); - // initialize allocated space - for (int address = result; address < result+size; ++address) { - trace(Callstack_depth+1, "mem") << "storing 0 in location " << address << end(); - put(Memory, address, 0); - } - Current_routine->alloc += size; - // no support yet for reclaiming memory between routines - assert(Current_routine->alloc <= Current_routine->alloc_max); - return result; -} - -//: statistics for debugging -//? :(before "End Globals") -//? int Total_alloc = 0; -//? int Num_alloc = 0; -//? int Total_free = 0; -//? int Num_free = 0; -//? :(before "End Reset") -//? if (!Memory.empty()) { -//? cerr << Total_alloc << "/" << Num_alloc -//? << " vs " << Total_free << "/" << Num_free << '\n'; -//? cerr << SIZE(Memory) << '\n'; -//? } -//? Total_alloc = Num_alloc = Total_free = Num_free = 0; - -:(code) -void ensure_space(int size) { - if (size > Initial_memory_per_routine) { - cerr << "can't allocate " << size << " locations, that's too much compared to " << Initial_memory_per_routine << ".\n"; - exit(1); - } - if (Current_routine->alloc + size > Current_routine->alloc_max) { - // waste the remaining space and create a new chunk - Current_routine->alloc = Memory_allocated_until; - Memory_allocated_until += Initial_memory_per_routine; - Current_routine->alloc_max = Memory_allocated_until; - trace(Callstack_depth+1, "new") << "routine allocated memory from " << Current_routine->alloc << " to " << Current_routine->alloc_max << end(); - } -} - -void test_new_initializes() { - Memory_allocated_until = 10; - put(Memory, Memory_allocated_until, 1); - run( - "def main [\n" - " 1:&:num <- new num:type\n" - "]\n" - ); - CHECK_TRACE_CONTENTS( - "mem: storing 0 in location 10\n" - "mem: storing 0 in location 11\n" - "mem: storing 10 in location 2\n" - ); -} - -void test_new_initializes_alloc_id() { - Memory_allocated_until = 10; - put(Memory, Memory_allocated_until, 1); - Next_alloc_id = 23; - run( - "def main [\n" - " 1:&:num <- new num:type\n" - "]\n" - ); - CHECK_TRACE_CONTENTS( - // initialize memory - "mem: storing 0 in location 10\n" - "mem: storing 0 in location 11\n" - // alloc-id in payload - "mem: storing alloc-id 23 in location 10\n" - // alloc-id in address - "mem: storing 23 in location 1\n" - ); -} - -void test_new_size() { - run( - "def main [\n" - " 10:&:num <- new num:type\n" - " 12:&:num <- new num:type\n" - " 20:num/alloc1, 21:num/alloc2 <- deaddress 10:&:num, 12:&:num\n" - " 30:num <- subtract 21:num/alloc2, 20:num/alloc1\n" - "]\n" - ); - CHECK_TRACE_CONTENTS( - // size of number + alloc id - "mem: storing 2 in location 30\n" - ); -} - -void test_new_array_size() { - run( - "def main [\n" - " 10:&:@:num <- new num:type, 5\n" - " 12:&:num <- new num:type\n" - " 20:num/alloc1, 21:num/alloc2 <- deaddress 10:&:num, 12:&:num\n" - " 30:num <- subtract 21:num/alloc2, 20:num/alloc1\n" - "]\n" - ); - CHECK_TRACE_CONTENTS( - // 5 locations for array contents + array length + alloc id - "mem: storing 7 in location 30\n" - ); -} - -void test_new_empty_array() { - run( - "def main [\n" - " 10:&:@:num <- new num:type, 0\n" - " 12:&:num <- new num:type\n" - " 20:num/alloc1, 21:num/alloc2 <- deaddress 10:&:@:num, 12:&:num\n" - " 30:num <- subtract 21:num/alloc2, 20:num/alloc1\n" - "]\n" - ); - CHECK_TRACE_CONTENTS( - "run: {10: (\"address\" \"array\" \"number\")} <- new {num: \"type\"}, {0: \"literal\"}\n" - "mem: array length is 0\n" - // one location for array length and one for alloc id - "mem: storing 2 in location 30\n" - ); -} - -//: If a routine runs out of its initial allocation, it should allocate more. -void test_new_overflow() { - Initial_memory_per_routine = 3; // barely enough room for point allocation below - run( - "def main [\n" - " 10:&:num <- new num:type\n" - " 12:&:point <- new point:type\n" // not enough room in initial page - "]\n" - ); - CHECK_TRACE_CONTENTS( - "new: routine allocated memory from 1000 to 1003\n" - "new: routine allocated memory from 1003 to 1006\n" - ); -} - -void test_new_without_ingredient() { - Hide_errors = true; - run( - "def main [\n" - " 1:&:num <- new\n" // missing ingredient - "]\n" - ); - CHECK_TRACE_CONTENTS( - "error: main: 'new' requires one or two ingredients, but got '1:&:num <- new'\n" - ); -} - -//: a little helper: convert address to number - -:(before "End Primitive Recipe Declarations") -DEADDRESS, -:(before "End Primitive Recipe Numbers") -put(Recipe_ordinal, "deaddress", DEADDRESS); -:(before "End Primitive Recipe Checks") -case DEADDRESS: { - // primary goal of these checks is to forbid address arithmetic - for (int i = 0; i < SIZE(inst.ingredients); ++i) { - if (!is_mu_address(inst.ingredients.at(i))) { - raise << maybe(get(Recipe, r).name) << "'deaddress' requires address ingredients, but got '" << inst.ingredients.at(i).original_string << "'\n" << end(); - goto finish_checking_instruction; - } - } - if (SIZE(inst.products) > SIZE(inst.ingredients)) { - raise << maybe(get(Recipe, r).name) << "too many products in '" << to_original_string(inst) << "'\n" << end(); - break; - } - for (int i = 0; i < SIZE(inst.products); ++i) { - if (!is_real_mu_number(inst.products.at(i))) { - raise << maybe(get(Recipe, r).name) << "'deaddress' requires number products, but got '" << inst.products.at(i).original_string << "'\n" << end(); - goto finish_checking_instruction; - } - } - break; -} -:(before "End Primitive Recipe Implementations") -case DEADDRESS: { - products.resize(SIZE(ingredients)); - for (int i = 0; i < SIZE(ingredients); ++i) { - products.at(i).push_back(ingredients.at(i).at(/*skip alloc id*/1)); - } - break; -} |