authorgravatar for benjamin.feng@glassdoor.comBenjamin Feng <benjamin.feng@glassdoor.com> 2019-12-05 17:59:43-06:00
committergravatar for benjamin.feng@glassdoor.comBenjamin Feng <benjamin.feng@glassdoor.com> 2019-12-05 18:01:49-06:00
log7d1c4fe4dcb6188d2af0f65bf713aca8d326ea46
treeb5f87a99039e36396db6fe8b043bc85ca2fd118d
parent30da6d49f435b7ef317b059113ec1fab21d72d00

Switch bitmask to enums

1 files changed, 15 insertions(+), 11 deletions(-)

lib/std/heap.zig+15-11
......@@ -256,28 +256,32 @@ const WasmPageAllocator = struct {
256256 // TODO: figure out why __heap_base cannot be found
257257 var heap_base_wannabe align(16) = [_]u8{0} ** 256;
258258
259 const PageStatus = enum(u1) {
260 used = 0,
261 free = 1,
262
263 pub const all_used: u8 = 0;
264 };
265
259266 const FreeBlock = struct {
260267 bytes: []align(16) u8,
261268
262269 const Io = std.packed_int_array.PackedIntIo(u1, .Little);
263270
264 const used = 0;
265 const free = 1;
266
267271 fn totalPages(self: FreeBlock) usize {
268272 return self.bytes.len * 8;
269273 }
270274
271 fn getBit(self: *FreeBlock, idx: usize) u1 {
275 fn getBit(self: *FreeBlock, idx: usize) PageStatus {
272276 const bit_offset = 0;
273 return Io.get(self.bytes, idx, bit_offset);
277 return @intToEnum(PageStatus, Io.get(self.bytes, idx, bit_offset));
274278 }
275279
276 fn setBits(self: *FreeBlock, start_idx: usize, len: usize, val: u1) void {
280 fn setBits(self: *FreeBlock, start_idx: usize, len: usize, val: PageStatus) void {
277281 const bit_offset = 0;
278282 var i: usize = 0;
279283 while (i < len) : (i += 1) {
280 Io.set(self.bytes, start_idx + i, bit_offset, val);
284 Io.set(self.bytes, start_idx + i, bit_offset, @enumToInt(val));
281285 }
282286 }
283287
......@@ -302,10 +306,10 @@ const WasmPageAllocator = struct {
302306 var j: usize = i * 128;
303307 while (j < (i + 1) * 128) : (j += 1) {
304308 var count: usize = 0;
305 while (j + count < self.totalPages() and self.getBit(j + count) == 1) {
309 while (j + count < self.totalPages() and self.getBit(j + count) == .free) {
306310 count += 1;
307311 if (count >= num_pages) {
308 self.setBits(j, num_pages, used);
312 self.setBits(j, num_pages, .used);
309313 return j;
310314 }
311315 }
......@@ -316,7 +320,7 @@ const WasmPageAllocator = struct {
316320 }
317321
318322 fn recycle(self: *FreeBlock, start_idx: usize, len: usize) void {
319 self.setBits(start_idx, len, free);
323 self.setBits(start_idx, len, .free);
320324 }
321325 };
322326
......@@ -391,7 +395,7 @@ const WasmPageAllocator = struct {
391395
392396 extended.bytes = @intToPtr([*]align(16) u8, free_end * std.mem.page_size)[0..std.mem.page_size];
393397 // Since this is the first page being freed and we consume it, assume *nothing* is free.
394 std.mem.set(u8, extended.bytes, FreeBlock.used);
398 std.mem.set(u8, extended.bytes, PageStatus.all_used);
395399 }
396400 const clamped_start = std.math.max(extendedOffset(), free_start);
397401 extended.recycle(clamped_start - extendedOffset(), free_end - clamped_start);