Ekdohibs
/
zig
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Switch bitmask to enums

master
Benjamin Feng 2019-12-05 17:59:43 -06:00
parent 30da6d49f4
commit 7d1c4fe4dc
1 changed files with 15 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
lib/std/heap.zig
View File

@ -256,28 +256,32 @@ const WasmPageAllocator = struct {
// TODO: figure out why __heap_base cannot be found
var heap_base_wannabe align(16) = [_]u8{0} ** 256;
const PageStatus = enum(u1) {
used = 0,
free = 1,
pub const all_used: u8 = 0;
};
const FreeBlock = struct {
bytes: []align(16) u8,
const Io = std.packed_int_array.PackedIntIo(u1, .Little);
const used = 0;
const free = 1;
fn totalPages(self: FreeBlock) usize {
return self.bytes.len * 8;
}
fn getBit(self: *FreeBlock, idx: usize) u1 {
fn getBit(self: *FreeBlock, idx: usize) PageStatus {
const bit_offset = 0;
return Io.get(self.bytes, idx, bit_offset);
return @intToEnum(PageStatus, Io.get(self.bytes, idx, bit_offset));
}
fn setBits(self: *FreeBlock, start_idx: usize, len: usize, val: u1) void {
fn setBits(self: *FreeBlock, start_idx: usize, len: usize, val: PageStatus) void {
const bit_offset = 0;
var i: usize = 0;
while (i < len) : (i += 1) {
Io.set(self.bytes, start_idx + i, bit_offset, val);
Io.set(self.bytes, start_idx + i, bit_offset, @enumToInt(val));
}
}
@ -302,10 +306,10 @@ const WasmPageAllocator = struct {
var j: usize = i * 128;
while (j < (i + 1) * 128) : (j += 1) {
var count: usize = 0;
while (j + count < self.totalPages() and self.getBit(j + count) == 1) {
while (j + count < self.totalPages() and self.getBit(j + count) == .free) {
count += 1;
if (count >= num_pages) {
self.setBits(j, num_pages, used);
self.setBits(j, num_pages, .used);
return j;
}
}
@ -316,7 +320,7 @@ const WasmPageAllocator = struct {
}
fn recycle(self: *FreeBlock, start_idx: usize, len: usize) void {
self.setBits(start_idx, len, free);
self.setBits(start_idx, len, .free);
}
};
@ -391,7 +395,7 @@ const WasmPageAllocator = struct {
extended.bytes = @intToPtr([*]align(16) u8, free_end * std.mem.page_size)[0..std.mem.page_size];
// Since this is the first page being freed and we consume it, assume *nothing* is free.
std.mem.set(u8, extended.bytes, FreeBlock.used);
std.mem.set(u8, extended.bytes, PageStatus.all_used);
}
const clamped_start = std.math.max(extendedOffset(), free_start);
extended.recycle(clamped_start - extendedOffset(), free_end - clamped_start);