authorgravatar for shritesh@shritesh.comShritesh Bhattarai <shritesh@shritesh.com> 2019-04-16 12:23:45-05:00
committergravatar for shritesh@shritesh.comShritesh Bhattarai <shritesh@shritesh.com> 2019-04-16 12:23:45-05:00
log0c28a18d967a6dbf1431457cc1cb63f61e40d2b4
tree228af639118f38e2b83d381471c2d2d665c5d54a
parent4235982fe6965ce4fe02f1cfcb4d919752369379

WasmAllocator: cleanup

1 files changed, 10 insertions(+), 10 deletions(-)

std/heap.zig+10-10
...@@ -318,9 +318,10 @@ pub const FixedBufferAllocator = struct {...@@ -318,9 +318,10 @@ pub const FixedBufferAllocator = struct {
318 }318 }
319};319};
320320
321// FIXME: Exposed LLVM intrinsics is a bug
322// See: https://github.com/ziglang/zig/issues/2291
321extern fn @"llvm.wasm.memory.size.i32"(u32) u32;323extern fn @"llvm.wasm.memory.size.i32"(u32) u32;
322extern fn @"llvm.wasm.memory.grow.i32"(u32, u32) i32;324extern fn @"llvm.wasm.memory.grow.i32"(u32, u32) i32;
323const WASM_PAGE_SIZE = 64 * 1024; // 64 kilobytes
324325
325pub const wasm_allocator = &wasm_allocator_state.allocator;326pub const wasm_allocator = &wasm_allocator_state.allocator;
326var wasm_allocator_state = WasmAllocator{327var wasm_allocator_state = WasmAllocator{
...@@ -333,7 +334,7 @@ var wasm_allocator_state = WasmAllocator{...@@ -333,7 +334,7 @@ var wasm_allocator_state = WasmAllocator{
333 .end_index = 0,334 .end_index = 0,
334};335};
335336
336pub const WasmAllocator = struct {337const WasmAllocator = struct {
337 allocator: Allocator,338 allocator: Allocator,
338 start_ptr: [*]u8,339 start_ptr: [*]u8,
339 num_pages: usize,340 num_pages: usize,
...@@ -347,11 +348,11 @@ pub const WasmAllocator = struct {...@@ -347,11 +348,11 @@ pub const WasmAllocator = struct {
347 const adjusted_index = self.end_index + (adjusted_addr - addr);348 const adjusted_index = self.end_index + (adjusted_addr - addr);
348 const new_end_index = adjusted_index + size;349 const new_end_index = adjusted_index + size;
349350
350 const required_memory = new_end_index - (self.num_pages * WASM_PAGE_SIZE);351 if (new_end_index > self.num_pages * os.page_size) {
352 const required_memory = new_end_index - (self.num_pages * os.page_size);
351353
352 if (required_memory > 0) {354 var num_pages: u32 = required_memory / os.page_size;
353 var num_pages: u32 = @divTrunc(required_memory, WASM_PAGE_SIZE);355 if (required_memory % os.page_size != 0) {
354 if (@rem(required_memory, WASM_PAGE_SIZE) != 0) {
355 num_pages += 1;356 num_pages += 1;
356 }357 }
357358
...@@ -369,7 +370,7 @@ pub const WasmAllocator = struct {...@@ -369,7 +370,7 @@ pub const WasmAllocator = struct {
369 return result;370 return result;
370 }371 }
371372
372 // Check if memory is the last "item" and it aligns. That lets us expand or reclaim memory373 // Check if memory is the last "item" and is aligned correctly
373 fn is_last_item(allocator: *Allocator, memory: []u8, alignment: u29) bool {374 fn is_last_item(allocator: *Allocator, memory: []u8, alignment: u29) bool {
374 const self = @fieldParentPtr(WasmAllocator, "allocator", allocator);375 const self = @fieldParentPtr(WasmAllocator, "allocator", allocator);
375 return memory.ptr == self.start_ptr + self.end_index - memory.len and mem.alignForward(@ptrToInt(memory.ptr), alignment) == @ptrToInt(memory.ptr);376 return memory.ptr == self.start_ptr + self.end_index - memory.len and mem.alignForward(@ptrToInt(memory.ptr), alignment) == @ptrToInt(memory.ptr);
...@@ -380,14 +381,14 @@ pub const WasmAllocator = struct {...@@ -380,14 +381,14 @@ pub const WasmAllocator = struct {
380381
381 // Initialize start_ptr at the first realloc382 // Initialize start_ptr at the first realloc
382 if (self.num_pages == 0) {383 if (self.num_pages == 0) {
383 self.start_ptr = @intToPtr([*]u8, @intCast(usize, @"llvm.wasm.memory.size.i32"(0)) * WASM_PAGE_SIZE);384 self.start_ptr = @intToPtr([*]u8, @intCast(usize, @"llvm.wasm.memory.size.i32"(0)) * os.page_size);
384 }385 }
385386
386 if (is_last_item(allocator, old_mem, new_align)) {387 if (is_last_item(allocator, old_mem, new_align)) {
387 const start_index = self.end_index - old_mem.len;388 const start_index = self.end_index - old_mem.len;
388 const new_end_index = start_index + new_size;389 const new_end_index = start_index + new_size;
389390
390 if (new_end_index > self.num_pages * WASM_PAGE_SIZE) {391 if (new_end_index > self.num_pages * os.page_size) {
391 _ = try alloc(allocator, new_end_index - self.end_index, new_align);392 _ = try alloc(allocator, new_end_index - self.end_index, new_align);
392 }393 }
393 const result = self.start_ptr[start_index..new_end_index];394 const result = self.start_ptr[start_index..new_end_index];
...@@ -404,7 +405,6 @@ pub const WasmAllocator = struct {...@@ -404,7 +405,6 @@ pub const WasmAllocator = struct {
404 }405 }
405406
406 fn shrink(allocator: *Allocator, old_mem: []u8, old_align: u29, new_size: usize, new_align: u29) []u8 {407 fn shrink(allocator: *Allocator, old_mem: []u8, old_align: u29, new_size: usize, new_align: u29) []u8 {
407 // TODO: Use is_last_item or other heuristic here
408 return old_mem[0..new_size];408 return old_mem[0..new_size];
409 }409 }
410};410};