diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/std/heap/general_purpose_allocator.zig | 46 |
1 files changed, 30 insertions, 16 deletions
diff --git a/lib/std/heap/general_purpose_allocator.zig b/lib/std/heap/general_purpose_allocator.zig index 34bd50bc13..4b9a5aea66 100644 --- a/lib/std/heap/general_purpose_allocator.zig +++ b/lib/std/heap/general_purpose_allocator.zig @@ -561,24 +561,25 @@ pub fn GeneralPurposeAllocator(comptime config: Config) type { return error.OutOfMemory; } + // Returns true if an allocation of `size` bytes is within the specified + // limits if enable_memory_limit is true + fn isAllocationAllowed(self: *Self, size: usize) bool { + if (config.enable_memory_limit) { + const new_req_bytes = self.total_requested_bytes + size; + if (new_req_bytes > self.requested_memory_limit) + return false; + self.total_requested_bytes = new_req_bytes; + } + + return true; + } + fn alloc(allocator: *Allocator, len: usize, ptr_align: u29, len_align: u29, ret_addr: usize) Error![]u8 { const self = @fieldParentPtr(Self, "allocator", allocator); const held = self.mutex.acquire(); defer held.release(); - const prev_req_bytes = self.total_requested_bytes; - if (config.enable_memory_limit) { - const new_req_bytes = prev_req_bytes + len; - if (new_req_bytes > self.requested_memory_limit) { - return error.OutOfMemory; - } - self.total_requested_bytes = new_req_bytes; - } - errdefer if (config.enable_memory_limit) { - self.total_requested_bytes = prev_req_bytes; - }; - const new_aligned_size = math.max(len, ptr_align); if (new_aligned_size > largest_bucket_object_size) { try self.large_allocations.ensureCapacity( @@ -588,17 +589,30 @@ pub fn GeneralPurposeAllocator(comptime config: Config) type { const slice = try self.backing_allocator.allocFn(self.backing_allocator, len, ptr_align, len_align, ret_addr); + // The backing allocator may return a memory block bigger than + // `len`, use the effective size for bookkeeping purposes + if (!self.isAllocationAllowed(slice.len)) { + // Free the block so no memory is leaked + const new_len = try self.backing_allocator.resizeFn(self.backing_allocator, slice, ptr_align, 0, 0, ret_addr); + assert(new_len == 0); + return error.OutOfMemory; + } + const gop = self.large_allocations.getOrPutAssumeCapacity(@ptrToInt(slice.ptr)); assert(!gop.found_existing); // This would mean the kernel double-mapped pages. gop.entry.value.bytes = slice; collectStackTrace(ret_addr, &gop.entry.value.stack_addresses); return slice; - } else { - const new_size_class = math.ceilPowerOfTwoAssert(usize, new_aligned_size); - const ptr = try self.allocSlot(new_size_class, ret_addr); - return ptr[0..len]; } + + if (!self.isAllocationAllowed(len)) { + return error.OutOfMemory; + } + + const new_size_class = math.ceilPowerOfTwoAssert(usize, new_aligned_size); + const ptr = try self.allocSlot(new_size_class, ret_addr); + return ptr[0..len]; } fn createBucket(self: *Self, size_class: usize, bucket_index: usize) Error!*BucketHeader { |