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| author | Shawn Landden <shawn@git.icu> | 2019-04-09 10:48:09 -0500 |
|---|---|---|
| committer | Andrew Kelley <andrew@ziglang.org> | 2019-04-29 13:47:24 -0400 |
| commit | 3c13aa178b007cae19800579b40e82bef127f388 (patch) | |
| tree | a15b00dad61d1f488186db5f8ee1f2c1289df72c /std | |
| parent | 8afa1e800b9957bff707ca8f57e3c38fc38e2597 (diff) | |
| download | zig-3c13aa178b007cae19800579b40e82bef127f388.tar.gz zig-3c13aa178b007cae19800579b40e82bef127f388.zip | |
std.heap: do not excessively call mmap, and munmap in direct allocator
Diffstat (limited to 'std')
| -rw-r--r-- | std/heap.zig | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/std/heap.zig b/std/heap.zig index 239a65961a..bb2cd4f4d8 100644 --- a/std/heap.zig +++ b/std/heap.zig @@ -59,6 +59,8 @@ pub const DirectAllocator = struct { fn alloc(allocator: *Allocator, n: usize, alignment: u29) error{OutOfMemory}![]u8 { const self = @fieldParentPtr(DirectAllocator, "allocator", allocator); + if (n == 0) + return (([*]u8)(undefined))[0..0]; switch (builtin.os) { Os.linux, Os.macosx, Os.ios, Os.freebsd, Os.netbsd => { @@ -140,7 +142,9 @@ pub const DirectAllocator = struct { } const result = try alloc(allocator, new_size, new_align); @memcpy(result.ptr, old_mem.ptr, std.math.min(old_mem.len, result.len)); - _ = os.posix.munmap(@ptrToInt(old_mem.ptr), old_mem.len); + if (old_mem.len > 0) { + _ = os.posix.munmap(@ptrToInt(old_mem.ptr), old_mem.len); + } return result; }, Os.windows => { |