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make sure the rodata refcounts aren't incremented

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Brendan Hansknecht 2022-04-01 15:02:01 -07:00
parent cf238862f4
commit 2093405ffc
1 changed files with 21 additions and 14 deletions
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35
compiler/builtins/bitcode/src/utils.zig
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@ -1,5 +1,6 @@
const std = @import("std");
const always_inline = std.builtin.CallOptions.Modifier.always_inline;
const Monotonic = std.builtin.AtomicOrder.Monotonic;
pub fn WithOverflow(comptime T: type) type {
return extern struct { value: T, has_overflowed: bool };
@ -126,20 +127,25 @@ const Refcount = enum {
atomic,
};
const RC_TYPE = Refcount.normal;
const RC_TYPE = Refcount.atomic;
pub fn increfC(ptr_to_refcount: *isize, amount: isize) callconv(.C) void {
if (RC_TYPE == Refcount.none) return;
var refcount = ptr_to_refcount.*;
var masked_amount = if (refcount < REFCOUNT_MAX_ISIZE) amount else 0;
switch (RC_TYPE) {
Refcount.normal => {
ptr_to_refcount.* = refcount + masked_amount;
},
Refcount.atomic => {
var last = @atomicRmw(isize, ptr_to_refcount, std.builtin.AtomicRmwOp.Add, masked_amount, std.builtin.AtomicOrder.Monotonic);
},
else => unreachable,
if (refcount < REFCOUNT_MAX_ISIZE) {
switch (RC_TYPE) {
Refcount.normal => {
ptr_to_refcount.* = std.math.max(refcount + amount, REFCOUNT_MAX_ISIZE);
},
Refcount.atomic => {
var next = std.math.max(refcount + amount, REFCOUNT_MAX_ISIZE);
while (@cmpxchgWeak(isize, ptr_to_refcount, refcount, next, Monotonic, Monotonic)) |found| {
refcount = found;
next = std.math.max(refcount + amount, REFCOUNT_MAX_ISIZE);
}
},
else => unreachable,
}
}
}
@ -198,10 +204,11 @@ inline fn decref_ptr_to_refcount(
}
},
Refcount.atomic => {
var amount: isize = if (refcount_ptr[0] < REFCOUNT_MAX_ISIZE) 1 else 0;
var last = @atomicRmw(isize, &refcount_ptr[0], std.builtin.AtomicRmwOp.Sub, amount, std.builtin.AtomicOrder.Monotonic);
if (last == REFCOUNT_ONE_ISIZE) {
dealloc(@ptrCast([*]u8, refcount_ptr) - (extra_bytes - @sizeOf(usize)), alignment);
if (refcount_ptr[0] < REFCOUNT_MAX_ISIZE) {
var last = @atomicRmw(isize, &refcount_ptr[0], std.builtin.AtomicRmwOp.Sub, 1, Monotonic);
if (last == REFCOUNT_ONE_ISIZE) {
dealloc(@ptrCast([*]u8, refcount_ptr) - (extra_bytes - @sizeOf(usize)), alignment);
}
}
},
else => unreachable,