From 2a03d6b007163fbd83567a6b0907a1866c1f92e8 Mon Sep 17 00:00:00 2001
From: Andrew Kelley <andrew@ziglang.org>
Date: Wed, 23 Sep 2026 13:12:16 -0700
Subject: [PATCH] Maker: properly deinit compiler child procs

Problem was that when Maker.Step.Compile was deinitialized, it would
reap the memory for the child process, but not actually kill & wait for
the termination of the process. Leaving the extra processes running
caused "Reusing Cache Artifacts" deadlocks, not to mention wasting
resources.

closes #36513
---
 lib/compiler/Maker.zig              |  3 ++-
 lib/compiler/Maker/Step.zig         | 23 ++++++++++++++++-------
 lib/compiler/Maker/Step/Compile.zig |  7 +++++++
 lib/compiler/Maker/Step/Fmt.zig     |  3 ++-
 lib/compiler/Maker/Step/Run.zig     |  3 ++-
 5 files changed, 29 insertions(+), 10 deletions(-)

diff --git a/lib/compiler/Maker.zig b/lib/compiler/Maker.zig
index 05ce0fe17e64c265e5c2e87226362308a770a9d0..681a91341b99cdaa0a837d783f974924a036f803 100644
--- a/lib/compiler/Maker.zig
+++ b/lib/compiler/Maker.zig
@@ -2674,7 +2674,8 @@ fn makeSteps(
 
 fn deinit(maker: *Maker) void {
     const gpa = maker.gpa;
-    for (maker.steps) |*step| step.deinit(gpa);
+    const io = maker.graph.io;
+    for (maker.steps) |*step| step.deinit(gpa, io);
     maker.memory_blocked_steps.deinit(gpa);
     maker.initial_steps.deinit(gpa);
     maker.step_stack.deinit(gpa);
diff --git a/lib/compiler/Maker/Step.zig b/lib/compiler/Maker/Step.zig
index 8496548b7a8970292533c1fca07ff58cc2b265aa..fc1b7f5b324659d8381a7bcbe9d1be7b567cea41 100644
--- a/lib/compiler/Maker/Step.zig
+++ b/lib/compiler/Maker/Step.zig
@@ -309,15 +309,13 @@ pub fn make(
     }
 }
 
-pub fn deinit(step: *Step, gpa: Allocator) void {
+pub fn deinit(step: *Step, gpa: Allocator, io: Io) void {
     step.clearResultStderr(gpa);
     step.clearFailedCommand(gpa);
     step.clearErrorBundle(gpa);
     step.inputs.deinit(gpa);
-    if (step.getZigProcess()) |zp| gpa.destroy(zp);
     switch (step.extended) {
         .check_file,
-        .compile,
         .config_header,
         .fail,
         .find_program,
@@ -331,7 +329,7 @@ pub fn deinit(step: *Step, gpa: Allocator) void {
         .update_source_files,
         .write_file,
         => {},
-        inline .fmt, .run => |*extended| extended.deinit(gpa),
+        inline .compile, .fmt, .run => |*extended| extended.deinit(gpa, io),
     }
     step.* = undefined;
 }
@@ -455,6 +453,11 @@ pub const ZigProcess = struct {
         zp.multi_reader.deinit();
         zp.* = undefined;
     }
+
+    pub fn destroy(zp: *ZigProcess, gpa: Allocator, io: Io) void {
+        zp.deinit(io);
+        gpa.destroy(zp);
+    }
 };
 
 /// Assumes that argv contains `--listen=-` and that the process being spawned
@@ -482,9 +485,8 @@ pub fn evalZigProcess(
         zp.progress_ipc_index = null;
         var exited = false;
         defer if (exited) {
-            s.extended.compile.zig_process = null;
-            zp.deinit(io);
-            gpa.destroy(zp);
+            s.clearZigProcess();
+            zp.destroy(gpa, io);
         } else zp.saveState(prog_node);
         const result = zigProcessUpdate(step_index, maker, zp, watch) catch |err| switch (err) {
             error.BrokenPipe, error.EndOfStream => |reason| {
@@ -730,6 +732,13 @@ pub fn getZigProcess(s: *Step) ?*ZigProcess {
     };
 }
 
+fn clearZigProcess(s: *Step) void {
+    (switch (s.extended) {
+        .compile => |*compile| &compile.zig_process,
+        else => return,
+    }).* = null;
+}
+
 fn sendMessage(io: Io, file: Io.File, tag: std.zig.Client.Message.Tag) !void {
     const header: std.zig.Client.Message.Header = .{
         .tag = tag,
diff --git a/lib/compiler/Maker/Step/Compile.zig b/lib/compiler/Maker/Step/Compile.zig
index cd144b077fbc250136b75b9b4511cbf110bd5c16..2e02f3407b6bfbbc4034eb6570732fe26b91271a 100644
--- a/lib/compiler/Maker/Step/Compile.zig
+++ b/lib/compiler/Maker/Step/Compile.zig
@@ -86,6 +86,13 @@ pub fn make(
     }
 }
 
+pub fn deinit(compile: *Compile, gpa: Allocator, io: Io) void {
+    if (compile.zig_process) |zp| {
+        zp.destroy(gpa, io);
+        compile.zig_process = null;
+    }
+}
+
 fn updateGeneratedFile(
     maker: *Maker,
     arena: Allocator,
diff --git a/lib/compiler/Maker/Step/Fmt.zig b/lib/compiler/Maker/Step/Fmt.zig
index 72267c6e9fedeef3707e5e14b681c87d7636bf4e..d936382bdf7d54012b86f714adc1b67758d453c8 100644
--- a/lib/compiler/Maker/Step/Fmt.zig
+++ b/lib/compiler/Maker/Step/Fmt.zig
@@ -64,6 +64,7 @@ pub fn make(
     try step.handleChildProcessTerm(maker, run_result.term);
 }
 
-pub fn deinit(fmt: *Fmt, gpa: std.mem.Allocator) void {
+pub fn deinit(fmt: *Fmt, gpa: std.mem.Allocator, io: std.Io) void {
+    _ = io;
     fmt.argv.deinit(gpa);
 }
diff --git a/lib/compiler/Maker/Step/Run.zig b/lib/compiler/Maker/Step/Run.zig
index a31694851d1793008a30e0b159ce2a75a47d497b..7421d579ad8129e56515e90c16fdf7d1d9593e14 100644
--- a/lib/compiler/Maker/Step/Run.zig
+++ b/lib/compiler/Maker/Step/Run.zig
@@ -372,7 +372,8 @@ pub fn make(
     step.clearFailedCommand(gpa);
 }
 
-pub fn deinit(run: *Run, gpa: Allocator) void {
+pub fn deinit(run: *Run, gpa: Allocator, io: Io) void {
+    _ = io;
     run.fuzz_tests.deinit(gpa);
 }
 
-- 
2.54.0