Do not keep the build.zig cache manifest file locked. #7041
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Turns out #3825 caught me again... That is why on Windows it just exists with status code 1, without printing anything. |
This allows to have multiple instances of `zig build` at the same time. For example when you have a long running `zig build run` and then want to run `zig build somethingelse`.
src/main.zig
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| // To be able to have multiple instances of `zig build` running on Windows with a difference in | ||
| // the source of the `build.zig` file, we have to copy the executable to a name that includes | ||
| // a hash of the content of the `build.zig` file and then execute that file, instead of the | ||
| // original build executable. | ||
| const build_zig_file = try build_directory.handle.openFile(build_zig_basename, .{}); | ||
| defer build_zig_file.close(); | ||
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| var bin_digest: [Cache.bin_digest_len]u8 = undefined; | ||
| try Cache.hashFile(build_zig_file, &bin_digest); | ||
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| var file_name: [Cache.hex_digest_len]u8 = undefined; | ||
| _ = std.fmt.bufPrint(&file_name, "{x}", .{bin_digest}) catch unreachable; | ||
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| const temp_file_basename = try std.zig.binNameAlloc(arena, .{ | ||
| .root_name = &file_name, | ||
| .target = target_info.target, | ||
| .output_mode = .Exe, | ||
| }); | ||
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| const dir = comp.bin_file.options.emit.?.directory.handle; | ||
| _ = try fs.Dir.updateFile(dir, exe_basename, dir, temp_file_basename, .{}); | ||
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Should we only do this on Windows or also on other platforms?
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Hmm. I think we should try to keep the behavior the same across platforms, smoothing over this particular difference.
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We can also check before compiling if the build executable is able to be written to (thus not being executed) and only then overwrite the original build executable and otherwise do the method I coded in. In that way there is only a bit over overhead in storage when running multiple zig build commands at the same time and most of the time you are running only one command at the same time anyway, so then you can just overwrite the build executable anyway.
Well at least it's fixed now! You can update the dev kit by adding |
src/main.zig
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| const dir = comp.bin_file.options.emit.?.directory.handle; | ||
| _ = try fs.Dir.updateFile(dir, exe_basename, dir, temp_file_basename, .{}); |
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Since you're not updating anything:
| _ = try fs.Dir.updateFile(dir, exe_basename, dir, temp_file_basename, .{}); | |
| try dir.copyFile(exe_basename, dir, temp_file_basename, .{}); |
This allows to have multiple instances of
zig buildat the sametime. For example when you have a long running
zig build runandthen want to run
zig build somethingelse.I tried to implement this on windows, however when having a long running command (
zig build run) and then running the next command (zig build another) immediately exits with code 1 without printing anything. This also happens before I applied this patch, so it is a different issue. However I don't have a debug build of zig on windows to debug this issue.Note on Windows we need some other solution, because we can't change a running executable (build runner):
Related: #7042