1 // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 //! Job management on Windows for bootstrapping
13 //! Most of the time when you're running a build system (e.g. make) you expect
14 //! Ctrl-C or abnormal termination to actually terminate the entire tree of
15 //! process in play, not just the one at the top. This currently works "by
16 //! default" on Unix platforms because Ctrl-C actually sends a signal to the
17 //! *process group* rather than the parent process, so everything will get torn
18 //! down. On Windows, however, this does not happen and Ctrl-C just kills the
21 //! To achieve the same semantics on Windows we use Job Objects to ensure that
22 //! all processes die at the same time. Job objects have a mode of operation
23 //! where when all handles to the object are closed it causes all child
24 //! processes associated with the object to be terminated immediately.
25 //! Conveniently whenever a process in the job object spawns a new process the
26 //! child will be associated with the job object as well. This means if we add
27 //! ourselves to the job object we create then everything will get torn down!
29 //! Unfortunately most of the time the build system is actually called from a
30 //! python wrapper (which manages things like building the build system) so this
31 //! all doesn't quite cut it so far. To go the last mile we duplicate the job
32 //! object handle into our parent process (a python process probably) and then
33 //! close our own handle. This means that the only handle to the job object
34 //! resides in the parent python process, so when python dies the whole build
35 //! system dies (as one would probably expect!).
37 //! Note that this module has a #[cfg(windows)] above it as none of this logic
38 //! is required on Unix.
40 #![allow(bad_style, dead_code)]
47 type HANDLE = *mut u8;
50 type LPHANDLE = *mut HANDLE;
51 type LPVOID = *mut u8;
52 type JOBOBJECTINFOCLASS = i32;
54 type LARGE_INTEGER = i64;
56 type ULONG_PTR = usize;
59 const FALSE: BOOL = 0;
60 const DUPLICATE_SAME_ACCESS: DWORD = 0x2;
61 const PROCESS_DUP_HANDLE: DWORD = 0x40;
62 const JobObjectExtendedLimitInformation: JOBOBJECTINFOCLASS = 9;
63 const JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE: DWORD = 0x2000;
64 const JOB_OBJECT_LIMIT_PRIORITY_CLASS: DWORD = 0x00000020;
65 const SEM_FAILCRITICALERRORS: UINT = 0x0001;
66 const SEM_NOGPFAULTERRORBOX: UINT = 0x0002;
67 const BELOW_NORMAL_PRIORITY_CLASS: DWORD = 0x00004000;
70 fn CreateJobObjectW(lpJobAttributes: *mut u8, lpName: *const u8) -> HANDLE;
71 fn CloseHandle(hObject: HANDLE) -> BOOL;
72 fn GetCurrentProcess() -> HANDLE;
73 fn OpenProcess(dwDesiredAccess: DWORD,
75 dwProcessId: DWORD) -> HANDLE;
76 fn DuplicateHandle(hSourceProcessHandle: HANDLE,
77 hSourceHandle: HANDLE,
78 hTargetProcessHandle: HANDLE,
79 lpTargetHandle: LPHANDLE,
80 dwDesiredAccess: DWORD,
82 dwOptions: DWORD) -> BOOL;
83 fn AssignProcessToJobObject(hJob: HANDLE, hProcess: HANDLE) -> BOOL;
84 fn SetInformationJobObject(hJob: HANDLE,
85 JobObjectInformationClass: JOBOBJECTINFOCLASS,
86 lpJobObjectInformation: LPVOID,
87 cbJobObjectInformationLength: DWORD) -> BOOL;
88 fn SetErrorMode(mode: UINT) -> UINT;
92 struct JOBOBJECT_EXTENDED_LIMIT_INFORMATION {
93 BasicLimitInformation: JOBOBJECT_BASIC_LIMIT_INFORMATION,
95 ProcessMemoryLimit: SIZE_T,
96 JobMemoryLimit: SIZE_T,
97 PeakProcessMemoryUsed: SIZE_T,
98 PeakJobMemoryUsed: SIZE_T,
103 ReadOperationCount: ULONGLONG,
104 WriteOperationCount: ULONGLONG,
105 OtherOperationCount: ULONGLONG,
106 ReadTransferCount: ULONGLONG,
107 WriteTransferCount: ULONGLONG,
108 OtherTransferCount: ULONGLONG,
112 struct JOBOBJECT_BASIC_LIMIT_INFORMATION {
113 PerProcessUserTimeLimit: LARGE_INTEGER,
114 PerJobUserTimeLimit: LARGE_INTEGER,
116 MinimumWorkingsetSize: SIZE_T,
117 MaximumWorkingsetSize: SIZE_T,
118 ActiveProcessLimit: DWORD,
120 PriorityClass: DWORD,
121 SchedulingClass: DWORD,
124 pub unsafe fn setup(build: &mut Build) {
125 // Enable the Windows Error Reporting dialog which msys disables,
126 // so we can JIT debug rustc
127 let mode = SetErrorMode(0);
128 SetErrorMode(mode & !SEM_NOGPFAULTERRORBOX);
130 // Create a new job object for us to use
131 let job = CreateJobObjectW(0 as *mut _, 0 as *const _);
132 assert!(job != 0 as *mut _, "{}", io::Error::last_os_error());
134 // Indicate that when all handles to the job object are gone that all
135 // process in the object should be killed. Note that this includes our
136 // entire process tree by default because we've added ourselves and our
137 // children will reside in the job by default.
138 let mut info = mem::zeroed::<JOBOBJECT_EXTENDED_LIMIT_INFORMATION>();
139 info.BasicLimitInformation.LimitFlags = JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE;
140 if build.config.low_priority {
141 info.BasicLimitInformation.LimitFlags |= JOB_OBJECT_LIMIT_PRIORITY_CLASS;
142 info.BasicLimitInformation.PriorityClass = BELOW_NORMAL_PRIORITY_CLASS;
144 let r = SetInformationJobObject(job,
145 JobObjectExtendedLimitInformation,
146 &mut info as *mut _ as LPVOID,
147 mem::size_of_val(&info) as DWORD);
148 assert!(r != 0, "{}", io::Error::last_os_error());
150 // Assign our process to this job object. Note that if this fails, one very
151 // likely reason is that we are ourselves already in a job object! This can
152 // happen on the build bots that we've got for Windows, or if just anyone
153 // else is instrumenting the build. In this case we just bail out
154 // immediately and assume that they take care of it.
156 // Also note that nested jobs (why this might fail) are supported in recent
157 // versions of Windows, but the version of Windows that our bots are running
158 // at least don't support nested job objects.
159 let r = AssignProcessToJobObject(job, GetCurrentProcess());
165 // If we've got a parent process (e.g. the python script that called us)
166 // then move ownership of this job object up to them. That way if the python
167 // script is killed (e.g. via ctrl-c) then we'll all be torn down.
169 // If we don't have a parent (e.g. this was run directly) then we
170 // intentionally leak the job object handle. When our process exits
171 // (normally or abnormally) it will close the handle implicitly, causing all
172 // processes in the job to be cleaned up.
173 let pid = match env::var("BOOTSTRAP_PARENT_ID") {
178 let parent = OpenProcess(PROCESS_DUP_HANDLE, FALSE, pid.parse().unwrap());
179 assert!(parent != 0 as *mut _, "{}", io::Error::last_os_error());
180 let mut parent_handle = 0 as *mut _;
181 let r = DuplicateHandle(GetCurrentProcess(), job,
182 parent, &mut parent_handle,
183 0, FALSE, DUPLICATE_SAME_ACCESS);
185 // If this failed, well at least we tried! An example of DuplicateHandle
186 // failing in the past has been when the wrong python2 package spawned this
187 // build system (e.g. the `python2` package in MSYS instead of
188 // `mingw-w64-x86_64-python2`. Not sure why it failed, but the "failure
189 // mode" here is that we only clean everything up when the build system
190 // dies, not when the python parent does, so not too bad.