summaryrefslogtreecommitdiff
path: root/process-win.c
blob: 58b7f738053267d22d905c6eb5d411430d077c3d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
#error "@TODO :  implement process_write, separate_stderr, working_directory"

#include "process.h"

struct Process {
	HANDLE pipe_read, pipe_write;
	HANDLE job;
	PROCESS_INFORMATION process_info;
	char error[200];
};

static void get_last_error_str(char *out, size_t out_sz) {
	size_t size = FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
         NULL, GetLastError(), MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), out, (DWORD)out_sz - 1, NULL);
	out[size] = 0;
	char *cr = strchr(out, '\r');
	if (cr) *cr = '\0'; // get rid of carriage return+newline at end of error
}

bool process_run(Process *process, char const *command) {
	// thanks to https://stackoverflow.com/a/35658917 for the pipe code
	// thanks to https://devblogs.microsoft.com/oldnewthing/20131209-00/?p=2433 for the job code

	bool success = false;
	memset(process, 0, sizeof *process);
	char *command_line = str_dup(command);
	if (!command_line) {
		strbuf_printf(process->error, "Out of memory.");
		return false;
	}
	// we need to create a "job" for this, because when you kill a process on windows,
	// all its children just keep going. so cmd.exe would die, but not the actual build process.
	// jobs fix this, apparently.
	HANDLE job = CreateJobObjectA(NULL, NULL);
	if (job) {
		JOBOBJECT_EXTENDED_LIMIT_INFORMATION job_info = {0};
		job_info.BasicLimitInformation.LimitFlags = JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE;
		SetInformationJobObject(job, JobObjectExtendedLimitInformation, &job_info, sizeof job_info);
		HANDLE pipe_read, pipe_write;
		SECURITY_ATTRIBUTES security_attrs = {sizeof(SECURITY_ATTRIBUTES)};
		security_attrs.bInheritHandle = TRUE;
		if (CreatePipe(&pipe_read, &pipe_write, &security_attrs, 0)) {
			STARTUPINFOA startup = {sizeof(STARTUPINFOA)};
			startup.dwFlags = STARTF_USESHOWWINDOW | STARTF_USESTDHANDLES;
			startup.hStdOutput = pipe_write;
			startup.hStdError = pipe_write;
			startup.wShowWindow = SW_HIDE;
			PROCESS_INFORMATION *process_info = &process->process_info;
			if (CreateProcessA(NULL, command_line, NULL, NULL, TRUE, CREATE_NEW_CONSOLE | CREATE_SUSPENDED,
				NULL, NULL, &startup, process_info)) {
				// create a suspended process, add it to the job, then resume (unsuspend) the process
				if (AssignProcessToJobObject(job, process_info->hProcess)) {
					if (ResumeThread(process_info->hThread) != (DWORD)-1) {
						process->job = job;
						process->pipe_read = pipe_read;
						process->pipe_write = pipe_write;
						success = true;
					}
				}
				if (!success) {
					TerminateProcess(process_info->hProcess, 1);
					CloseHandle(process_info->hProcess);
					CloseHandle(process_info->hThread);
				}
			} else {
				char buf[150];
				get_last_error_str(buf, sizeof buf);
				strbuf_printf(process->error, "Couldn't run `%s`: %s", command, buf);
			}
			free(command_line);
			if (!success) {
				CloseHandle(pipe_read);
				CloseHandle(pipe_write);
			}
		} else {
			char buf[150];
			get_last_error_str(buf, sizeof buf);
			strbuf_printf(process->error, "Couldn't create pipe: %s", buf);
		}
		if (!success)
			CloseHandle(job);
	}
	return success;
}

char const *process_geterr(Process *p) {
	return *p->error ? p->error : NULL;
}

long long process_read(Process *process, char *data, size_t size) {
	DWORD bytes_read = 0, bytes_avail = 0, bytes_left = 0;
	if (PeekNamedPipe(process->pipe_read, data, (DWORD)size, &bytes_read, &bytes_avail, &bytes_left)) {
		if (bytes_read == 0) {
			return -1;
		} else {
			ReadFile(process->pipe_read, data, (DWORD)size, &bytes_read, NULL); // make sure data is removed from pipe
			return bytes_read;
		}
	} else {
		char buf[150];
		get_last_error_str(buf, sizeof buf);
		strbuf_printf(process->error, "Couldn't read from pipe: %s", buf);
		return -2;
	}
}

void process_kill(Process *process) {
	CloseHandle(process->job);
	CloseHandle(process->pipe_read);
	CloseHandle(process->pipe_write);
	CloseHandle(process->process_info.hProcess);
	CloseHandle(process->process_info.hThread);
}

int process_check_status(Process *process, char *message, size_t message_size) {
	HANDLE hProcess = process->process_info.hProcess;
	DWORD exit_code = 1;
	if (GetExitCodeProcess(hProcess, &exit_code)) {
		if (exit_code == STILL_ACTIVE) {
			return 0;
		} else {
			process_kill(process);
			if (exit_code == 0) {
				str_printf(message, message_size, "exited successfully");
				return +1;
			} else {
				str_printf(message, message_size, "exited with code %d", (int)exit_code);
				return -1;
			}
		}
	} else {
		// something has gone wrong.
		str_printf(message, message_size, "couldn't get process exit status");
		process_kill(process);
		return -1;
	}
}