1 #include "threadimpl.h"
2 
3 static Lock thewaitlock;
4 static Channel *thewaitchan;
5 
6 static void
7 execproc(void *v)
8 {
9 	int pid;
10 	Channel *c;
11 	Execjob *e;
12 	Waitmsg *w;
13 
14 	e = v;
15 	pid = _threadspawn(e->fd, e->cmd, e->argv);
16 	sendul(e->c, pid);
17 	if(pid > 0){
18 		w = waitfor(pid);
19 		if((c = thewaitchan) != nil)
20 			sendp(c, w);
21 		else
22 			free(w);
23 	}
24 	threadexits(nil);
25 }
26 
27 int
28 _runthreadspawn(int *fd, char *cmd, char **argv)
29 {
30 	int pid;
31 	Execjob e;
32 
33 	e.fd = fd;
34 	e.cmd = cmd;
35 	e.argv = argv;
36 	e.c = chancreate(sizeof(void*), 0);
37 	proccreate(execproc, &e, 65536);
38 	pid = recvul(e.c);
39 	chanfree(e.c);
40 	return pid;
41 }
42 
43 Channel*
44 threadwaitchan(void)
45 {
46 	if(thewaitchan)
47 		return thewaitchan;
48 	lock(&thewaitlock);
49 	if(thewaitchan){
50 		unlock(&thewaitlock);
51 		return thewaitchan;
52 	}
53 	thewaitchan = chancreate(sizeof(Waitmsg*), 4);
54 	chansetname(thewaitchan, "threadwaitchan");
55 	unlock(&thewaitlock);
56 	return thewaitchan;
57 }
58 
59 int
60 _threadspawn(int fd[3], char *cmd, char *argv[])
61 {
62 	int i, n, p[2], pid;
63 	char exitstr[100];
64 
65 	if(pipe(p) < 0)
66 		return -1;
67 	if(fcntl(p[0], F_SETFD, 1) < 0 || fcntl(p[1], F_SETFD, 1) < 0){
68 		close(p[0]);
69 		close(p[1]);
70 		return -1;
71 	}
72 	switch(pid = fork()){
73 	case -1:
74 		close(p[0]);
75 		close(p[1]);
76 		return -1;
77 	case 0:
78 		/* can't RFNOTEG - will lose tty */
79 		dup2(fd[0], 0);
80 		dup2(fd[1], 1);
81 		dup2(fd[2], 2);
82 		if(!isatty(0) && !isatty(1) && !isatty(2))
83 			rfork(RFNOTEG);
84 		for(i=3; i<100; i++)
85 			if(i != p[1])
86 				close(i);
87 		execvp(cmd, argv);
88 		fprint(p[1], "%d", errno);
89 		close(p[1]);
90 		_exit(0);
91 	}
92 
93 	close(p[1]);
94 	n = read(p[0], exitstr, sizeof exitstr-1);
95 	close(p[0]);
96 	if(n > 0){	/* exec failed */
97 		free(waitfor(pid));
98 		exitstr[n] = 0;
99 		errno = atoi(exitstr);
100 		return -1;
101 	}
102 
103 	close(fd[0]);
104 	if(fd[1] != fd[0])
105 		close(fd[1]);
106 	if(fd[2] != fd[1] && fd[2] != fd[0])
107 		close(fd[2]);
108 	return pid;
109 }
110 
111 int
112 threadspawn(int fd[3], char *cmd, char *argv[])
113 {
114 	return _runthreadspawn(fd, cmd, argv);
115 }
116 
117 int
118 threadspawnl(int fd[3], char *cmd, ...)
119 {
120 	char **argv, *s;
121 	int n, pid;
122 	va_list arg;
123 
124 	va_start(arg, cmd);
125 	for(n=0; va_arg(arg, char*) != nil; n++)
126 		;
127 	n++;
128 	va_end(arg);
129 
130 	argv = malloc(n*sizeof(argv[0]));
131 	if(argv == nil)
132 		return -1;
133 
134 	va_start(arg, cmd);
135 	for(n=0; (s=va_arg(arg, char*)) != nil; n++)
136 		argv[n] = s;
137 	argv[n] = 0;
138 	va_end(arg);
139 
140 	pid = threadspawn(fd, cmd, argv);
141 	free(argv);
142 	return pid;
143 }
144 
145 int
146 _threadexec(Channel *cpid, int fd[3], char *cmd, char *argv[])
147 {
148 	int pid;
149 
150 	pid = threadspawn(fd, cmd, argv);
151 	if(cpid){
152 		if(pid < 0)
153 			chansendul(cpid, ~0);
154 		else
155 			chansendul(cpid, pid);
156 	}
157 	return pid;
158 }
159 
160 void
161 threadexec(Channel *cpid, int fd[3], char *cmd, char *argv[])
162 {
163 	if(_threadexec(cpid, fd, cmd, argv) >= 0)
164 		threadexits("threadexec");
165 }
166 
167 void
168 threadexecl(Channel *cpid, int fd[3], char *cmd, ...)
169 {
170 	char **argv, *s;
171 	int n, pid;
172 	va_list arg;
173 
174 	va_start(arg, cmd);
175 	for(n=0; va_arg(arg, char*) != nil; n++)
176 		;
177 	n++;
178 	va_end(arg);
179 
180 	argv = malloc(n*sizeof(argv[0]));
181 	if(argv == nil){
182 		if(cpid)
183 			chansendul(cpid, ~0);
184 		return;
185 	}
186 
187 	va_start(arg, cmd);
188 	for(n=0; (s=va_arg(arg, char*)) != nil; n++)
189 		argv[n] = s;
190 	argv[n] = 0;
191 	va_end(arg);
192 
193 	pid = _threadexec(cpid, fd, cmd, argv);
194 	free(argv);
195 
196 	if(pid >= 0)
197 		threadexits("threadexecl");
198 }
199