diff options
| -rw-r--r-- | src/libthread/daemonize.c | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/src/libthread/daemonize.c b/src/libthread/daemonize.c new file mode 100644 index 00000000..65af29ab --- /dev/null +++ b/src/libthread/daemonize.c @@ -0,0 +1,98 @@ +#include <u.h> +#include <sys/signal.h> +#include <sys/wait.h> +#include <libc.h> +#include <thread.h> +#include "threadimpl.h" + +#undef pipe +#undef wait + +static int sigpid; +static int threadpassfd; + +static void +child(void) +{ + int status; + if(wait(&status) == sigpid && WIFEXITED(status)) + _exit(WEXITSTATUS(status)); +} + +static void +sigpass(int sig) +{ + if(sig == SIGCHLD) + child(); + else + kill(sigpid, sig); +} + +void +_threadsetupdaemonize(void) +{ + int i, n, pid; + int p[2]; + char buf[20]; + + sigpid = 1; + + threadlinklibrary(); + + if(pipe(p) < 0) + sysfatal("passer pipe: %r"); + + /* hide these somewhere they won't cause harm */ + if(dup(p[0], 98) < 0 || dup(p[1], 99) < 0) + sysfatal("passer pipe dup: %r"); + close(p[0]); + close(p[1]); + p[0] = 98; + p[1] = 99; + + /* close on exec */ + if(fcntl(p[0], F_SETFD, 1) < 0 || fcntl(p[1], F_SETFD, 1) < 0) + sysfatal("passer pipe pipe fcntl: %r"); + + switch(pid = fork()){ + case -1: + sysfatal("passer fork: %r"); + default: + close(p[1]); + break; + case 0: + rfork(RFNOTEG); + close(p[0]); + threadpassfd = p[1]; + return; + } + + sigpid = pid; + for(i=0; i<NSIG; i++){ + struct sigaction sa; + + memset(&sa, 0, sizeof sa); + sa.sa_handler = sigpass; + sa.sa_flags |= SA_RESTART; + sigaction(i, &sa, nil); + } + + for(;;){ + n = read(p[0], buf, sizeof buf-1); + if(n == 0) /* program exited */ + child(); + if(n > 0) + break; + sysfatal("passer pipe read: %r"); + } + buf[n] = 0; + _exit(atoi(buf)); +} + +void +threaddaemonize(void) +{ + write(threadpassfd, "0", 1); + close(threadpassfd); + threadpassfd = -1; +} |