From bafd94f154d0a6fdf04706f7cf5687dcc8ba634b Mon Sep 17 00:00:00 2001 From: Eric Andersen Date: Wed, 2 May 2001 16:11:59 +0000 Subject: First pass at getting job control working. This gets the infrastructure in place, but something is still missing/wrong in there. Testing with 'grep foo &' seems to put _hush_ into the background. Pondering... -Erik --- shell/hush.c | 155 ++++++++++++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 142 insertions(+), 13 deletions(-) (limited to 'shell/hush.c') diff --git a/shell/hush.c b/shell/hush.c index 4641e59c8..ed4979818 100644 --- a/shell/hush.c +++ b/shell/hush.c @@ -213,7 +213,6 @@ struct pipe { int job_context; /* bitmask defining current context */ pipe_style followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */ reserved_style r_mode; /* supports if, for, while, until */ - struct jobset *job_list; }; struct jobset { @@ -244,7 +243,7 @@ static int fake_mode=0; static int interactive=0; static struct close_me *close_me_head = NULL; static char *cwd; -/* static struct jobset job_list = { NULL, NULL }; */ +static struct jobset *job_list; static unsigned int last_bg_pid=0; static char *PS1; static char *PS2 = "> "; @@ -377,6 +376,11 @@ static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *in static int parse_stream_outer(struct in_str *inp); static int parse_string_outer(const char *s); static int parse_file_outer(FILE *f); +/* job management: */ +static void checkjobs(); +static void insert_bg_job(struct pipe *pi); +static void remove_bg_job(struct pipe *pi); +static void free_pipe(struct pipe *pi); /* Table of built-in functions. They can be forked or not, depending on * context: within pipes, they fork. As simple commands, they do not. @@ -481,7 +485,7 @@ static int builtin_fg_bg(struct child_prog *child) return EXIT_FAILURE; } - for (job = child->family->job_list->head; job; job = job->next) { + for (job = job_list->head; job; job = job->next) { if (job->jobid == jobNum) { break; } @@ -498,7 +502,7 @@ static int builtin_fg_bg(struct child_prog *child) /* suppress messages when run from /linuxrc mag@sysgo.de */ if (tcsetpgrp(0, job->pgrp) && errno != ENOTTY) perror_msg("tcsetpgrp"); - child->family->job_list->fg = job; + job_list->fg = job; } /* Restart the processes in the job */ @@ -533,7 +537,7 @@ static int builtin_jobs(struct child_prog *child) struct pipe *job; char *status_string; - for (job = child->family->job_list->head; job; job = job->next) { + for (job = job_list->head; job; job = job->next) { if (job->running_progs == job->stopped_progs) status_string = "Stopped"; else @@ -1031,6 +1035,121 @@ static void pseudo_exec(struct child_prog *child) } } +static void insert_bg_job(struct pipe *pi) +{ + struct pipe *thejob; + + /* Linear search for the ID of the job to use */ + pi->jobid = 1; + for (thejob = job_list->head; thejob; thejob = thejob->next) + if (thejob->jobid >= pi->jobid) + pi->jobid = thejob->jobid + 1; + + /* add thejob to the list of running jobs */ + if (!job_list->head) { + thejob = job_list->head = xmalloc(sizeof(*thejob)); + } else { + for (thejob = job_list->head; thejob->next; thejob = thejob->next) /* nothing */; + thejob->next = xmalloc(sizeof(*thejob)); + thejob = thejob->next; + } + + /* physically copy the struct job */ + *thejob = *pi; + thejob->next = NULL; + thejob->running_progs = thejob->num_progs; + thejob->stopped_progs = 0; + + /* we don't wait for background thejobs to return -- append it + to the list of backgrounded thejobs and leave it alone */ + printf("[%d] %d\n", pi->jobid, pi->pgrp); + last_bg_pid = pi->pgrp; +} + +/* remove a backgrounded job from a jobset */ +static void remove_bg_job(struct pipe *pi) +{ + struct pipe *prev_pipe; + + free_pipe(pi); + if (pi == job_list->head) { + job_list->head = pi->next; + } else { + prev_pipe = job_list->head; + while (prev_pipe->next != pi) + prev_pipe = prev_pipe->next; + prev_pipe->next = pi->next; + } + + free(pi); +} + +/* free up all memory from a pipe */ +static void free_pipe(struct pipe *pi) +{ + int i; + + for (i = 0; i < pi->num_progs; i++) { + free(pi->progs[i].argv); + if (pi->progs[i].redirects) + free(pi->progs[i].redirects); + } + if (pi->progs) + free(pi->progs); + if (pi->text) + free(pi->text); + if (pi->cmdbuf) + free(pi->cmdbuf); + memset(pi, 0, sizeof(struct pipe)); +} + +/* Checks to see if any background processes have exited -- if they + have, figure out why and see if a job has completed */ +static void checkjobs() +{ + int status; + int prognum = 0; + struct pipe *pi; + pid_t childpid; + + while ((childpid = waitpid(-1, &status, WNOHANG | WUNTRACED)) > 0) { + for (pi = job_list->head; pi; pi = pi->next) { + prognum = 0; + while (prognum < pi->num_progs && + pi->progs[prognum].pid != childpid) prognum++; + if (prognum < pi->num_progs) + break; + } + + if (WIFEXITED(status) || WIFSIGNALED(status)) { + /* child exited */ + pi->running_progs--; + pi->progs[prognum].pid = 0; + + if (!pi->running_progs) { + printf(JOB_STATUS_FORMAT, pi->jobid, "Done", pi->text); + remove_bg_job(pi); + } + } else { + /* child stopped */ + pi->stopped_progs++; + pi->progs[prognum].is_stopped = 1; + + if (pi->stopped_progs == pi->num_progs) { + printf(JOB_STATUS_FORMAT, pi->jobid, "Stopped", + pi->text); + } + } + } + + /* move the shell to the foreground */ + if (tcsetpgrp(0, getpgrp()) && errno != ENOTTY) + perror_msg("tcsetpgrp"); + + if (childpid == -1 && errno != ECHILD) + perror_msg("waitpid"); +} + /* run_pipe_real() starts all the jobs, but doesn't wait for anything * to finish. See pipe_wait(). * @@ -1106,6 +1225,8 @@ static int run_pipe_real(struct pipe *pi) /* XXX test for failed fork()? */ if (!(child->pid = fork())) { + signal(SIGTTOU, SIG_DFL); + close_all(); if (nextin != 0) { @@ -1174,22 +1295,25 @@ static int run_list_real(struct pipe *pi) /* XXX check bash's behavior with nontrivial pipes */ /* XXX compute jobid */ /* XXX what does bash do with attempts to background builtins? */ +#if 0 printf("[%d] %d\n", pi->jobid, pi->pgrp); last_bg_pid = pi->pgrp; +#endif + insert_bg_job(pi); rcode = EXIT_SUCCESS; } else { if (interactive) { /* move the new process group into the foreground */ /* suppress messages when run from /linuxrc mag@sysgo.de */ - signal(SIGTTIN, SIG_IGN); - signal(SIGTTOU, SIG_IGN); + //signal(SIGTTIN, SIG_IGN); + //signal(SIGTTOU, SIG_IGN); if (tcsetpgrp(0, pi->pgrp) && errno != ENOTTY) perror_msg("tcsetpgrp"); rcode = pipe_wait(pi); if (tcsetpgrp(0, getpgrp()) && errno != ENOTTY) perror_msg("tcsetpgrp"); - signal(SIGTTIN, SIG_DFL); - signal(SIGTTOU, SIG_DFL); + //signal(SIGTTIN, SIG_DFL); + //signal(SIGTTOU, SIG_DFL); } else { rcode = pipe_wait(pi); } @@ -1202,6 +1326,7 @@ static int run_list_real(struct pipe *pi) skip_more_in_this_rmode=rmode; /* return rcode; */ /* XXX broken if list is part of if/then/else */ } + checkjobs(); return rcode; } @@ -1298,7 +1423,7 @@ static int globhack(const char *src, int flags, glob_t *pglob) int cnt, pathc; const char *s; char *dest; - for (cnt=1, s=src; s && *s; s++) { + for (cnt=1, s=src; *s; s++) { if (*s == '\\') s++; cnt++; } @@ -1315,7 +1440,7 @@ static int globhack(const char *src, int flags, glob_t *pglob) if (pglob->gl_pathv == NULL) return GLOB_NOSPACE; pglob->gl_pathv[pathc-1]=dest; pglob->gl_pathv[pathc]=NULL; - for (s=src; s && *s; s++, dest++) { + for (s=src; *s; s++, dest++) { if (*s == '\\') s++; *dest = *s; } @@ -1482,8 +1607,6 @@ int reserved_word(o_string *dest, struct p_context *ctx) { "done", RES_DONE, FLAG_END } }; struct reserved_combo *r; - if (dest->data == NULL) - return 0; for (r=reserved_list; #define NRES sizeof(reserved_list)/sizeof(struct reserved_combo) r