diff options
Diffstat (limited to 'job.c')
| -rw-r--r-- | job.c | 72 |
1 files changed, 36 insertions, 36 deletions
@@ -310,8 +310,6 @@ extern int shell_function_pid, shell_function_completed; complete child, waiting for it to die if necessary. If ERR is nonzero, print an error message first. */ -static int rc_block, rc_reap_all, rc_got_block, rc_start_rfd, rc_end_rfd; - void reap_children (block, err) int block, err; @@ -326,11 +324,6 @@ reap_children (block, err) # define REAP_MORE dead_children #endif - rc_block = block; - rc_reap_all = 0; - rc_got_block = 0; - rc_start_rfd = job_rfd; - /* As long as: We have at least one child outstanding OR a shell function in progress, @@ -451,7 +444,6 @@ reap_children (block, err) { /* No local children are dead. */ reap_more = 0; - rc_reap_all = 1; if (!block || !any_remote) break; @@ -677,10 +669,8 @@ reap_children (block, err) /* Only block for one child. */ block = 0; - rc_block = block; } - rc_end_rfd = job_rfd; return; } @@ -691,11 +681,12 @@ free_child (child) register struct child *child; { /* If this child is the only one it was our "free" job, so don't put a - token back for it. */ + token back for it. This child has already been removed from the list, + so if there any left this wasn't the last one. */ - if (job_fds[1] >= 0 && (child != children || child->next != 0)) + if (job_fds[1] >= 0 && children) { - char *token = '+'; + char token = '+'; /* Write a job token back to the pipe. */ @@ -874,7 +865,7 @@ start_job_command (child) ? "%s" : (char *) 0, p); /* Optimize an empty command. People use this for timestamp rules, - and forking a useless shell all the time leads to inefficiency. */ + so avoid forking a useless shell. */ #if !defined(VMS) && !defined(_AMIGA) if ( @@ -1361,6 +1352,7 @@ new_job (file) /* Wait for a job slot to be freed up. If we allow an infinite number don't bother; also job_slots will == 0 if we're using the jobserver. */ + if (job_slots != 0) while (job_slots_used == job_slots) reap_children (1, 0); @@ -1369,41 +1361,49 @@ new_job (file) /* If we are controlling multiple jobs make sure we have a token before starting the child. */ + /* This can be inefficient. There's a decent chance that this job won't + actually have to run any subprocesses: the command script may be empty + or otherwise optimized away. It would be nice if we could defer + obtaining a token until just before we need it, in start_job_command. + To do that we'd need to keep track of whether we'd already obtained a + token (since start_job_command is called for each line of the job, not + just once). Also more thought needs to go into the entire algorithm; + this is where the old parallel job code waits, so... */ + else if (job_fds[0] >= 0) - if (children == 0) - { - char token = '-'; + while (1) + { + char token; - while (token == '-') /* If we don't already have a job started, use our "free" token. */ - if (children == 0) - token = '+'; + if (!children) + break; /* Read a token. As long as there's no token available we'll block. If we get a SIGCHLD we'll return with EINTR. If one happened before we got here we'll return immediately with EBADF because the signal handler closes the dup'd file descriptor. */ - else if (read (job_rfd, &c->job_token, 1) < 1) + if (read (job_rfd, &token, 1) == 1) { - if (errno != EINTR && errno != EBADF) - pfatal_with_name (_("read jobs pipe")); + if (debug_flag) + printf (_("Obtained token for child 0x%08lx (%s).\n"), + (unsigned long int) c, c->file->name); + break; + } - /* Re-dup the read side of the pipe, so the signal handler can - notify us if we miss a child. */ - if (job_rfd < 0) - job_rfd = dup (job_fds[0]); + if (errno != EINTR && errno != EBADF) + pfatal_with_name (_("read jobs pipe")); - /* Something's done. We don't want to block for a whole child, - just reap whatever's there. */ - reap_children (0, 0); - } + /* Re-dup the read side of the pipe, so the signal handler can + notify us if we miss a child. */ + if (job_rfd < 0) + job_rfd = dup (job_fds[0]); - assert (c->job_token != '-'); - if (debug_flag) - printf (_("Obtained token for child 0x%08lx (%s).\n"), - (unsigned long int) c, c->file->name); - } + /* Something's done. We don't want to block for a whole child, + just reap whatever's there. */ + reap_children (0, 0); + } #endif /* The job is now primed. Start it running. |