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Refactor process_clean_after_marking

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This untangles some of the complicated logic and loops around posting
job exit events, and invoking the fish_job_summary function. No
functional change here (hopefully).
This commit is contained in:
ridiculousfish 2021-11-03 15:03:37 -07:00
parent 00a1df3811
commit c4fb857dac
2 changed files with 176 additions and 150 deletions
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318
src/proc.cpp
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@ -120,23 +120,15 @@ bool job_t::is_completed() const {
return true;
}
bool job_t::should_report_process_exits() const {
// This implements the behavior of process exit events only being sent for jobs containing an
// external process. Bizarrely the process exit event is for the pgroup leader which may be fish
// itself.
// TODO: rationalize this.
bool job_t::posts_job_exit_events() const {
// If we never got a pgid then we never launched the external process, so don't report it.
if (!this->get_pgid()) {
return false;
}
if (!this->get_pgid()) return false;
// Only report root job exits.
// For example in `ls | begin ; cat ; end` we don't need to report the cat sub-job.
if (!flags().is_group_root) {
return false;
}
if (!flags().is_group_root) return false;
// Return whether we have an external process.
// Only jobs with external processes post job_exit events.
return this->has_external_proc();
}
@ -489,35 +481,148 @@ static void process_mark_finished_children(parser_t &parser, bool block_ok) {
reap_disowned_pids();
}
/// Call the fish_job_summary function with the given args.
static void call_job_summary(parser_t &parser, const wcstring_list_t &args) {
wcstring buffer = wcstring(L"fish_job_summary");
for (const wcstring &arg : args) {
buffer.push_back(L' ');
buffer.append(escape_string(arg, ESCAPE_ALL));
/// Given a job that has completed, generate job_exit, process_exit, and caller_exit events.
static void generate_exit_events(const job_ref_t &j, std::vector<event_t> *out_evts) {
// Generate proc and job exit events, except for jobs originating in event handlers.
if (!j->from_event_handler()) {
// process_exit events.
for (const auto &proc : j->processes) {
if (proc->pid > 0) {
out_evts->push_back(event_t::process_exit(proc->pid, proc->status.status_value()));
}
}
// job_exit events.
if (j->posts_job_exit_events()) {
if (auto last_pid = j->get_last_pid()) {
out_evts->push_back(event_t::job_exit(*last_pid, j->internal_job_id));
}
}
}
event_t event(event_type_t::generic);
event.desc.str_param1 = L"fish_job_summary";
auto prev_statuses = parser.get_last_statuses();
block_t *b = parser.push_block(block_t::event_block(event));
parser.eval(buffer, io_chain_t());
parser.pop_block(b);
parser.set_last_statuses(std::move(prev_statuses));
// Generate caller_exit events.
out_evts->push_back(event_t::caller_exit(j->internal_job_id, j->job_id()));
}
/// Format information about job status for the user to look at.
using job_status_t = enum { JOB_STOPPED, JOB_ENDED };
static void print_job_status(parser_t &parser, const job_t *j, job_status_t status) {
wcstring_list_t args = {
to_string(j->job_id()),
to_string(static_cast<int>(j->is_foreground())),
j->command(),
status == JOB_STOPPED ? L"STOPPED" : L"ENDED",
};
call_job_summary(parser, args);
/// \return whether to emit a fish_job_summary call for a process.
static bool proc_wants_summary(const shared_ptr<job_t> &j, const process_ptr_t &p) {
// Are we completed with a pid?
if (!p->completed || !p->pid) return false;
// Did we die due to a signal other than SIGPIPE?
auto s = p->status;
if (!s.signal_exited() || s.signal_code() == SIGPIPE) return false;
// Does the job want to suppress notifications?
// Note we always report crashes.
if (j->skip_notification() && !contains(crashsignals, s.signal_code())) return false;
return true;
}
/// \return whether to emit a fish_job_summary call for a job as a whole. We may also emit this for
/// its individual processes.
static bool job_wants_summary(const shared_ptr<job_t> &j) {
// Did we already print a status message?
if (j->flags().notified) return false;
// Do we just skip notifications?
if (j->skip_notification()) return false;
// Do we have a single process which will also report? If so then that suffices for us.
if (j->processes.size() == 1 && proc_wants_summary(j, j->processes.front())) return false;
// Are we foreground?
// The idea here is to not print status messages for jobs that execute in the foreground (i.e.
// without & and without being `bg`).
if (j->is_foreground()) return false;
return true;
}
/// \return whether we want to emit a fish_job_summary call for a job or any of its processes.
bool job_or_proc_wants_summary(const shared_ptr<job_t> &j) {
if (job_wants_summary(j)) return true;
for (const auto &p : j->processes) {
if (proc_wants_summary(j, p)) return true;
}
return false;
}
/// Invoke the fish_job_summary function by executing the given command.
static void call_job_summary(parser_t &parser, const wcstring &cmd) {
event_t event(event_type_t::generic);
event.desc.str_param1 = L"fish_job_summary";
block_t *b = parser.push_block(block_t::event_block(event));
auto saved_status = parser.get_last_statuses();
parser.eval(cmd, io_chain_t());
parser.set_last_statuses(saved_status);
parser.pop_block(b);
}
// \return a command which invokes fish_job_summary.
// The process pointer may be null, in which case it represents the entire job.
// Note this implements the arguments which fish_job_summary expects.
wcstring summary_command(const job_ref_t &j, const process_ptr_t &p = nullptr) {
wcstring buffer = L"fish_job_summary";
// Job id.
append_format(buffer, L" %d", j->job_id());
// 1 if foreground, 0 if background.
append_format(buffer, L" %d", static_cast<int>(j->is_foreground()));
// Command.
buffer.push_back(L' ');
buffer.append(escape_string(j->command(), ESCAPE_ALL));
if (!p) {
// No process, we are summarizing the whole job.
buffer.append(j->is_stopped() ? L" STOPPED" : L" ENDED");
} else {
// We are summarizing a process which exited with a signal.
// Arguments are the signal name and description.
int sig = p->status.signal_code();
buffer.push_back(L' ');
buffer.append(escape_string(sig2wcs(sig), ESCAPE_ALL));
buffer.push_back(L' ');
buffer.append(escape_string(signal_get_desc(sig), ESCAPE_ALL));
// If we have multiple processes, we also append the pid and argv.
if (j->processes.size() > 1) {
append_format(buffer, L" %d", p->pid);
buffer.push_back(L' ');
buffer.append(escape_string(p->argv0(), ESCAPE_ALL));
}
}
return buffer;
}
// Summarize a list of jobs, by emitting calls to fish_job_summary.
// Note the given list must NOT be the parser's own job list, since the call to fish_job_summary
// could modify it.
static bool summarize_jobs(parser_t &parser, const std::vector<job_ref_t> &jobs) {
if (jobs.empty()) return false;
for (const auto &j : jobs) {
if (j->is_stopped()) {
call_job_summary(parser, summary_command(j));
} else {
// Completed job.
for (const auto &p : j->processes) {
if (proc_wants_summary(j, p)) {
call_job_summary(parser, summary_command(j, p));
}
}
// Overall status for the job.
if (job_wants_summary(j)) {
call_job_summary(parser, summary_command(j));
}
}
}
return true;
}
/// Remove all disowned jobs whose job chain is fully constructed (that is, do not erase disowned
@ -534,67 +639,6 @@ static void remove_disowned_jobs(job_list_t &jobs) {
}
}
/// Given a a process in a job, print the status message for the process as appropriate, and then
/// mark the status code so we don't print again. Populate any events into \p exit_events.
/// \return true if we printed a status message, false if not.
static bool try_clean_process_in_job(parser_t &parser, process_t *p, job_t *j,
std::vector<event_t> *exit_events) {
if (p->marked_exit_event || !p->completed || !p->pid) {
return false;
}
p->marked_exit_event = true;
auto s = p->status;
// Add an exit event if the process did not come from a job handler.
if (!j->from_event_handler()) {
exit_events->push_back(event_t::process_exit(p->pid, s.status_value()));
}
// Ignore SIGPIPE. We issue it ourselves to the pipe writer when the pipe reader dies.
if (!s.signal_exited() || s.signal_code() == SIGPIPE) {
return false;
}
int proc_is_job = (p->is_first_in_job && p->is_last_in_job);
if (proc_is_job) j->mut_flags().notified = true;
// Handle signals other than SIGPIPE.
// Always report crashes.
if (j->skip_notification() && !contains(crashsignals, s.signal_code())) {
return false;
}
wcstring_list_t args;
args.reserve(proc_is_job ? 5 : 7);
args.push_back(to_string(j->job_id()));
args.push_back(to_string(static_cast<int>(j->is_foreground())));
args.push_back(j->command());
args.push_back(sig2wcs(s.signal_code()));
args.push_back(signal_get_desc(s.signal_code()));
if (!proc_is_job) {
args.push_back(to_string(p->pid));
args.push_back(p->argv0());
}
call_job_summary(parser, args);
return true;
}
/// \return whether this job wants a status message printed when it stops or completes.
static bool job_wants_message(const shared_ptr<job_t> &j) {
// Did we already print a status message?
if (j->flags().notified) return false;
// Do we just skip notifications?
if (j->skip_notification()) return false;
// Are we foreground?
// The idea here is to not print status messages for jobs that execute in the foreground (i.e.
// without & and without being `bg`).
if (j->is_foreground()) return false;
return true;
}
/// Given that a job has completed, check if it may be wait'ed on; if so add it to the wait handle
/// store. Then mark all wait handles as complete.
static void save_wait_handle_for_completed_job(const shared_ptr<job_t> &job,
@ -620,15 +664,13 @@ static void save_wait_handle_for_completed_job(const shared_ptr<job_t> &job,
/// \return whether something was printed.
static bool process_clean_after_marking(parser_t &parser, bool allow_interactive) {
ASSERT_IS_MAIN_THREAD();
bool printed = false;
// This function may fire an event handler, we do not want to call ourselves recursively (to
// avoid infinite recursion).
if (parser.libdata().is_cleaning_procs) {
return false;
}
parser.libdata().is_cleaning_procs = true;
const cleanup_t cleanup([&] { parser.libdata().is_cleaning_procs = false; });
const scoped_push<bool> cleaning(&parser.libdata().is_cleaning_procs, true);
// This may be invoked in an exit handler, after the TERM has been torn down
// Don't try to print in that case (#3222)
@ -641,65 +683,49 @@ static bool process_clean_after_marking(parser_t &parser, bool allow_interactive
// complete.
std::vector<event_t> exit_events;
// A helper to indicate if we should process a job.
// Defer processing under-construction jobs or jobs that want a message when we are not
// interactive.
auto should_process_job = [=](const shared_ptr<job_t> &j) {
// Do not attempt to process jobs which are not yet constructed.
// Do not attempt to process jobs that need to print a status message,
// unless we are interactive, in which case printing is OK.
return j->is_constructed() && (interactive || !job_wants_message(j));
return j->is_constructed() && (interactive || !job_or_proc_wants_summary(j));
};
// Print status messages for completed or stopped jobs.
// The list of jobs to summarize. Some of these jobs are completed and are removed from the
// parser's job list, others are stopped and remain in the list.
std::vector<job_ref_t> jobs_to_summarize;
// Handle stopped jobs. These stay in our list.
for (const auto &j : parser.jobs()) {
if (!should_process_job(j)) continue;
// Clean processes within the job.
// Note this may print the message on behalf of the job, affecting the result of
// job_wants_message().
for (process_ptr_t &p : j->processes) {
if (try_clean_process_in_job(parser, p.get(), j.get(), &exit_events)) {
printed = true;
}
}
// Print the message if we need to.
if (job_wants_message(j) && (j->is_completed() || j->is_stopped())) {
print_job_status(parser, j.get(), j->is_completed() ? JOB_ENDED : JOB_STOPPED);
if (!j->is_completed() && j->is_stopped() && should_process_job(j) &&
job_wants_summary(j)) {
j->mut_flags().notified = true;
printed = true;
}
// Prepare events for completed jobs
if (j->is_completed()) {
// If this job already came from an event handler,
// don't create an event or it's easy to get an infinite loop.
if (!j->from_event_handler() && j->should_report_process_exits()) {
if (auto last_pid = j->get_last_pid()) {
exit_events.push_back(event_t::job_exit(*last_pid, j->internal_job_id));
}
}
// Caller exit events we still create, which anecdotally fixes `source (thing | psub)`
// inside event handlers. This seems benign since this event is barely used (basically
// only psub), and it seems hard to construct an infinite loop with it.
exit_events.push_back(event_t::caller_exit(j->internal_job_id, j->job_id()));
jobs_to_summarize.push_back(j);
}
}
// Remove completed jobs.
// Do this before calling out to user code in the event handler below, to ensure an event
// handler doesn't remove jobs on our behalf.
auto &jobs = parser.jobs();
for (auto iter = jobs.begin(); iter != jobs.end();) {
const shared_ptr<job_t> &j = *iter;
if (should_process_job(j) && j->is_completed()) {
// If this job finished in the background, we have to remember to wait on it.
save_wait_handle_for_completed_job(j, parser.get_wait_handles());
iter = jobs.erase(iter);
} else {
// Remove completed, processable jobs from our job list.
for (auto iter = parser.jobs().begin(); iter != parser.jobs().end();) {
const job_ref_t &j = *iter;
if (!should_process_job(j) || !j->is_completed()) {
++iter;
continue;
}
// We are committed to removing this job.
// Remember it for summary later, generate exit events, maybe save its wait handle if it
// finished in the background.
if (job_or_proc_wants_summary(j)) jobs_to_summarize.push_back(j);
generate_exit_events(j, &exit_events);
save_wait_handle_for_completed_job(j, parser.get_wait_handles());
// Remove it.
iter = parser.jobs().erase(iter);
}
// Emit calls to fish_job_summary.
bool printed = summarize_jobs(parser, jobs_to_summarize);
// Post pending exit events.
for (const auto &evt : exit_events) {
event_fire(parser, evt);

8
src/proc.h
View file

@ -458,9 +458,8 @@ class job_t : noncopyable_t {
/// \return whether this job's group is in the foreground.
bool is_foreground() const;
/// \return whether we should report process exit events.
/// This implements some historical behavior which has not been justified.
bool should_report_process_exits() const;
/// \return whether we should post job_exit events.
bool posts_job_exit_events() const;
/// \return whether this job and its parent chain are fully constructed.
bool job_chain_is_fully_constructed() const;
@ -478,6 +477,7 @@ class job_t : noncopyable_t {
/// \returns the statuses for this job.
maybe_t<statuses_t> get_statuses() const;
};
using job_ref_t = std::shared_ptr<job_t>;
/// Whether this shell is attached to a tty.
bool is_interactive_session();
@ -494,7 +494,7 @@ bool no_exec();
void mark_no_exec();
// List of jobs.
typedef std::deque<shared_ptr<job_t>> job_list_t;
using job_list_t = std::deque<job_ref_t>;
/// The current job control mode.
///