Prior to this change, a function with an on-job-exit event handler must be
added with the pgid of the job. But sometimes the pgid of the job is fish
itself (if job control is disabled) and the previous commit made last_pid
an actual pid from the job, instead of its pgroup.
Switch on-job-exit to accept any pid from the job (except fish itself).
This allows it to be used directly with $last_pid, except that it now
works if job control is off. This is implemented by "resolving" the pid to
the internal job id at the point the event handler is added.
Also switch to passing the last pid of the job, rather than its pgroup.
This aligns better with $last_pid.
When a job is placed in the background, fish will set the `$last_pid`
variable. Prior to this change, `$last_pid` was set to the process group
leader of the job. However this caussed problems when the job ran in
fish's process group, because then fish itself would be the process group
leader and commands like `wait` would not work.
Switch `$last_pid` to be the actual last pid of the pipeline. This brings
it in line with the `$!` variable from zsh and bash.
This is technically a breaking change, but it is unlikely to cause
problems, because `$last_pid` was already rather broken.
Fixes#5036Fixes#5832Fixes#7721
In preparation for using wait handles in --on-process-exit events, factor
wait handles into their own wait handle store. Also switch them to
per-process instead of per-job, which is a simplification.
This switches builtin_wait from waiting on jobs in the active job list, to
waiting on the wait handles. The wait handles may be either derived from
the job list itself, or from saved wait handles from jobs that exited in
the background.
Fixes#7210
This is preparing to address the problem where fish cannot wait on a
reaped job, because it only looks at the active job list. Introduce the
idea of a "wait handle," which is a thing that `wait` can use to check if
a job is finished. A job may produce its wait handle on demand, and
parser_t will save the wait handle from wait-able jobs at the point they
are reaped.
This change merely introduces the idea; the next change makes builtin_wait
start using it.
Several functions including wgetopt and execve operate on null-terminated
arrays of nul-terminated pointers: a list of pointers to C strings where
the last pointer is null. Prior to this change, each process_t stored its
argv in such an array. This had two problems:
1. It was awkward to work with this type, instead of using std::vector,
etc.
2. The process's arguments would be rearranged by builtins which is
surprising
Our null terminated arrays were built around a fancy type that would copy
input strings and also generate an array of pointers to them, in one big
allocation.
Switch to a new model where we construct an array of pointers over
existing strings. So you can supply a `vector<string>` and now
`null_terminated_array_t` will just make a list of pointers to them. Now
processes can just store their argv in a familiar wcstring_list_t.
Prior to this change, builtins would take their arguments as `wchar_t **`.
This implies that the order of the arguments may be changed (which is
true, `wgetopter` does so) but also that the strings themselves may be
changed, which no builtin should do.
Switch them all to take `const wchar_t **` instead: now the arguments may
be rearranged but their contents may no longer be modified.
After commit 6dd6a57c60, 3 remaining
builtins were affected by uint8_t overflow: `exit`, `return`, and
`functions --query`.
This commit:
- Moves the overflow check from `builtin_set_query` to `builtin_run`.
- Removes a conflicting int -> uint8_t conversion in `builtin_return`.
- Adds tests for the 3 remaining affected builtins.
- Simplifies the wording for the documentation for `set --query`.
- Does not change documentation for `functions --query`, because it does
not state the exit code in its API.
- Updates the CHANGELOG to reflect the change to all builtins.
Prior to this change, the functions in exec.cpp would return true or false
and it was not clear what significance that value had.
Switch to an enum to make this more explicit. In particular we have the
idea of a "pipeline breaking" error which should us to skip processes
which have not yet launched; if no process launches then we can bail out
to a different path which avoids reaping processes.
Prior to this change, if fish were launched connected to a tty but not as
pgroup leader, it would attempt to become pgroup leader only if
--interactive is explicitly passed. But bash will unconditionally attempt
to become pgroup leader if launched interactively. This can result in
scenarios where fish is running interactively but in another pgroup. The
most obvious impact is that control-C will result in the pgroup leader
(not fish) exiting and make fish orphaned.
Switch to matching the bash behavior here - we will always try to become
pgroup leader if interactive.
Fixes#7060.
The 'time' prefix may come about either because the job itself is marked
with time, or because of the "inside out" weirdness of 'not time...'.
Factor this logic together and precompute it for a job.
This moves us slightly closer towards fish code in the background. The idea is
that a background job may still have "foreground" sub-jobs, example:
begin ; sleep 5 ; end &
The begin/end job runs in the background but should wait for `sleep`.
Prior to this fix, fish would see the overall job group is in the background
and not wait for any of its processes. With this change we detach waiting from
is_foreground.
This changes how fish attempts to protect itself from calling tcsetpgrp() too
aggressively. Recall that tcsetpgrp() will "force" itself, if SIGTTOU is
ignored (which it is in fish when job control is enabled).
Prior to this fix, we avoided SIGTTINs by only transferring the tty ownership
if fish was already the owner. This dated from a time before we had really
nailed down how pgroups should be assigned. Now we more deliberately assign a
job's pgroup so we don't need this conservative check.
However we still need logic to avoid transferring the tty if fish is not the
owner. The bad case is when job control is enabled while fish is running in the
background - here fish would transfer the tty and "steal" from the foreground
process.
So retain the checks of the current tty owner but migrate them to the point of
calling tcsetpgrp() itself.
add_disowned_pgid skipped jobs that have a PGID equal to the running
process. However, this includes processes started in config.fish or when
job control is turned off, so they never get waited on.
Instead, refactor this function to add_disowned_job, and add either the PGID or
all the PIDs of the job to the list of disowned PIDs/PGIDs.
Fixes#7183.
Assigning the tty is really a function of a job group, not an individual
job. Reflect that in terminal_maybe_give_to_job_group and also
terminal_return_from_job_group.
When fish receives a "cancellation inducing" signal (SIGINT in particular)
it has to unwind execution - for example while loops or whatever else that
is executing. There are two ways this may come about:
1. The fish process received the signal
2. A child process received the signal
An example of the second case is:
some_command | some_function
Here `some_command` is the tty owner and so will receive control-C, but
then fish has to cancel function execution.
Prior to this change, these were handled uniformly: both would just set a
cancellation signal inside the parser. However in the future we will have
multiple parsers and it may not be obvious which one to set the flag in.
So instead distinguish these cases: if a process receives SIGINT we mark
the signal in its job group, and if fish receives it we set a global
variable.
Initially I wanted to pick a different name to avoid confusion with
process groups, but really job trees *are* process groups. So name them
to reflect that fact.
Also rename "placeholder" to "internal" which is clearer.
Prior to this, jobs all had a pgid, and fish has to work hard to ensure
that pgids were inherited properly for nested jobs. But now the job tree
is the source of truth and there is only one location for the pgid.
Job trees come in two flavors: “placeholders” for jobs which are only fish
functions, and non-placeholders which need to track a pgid. This adds
logic to allow a job to decide if its parent's job tree is appropriate,
and allocating a new tree if not.
job_tree represents the data that should be shared between a job and any
jobs that may be spawned by functions or eval run as part of that job. It
reifies shared data that before was handled piecemeal.
The `function --on-job-exit caller` feature allows a command substitution
to observe when the parent job exits. This has never worked very well - in
particular it is based on job IDs, so a function that observes this will
run multiple times. Implement it properly.
Do this by having a not-recycled "internal job id".
This is only used by psub, but ensure it works properly none-the-less.
