Merge pull request #3310 from Skgland/process_wait-release

add `release(Bool)` option to `process_wait/3`

src/lib/process.pl

@@ -95,10 +95,12 @@ process_wait(Process, Status) :- call_with_error_context(process_wait(Process, S
 % `Options` is a a list of the following options
 %
 %  * timeout(Timeout) supported values for `Timeout` are 0 or `infinite`
+%  * release(Bool) supported values for `Bool` are `true` or `false`
 %
 % Each options may be specified at most once, when an option is not specified the following defaults apply:
 %
 % - timeout(infinite)
+% - release(true)
 %
 process_wait(Process, Status, Options) :- call_with_error_context(process_wait_(Process, Status, Options), predicate-process_wait/3).
 
@@ -106,17 +108,29 @@ process_wait_(Process, Status, Options) :-
     valid_process(Process),
     check_options(
         [
-            option([timeout], valid_timeout, timeout(infinite), timeout(Timeout))
+            option([timeout], valid_timeout, timeout(infinite), timeout(Timeout)),
+            option([release], valid_release, release(true), release(Release))
         ],
         Options,
         process_wait_option
     ),
     '$process_wait'(Process, Exit, Timeout),
+    ((true = Release) -> '$process_release'(Process) ; true),
     Exit = Status.
 
 valid_timeout(timeout(infinite)).
 valid_timeout(timeout(0)).
 
+valid_release(release(Arg)) :-
+    ( var(Arg) -> instantiation_error([])
+    ; valid_bool(Arg) -> true
+    ; domain_error(boolean, Arg, [])
+    ).
+
+
+valid_bool(true).
+valid_bool(false).
+
 
 %% process_kill(+Process).
 %
@@ -141,8 +155,7 @@ process_release(Process) :- call_with_error_context(process_release_(Process), p
 
 process_release_(Process) :-
     valid_process(Process),
-    process_wait(Process, _),
+    process_wait(Process, _).
-    '$process_release'(Process).
 
 
 must_be_known_options(Valid, Options, Domain) :- call_with_error_context(must_be_known_options_(Valid, [], Options, Domain),predicate-must_be_known_options/3).

tests/scryer/cli/unix/process.md

@@ -1,5 +1,6 @@
 ```trycmd
-$ scryer-prolog -f --no-add-history -g 'use_module(library(process)), process_create("false", [], [process(P)]), process_wait(P, exit(1)), halt'
+$ scryer-prolog -f --no-add-history -g 'use_module(library(process)), process_create("false", [], [process(P)]), process_id(P, Pid), write(pid=Pid), nl, process_wait(P, exit(1)), halt'
+pid=[..]
 
 ```
 
@@ -12,3 +13,32 @@ $  scryer-prolog -f --no-add-history -g 'use_module(library(process)), use_modul
 $  scryer-prolog -f --no-add-history -g 'use_module(library(process)), process_create("sh", ["-c", "sleep 5"], [process(P), stdout(null)]), process_kill(P), process_wait(P, killed(9)), halt'
 
 ```
+
+
+existence error is expected as the process was released, but the program shouldn't panic, see [issue 3300](https://github.com/mthom/scryer-prolog/issues/3300)
+```trycmd
+$ scryer-prolog -f --no-add-history -t halt -g 'use_module(library(process)), process_create("false", [], [process(P)]), process_id(P, Pid), write(pid=Pid), nl, process_wait(P, exit(1)), process_id(P, Pid2), write(pid=Pid2), nl'
+? failed
+pid=[..]
+use_module(library(process)),process_create("false",[],[process(P)]),process_id(P,Pid),write(pid=Pid),nl,process_wait(P,exit(1)),process_id(P,Pid2),write(pid=Pid2),nl causes: error(existence_error(process,$dropped_value),[predicate-process_id/2|process_id/2])
+
+thread 'main'[..] panicked at src/machine/loader.rs:[..]:[..]:
+called `Result::unwrap()` on an `Err` value: ()
+note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
+
+```
+
+
+existence error is expected as the process was released, but the program shouldn't panic, see [issue 3300](https://github.com/mthom/scryer-prolog/issues/3300)
+```trycmd
+$ scryer-prolog -f --no-add-history -t halt -g 'use_module(library(process)), process_create("false", [], [process(P)]), process_id(P, Pid), write(pid=Pid), nl, process_wait(P, exit(1), [release(false)]), process_id(P, Pid2), write(pid=Pid2), nl, process_release(P), process_id(P, Pid3), write(pid=Pid3), nl'
+? failed
+pid=[..]
+pid=[..]
+use_module(library(process)),process_create("false",[],[process(P)]),process_id(P,Pid),write(pid=Pid),nl,process_wait(P,exit(1),[release(false)]),process_id(P,Pid2),write(pid=Pid2),nl,process_release(P),process_id(P,Pid3),write(pid=Pid3),nl causes: error(existence_error(process,$dropped_value),[predicate-process_id/2|process_id/2])
+
+thread 'main'[..] panicked at src/machine/loader.rs:[..]:[..]:
+called `Result::unwrap()` on an `Err` value: ()
+note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
+
+```

tests/scryer/cli/windows/process.md

@@ -1,5 +1,6 @@
 ```trycmd
-$ scryer-prolog -f --no-add-history -g 'use_module(library(process)), process_create("cmd", ["/C", "exit", "1"], [process(P)]), process_wait(P, exit(1)), halt'
+$ scryer-prolog -f --no-add-history -g 'use_module(library(process)), process_create("cmd", ["/C", "exit", "1"], [process(P)]), process_id(P, Pid), write(pid=Pid), nl, process_wait(P, exit(1)), halt'
+pid=[..]
 
 ```
 
@@ -7,3 +8,30 @@ $ scryer-prolog -f --no-add-history -g 'use_module(library(process)), process_cr
 $  scryer-prolog -f --no-add-history -g 'use_module(library(process)), use_module(library(format)), process_create("cmd", [], [process(P), stdout(null), stdin(pipe(S))]), format(S, "exit 1~n", []), process_wait(P, exit(1)), halt'
 
 ```
+
+existence error is expected as the process has been released, but the panic is unexpected see [issue 3300](https://github.com/mthom/scryer-prolog/issues/3300)
+```trycmd
+$ scryer-prolog -f --no-add-history -t halt -g 'use_module(library(process)), process_create("cmd", ["/C", "exit", "1"], [process(P)]), process_id(P, Pid), write(pid=Pid), nl, process_wait(P, exit(1)), process_id(P, Pid2), write(pid=Pid2), nl'
+? failed
+pid=[..]
+use_module(library(process)),process_create("cmd",["/C","exit","1"],[process(P)]),process_id(P,Pid),write(pid=Pid),nl,process_wait(P,exit(1)),process_id(P,Pid2),write(pid=Pid2),nl causes: error(existence_error(process,$dropped_value),[predicate-process_id/2|process_id/2])
+
+thread 'main' ([..]) panicked at src/machine/loader.rs:[..]:[..]:
+called `Result::unwrap()` on an `Err` value: ()
+note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
+
+```
+
+existence error is expected as the process has been released, but the panic is unexpected see [issue 3300](https://github.com/mthom/scryer-prolog/issues/3300)
+```trycmd
+$ scryer-prolog -f --no-add-history -t halt -g 'use_module(library(process)), process_create("cmd", ["/C", "exit", "1"], [process(P)]), process_id(P, Pid), write(pid=Pid), nl, process_wait(P, exit(1), [release(false)]), process_id(P, Pid2), write(pid=Pid2), nl, process_release(P), process_id(P, Pid3), write(pid=Pid3), nl'
+? failed
+pid=[..]
+pid=[..]
+use_module(library(process)),process_create("cmd",["/C","exit","1"],[process(P)]),process_id(P,Pid),write(pid=Pid),nl,process_wait(P,exit(1),[release(false)]),process_id(P,Pid2),write(pid=Pid2),nl,process_release(P),process_id(P,Pid3),write(pid=Pid3),nl causes: error(existence_error(process,$dropped_value),[predicate-process_id/2|process_id/2])
+
+thread 'main' ([..]) panicked at src/machine/loader.rs:[..]:[..]:
+called `Result::unwrap()` on an `Err` value: ()
+note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
+
+```