From e1089de23a7e3b316e0c06b4e60c7f6e05d8d5dd Mon Sep 17 00:00:00 2001
From: tv <tv@iiso>
Date: Tue, 20 Sep 2011 02:17:23 +0200
Subject: //hyper/process/spawn: initial commit

---
 hyper/process/spawn | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)
 create mode 100755 hyper/process/spawn

(limited to 'hyper/process/spawn')

diff --git a/hyper/process/spawn b/hyper/process/spawn
new file mode 100755
index 00000000..a0043ec7
--- /dev/null
+++ b/hyper/process/spawn
@@ -0,0 +1,70 @@
+#! /bin/sh
+#
+# spawn [command [argument ...]]
+#
+spawn() {
+  set -euf
+
+  # create and change working directory
+  wd=`mktemp -d`
+  defer rmdir $wd
+  cd $wd
+
+  # create named pipes for the child process's stdio
+  mkfifo 0 1 2
+  defer rm 0 1 2
+
+  # spawn child process
+  (exec 0>&- 1>&- 2>&- 0<>0 1<>1 2<>2 "$@") &
+  pid=$!
+
+  # setup a trap to kill the child process if this (parent) process dies
+  defer kill $pid
+
+  # write child process's pid 
+  echo $pid >pid
+  defer rm pid
+
+  # create dummy directory for easier debugging
+  mkdir -vp /tmp/dummy
+  ln -vsnf $wd/0 $wd/1 $wd/2 $wd/pid /tmp/dummy/
+  defer rm -v /tmp/dummy/0 /tmp/dummy/1 /tmp/dummy/2 /tmp/dummy/pid
+
+  # wait for the child process's 
+  set +e
+  wait $pid
+  code=$?
+  set -e
+
+  # the child is already dead
+  cancel kill $pid
+
+  # return the same way wait did
+  (exit $code)
+}
+
+#
+# defer [command [argument ...]]
+#
+# Defer execution of a command.  Deferred commands are executed in LIFO
+# order immediately before the script terminates.  See (golang's defer
+# statement for more information how this should work).
+#
+defer() {
+  defer="$*${defer+
+$defer}"
+  trap "$defer" EXIT
+}
+
+#
+# cancel [command [argument ...]]
+#
+# Cancel a deferred command.  The arguments have to match exactly a
+# prior defer call or else chaos and mayhem shall haunt thee and shi-
+#
+cancel() {
+  defer="`echo "$defer" | grep -Fxv "$*"`"
+  trap "$defer" EXIT
+}
+
+spawn "$@"
-- 
cgit v1.2.3


From 08a6dc70d957912c864516ad705c7c724f363b73 Mon Sep 17 00:00:00 2001
From: tv <tv@iiso>
Date: Tue, 20 Sep 2011 03:05:14 +0200
Subject: //hyper/process/spawn: defer w/ dash-compat trap

---
 hyper/process/spawn | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

(limited to 'hyper/process/spawn')

diff --git a/hyper/process/spawn b/hyper/process/spawn
index a0043ec7..c2b829ca 100755
--- a/hyper/process/spawn
+++ b/hyper/process/spawn
@@ -53,7 +53,6 @@ spawn() {
 defer() {
   defer="$*${defer+
 $defer}"
-  trap "$defer" EXIT
 }
 
 #
@@ -64,7 +63,8 @@ $defer}"
 #
 cancel() {
   defer="`echo "$defer" | grep -Fxv "$*"`"
-  trap "$defer" EXIT
 }
 
+# setup deferred execution and spawn command
+trap 'eval "${defer-}"; defer=' EXIT INT
 spawn "$@"
-- 
cgit v1.2.3


From b3a318886407c98b3e91df9173c2d9c2cf195de3 Mon Sep 17 00:00:00 2001
From: tv <tv@iiso>
Date: Tue, 20 Sep 2011 15:09:19 +0200
Subject: //hyper spawn: use well known //proc dir

this commit also spawns the command in the current $PWD so
spawn ls & co. are viable commands.

this commit also sets up a trap for TERM, so dash behaves nicely, again.

also we now've got more documentation and debug output [if called with
sh -x].
---
 hyper/process/spawn | 58 +++++++++++++++++++++++++++++++++++++++++------------
 1 file changed, 45 insertions(+), 13 deletions(-)

(limited to 'hyper/process/spawn')

diff --git a/hyper/process/spawn b/hyper/process/spawn
index c2b829ca..95854c7d 100755
--- a/hyper/process/spawn
+++ b/hyper/process/spawn
@@ -1,34 +1,61 @@
 #! /bin/sh
 #
-# spawn [command [argument ...]]
+# [sh -x] spawn [command [argument ...]]
+#
+# export id to create&destroy or reuse the working directory //proc/$id/.
+# this feature is for debug only and marked as deprecated, so don't rely
+# on it too hard.
 #
 spawn() {
   set -euf
 
-  # create and change working directory
-  wd=`mktemp -d`
-  defer rmdir $wd
+  # establish working subdirectory in //proc.  we're mking only
+  # transient dirs, i.e. if we mkdir, then we also defer rmdir.
+  if test -n "${id-}"; then
+    : "using id=$id from env"
+    wd=$pd/$id
+    if ! test -d $wd; then
+      : "make transient $wd/"
+      mkdir $wd
+      defer rmdir $wd
+    elif ! test `ls $wd | wc -l` = 0; then
+      : "$wd/ is not empty!"
+      exit 23
+    else
+      : "reuse existing $wd/"
+    fi
+  else
+    id=`cd $pd && mktemp -d XXXXXXXXXXXXXXXX`
+    wd=$pd/$id
+    defer rmdir $wd
+    : "made transient $wd/"
+  fi
+
+  # change to //proc working directory
+  cwd="$PWD"
   cd $wd
+  #defer cd $cwd # no need for this, b/c at that time we're aldeady dead
 
   # create named pipes for the child process's stdio
   mkfifo 0 1 2
   defer rm 0 1 2
 
   # spawn child process
-  (exec 0>&- 1>&- 2>&- 0<>0 1<>1 2<>2 "$@") &
+  ( : "in $PWD/ spawn ${*-"nothing"}"
+    exec 0>&- 1>&- 2>&- 0<>0 1<>1 2<>2
+    cd "$cwd"
+    exec "$@") &
   pid=$!
 
   # setup a trap to kill the child process if this (parent) process dies
   defer kill $pid
 
-  # write child process's pid 
+  # store misc. info.
+  ln -snf $cwd cwd
+  echo $id >id
+  echo $$ >ppid
   echo $pid >pid
-  defer rm pid
-
-  # create dummy directory for easier debugging
-  mkdir -vp /tmp/dummy
-  ln -vsnf $wd/0 $wd/1 $wd/2 $wd/pid /tmp/dummy/
-  defer rm -v /tmp/dummy/0 /tmp/dummy/1 /tmp/dummy/2 /tmp/dummy/pid
+  defer rm cwd id pid ppid
 
   # wait for the child process's 
   set +e
@@ -65,6 +92,11 @@ cancel() {
   defer="`echo "$defer" | grep -Fxv "$*"`"
 }
 
+# setup //proc directory
+pd=/tmp/krebs/proc
+mkdir -p $pd
+test -w $pd
+
 # setup deferred execution and spawn command
-trap 'eval "${defer-}"; defer=' EXIT INT
+trap 'eval "${defer-}"; defer=' EXIT INT TERM
 spawn "$@"
-- 
cgit v1.2.3


From 549515312ac5442bb7b8984665e7a79aba862a3c Mon Sep 17 00:00:00 2001
From: tv <tv@iiso>
Date: Tue, 20 Sep 2011 15:13:22 +0200
Subject: //hyper spawn: fix spawn-debug-output for dash

---
 hyper/process/spawn | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'hyper/process/spawn')

diff --git a/hyper/process/spawn b/hyper/process/spawn
index 95854c7d..f800a1bb 100755
--- a/hyper/process/spawn
+++ b/hyper/process/spawn
@@ -41,7 +41,7 @@ spawn() {
   defer rm 0 1 2
 
   # spawn child process
-  ( : "in $PWD/ spawn ${*-"nothing"}"
+  ( : "in $PWD/ spawn ${*:-"nothing"}"
     exec 0>&- 1>&- 2>&- 0<>0 1<>1 2<>2
     cd "$cwd"
     exec "$@") &
-- 
cgit v1.2.3


From fa1e71f1376a4983251821c6b74275dd4b726b4e Mon Sep 17 00:00:00 2001
From: tv <tv@iiso>
Date: Tue, 20 Sep 2011 15:33:00 +0200
Subject: //process spawn: rm crufty "s

---
 hyper/process/spawn | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'hyper/process/spawn')

diff --git a/hyper/process/spawn b/hyper/process/spawn
index f800a1bb..01ca2a04 100755
--- a/hyper/process/spawn
+++ b/hyper/process/spawn
@@ -41,7 +41,7 @@ spawn() {
   defer rm 0 1 2
 
   # spawn child process
-  ( : "in $PWD/ spawn ${*:-"nothing"}"
+  ( : "in $PWD/ spawn ${*:-nothing}"
     exec 0>&- 1>&- 2>&- 0<>0 1<>1 2<>2
     cd "$cwd"
     exec "$@") &
-- 
cgit v1.2.3


From 8e30185619d6cdc8ec2cd5dd0f341ffabef2d563 Mon Sep 17 00:00:00 2001
From: tv <tv@iiso>
Date: Tue, 20 Sep 2011 15:37:26 +0200
Subject: //hyper spawn: defer cd, so Solaris's sh can rmdir

---
 hyper/process/spawn | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'hyper/process/spawn')

diff --git a/hyper/process/spawn b/hyper/process/spawn
index 01ca2a04..cf93eb6b 100755
--- a/hyper/process/spawn
+++ b/hyper/process/spawn
@@ -34,7 +34,7 @@ spawn() {
   # change to //proc working directory
   cwd="$PWD"
   cd $wd
-  #defer cd $cwd # no need for this, b/c at that time we're aldeady dead
+  defer cd $cwd
 
   # create named pipes for the child process's stdio
   mkfifo 0 1 2
-- 
cgit v1.2.3


From fcbb481cbd888d6ab66b09e649c754a012198e53 Mon Sep 17 00:00:00 2001
From: tv <tv@iiso>
Date: Tue, 20 Sep 2011 15:45:30 +0200
Subject: //hyper spawn: set +x before rediring popes

---
 hyper/process/spawn | 1 +
 1 file changed, 1 insertion(+)

(limited to 'hyper/process/spawn')

diff --git a/hyper/process/spawn b/hyper/process/spawn
index cf93eb6b..65e94d86 100755
--- a/hyper/process/spawn
+++ b/hyper/process/spawn
@@ -42,6 +42,7 @@ spawn() {
 
   # spawn child process
   ( : "in $PWD/ spawn ${*:-nothing}"
+    set +x # disable debug output so we don't clobber 2
     exec 0>&- 1>&- 2>&- 0<>0 1<>1 2<>2
     cd "$cwd"
     exec "$@") &
-- 
cgit v1.2.3