parallel: implemented -j file. Passes testsuite.

doc/FUTURE_IDEAS

@@ -1,13 +1,7 @@
-== Change number of jobs while running ==
-
-Read -j from file. If the file is changed when a job completes the
-file is re-read and the new number of jobs computed. If the number is
-lower than before currently running jobs will be allowed to finish but
-new jobs will not be started.
-
 == Bug ==
 
 (echo ; echo abc ; echo abc; echo ; echo bbc) | parallel --colsep b -v echo {1}{2}
+(echo ; echo abc ; echo abc; echo ; echo bbc) | parallel --colsep d -v echo {1}{2}
 
 == SQL ==
 

src/parallel

@@ -413,6 +413,24 @@ If the evaluated number is less than 1 then 1 will be used.  See also
 B<--use-cpus-instead-of-cores>.
 
 
+=item B<--jobs> I<procfile> (beta test)
+
+=item B<-j> I<procfile> (beta test)
+
+=item B<--max-procs> I<procfile> (beta test)
+
+=item B<-P> I<procfile> (beta test)
+
+Read parameter from file. Use the content of I<procfile> as parameter
+for I<-j>. E.g. I<procfile> could contain the string 100% or +2 or
+10. If I<procfile> is changed when a job completes, I<procfile> is
+read again and the new number of jobs is computed. If the number is
+lower than before, running jobs will be allowed to finish but new jobs
+will not be started until the wanted number of jobs has been reached.
+This makes it possible to change the number of simultaneous running
+jobs while GNU B<parallel> is running.
+
+
 =item B<--keeporder>
 
 =item B<-k>
@@ -1590,21 +1608,6 @@ functionality without sacrifying ease of use.
 
 The following features are in some of the comparable tools:
 
-Execution
- E1. Running jobs in parallel
- E2. List running jobs
- E3. Finish running jobs, but do not start new jobs
- E4. Number of running jobs can depend on number of cpus
- E5. Finish running jobs, but do not start new jobs after first failure
-
-Outputs
- O1. Grouping output so output from different jobs do not mix
- O2. Send stderr to stderr
- O3. Send stdout to stdout
- O4. Order of output can be same as order of input
- O5. Stdout only contains stdout from the command
- O6. Stderr only contains stdout from the command
-
 Inputs
  I1. Arguments can be read from stdin
  I2. Arguments can be read from a file
@@ -1622,6 +1625,22 @@ Manipulation of input
  M5. Arguments can be replaced with context
  M6. Input can be treated as complete execution line
 
+Outputs
+ O1. Grouping output so output from different jobs do not mix
+ O2. Send stderr to stderr
+ O3. Send stdout to stdout
+ O4. Order of output can be same as order of input
+ O5. Stdout only contains stdout from the command
+ O6. Stderr only contains stdout from the command
+
+Execution
+ E1. Running jobs in parallel
+ E2. List running jobs
+ E3. Finish running jobs, but do not start new jobs
+ E4. Number of running jobs can depend on number of cpus
+ E5. Finish running jobs, but do not start new jobs after first failure
+ E6. Number of running jobs can be adjusted while running
+
 Remote execution
  R1. Jobs can be run on remote computers
  R2. Basefiles can be transferred
@@ -1646,23 +1665,53 @@ As every new version of the programs are not tested the table may be
 outdated. Please file a bug-report if you find errors (See REPORTING
 BUGS).
 
-parallel: E1 E2 E3 E4 E5 O1 O2 O3 O4 O5 O6 I1 I2 I3 I4 I5 I6 I7 M1 M2
+parallel:
-M3 M4 M5 M6 R1 R2 R3 R4 R5 R6 R7 R8 R9 S1 S2
+I1 I2 I3 I4 I5 I6 I7
+M1 M2 M3 M4 M5 M6
+O1 O2 O3 O4 O5 O6
+E1 E2 E3 E4 E5 E6
+R1 R2 R3 R4 R5 R6 R7 R8 R9
+S1 S2
 
-xargs:    E1  -  -  -  -  - O2 O3  - O5 O6 I1 I2  -  -  -  -  - - M2 M3  -
+xargs:
- -  -  -  -  -  -  -  x  -  -  - -
+I1 I2 -  -  -  -  -
+-  M2 M3 -  -  -
+-  O2 O3 -  O5 O6
+E1 -  -  -  -  -
+-  -  -  -  -  x  -  -  -
+-  -
 
-find -exec: - -  -  x  -  x O2 O3 O4 O5 O6  -  -  -  -  -  -  - - M2 M3  -
+find -exec:
- -  -  -  -  -  -  -  -  -  - x  x
+-  -  -  x  -  x  -
+-  M2 M3 -  -  -  -
+-  O2 O3 O4 O5 O6
+-  -  -  -  -  -  -
+-  -  -  -  -  -  -  -  -
+x  x
 
-make -j: E1 - - - E5 O1 O2 O3 - x O6 - - - - - - - - - - - - - - - - - -
+make -j:
-- - - -
+-  -  -  -  -  -  -
+-  -  -  -  -  -
+O1 O2 O3 -  x  O6
+E1 -  -  -  E5 -
+-  -  -  -  -  -  -  -  -
+-  -
 
-ppss: E1 E2 ?E3 E4 - O1 - - x - - I1 I2 - - - - I7 M1 - M3 - - M6 R1 R2
+ppss:
- R3 R4 - - ?R7 ? ? - -
+I1 I2 -  -  -  -  I7
+M1 -  M3 -  -  M6
+O1 -  -  x  -  -
+E1 E2 ?E3 E4 - -
+R1 R2 R3 R4 -  -  ?R7 ? ?
+- -
 
-pexec: E1 - - E4 - O1 O2 O3 - O5 O6 I1 I2 - I4 I5 - - M1 - M3 - - M6 R1
+pexec:
- - - - - R6 - - - S1 -
+I1 I2 -  I4 I5 -  -
+M1 -  M3 -  -  M6
+O1 O2 O3 -  O5 O6
+E1 -  -  E4 -  E6
+R1 -  -  -  -  R6 -  -  -
+S1 -
 
 xjobs: TODO - Please file a bug-report if you know what features xjobs
 supports (See REPORTING BUGS).
@@ -2590,10 +2639,7 @@ sub parse_options {
     # Needs to be done after setting $Global::command and $Global::command_line_max_len
     # as '-m' influences the number of commands that needs to be run
     if(defined $::opt_P) {
-	for my $sshlogin (keys %Global::host) {
+	compute_number_of_processes_for_sshlogins();
-	    $Global::host{$sshlogin}{'max_no_of_running'} =
-		compute_number_of_processes($::opt_P,$sshlogin);
-	}
     } else {
 	for my $sshlogin (keys %Global::host) {
 	    $Global::host{$sshlogin}{'max_no_of_running'} =
@@ -3102,6 +3148,13 @@ sub is_acceptable_command_line_length {
 
 # Number of parallel processes to run
 
+sub compute_number_of_processes_for_sshlogins {
+    for my $sshlogin (keys %Global::host) {
+	$Global::host{$sshlogin}{'max_no_of_running'} =
+	    compute_number_of_processes($::opt_P,$sshlogin);
+    }
+}
+
 sub compute_number_of_processes {
     # Number of processes wanted and limited by system ressources
     # Returns:
@@ -3203,7 +3256,7 @@ sub processes_available_by_system_limit {
     for (values %fh) { close $_ }
     # Cleanup: Kill the children
     for my $pid (@children) {
-	kill 15, $pid;
+	kill 9, $pid;
 	waitpid($pid,0);
     }
     wait();
@@ -3311,7 +3364,19 @@ sub user_requested_processes {
 		# -P 0 = infinity (or at least close)
 		$processes = 2**31;
 	    }
+	} elsif (-f $opt_P) {
+	    $Global::max_procs_file = $opt_P;
+	    $Global::max_procs_file_last_mod = (stat($Global::max_procs_file))[9];
+	    if(open(IN, $Global::max_procs_file)) {
+		my $opt_P_file = join("",<IN>);
+		close IN;
+		$processes = user_requested_processes($opt_P_file);
+	    } else {
+		print STDERR "Cannot open $opt_P\n";
+		exit(255);
+	    }
 	} else {
+	    print STDERR "Parsing of --jobs/-j/--max-procs/-P failed\n";
 	    die_usage();
 	}
 	if($processes < 1) {
@@ -3809,6 +3874,13 @@ sub start_more_jobs {
     #   number of jobs started
     my $jobs_started = 0;
     if(not $Global::start_no_new_jobs) {
+	if($Global::max_procs_file) {
+	    my $mtime = (stat($Global::max_procs_file))[9];
+	    if($mtime > $Global::max_procs_file_last_mod) {
+		$Global::max_procs_file_last_mod = $mtime;
+		compute_number_of_processes_for_sshlogins();
+	    }
+	}
 	for my $sshlogin (keys %Global::host) {
 	    debug("Running jobs on $sshlogin: $Global::host{$sshlogin}{'no_of_running'}\n");
 	    while ($Global::host{$sshlogin}{'no_of_running'} <
@@ -3998,6 +4070,7 @@ sub print_job {
     close $out;
     close $err;
 }
+
 sub __READING_AND_QUOTING_ARGUMENTS__ {}
 
 sub get_command_line_with_sshlogin {
@@ -4218,6 +4291,7 @@ sub unget_arg {
 }
 
 sub __REMOTE_SSH__ {}
+
 sub read_sshloginfile {
     # Returns: N/A
     my $file = shift;

unittest/tests-to-run/test33.sh

@@ -0,0 +1,13 @@
+#!/bin/bash
+
+echo '### Test of -j filename'
+stdout parallel -j no_such_file echo ::: 1
+
+echo '### Test of -j filename'
+echo 3 >/tmp/jobs_to_run
+parallel -j /tmp/jobs_to_run -v sleep 0.{} ::: 9 8 7 6 5
+# Should give 7 8 9 5 6
+
+echo '### Test of -j filename with file content changing'
+(echo 1 >/tmp/jobs_to_run; sleep 3; echo 10 >/tmp/jobs_to_run) &
+parallel  -j /tmp/jobs_to_run -v sleep {} ::: 3.3 1.1 1.3 1.4 1.2 1 1 1 1 1 1 1 1 1 1 1

unittest/wanted-results/test33

@@ -0,0 +1,31 @@
+### Test of -j filename
+Parsing of --jobs/-j/--max-procs/-P failed
+Usage:
+parallel [options] [command [arguments]] < list_of_arguments)
+parallel [options] [command [arguments]] ::: arguments
+parallel [options] [command [arguments]] :::: argfile(s)
+
+See 'man parallel' for the options
+### Test of -j filename
+sleep 0.7
+sleep 0.8
+sleep 0.9
+sleep 0.5
+sleep 0.6
+### Test of -j filename with file content changing
+sleep 3.3
+sleep 1
+sleep 1
+sleep 1
+sleep 1
+sleep 1
+sleep 1
+sleep 1.1
+sleep 1.2
+sleep 1.3
+sleep 1.4
+sleep 1
+sleep 1
+sleep 1
+sleep 1
+sleep 1