niceload: minimal --sensor support.

src/niceload

@@ -59,6 +59,8 @@ if(not defined $::opt_run_mem) { $::opt_run_mem = $::opt_mem; }
 if(not defined $::opt_start_noswap) { $::opt_start_noswap = $::opt_noswap; }
 if(not defined $::opt_run_noswap) { $::opt_run_noswap = $::opt_noswap; }
 
+if(defined $::opt_load) { multiply_binary_prefix($::opt_load); }
+
 my $limit = Limit->new();
 my $process = Process->new($::opt_nice,@ARGV);
 if($::opt_pid) {
@@ -89,6 +91,37 @@ while($process->is_alive()) {
 
 exit($::exitstatus);
 
+sub multiply_binary_prefix {
+    # Evalualte numbers with binary prefix
+    # k=10^3, m=10^6, g=10^9, t=10^12, p=10^15, e=10^18, z=10^21, y=10^24
+    # K=2^10, M=2^20, G=2^30, T=2^40, P=2^50, E=2^70, Z=2^80, Y=2^80
+    # Ki=2^10, Mi=2^20, Gi=2^30, Ti=2^40, Pi=2^50, Ei=2^70, Zi=2^80, Yi=2^80
+    # ki=2^10, mi=2^20, gi=2^30, ti=2^40, pi=2^50, ei=2^70, zi=2^80, yi=2^80
+    # 13G = 13*1024*1024*1024 = 13958643712
+    my $s = shift;
+    $s =~ s/k/*1000/g;
+    $s =~ s/M/*1000*1000/g;
+    $s =~ s/G/*1000*1000*1000/g;
+    $s =~ s/T/*1000*1000*1000*1000/g;
+    $s =~ s/P/*1000*1000*1000*1000*1000/g;
+    $s =~ s/E/*1000*1000*1000*1000*1000*1000/g;
+    $s =~ s/Z/*1000*1000*1000*1000*1000*1000*1000/g;
+    $s =~ s/Y/*1000*1000*1000*1000*1000*1000*1000*1000/g;
+    $s =~ s/X/*1000*1000*1000*1000*1000*1000*1000*1000*1000/g;
+
+    $s =~ s/Ki?/*1024/gi;
+    $s =~ s/Mi?/*1024*1024/gi;
+    $s =~ s/Gi?/*1024*1024*1024/gi;
+    $s =~ s/Ti?/*1024*1024*1024*1024/gi;
+    $s =~ s/Pi?/*1024*1024*1024*1024*1024/gi;
+    $s =~ s/Ei?/*1024*1024*1024*1024*1024*1024/gi;
+    $s =~ s/Zi?/*1024*1024*1024*1024*1024*1024*1024/gi;
+    $s =~ s/Yi?/*1024*1024*1024*1024*1024*1024*1024*1024/gi;
+    $s =~ s/Xi?/*1024*1024*1024*1024*1024*1024*1024*1024*1024/gi;
+    $s = eval $s;
+    return $s;
+}
+
 sub get_options_from_array {
     # Run GetOptions on @array
     # Returns:
@@ -109,6 +142,7 @@ sub get_options_from_array {
 	 "factor|f=s" => \$::opt_factor,
 	 "hard|H" => \$::opt_hard,
 	 "soft|S" => \$::opt_soft,
+	 "sensor=s" => \$::opt_sensor,
 
 	 "si|sio|startio|start-io=s" => \$::opt_start_io,
 	 "ri|rio|runio|run-io=s" => \$::opt_run_io,
@@ -541,17 +575,82 @@ sub sleep_while_running {
 }
 
 
+# An non-blocking filehandle read that returns an array of lines read
+# Returns:  ($eof,@lines)
+my %nonblockGetLines_last;
+sub nonblockGetLines {
+    my ($fh,$timeout) = @_;
+
+    $timeout = 0 unless defined $timeout;
+    my $rfd = '';
+    $nonblockGetLines_last{$fh} = ''
+        unless defined $nonblockGetLines_last{$fh};
+
+    vec($rfd,fileno($fh),1) = 1;
+    return unless select($rfd, undef, undef, $timeout)>=0;
+    # I'm not sure the following is necessary?
+    return unless vec($rfd,fileno($fh),1);
+    my $buf = '';
+    my $n = sysread($fh,$buf,1024*1024);
+    my $eof = eof($fh);
+    # If we're done, make sure to send the last unfinished line
+    return ($eof,$nonblockGetLines_last{$fh}) unless $n;
+    # Prepend the last unfinished line
+    $buf = $nonblockGetLines_last{$fh}.$buf;
+    # And save any newly unfinished lines
+    $nonblockGetLines_last{$fh} =
+        (substr($buf,-1) !~ /[\r\n]/ && $buf =~ s/([^\r\n]*)$//)
+	? $1 : '';
+    $buf ? ($eof,split(/\n/,$buf)) : ($eof);
+}
+
+sub read_sensor {
+    my $self = shift;
+    my $fh = $self->{'sensor_fh'};
+    if(not $fh) {
+	# Start the sensor
+	open($fh, "-|", $::opt_sensor) || ::die_bug("Cannot open: $::opt_sensor");
+	$self->{'sensor_fh'} = $fh;
+    }
+    # Read as much as we can (non_block)
+    my ($eof,@lines) = nonblockGetLines($fh);
+    
+    # new load = last full line
+    foreach my $line ( @lines ) {
+	if(defined $line) {
+	    print "Pipe saw: $eof [$line]\n";
+	    $Global::last_sensor_reading = $line;
+	}
+    }
+    if($eof) { undef($self->{'sensor_fh'}); }
+
+    return $Global::last_sensor_reading;
+}
+
 sub load_status {
     # Returns:
-    #   loadavg
+    #   loadavg or sensor measurement
     my $self = shift;
+    if($::opt_sensor) {
+	if(not defined $self->{'load_status'} or
+	   $self->{'load_status_cache_time'} + $self->{'recheck'} < time) {
+	    $self->{'load_status'} = $self->read_sensor();
+	    while (not defined $self->{'load_status'}) {
+		sleep 1;
+		$self->{'load_status'} = $self->read_sensor();
+	    } 
+	    $self->{'load_status_cache_time'} = time;
+	}
+    } else {
+	# Normal load avg
 	# Cache for some seconds
 	if(not defined $self->{'load_status'} or
-       $self->{'load_status_cache_time'}+$self->{'recheck'} < time) {
+	   $self->{'load_status_cache_time'} + $self->{'recheck'} < time) {
 	    $self->{'load_status'} = load_status_linux();
 	    $self->{'load_status_cache_time'} = time;
 	}
-    ::debug("load_status: $self->{'load_status'}\n");
+    }
+    ::debug("load_status: ".$self->{'load_status'}."\n");
     return $self->{'load_status'};
 }
 

src/niceload.pod

@@ -7,7 +7,8 @@ niceload - slow down a program when the load average is above a certain limit
 =head1 SYNOPSIS
 
 B<niceload> [-v] [-h] [-n nice] [-I io] [-L load] [-M mem] [-N]
-[-t time] [-s time|-f factor] ( command | -p PID )
+[--sensor program] [-t time] [-s time|-f factor] ( command | -p PID )
+
 
 =head1 DESCRIPTION
 
@@ -131,6 +132,19 @@ Run limit. The running program will be slowed down if the system is
 above the limit. See: B<--io>, B<--load>, B<--mem>, B<--noswap>.
 
 
+=item B<--sensor> I<sensor program> (alpha testing)
+
+Read sensor. Use I<sensor program> to read a sensor.
+
+This will keep the CPU temperature below 80 deg C on GNU/Linux:
+
+  niceload -l 80000 -f 0.001 --sensor 'sort -n /sys/devices/platform/coretemp*/temp*_input' gzip *
+
+This will stop if the disk space < 100000.
+
+  niceload -H -l -100000 --sensor "df . | awk '{ print \$4 }'" echo
+
+
 =item B<--start-io> I<iolimit>
 
 =item B<--si> I<iolimit>