[freenet-dev] [freenet-cvs] r14897 - in trunk/freenet/src/freenet: client/async support

[David Sowder]

Based on my current limited understanding of NPTL, it does require NPTL 
to be turned off because otherwise, all PIDs will be the same.  If 
sub-threads with NPTL have their on PIDs, then my usual incantation for 
ps doesn't reveal them, so I wouldn't have something to look for the 
thread for.  I believe this code will likely return the same value for 
every thread if used with NPTL turned on.

Matthew Toseland wrote:
> Does this require NPTL to be turned off? Do sub-threads have their own PIDs 
> with NPTL?
>
> On Tuesday 28 August 2007 01:50, you wrote:
>   
>> Author: zothar
>> Date: 2007-08-28 00:50:36 +0000 (Tue, 28 Aug 2007)
>> New Revision: 14897
>>
>> Added:
>>    trunk/freenet/src/freenet/support/OSThread.java
>> Modified:
>>    trunk/freenet/src/freenet/client/async/BackgroundBlockEncoder.java
>> Log:
>> Potential debugging tool: provide getPID() and logPID() to get or log the 
>>     
> thread's PID on Linux with /proc/self/stat available to the JVM (support 
> could later be expanded with JNI or other methods).  These tools are 
> currently configured with static variables, are currently only configurable 
> at compile time and are currently off.
>   
>> Modified: trunk/freenet/src/freenet/client/async/BackgroundBlockEncoder.java
>> ===================================================================
>> --- trunk/freenet/src/freenet/client/async/BackgroundBlockEncoder.java	
>>     
> 2007-08-28 00:47:06 UTC (rev 14896)
>   
>> +++ trunk/freenet/src/freenet/client/async/BackgroundBlockEncoder.java	
>>     
> 2007-08-28 00:50:36 UTC (rev 14897)
>   
>> @@ -45,6 +45,7 @@
>>  	}
>>  	
>>  	public void run() {
>> +	    freenet.support.OSThread.logPID(this);
>>  		while(true) {
>>  			SingleBlockInserter sbi = null;
>>  			synchronized(this) {
>>
>> Added: trunk/freenet/src/freenet/support/OSThread.java
>> ===================================================================
>> --- trunk/freenet/src/freenet/support/OSThread.java	                        
>>     
> (rev 0)
>   
>> +++ trunk/freenet/src/freenet/support/OSThread.java	2007-08-28 00:50:36 UTC 
>>     
> (rev 14897)
>   
>> @@ -0,0 +1,208 @@
>> +/* This code is part of Freenet. It is distributed under the GNU General
>> + * Public License, version 2 (or at your option any later version). See
>> + * http://www.gnu.org/ for further details of the GPL. */
>> +package freenet.support;
>> +
>> +import java.io.File;
>> +import java.io.FileInputStream;
>> +import java.io.FileNotFoundException;
>> +import java.io.IOException;
>> +import java.util.regex.PatternSyntaxException;
>> +
>> +import freenet.support.Logger;
>> +
>> +/**
>> + * Get OS/Thread information using one or more methods
>> + */
>> +public class OSThread {
>> +
>> +    public static boolean getPIDEnabled = false;
>> +    public static boolean getPPIDEnabled = false;
>> +    public static boolean procSelfStatEnabled = false;
>> +
>> +    /**
>> +     * Get the thread's process ID or return -1 if it's unavailable for 
>>     
> some reason
>   
>> +     */
>> +	public synchronized static int getPID(Object o) {
>> +		if(!getPIDEnabled) {
>> +			return -1;
>> +		}
>> +		return getPIDFromProcSelfStat(o);
>> +	}
>> +
>> +    /**
>> +     * Get the thread's parent process ID or return -1 if it's unavailable 
>>     
> for some reason
>   
>> +     */
>> +	public synchronized static int getPPID(Object o) {
>> +		if(!getPPIDEnabled) {
>> +			return -1;
>> +		}
>> +		return getPPIDFromProcSelfStat(o);
>> +	}
>> +
>> +    /**
>> +     * Get the thread's process ID using the /proc/self/stat method or
>> +	 * return -1 if it's unavailable for some reason.  This is an ugly
>> +	 * hack required by Java to get the OS process ID of a thread on
>> +	 * Linux without using JNI.
>> +     */
>> +	public synchronized static int getPIDFromProcSelfStat(Object o) {
>> +		StringBuffer sb = null;
>> +		int b = -1;
>> +		int pid = -1;
>> +		String msg = null;
>> +
>> +		if(!getPIDEnabled) {
>> +			return -1;
>> +		}
>> +		if(!procSelfStatEnabled) {
>> +			return -1;
>> +		}
>> +
>> +		// read /proc/self/stat and parse for the PID
>> +		FileInputStream fis = null;
>> +		File procFile = new File("/proc/self/stat");
>> +		if(procFile.exists()) {
>> +			try {
>> +				fis = new FileInputStream(procFile);
>> +			} catch (FileNotFoundException e1) {
>> +				Logger.normal(o, "'/proc/self/stat' not found");
>> +				fis = null;
>> +			}
>> +			if(null != fis) {
>> +				sb = new StringBuffer();
>> +				while( true ) {
>> +					try {
>> +						b = fis.read();
>> +					} catch (IOException e) {
>> +						Logger.error(o, "Caught IOException in fis.read() of 
>>     
> OSThread.getPIDFromProcSelfStat()", e);
>   
>> +						b = -1;
>> +					}
>> +					if( -1 == b ) {
>> +						break;
>> +					}
>> +					sb.append( (char) b );
>> +				}
>> +				try {
>> +				    msg = "DEBUG: Gonna parse ["+sb.toString()+"]";
>> +					System.out.println(msg + ": " + o);
>> +			        Logger.normal(o, msg);
>> +					String[] procStrings = sb.toString().trim().split(" ");
>> +					if(4 <= procStrings.length) {
>> +						String pidString = procStrings[ 0 ];
>> +						try {
>> +							pid = Integer.parseInt( pidString.trim() );
>> +						} catch (NumberFormatException e) {
>> +							Logger.error(o, "Caught NumberFormatException in Integer.parseInt() 
>>     
> of OSThread.getPIDFromProcSelfStat() while parsing '"+pidString+"'", e);
>   
>> +						}
>> +					}
>> +				} catch (PatternSyntaxException e) {
>> +					Logger.error(o, "Caught PatternSyntaxException in 
>>     
> sb.toString().trim().split(\" \") of OSThread.getPIDFromProcSelfStat() while 
> parsing '"+sb.toString()+"'", e);
>   
>> +				}
>> +			}
>> +		}
>> +		return pid;
>> +	}
>> +
>> +    /**
>> +     * Get the thread's parent process ID using the /proc/self/stat
>> +	 * method or return -1 if it's unavailable for some reason.  This
>> +	 * is ugly hack required by Java to get the OS parent process ID of
>> +	 * a thread on Linux without using JNI.
>> +     */
>> +	public synchronized static int getPPIDFromProcSelfStat(Object o) {
>> +		StringBuffer sb = null;
>> +		int b = -1;
>> +		int ppid = -1;
>> +		String msg = null;
>> +
>> +		if(!getPPIDEnabled) {
>> +			return -1;
>> +		}
>> +		if(!procSelfStatEnabled) {
>> +			return -1;
>> +		}
>> +
>> +		// read /proc/self/stat and parse for the PPID
>> +		FileInputStream fis = null;
>> +		File procFile = new File("/proc/self/stat");
>> +		if(procFile.exists()) {
>> +			try {
>> +				fis = new FileInputStream(procFile);
>> +			} catch (FileNotFoundException e1) {
>> +				Logger.normal(o, "'/proc/self/stat' not found");
>> +				fis = null;
>> +			}
>> +			if(null != fis) {
>> +				sb = new StringBuffer();
>> +				while( true ) {
>> +					try {
>> +						b = fis.read();
>> +					} catch (IOException e) {
>> +						Logger.error(o, "Caught IOException in fis.read() of 
>>     
> OSThread.getPPIDFromProcSelfStat()", e);
>   
>> +						b = -1;
>> +					}
>> +					if( -1 == b ) {
>> +						break;
>> +					}
>> +					sb.append( (char) b );
>> +				}
>> +				try {
>> +				    msg = "DEBUG: Gonna parse ["+sb.toString()+"]";
>> +					System.out.println(msg + ": " + o);
>> +			        Logger.normal(o, msg);
>> +					String[] procStrings = sb.toString().trim().split(" ");
>> +					if(4 <= procStrings.length) {
>> +						String ppidString = procStrings[ 3 ];
>> +						try {
>> +							ppid = Integer.parseInt( ppidString.trim() );
>> +						} catch (NumberFormatException e) {
>> +							Logger.error(o, "Caught NumberFormatException in Integer.parseInt() 
>>     
> of OSThread.getPPIDFromProcSelfStat() while parsing '"+ppidString+"'", e);
>   
>> +						}
>> +					}
>> +				} catch (PatternSyntaxException e) {
>> +					Logger.error(o, "Caught PatternSyntaxException in 
>>     
> sb.toString().trim().split(\" \") of OSThread.getPPIDFromProcSelfStat() while 
> parsing '"+sb.toString()+"'", e);
>   
>> +				}
>> +			}
>> +		}
>> +		return ppid;
>> +	}
>> +
>> +    /**
>> +     * Log the thread's process ID or return -1 if it's unavailable for 
>>     
> some reason
>   
>> +     */
>> +	public synchronized static int logPID(Object o) {
>> +		if(!getPIDEnabled) {
>> +			return -1;
>> +		}
>> +		int pid = getPID(o);
>> +		String msg;
>> +		if(-1 != pid) {
>> +			msg = "This thread's OS PID is " + pid;
>> +		} else {
>> +			msg = "This thread's OS PID could not be determined";
>> +		}
>> +		System.out.println(msg + ": " + o);
>> +        Logger.normal(o, msg);
>> +        return pid;
>> +	}
>> +
>> +    /**
>> +     * Log the thread's process ID or return -1 if it's unavailable for 
>>     
> some reason
>   
>> +     */
>> +	public synchronized static int logPPID(Object o) {
>> +		if(!getPPIDEnabled) {
>> +			return -1;
>> +		}
>> +		int ppid = getPPID(o);
>> +		String msg;
>> +		if(-1 != ppid) {
>> +			msg = "This thread's OS PPID is " + ppid;
>> +		} else {
>> +			msg = "This thread's OS PPID could not be determined";
>> +		}
>> +		System.out.println(msg + ": "+o);
>> +        Logger.normal(o, msg);
>> +        return ppid;
>> +	}
>> +}
>>