From 07c1d0d975fbecf295a3c9f04f7b09e7a8b6ff99 Mon Sep 17 00:00:00 2001 From: Sverker Eriksson Date: Wed, 23 Sep 2015 20:09:49 +0200 Subject: erts: Review module erlang docs --- erts/doc/src/erlang.xml | 455 +++++++++++++++++++++++------------------------- 1 file changed, 222 insertions(+), 233 deletions(-) (limited to 'erts/doc') diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml index 8b20a5c12f..a51774b9f0 100644 --- a/erts/doc/src/erlang.xml +++ b/erts/doc/src/erlang.xml @@ -251,10 +251,7 @@

Example:

 > apply(lists, reverse, [[a, b, c]]).
-[c,b,a]
-

apply evaluates BIFs by using - the module name erlang.

- 
+[c,b,a]
 > apply(erlang, atom_to_list, ['Erlang']).
 "Erlang"

If the number of arguments are known at compile time, @@ -282,16 +279,16 @@ in the text representation. If Encoding is utf8 or unicode, the characters are encoded using UTF-8 - (that is, characters from 16#80 through 0xFF are + (that is, characters from 128 through 255 are encoded in two bytes).

atom_to_binary(Atom, latin1) never fails because the text representation of an atom can only - contain characters from 0 through 16#FF. In a future release, + contain characters from 0 through 255. In a future release, the text representation of atoms can be allowed to contain any Unicode character and atom_to_binary(Atom, latin1) will then fail if the text representation for Atom contains a Unicode - character greater than 16#FF.

 + character greater than 255.

Example:

 > atom_to_binary('Erlang', latin1).
@@ -358,9 +355,9 @@
         If Encoding
         is utf8 or unicode, the binary must contain
         valid UTF-8 sequences. Only Unicode characters up
-        to 0xFF are allowed.

+        to 255 are allowed.

         
binary_to_atom(Binary, utf8) fails if
-        the binary contains Unicode characters greater than 16#FF.
+        the binary contains Unicode characters greater than 255.
         In a future release, such Unicode characters can be allowed
         and binary_to_atom(Binary, utf8) does then not fail.
         For more information on Unicode support in atoms, see the
@@ -450,11 +447,11 @@
           position Stop in Binary.
 	  The positions in the
           binary are numbered starting from 1.

-          
The indexing style of using one-based indices for
-          binaries is deprecated for this function. New code is to
-          use the functions in module binary in STDLIB
-          instead. They therefore
-          use the same (zero-based) style of indexing.

+          
The one-based indexing for binaries used by
+	  this function is deprecated. New code is to use
+          binary:bin_to_list/3
+	  in STDLIB instead. All functions in module
+	  binary consistently use zero-based indexing.

       
     
 
@@ -698,7 +695,7 @@
       
         
Checks if the node local process identified by Pid
         executes old code for Module.

-        
The available Options are as follows:

+        
The available Options are as follows:

         
           {allow_gc, boolean()}
           
@@ -770,7 +767,7 @@
 
     
       
-      Convert time unit of a time value
+      Converts time unit of a time value.
       
 	
Converts the Time value of time unit
 	FromUnit to the corresponding
@@ -878,7 +875,7 @@
           
           line
           
-            
A packet is a line-terminated with newline. The
+            
A packet is a line terminated with newline. The
               newline character is included in the returned packet
               unless the line was truncated according to option
               line_length.
 
@@ -1809,7 +1806,7 @@ os_prompt%
Hash function (deprecated).

Returns a hash value for Term within the range - 1..Range. The range is 1..2^27-1.

+ 1..Range. The maximum range is 1..2^27-1.

This BIF is deprecated, as the hash value can differ on different architectures. The hash values for integer @@ -2034,7 +2031,7 @@ os_prompt%

This BIF is useful for builders of cross-reference tools.

Returns true if Module:Function/Arity - ia a BIF implemented in C, otherwise false.

+ is a BIF implemented in C, otherwise false.

 @@ -2366,8 +2363,8 @@ os_prompt%

Failure: badarg if String contains a bad representation of a process identifier.

-

This BIF is intended for debugging and for use in the - Erlang OS. It is not to be used in application programs.

+

This BIF is intended for debugging and is not to be used + in application programs.

 @@ -3161,9 +3158,9 @@ os_prompt% - At which node a pid, port, or reference is located. + At which node a pid, port, or reference originates. -

Returns the node where Arg is located. +

Returns the node where Arg originates. Arg can be a process identifier, a reference, or a port. If the local node is not @@ -3208,17 +3205,19 @@ os_prompt% known -

Nodes that are known to this node, for example, connected - and previously connected.

+

Nodes that are known to this node. That is, connected + nodes and nodes referred to by process identifiers, port + identifiers and references located on this node. + The set of known nodes is garbage collected. Notice that + this garbage collection can be delayed. For more + information, see + delayed_node_table_gc. +

Some equalities: [node()] = nodes(this), nodes(connected) = nodes([visible, hidden]), and nodes() = nodes(visible).

-

If the local node is not alive, - nodes(this) == nodes(known) == [nonode@nohost]. For - any other Arg the empty list - [] is returned.

 @@ -3260,7 +3259,7 @@ os_prompt% given in cd, env, args, and arg0 are subject to Unicode filename translation if the system is running in Unicode filename mode. To avoid - translation or force, that is, UTF-8, supply the executable + translation or to force, for example UTF-8, supply the executable and/or arguments as a binary in the correct encoding. For details, see the module file, the function @@ -3585,9 +3584,10 @@ os_prompt%

Portable hash function that gives the same hash for the same Erlang term regardless of machine architecture and ERTS version (the BIF was introduced in ERTS 4.9.1.1). - Range is 1..2^32. The function returns a hash value for + The function returns a hash value for Term within the range - 1..Range.

+ 1..Range. The maximum value for + Range is 2^32.

This BIF can be used instead of the old deprecated BIF erlang:hash/2, as it calculates better hashes for all data types, but consider using phash2/1,2 instead.

@@ -3604,9 +3604,10 @@ os_prompt%

Portable hash function that gives the same hash for the same Erlang term regardless of machine architecture and ERTS version (the BIF was introduced in ERTS 5.2). - Range is 1..2^32. The function returns a hash value for - Term within the range - 0..Range-1. When without argument + The function returns a hash value for + Term within the range + 0..Range-1. The maximum value for + Range is 2^32. When without argument Range, a value in the range 0..2^27-1 is returned.

This BIF is always to be used for hashing terms. It @@ -3625,8 +3626,8 @@ os_prompt%

Returns a string corresponding to the text representation of Pid.

-

This BIF is intended for debugging and for use in the - Erlang OS. It is not to be used in application programs.

+

This BIF is intended for debugging and is not to be used + in application programs.

 @@ -3641,19 +3642,18 @@ os_prompt% not reply with {Port, closed}. Any process can close a port with port_close/1, not only the port owner (the connected process). If the calling process is linked to - a port identified by Port, an exit signal is sent - because that link will be received before the return from - port_close/1

-

For comparison: Port ! {self(), close} fails with - badarg if Port cannot be sent to (that is, - Port refers not to a port and not to a process). If - Port is a closed port, nothing happens. - If Port + the port identified by Port, the exit + signal from the port is guaranteed to be delivered before + port_close/1 returns.

+

For comparison: Port ! {self(), close} + only fails with badarg if Port does + not refer to a port or a process. If Port + is a closed port, nothing happens. If Port is an open port and the calling process is the port owner, - the port replies with {Port, closed} when all buffers - have been flushed and the port really closes. If - the calling process is not the port owner, the - port owner fails with badsig.

+ the port replies with {Port, closed} when all buffers + have been flushed and the port really closes. If the calling + process is not the port owner, the port owner fails + with badsig.

Notice that any process can close a port using Port ! {PortOwner, close} as if it itself was the port owner, but the reply always goes to the port owner.

@@ -3665,10 +3665,10 @@ os_prompt% behavior.

Failure: badarg if Port is not an identifier of an open port, or the registered name of an open port. - If the calling process was linked to the port, the exit - identified by Port, the exit signal is sent because - this link was delivered to the calling process before this - exception occurs.

+ If the calling process was previously linked to the closed + port, identified by Port, the exit + signal from the port is guaranteed to be delivered before + this badarg exception occurs.

@@ -3683,10 +3683,10 @@ os_prompt% can send data to a port with port_command/2, not only the port owner (the connected process).

For comparison: Port ! {PortOwner, {command, Data}} - fails with badarg if Port - cannot be sent to (that - is, Port refers not to a port and not to a process). - If Port is a closed port, the data message disappears + only fails with badarg if Port + does not refer to a port or a process. If + Port is a closed port, the data message + disappears without a sound. If Port is open and the calling process is not the port owner, the port owner fails with badsig. The port owner fails with badsig @@ -3707,10 +3707,11 @@ os_prompt% badarg If Port is not an identifier of an open - port, or the registered name of an open port. If the calling - process was linked to the port, the exit signal is sent - because this link was delivered to the calling process - before this exception occurs. + port, or the registered name of an open port. If the + calling process was previously linked to the closed port, + identified by Port, the exit signal + from the port is guaranteed to be delivered before this + badarg exception occurs. badarg @@ -3754,10 +3755,11 @@ os_prompt% badarg If Port is not an identifier of an open - port, or the registered name of an open port. If the calling - process was linked to the port, the exit signal is sent - because this link was delivered to the calling process - before this exception occurs. + port, or the registered name of an open port. If the + calling process was previously linked to the closed port, + identified by Port, the exit signal + from the port is guaranteed to be delivered before this + badarg exception occurs. badarg @@ -3805,9 +3807,9 @@ os_prompt% set the port owner to be any process with port_connect/2.

For comparison: - Port ! {self(), {connect, Pid}} fails - with badarg if Port cannot be sent to (that is, - Port refers not to a port and not to a process). If + Port ! {self(), {connect, Pid}} + only fails with badarg if Port + does not refer to a port or a process. If Port is a closed port, nothing happens. If Port is an open port and the calling process is the port owner, @@ -3835,9 +3837,10 @@ os_prompt% If Port is not an identifier of an open port, or the registered name of an open port. If the calling - process was linked to the port, the exit signal is sent - because this link was delivered to the calling process - before this exception occurs. + process was previously linked to the closed port, + identified by Port, the exit signal + from the port is guaranteed to be delivered before this + badarg exception occurs. badarg If process identified by Pid is not an existing @@ -3906,9 +3909,10 @@ os_prompt% If Port is not an identifier of an open port, or the registered name of an open port. If the calling - process was linked to the port, the exit signal is sent - because this link was delivered to the calling process - before this exception occurs. + process was previously linked to the closed port, + identified by Port, the exit signal + from the port is guaranteed to be delivered before this + badarg exception occurs. badarg @@ -3937,11 +3941,10 @@ os_prompt% Port, or undefined if the port is not open. The order of the tuples is undefined, and all the tuples are not mandatory. - If undefined is returned and the calling process - was linked to a previously open port identified by - Port, an exit signal is sent because this link - was received by the process before the return from - port_info/1.

+ If the port is closed and the calling process + was previously linked to the port, the exit signal from the + port is guaranteed to be delivered before port_info/1 + returns undefined.

The result contains information about the following Items:

@@ -3968,11 +3971,10 @@ os_prompt%

Pid is the process identifier of the process connected to the port.

If the port identified by Port is not open, - undefined is returned. If undefined is returned and - the calling process was linked to a previously open port identified - by Port, an exit signal is sent because this link - was received by the process before the return from - port_info/2.

+ undefined is returned. If the port is closed and the + calling process was previously linked to the port, the exit + signal from the port is guaranteed to be delivered before + port_info/2 returns undefined.

Failure: badarg if Port is not a local port identifier, or an atom.

@@ -3985,11 +3987,10 @@ os_prompt%

Index is the internal index of the port. This index can be used to separate ports.

If the port identified by Port is not open, - undefined is returned. If undefined is returned and - the calling process was linked to a previously open port identified - by Port, an exit signal is sent because this link - was received by the process before the return from - port_info/2.

+ undefined is returned. If the port is closed and the + calling process was previously linked to the port, the exit + signal from the port is guaranteed to be delivered before + port_info/2 returns undefined.

Failure: badarg if Port is not a local port identifier, or an atom.

@@ -4002,11 +4003,10 @@ os_prompt%

Bytes is the total number of bytes read from the port.

If the port identified by Port is not open, - undefined is returned. If undefined is returned and - the calling process was linked to a previously open port identified - by Port, an exit signal is sent because this link - was received by the process before the return from - port_info/2.

+ undefined is returned. If the port is closed and the + calling process was previously linked to the port, the exit + signal from the port is guaranteed to be delivered before + port_info/2 returns undefined.

Failure: badarg if Port is not a local port identifier, or an atom.

@@ -4019,11 +4019,10 @@ os_prompt%

Pids is a list of the process identifiers of the processes that the port is linked to.

If the port identified by Port is not open, - undefined is returned. If undefined is returned and - the calling process was linked to a previously open port identified - by Port, an exit signal is sent because this link - was received by the process before the return from - port_info/2.

+ undefined is returned. If the port is closed and the + calling process was previously linked to the port, the exit + signal from the port is guaranteed to be delivered before + port_info/2 returns undefined.

Failure: badarg if Port is not a local port identifier, or an atom.

@@ -4042,11 +4041,10 @@ os_prompt%

Notice that these results are highly implementation-specific and can change in a future release.

If the port identified by Port is not open, - undefined is returned. If undefined is returned and - the calling process was linked to a previously open port identified - by Port, an exit signal is sent because this link - was received by the process before the return from - port_info/2.

+ undefined is returned. If the port is closed and the + calling process was previously linked to the port, the exit + signal from the port is guaranteed to be delivered before + port_info/2 returns undefined.

Failure: badarg if Port is not a local port identifier, or an atom.

@@ -4061,11 +4059,10 @@ os_prompt% port itself can have allocated memory that is not included in Bytes.

If the port identified by Port is not open, - undefined is returned. If undefined is returned and - the calling process was linked to a previously open port identified - by Port, an exit signal is sent because this link - was received by the process before the return from - port_info/2.

+ undefined is returned. If the port is closed and the + calling process was previously linked to the port, the exit + signal from the port is guaranteed to be delivered before + port_info/2 returns undefined.

Failure: badarg if Port is not a local port identifier, or an atom.

@@ -4078,11 +4075,10 @@ os_prompt%

Monitors represent processes that this port monitors.

If the port identified by Port is not open, - undefined is returned. If undefined is returned and - the calling process was linked to a previously open port identified - by Port, an exit signal is sent because this link - was received by the process before the return from - port_info/2.

+ undefined is returned. If the port is closed and the + calling process was previously linked to the port, the exit + signal from the port is guaranteed to be delivered before + port_info/2 returns undefined.

Failure: badarg if Port is not a local port identifier, or an atom.

@@ -4095,11 +4091,10 @@ os_prompt%

Name is the command name set by open_port/2.

If the port identified by Port is not open, - undefined is returned. If undefined is returned and - the calling process was linked to a previously open port identified - by Port, an exit signal is sent because this link - was received by the process before the return from - port_info/2.

+ undefined is returned. If the port is closed and the + calling process was previously linked to the port, the exit + signal from the port is guaranteed to be delivered before + port_info/2 returns undefined.

Failure: badarg if Port is not a local port identifier, or an atom.

@@ -4115,11 +4110,10 @@ os_prompt% Command}, Options). If the port is not the result of spawning an OS process, the value is undefined.

If the port identified by Port is not open, - undefined is returned. If undefined is returned and - the calling process was linked to a previously open port identified - by Port, an exit signal is sent because this link - was received by the process before the return from - port_info/2.

+ undefined is returned. If the port is closed and the + calling process was previously linked to the port, the exit + signal from the port is guaranteed to be delivered before + port_info/2 returns undefined.

Failure: badarg if Port is not a local port identifier, or an atom.

@@ -4135,11 +4129,10 @@ os_prompt% port_command/3, or Port ! {Owner, {command, Data}.

If the port identified by Port is not open, - undefined is returned. If undefined is returned and - the calling process was linked to a previously open port identified - by Port, an exit signal is sent before this link - was received by the process before the return from - port_info/2.

+ undefined is returned. If the port is closed and the + calling process was previously linked to the port, the exit + signal from the port is guaranteed to be delivered before + port_info/2 returns undefined.

Failure: badarg if Port is not a local port identifier, or an atom.

@@ -4164,11 +4157,10 @@ os_prompt% of bytes queued by the port using the ERTS driver queue implementation.

If the port identified by Port is not open, - undefined is returned. If undefined is returned and - the calling process was linked to a previously open port identified - by Port, an exit signal is sent because this link - was received by the process before the return from - port_info/2.

+ undefined is returned. If the port is closed and the + calling process was previously linked to the port, the exit + signal from the port is guaranteed to be delivered before + port_info/2 returns undefined.

Failure: badarg if Port is not a local port identifier, or an atom.

@@ -4181,11 +4173,10 @@ os_prompt%

RegisteredName is the registered name of the port. If the port has no registered name, [] is returned.

If the port identified by Port is not open, - undefined is returned. If undefined is returned and - the calling process was linked to a previously open port identified - by Port, an exit signal is sent because this link - was received by the process before the return from - port_info/2.

+ undefined is returned. If the port is closed and the + calling process was previously linked to the port, the exit + signal from the port is guaranteed to be delivered before + port_info/2 returns undefined.

Failure: badarg if Port is not a local port identifier, or an atom.

@@ -4198,15 +4189,15 @@ os_prompt%

Returns a string corresponding to the text representation of the port identifier Port.

-

This BIF is intended for debugging and for use in the - Erlang OS. It is not to be used in application programs.

+

This BIF is intended for debugging. It is not to be used + in application programs.

 - Lists all open ports. + Lists all existing ports.

Returns a list of port identifiers corresponding to all the ports existing on the local node.

@@ -4502,8 +4493,8 @@ os_prompt%

Returns information about the process identified by Pid, as specified by - Item or ItemList, - or undefined if the process is not alive.

+ Item or ItemList. + Returns undefined if the process is not alive.

If the process is alive and a single Item is given, the returned value is the corresponding InfoTuple, unless Item =:= registered_name @@ -4774,8 +4765,7 @@ os_prompt% badarg If Pid is not a local process. badarg - If Item is an invalid - Item. + If Item is an invalid item. @@ -4847,8 +4837,7 @@ os_prompt% exception of given class, reason, and call stack backtrace (stacktrace).

-

This BIF is intended for debugging and for use in - the Erlang OS. Avoid to use it in applications, +

This BIF is intended for debugging. Avoid to use it in applications, unless you really know what you are doing.

Class is error, exit, or @@ -4963,8 +4952,8 @@ os_prompt%

Returns a string corresponding to the text representation of Ref.

-

This BIF is intended for debugging and for use in the - Erlang OS. It is not to be used in application programs.

+

This BIF is intended for debugging and is not to be used + in application programs.

 @@ -5208,7 +5197,7 @@ true Msg, [nosuspend | Options]), but with a Boolean return value.

This function behaves like - erlang:send_nosuspend/2), + erlang:send_nosuspend/2, but takes a third parameter, a list of options. The only option is noconnect, which makes the function return false if @@ -5267,13 +5256,23 @@ true Size of a tuple or binary. -

Returns an integer that is the size of argument - Item, which must be a tuple or a binary, - for example:

+

Returns the number of elements in a tuple or the number of + bytes in a binary or bitstring, for example:

 > size({morni, mulle, bwange}).
-3
+3 +> size(<<11, 22, 33>>). +3 + +

For bitstrings the number of whole bytes is returned. That is, if the number of bits + in the bitstring is not divisible by 8, the resulting + number of bytes is rounded down.

Allowed in guard tests.

+

See also + tuple_size/1, + byte_size/1 + and + bit_size/1.

@@ -5307,9 +5306,7 @@ true

Returns the process identifier of a new process started by the application of Module:Function - to Args. - The new created process is placed in the system scheduler - queue and will be run some time later.

+ to Args.

error_handler:undefined_function(Module, Function, Args) is evaluated by the new process if @@ -5319,8 +5316,8 @@ true can be redefined (see process_flag/2). If error_handler is undefined, or the user has - redefined the default error_handler, its replacement is - undefined, and a failure with reason undef occurs.

+ redefined the default error_handler and its replacement is + undefined, a failure with reason undef occurs.

Example:

 > spawn(speed, regulator, [high_speed, thin_cut]).
@@ -5364,10 +5361,9 @@ true
list [] on Node. A link is created between the calling process and the new process, atomically. If Node does not exist, - a useless pid is - returned (and, because of the link, an exit signal with exit - reason noconnection is received). Otherwise works - like spawn/3.

+ a useless pid is returned and an exit signal with + reason noconnection is sent to the calling + process. Otherwise works like spawn/3.

 @@ -5376,7 +5372,7 @@ true Creates and links to a new process with a function as entry point.

Returns the process identifier of a new process started by - the applicatio of Module:Function + the application of Module:Function to Args. A link is created between the calling process and the new process, atomically. Otherwise works like @@ -5394,10 +5390,9 @@ true to Args on Node. A link is created between the calling process and the new process, atomically. If Node does - not exist, a useless pid - is returned (and, because of the link, an exit signal with exit - reason noconnection is received). Otherwise works - like spawn/3.

+ not exist, a useless pid is returned and an exit signal with + reason noconnection is sent to the calling + process. Otherwise works like spawn/3.

 @@ -5761,7 +5756,7 @@ true Information about runtime.

Returns information about runtime, in milliseconds.

-

The runtime is the sum of the runtime for all threads +

This is the sum of the runtime for all threads in the Erlang runtime system and can therefore be greater than the wall clock time.

Example:

@@ -5787,7 +5782,7 @@ true activation. The time unit is undefined and can be subject to change between releases, OSs, and system restarts. scheduler_wall_time is only to be used to - calculate relative values for scheduler-use. + calculate relative values for scheduler-utilization. ActiveTime can never exceed TotalTime.

The definition of a busy scheduler is when it is not idle @@ -5808,14 +5803,14 @@ true is turned off.

The list of scheduler information is unsorted and can appear in different order between calls.

-

Using scheduler_wall_time to calculate scheduler-use:

+

Using scheduler_wall_time to calculate scheduler-utilization:

 > erlang:system_flag(scheduler_wall_time, true).
 false
 > Ts0 = lists:sort(erlang:statistics(scheduler_wall_time)), ok.
 ok

Some time later the user takes another snapshot and calculates - scheduler-use per scheduler, for example:

+ scheduler-utilization per scheduler, for example:

 > Ts1 = lists:sort(erlang:statistics(scheduler_wall_time)), ok.
 ok
@@ -5829,7 +5824,7 @@ ok
  {6,0.9739235846420741},
  {7,0.973237033077876},
  {8,0.9741297293248656}]
-

Using the same snapshots to calculate a total scheduler-use:

+

Using the same snapshots to calculate a total scheduler-utilization:

 > {A, T} = lists:foldl(fun({{_, A0, T0}, {_, A1, T1}}, {Ai,Ti}) ->
 	{Ai + (A1 - A0), Ti + (T1 - T0)} end, {0, 0}, lists:zip(Ts0,Ts1)), A/T.
@@ -5961,9 +5956,7 @@ ok
         
Suspends the process identified by
         Suspendee. The same as calling
 	erlang:suspend_process(Suspendee,
-        []).
-        For more information, see
-        erlang:suspend_process/2.

+        []).

         
           
This BIF is intended for debugging only.

         
@@ -6163,7 +6156,7 @@ ok
         
         
Controls if and how schedulers are bound to logical
            processors.

-        
When erlang:system_flag(scheduler_bind_type, How
+        
When erlang:system_flag(scheduler_bind_type, How)
            is called, an asynchronous signal is sent to all schedulers
            online, causing them to try to bind or unbind as requested.

         
If a scheduler fails to bind, this is often silently
@@ -6283,9 +6276,9 @@ ok
         Sets the number of schedulers online. Range is
         .

         
Returns the old value of the flag.

-        
The emulator was built with support for
-        dirty schedulers.
-        Changing the number of schedulers online can also change the
+        
If the emulator was built with support for
+        dirty schedulers,
+        changing the number of schedulers online can also change the
         number of dirty CPU schedulers online. For example, if 12
         schedulers and 6 dirty CPU schedulers are online, and
         system_flag/2 is used to set the number of schedulers
@@ -6563,7 +6556,7 @@ ok
           
           
             
Returns the automatically detected
-               CpuTopology. The
+               CpuTopologyy. The
 	       emulator detects the CPU topology on some newer
 	       Linux, Solaris, FreeBSD, and Windows systems.
                On Windows system with more than 32 logical processors,
@@ -7030,10 +7023,10 @@ ok
           
             
Returns a list of Pids when
               multi-scheduling is blocked, otherwise the empty list is
-              returned. The Pids in the list are
-              Pids of the processes currently
-              blocking multi-scheduling. A Pid is
-              present only once in the list, even if the corresponding
+              returned. The Pids in the list
+	      represent all the processes currently
+              blocking multi-scheduling. A Pid occurs
+              only once in the list, even if the corresponding
               process has blocked multiple times.

             
See also
               erlang:system_flag(multi_scheduling, BlockState),
@@ -7177,7 +7170,7 @@ ok
 	      time unit.

 	    
           
-	  port_parallelism
+	  port_parallelism
 	  
 	  
 	  
Returns the default port parallelism scheduling hint used.
@@ -7569,7 +7562,7 @@ ok
               fairly "normal". However, longer schedule times can
               indicate swapping or a misbehaving NIF/driver.
               Misbehaving NIFs and drivers can cause bad resource
-              use and bad overall system performance.

+              utilization and bad overall system performance.

           
           {large_heap, Size}
           
@@ -7756,15 +7749,15 @@ ok
         
           0 - No compression is done (it is the same as
             giving no compressed option).
-          1 - Takes least time but cannot compress,
+          1 - Takes least time but may not compress
             as well as the higher levels.
-          9 - Takes most time and can produce a smaller
-            result. Notice "can" in the preceding sentence; depending
+          6 - Default level when option compressed
+	    is provided.
+          9 - Takes most time and tries to produce a smaller
+            result. Notice "tries" in the preceding sentence; depending
             on the input term, level 9 compression either does or does
             not produce a smaller result than level 1 compression.
         
-        
compressed and {compressed, 6} give the same
-          result.

         
Option {minor_version, Version}
           can be used to control
           some encoding details. This option was introduced in OTP R11B-4.
@@ -7938,8 +7931,8 @@ timestamp() ->
           
         
         
FlagList can contain any number of the
-          following flags (the "message tags" refers to the list of the
-          following messages):

+          following flags (the "message tags" refers to the list of
+	  trace messages):

         
           all
           
@@ -7985,7 +7978,7 @@ timestamp() ->
               {silent, false}.

             
The silent trace flag facilitates setting up
               a trace on many or even all processes in the system.
-              The trace is activated and deactivated using the match
+              The trace can then be activated and deactivated using the match
               specification function {silent,Bool}, giving
               a high degree of control of which functions with which 
               arguments that trigger the trace.

@@ -8088,15 +8081,14 @@ timestamp() ->
           set_on_link is the same as having
           set_on_first_link alone. Likewise for
           set_on_spawn and set_on_first_spawn.

-        
If flag timestamp is not given, the tracing
-          process receives the trace messages described in the
-          following. Pid is the process identifier of the
-          traced process in which
-          the traced event has occurred. The third tuple element
-          is the message tag.

+        
The tracing process receives the trace messages described
+	in the following list. Pid is the process identifier of the
+	traced process in which the traced event has occurred. The
+	third tuple element is the message tag.

         
If flag timestamp is given, the first tuple
           element is trace_ts instead, and the time-stamp
-          is added last in the tuple.

+          is added last in the message tuple.

+        
         
           {trace, Pid, 'receive', Msg}
           
@@ -8301,13 +8293,12 @@ timestamp() ->
           denotes all processes
           that currently are traced in the node.

         
Example: Process A is Tracee,
-          port B is
-          tracer, and process C is the port owner of B.
-          C wants to close B when A exits. C
-          can ensure that the trace is not truncated by calling
-          erlang:trace_delivered(A) when A exits and waits
-          for message {trace_delivered, A, Ref}
-          before closing B.

+	  port B is tracer, and process C is the port
+	  owner of B. C wants to close B when
+	  A exits. To ensure that the trace is not truncated,
+	  C can call erlang:trace_delivered(A), when
+	  A exits, and wait for message {trace_delivered, A,
+	  Ref} before closing B.

         
Failure: badarg if Tracee
           does not refer to a
           process (dead or alive) on the same node as the caller of
@@ -8317,7 +8308,7 @@ timestamp() ->
 
     
       
-     Traces information about a process or function.
+     Trace information about a process or function.
       
       
       
@@ -8444,23 +8435,21 @@ timestamp() ->
       
       
         
Enables or disables call tracing for
-          exported functions. Must be combined with
+          one or more functions. Must be combined with
           erlang:trace/3
           to set the call trace flag for one or more processes.

         
Conceptually, call tracing works as follows. Inside
           the Erlang Virtual Machine, a set of processes and
-          a set of functions are to be traced. Tracing is
-          enabled on the intersection of the set. That is, if a process
-          included in the traced process set calls a function included
-          in the traced function set, the trace action is taken.
+          a set of functions are to be traced. If a traced process
+          calls a traced function, the trace action is taken.
           Otherwise, nothing happens.

         
To add or remove one or more processes to the set of traced
           processes, use
           erlang:trace/3.

-        
To add or remove exported functions to the set of traced
-          functions, use erlang:trace_pattern/2.

+        
To add or remove functions to the set of traced
+          functions, use erlang:trace_pattern/3.

         
The BIF erlang:trace_pattern/3 can also add match
-          specifications to an exported function. A match specification
+          specifications to a function. A match specification
           comprises a pattern that the function arguments must
           match, a guard expression that must evaluate to true,
           and an action to be performed. The default action is to send a
@@ -8469,22 +8458,22 @@ timestamp() ->
         
Argument MFA is to be a tuple, such as
           {Module, Function, Arity}, or the atom on_load
           (described in the following). It can be the module, function,
-          and arity for an exported function (or a BIF in any module).
-          The atom '_' can be used to mean any of that kinds.
-          Wildcards can be used in any of the following ways:

+          and arity for a function (or a BIF in any module).
+          The atom '_' can be used as a wildcard in any of the
+	  following ways:

         
           {Module,Function,'_'}
           
-            
All exported functions of any arity named Function
+            
All functions of any arity named Function
               in module Module.

           
           {Module,'_','_'}
           
-            
All exported functions in module Module.

+            
All functions in module Module.

           
           {'_','_','_'}
           
-            
All exported functions in all loaded modules.

+            
All functions in all loaded modules.

           
         
         
Other combinations, such as {Module,'_',Arity}, are
@@ -8498,12 +8487,12 @@ timestamp() ->
         
           false
           
-            
Disables tracing for the matching function or functions.
+            
Disables tracing for the matching functions.
               Any match specification is removed.

           
           true
           
-            
Enables tracing for the matching function or functions.

+            
Enables tracing for the matching functions.

           
           MatchSpecList
           
@@ -8534,7 +8523,7 @@ timestamp() ->
             
Turns on or off call tracing for global function calls
               (that is, calls specifying the module explicitly). Only
               exported functions match and only global calls
-              generate trace messages. This is the default.

+              generate trace messages. This is the default.

           
           local
           
@@ -8615,7 +8604,7 @@ timestamp() ->
           use the BIF
           erlang:trace_info/2
           to retrieve the existing match specification.

-        
Returns the number of exported functions matching
+        
Returns the number of functions matching
           argument MFA. This is zero if none matched.

       
     
@@ -8791,7 +8780,7 @@ timestamp() ->
     
     
       
-      Removes a link, if there is one, to another process or port.
+      Removes a link to another process or port.
       
         
Removes the link, if there is one, between the calling
           process and the process or port referred to by
@@ -8805,9 +8794,9 @@ timestamp() ->
           Id has no effect on the caller
           in the future (unless
           the link is setup again). If the caller is trapping exits, an
-          {'EXIT', Id, _}
-          message is received, as the link can have
-          been placed in the caller's message queue before the call.

+          {'EXIT', Id, _} message from the link
+	  can have been placed in the caller's message queue before
+	  the call.

         
Notice that the {'EXIT', Id, _}
           message can be the
           result of the link, but can also be the result of Id
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