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Observer
Release Notes
Version 0.9.8.1

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- Observer Release Notes
  - Top of chapter
  - Observer 0.9.8.1
  - Observer 0.9.8
  - Observer 0.9.7.4
  - Observer 0.9.7.3
  - Observer 0.9.7.2
  - Observer 0.9.7.1
  - Observer 0.9.7 (R11B)
  - Observer 0.9.6.2
  - Observer 0.9.6.1

# 1 Observer Release Notes

This document describes the changes made to the Observer application.

### 1.1 Observer 0.9.8.1

#### Improvements and New Features

- Major improvements of the Erlang distribution for Erlang runtime systems with SMP support. Previously distribution port locks were heavily contended, and all encoding and decoding for a specific distribution channel had to be done in sequence. Lock contention due to the distribution is now negligible and both encoding and decoding of Erlang messages can be done in parallel.

  The old atom cache protocol used by the Erlang distribution has been dropped since it effectively prevented all parallel encoding and decoding of messages passed over the same distribution channel.

  A new atom cache protocol has been introduced which isolates atom cache accesses and makes parallel encoding and decoding of messages passed over the same distribution channel possible. The new atom cache protocol also use an atom cache size 8 times larger than before. The new atom cache protocol is documented in the ERTS users guide.

  Erlang messages received via the distribution are now decoded by the receiving Erlang processes without holding any distribution channel specific locks. Erlang messages and signals sent over the distribution are as before encoded by the sending Erlang process, but now without holding any distribution channel specific locks during the encoding. That is, both encoding and decoding can be and are done in parallel regardless of distribution channel used.

  The part that cannot be parallelized is the atom cache updates. Atom cache updates are therefore now scheduled on the distribution port. Since it is only one entity per distribution channel doing this work there is no lock contention due to the atom cache updates.

  The new runtime system does not understand the old atom cache protocol. New and old runtime systems can however still communicate, but no atom cache will be used.

  Own Id: OTP-7774

### 1.2 Observer 0.9.8

#### Improvements and New Features

- etop would crash if the emulator's custom allocators had been turned off (e.g. using the +Meamin option).

  Own Id: OTP-7519

- The copyright notices have been updated.

  Own Id: OTP-7851

### 1.3 Observer 0.9.7.4

#### Improvements and New Features

- Minor Makefile changes.

  Own Id: OTP-6689

- Obsolete guard tests (such as list()) have been replaced with the modern guard tests (such as is_list()).

  Own Id: OTP-6725

### 1.4 Observer 0.9.7.3

#### Improvements and New Features

- This application has been updated to eliminate warnings by Dialyzer.

  Own Id: OTP-6551

### 1.5 Observer 0.9.7.2

#### Fixed Bugs and Malfunctions

- Several minor bugs and race conditions eliminated in the runtime_tools and observer applications.

  Own Id: OTP-6265

### 1.6 Observer 0.9.7.1

#### Fixed Bugs and Malfunctions

- Crash dump with large integers could crash the crashdump_viewer.

  Own Id: OTP-6301

### 1.7 Observer 0.9.7 (R11B)

#### Fixed Bugs and Malfunctions

- Fixed a bug in etop which made the Load and Memory information in the header incorrect -- for example the value shown for binary (memory allocated for binaries) was actually the number of currently running processes. (Thanks to Rikard Johansson.)

  Own Id: OTP-6075

### 1.8 Observer 0.9.6.2

#### Fixed Bugs and Malfunctions

- The Observer application has been recompiled because of a compiler bug.

  Own Id: OTP-5700

### 1.9 Observer 0.9.6.1

#### Fixed Bugs and Malfunctions

- crashdump_viewer is faster when showing message, dictionary, and stack dump for large processes.

  Own Id: OTP-5408