diff options
| -rw-r--r-- | Doc/tut/tut.tex | 26 |
1 files changed, 15 insertions, 11 deletions
diff --git a/Doc/tut/tut.tex b/Doc/tut/tut.tex index 978db65..970c8ad 100644 --- a/Doc/tut/tut.tex +++ b/Doc/tut/tut.tex @@ -4868,12 +4868,12 @@ numbers respectively): \section{Multi-threading\label{multi-threading}} Threading is a technique for decoupling tasks which are not sequentially -dependent. Python threads are driven by the operating system and run -in a single process and share memory space in a single interpreter. +dependent. Threads can be used to improve the responsiveness of +applications that accept user input while other tasks run in the +background. A related use case is running I/O in parallel with +computations in another thread. -Threads can be used to improve the responsiveness of applications that -accept user input while other tasks run in the background. The -following code shows how the high level +The following code shows how the high level \ulink{\module{threading}}{../lib/module-threading.html} module can run tasks in background while the main program continues to run: @@ -4891,8 +4891,12 @@ tasks in background while the main program continues to run: f.close() print 'Finished background zip of: ', self.infile - AsyncZip('mydata.txt', 'myarchive.zip').start() - print 'The main program continues to run' + background = AsyncZip('mydata.txt', 'myarchive.zip') + background.start() + print 'The main program continues to run in foreground.' + + background.join() # Wait for the background task to finish + print 'Main program waited until background was done.' \end{verbatim} The principal challenge of multi-threaded applications is coordinating @@ -4901,13 +4905,13 @@ module provides a number of synchronization primitives including locks, events, condition variables, and semaphores. While those tools are powerful, minor design errors can result in -problems that are difficult to reproduce. A simpler and more robust -approach to task coordination is concentrating all access to a resource +problems that are difficult to reproduce. So, the preferred approach +to task coordination is to concentrate all access to a resource in a single thread and then using the \ulink{\module{Queue}}{../lib/module-Queue.html} module to feed that -thread with requests from other threads. Applications that use +thread with requests from other threads. Applications using \class{Queue} objects for inter-thread communication and coordination -tend to be easier to design, more readable, and more reliable. +are easier to design, more readable, and more reliable. \section{Logging\label{logging}} |