Changes between Version 6 and Version 7 of AppIntro

Timestamp:

Jan 1, 2010, 1:19:45 PM (15 years ago)

Author:

davea

Comment:

--

AppIntro

@@ -14 +14 @@
 input files, output files - are stored in the project directory.
 
-Each job runs in a separate '''slot directory''',
+Each job runs in its own '''slot directory''',
 which contains '''links''' to all the files needed by that job
-(these are like UNIX symbolic links; since Windows NTFS doesn't support
+(these are like UNIX symbolic links;
+however, since Windows NTFS doesn't support
 symbolic links, BOINC implements them as XML files).
 The names of the link files are called '''logical names''',
@@ -24 +25 @@
 
 The BOINC client expects each application to create a specially-named "finish file"
-when it is done; this lets it reliably detect when the application has finished
+when it is done; this lets the client reliably detect that the application has finished
 (rather than, e.g., being killed).
 
@@ -34 +35 @@
  * The application tells the client its current CPU time, and when it has checkpointed.
 
-This communication is implemented using a shared-memory structure.
+This communication is implemented using shared memory.
 There is a separate shared-memory structure for each running application.
 
 [[Image(client_msgs.png)]]
 
-=== The BOINC runtime library ===
+If you run an existing, unmodified program under BOINC
+there will be several problems:
 
-Suppose you tried to run an existing, unmodified program under BOINC.
-There would be two problems:
-
- * When the program opens and reads its input files, it would get the contents of the XML link files - not what it expects. Similarly, the output would be written to the wrong directory.
- * When the program finishes, it wouldn't create a finish file, so the BOINC client would restart it repeatedly.
- * The BOINC client wouldn't know the application's CPU time; it would display zero, and volunteers would be confused. In addition, with the default configuration, users wouldn't get any credits if the CPU time is zero.
-
-The easiest way to solve these problems is to modify your program as follows:
- * Add calls to BOINC initialization and finalization routines.
- * Precede with fopen() call with a BOINC function that maps logical to physical names.
- * Link it with the BOINC runtime library.
+ * When the program opens and reads its input files,
+ it will get the contents of the XML link files - not what it expects.
+ * The application won't suspend, resume and quit properly.
+ * When the program finishes, it won't create a finish file,
+ so the BOINC client would restart it repeatedly.
+ * The BOINC client won't know the application's CPU time;
+ it would display zero, and volunteers would be confused.
 
 === The BOINC wrapper ===
 
-Suppose you have a program that is difficult or impossible to modify
-to use the BOINC runtime library (e.g., source code is not available).
-You can run it under BOINC, using the '''BOINC wrapper'''.
-The wrapper acts as a main program,
-managing communication with the BOINC client,
-and running your program as a subprocess.
+The simplest way to run an existing application under BOINC
+is to use the [WrapperApp BOINC wrapper].
+This lets you run any executable (or sequence of executables)
+with no modification.
 
-=== Language alternatives ===
+=== Native BOINC applications ===
+
+With some minor source code modifications, you can run
+an application directly without need for the wrapper.
+The changes are:
+
+ * Add calls to BOINC initialization and finalization routines.
+ * Precede each fopen() call with a BOINC function that maps logical to physical names.
+ * Link it with the BOINC runtime library.
 
 The BOINC runtime library is implemented in C++