Re: Resetting profiling range

[Jonathan Larmour <jifl at eCosCentric dot com>]

Øyvind Harboe wrote:
> The attached patch allow invoking profile_on() multiple times to set
> up a fresh profiling range.

This looks good, but I made some changes. I thought profile_off was worth
exporting if it exists, and I moved where the doc is, and tweaked it.

Also please remember in future where possible to mention each file modified
in the changelog entry (where reasonable as per FSF/GNU standards:
<http://www.gnu.org/prep/standards/html_node/Change-Logs.html> although we
aren't usually quite as pedantic as that).

Thanks for contributing!

Jifl

Index: ChangeLog
===================================================================
RCS file: /cvs/ecos/ecos/packages/services/profile/gprof/current/ChangeLog,v
retrieving revision 1.6.10036.4
diff -u -5 -p -r1.6.10036.4 ChangeLog
--- ChangeLog   14 Sep 2006 12:21:56 -0000      1.6.10036.4
+++ ChangeLog   21 Dec 2007 16:23:17 -0000
@@ -1,5 +1,14 @@
+2007-12-14  Oyvind Harboe  <oyvind.harboe@zylin.com>
+2007-12-21  Jonathan Larmour  <jifl@eCosCentric.com>
+
+       * include/profile.h: Declare profile_off.
+       * src/profile.c: Added support for invoking profile_on() multiple
+       times. It now stops profiling and sets up a fresh profiling range
+       on every invocation using new profile_off() function.
+       * doc/profile.sgml: Document it.
+
 2005-05-13  Peter Korsgaard  <jacmet@sunsite.dk>

        * doc/profile.sgml: Fixed typo in HAL support section.

 2005-02-18  Bart Veer  <bartv@ecoscentric.com>
Index: doc/profile.sgml
===================================================================
RCS file:
/cvs/ecos/ecos/packages/services/profile/gprof/current/doc/profile.sgml,v
retrieving revision 1.2.10036.3
diff -u -5 -p -r1.2.10036.3 profile.sgml
--- doc/profile.sgml    14 Sep 2006 12:21:57 -0000      1.2.10036.3
+++ doc/profile.sgml    21 Dec 2007 16:23:18 -0000
@@ -265,10 +265,23 @@ disproportionally sample code that runs
 clock.
         </para></listitem>
       </varlistentry>
     </variablelist>
     <para>
+<function>profile_on</function> can be invoked multiple times, and
+on subsequent invocations, it will delete profiling data
+and allocate a fresh profiling range.
+    </para>
+    <para>
+Profiling can be turned off using the function
+<function>profile_off</function>:
+<programlisting>
+void profile_off(void);
+</programlisting>
+This will also reset any existing profile data.
+    </para>
+    <para>
 If the eCos configuration includes a TCP/IP stack and if a tftp daemon
 will be used to <link linkend="gprof-extract">extract</link> the data
 from the target then the call to <function>profile_on</function>
 should happen after the network is up. <filename>profile_on</filename>
 will attempt to start a tftp daemon thread, and this will fail if
Index: include/profile.h
===================================================================
RCS file:
/cvs/ecos/ecos/packages/services/profile/gprof/current/include/profile.h,v
retrieving revision 1.2.10036.2
diff -u -5 -p -r1.2.10036.2 profile.h
--- include/profile.h   14 Sep 2006 12:21:57 -0000      1.2.10036.2
+++ include/profile.h   21 Dec 2007 16:23:18 -0000
@@ -63,10 +63,13 @@

 // Enable profiling
 __externC void profile_on(void *start_addr, void *end_addr,
                           int bucket_size, int sample_resolution);

+// Disable and reset profiling
+__externC void profile_off(void);
+
 // Callback used by timer routine
 __externC void __profile_hit(CYG_ADDRWORD pc);

 // Callgraph support
 __externC void __profile_mcount(CYG_ADDRWORD /* caller_pc */, CYG_ADDRWORD
/* callee_pc */);
Index: src/profile.c
===================================================================
RCS file:
/cvs/ecos/ecos/packages/services/profile/gprof/current/src/profile.c,v
retrieving revision 1.4.10036.2
diff -u -5 -p -r1.4.10036.2 profile.c
--- src/profile.c       14 Sep 2006 12:21:57 -0000      1.4.10036.2
+++ src/profile.c       21 Dec 2007 16:23:18 -0000
@@ -433,26 +433,65 @@ static struct tftpd_fileops profile_tftp
     &profile_tftp_read
 };
 #endif

 //
----------------------------------------------------------------------------
+// stop profiling
+void
+profile_off(void)
+{
+    // suspend currently running profiling
+    profile_enabled = 0;
+    // Clear all pre-existing profile data
+    profile_reset();
+    if (profile_hist_data) {
+       free(profile_hist_data);
+        profile_hist_data = NULL;
+    }
+#ifdef CYGPKG_PROFILE_CALLGRAPH
+    if (profile_arc_hashtable) {
+       free(profile_arc_hashtable);
+        profile_arc_hashtable=NULL;
+    }
+    if (profile_arc_records) {
+       free(profile_arc_records);
+        profile_arc_records=NULL;
+    }
+#endif
+}
+
+
+//
----------------------------------------------------------------------------
 // profile_on() has to be called by application code to start profiling.
 // Application code will determine the start and end addresses, usually
 // _stext and _etext, but it is possible to limit profiling to only
 // some of the code. The bucket size controls how many PC addresses
 // will be treated as a single hit: a smaller bucket increases precision
 // but requires more memory. The resolution is used to initialize the
 // profiling timer: more frequent interrupts means more accurate results
 // but increases the risk of an overflow.
+//
+// profile_on() can be invoked multiple times. If invoked a second time
+// it will stop the current profiling run and create a new profiling
+// range.
+
+

 void
 profile_on(void *_start, void *_end, int _bucket_size, int resolution)
 {
     int             bucket_size;
     cyg_uint32      version     = GMON_VERSION;
     CYG_ADDRWORD    text_size   = (CYG_ADDRWORD)_end - (CYG_ADDRWORD)_start;

+    if (profile_enabled)
+    {
+       // invoking profile_on a second time
+       profile_off();
+    }
+
+
     // Initialize statics. This also ensures that they won't be
     // garbage collected by the linker so a gdb script can safely
     // reference them.
     memcpy(profile_gmon_hdr.cookie, GMON_MAGIC, 4);
     memcpy(profile_gmon_hdr.version, &version, 4);
@@ -538,10 +577,11 @@ profile_on(void *_start, void *_end, int

     profile_enabled = 1;

 #ifdef CYGPKG_PROFILE_TFTP
     // Create a TFTP server to provide the data
+    // invoking this a second time is harmless
     (void) tftpd_start(CYGNUM_PROFILE_TFTP_PORT, &profile_tftp_fileops);
 #endif
 }

 // EOF profile.c


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