Hexley Ball / Mbed 2 deprecated stringtest

This program explores how the compiler treats const string arrays.

Dependencies:   mbed

Files at this revision

API Documentation at this revision

Revision 0:07e4abe04bad, committed 2011-04-05

Comitter:
hexley
Date:
Tue Apr 05 20:37:25 2011 +0000
Commit message:

Changed in this revision

main.cpp Show annotated file Show diff for this revision Revisions of this file
mbed.bld Show annotated file Show diff for this revision Revisions of this file 
diff -r 000000000000 -r 07e4abe04bad main.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Tue Apr 05 20:37:25 2011 +0000
@@ -0,0 +1,147 @@
+/*********************************************************************************
+* This test program loads a large array of const strings, then reports how much
+* RAM is still available.
+*
+* Without the array, 24,196 bytes of RAM are free.
+* With an 8000-char array, 13,476 bytes of RAM are free 
+* The const string of 8000 chars thus consumes 10720 bytes of RAM.
+*********************************************************************************/
+#include "mbed.h"
+#include <string>
+
+DigitalOut fan(p21);        // Needed for my breadboard
+
+#define TEST8000          // Comment this line to find the baseline value for free RAM
+
+#ifdef TEST8000
+// teststring is an array of 100 x 80 character strings
+const string teststring[] = {
+     "This is the first line of 100 80-character strings in the 'teststring[]' array.",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",   
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",   
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",   
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",   
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",   
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",   
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",   
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",   
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",   
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",
+     "0123456789012345678901234567890123456789012345678901234567890123456789012345678",   
+ };
+#endif
+
+int main() { 
+     int low = 0;
+     int high = 0x8001;     
+     fan = 0;
+
+#ifdef TEST8000     
+     // Include at least one reference to the array, to keep the optimizer happy
+     printf("The first string is %s\r\n", teststring[0]);
+#endif
+     
+     // Compute free memory, using Segundo Equipo's AvailableMemory.cpp code
+    __disable_irq(); 
+     while (high - low > 1) {
+         int mid = (low + high) / 2;
+         void* p = malloc(mid);
+         if (p == NULL) {
+             high = mid;
+         } else {
+             free(p);
+             low = mid;
+         }
+     }
+    __enable_irq();
+ 
+     printf("Test program 'stringtest' reports space available in RAM = %d\r\n", low);
+}

diff -r 000000000000 -r 07e4abe04bad mbed.bld
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Tue Apr 05 20:37:25 2011 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/63bcd7ba4912