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 
--- /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);
+}

--- /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