Dynamic Memory Monitor for Teensy 3.x by Adrian Hunt

Teensy 3.x RAM Monitor copyright by Adrian Hunt (c) 2015 - 2016

simplifies memory monitoring; providing both "raw" memory information and with frequent calls to the run() function, adjusted information with simulated stack allocations. memory is also monitored for low memory state and stack and heap crashes.

raw memory information methods:

 int32_t unallocated() const;

calculates space between heap and current stack. will return negitive if heap and stack currently overlap, corruption is very likely.

 uint32_t stack_used() const;

calculates the current stack size.

 uint32_t heap_total() const;

return the heap size.

 uint32_t heap_used() const;

returns allocated heap.

 uint32_t heap_free() const;

returns unused heap.

 int32_t free() const;

calculates total free ram; unallocated and unused heap. note that this uses the current stack size.

 uint32_t total() const;

returns total physical ram.

extended memory information. These methods require the RamMonitor object to be initialized and the run() method called regularly.

 uint32_t stack_total() const;

returns the memory required for the stack. this is determind by historical stack usage.

 int32_t stack_free() const;

returns stack space that can be used before the stack grows and total size is increased.

 int32_t adj_unallocd() const;

calculates unallocated memory, reserving space for the stack.

 int32_t adj_free() const;

calculates total free ram by using adjusted unallocated and unused heap.

 bool warning_lowmem() const;
 bool warning_crash() const;

return warning states: low memory is flagged when adjusted unallocated memory is below a set value. crash is flagged when reserved stack space over- laps heap and there is a danger of corruption.

 void initialize();

initializes the RamMonitor object enabling stack monitoring and the extended information methods.

 void run();

detects stack growth and updates memory warnings. this function must be called regulary.

when using the extended memory information methods, a single RamMonitor object should be create at global level. two static constants define values that control stack allocation step size and the low memory warning level. these values are in bytes. the stack allocation step must be divisable by 4.

 static const uint16_t STACKALLOCATION;
 static const uint16_t LOWMEM;