The Mail class allows you to control, send, receive or wait for mail. More...

#include <Mail.h>

Inheritance diagram for Mail< T, queue_sz >:

Public Member Functions
	Mail ()
	Create and initialize Mail queue. More...

bool	empty () const
	Check if the mail queue is empty. More...

bool	full () const
	Check if the mail queue is full. More...

T *	alloc (MBED_UNUSED uint32_t millisec=0)
	Allocate a memory block of type T, without blocking. More...

T *	alloc_for (uint32_t millisec)
	Allocate a memory block of type T, optionally blocking. More...

T *	alloc_until (uint64_t millisec)
	Allocate a memory block of type T, blocking. More...

T *	calloc (MBED_UNUSED uint32_t millisec=0)
	Allocate a memory block of type T, and set memory block to zero. More...

T *	calloc_for (uint32_t millisec)
	Allocate a memory block of type T, optionally blocking, and set memory block to zero. More...

T *	calloc_until (uint64_t millisec)
	Allocate a memory block of type T, blocking, and set memory block to zero. More...

osStatus	put (T *mptr)
	Put a mail in the queue. More...

osEvent	get (uint32_t millisec=osWaitForever)
	Get a mail from the queue. More...

osStatus	free (T *mptr)
	Free a memory block from a mail. More...

Detailed Description

template<typename T, uint32_t queue_sz>
class rtos::Mail< T, queue_sz >

The Mail class allows you to control, send, receive or wait for mail.

A mail is a memory block that is sent to a thread or interrupt service routine (ISR).

Template Parameters

T	Data type of a single mail message element.
queue_sz	Maximum number of mail messages in queue.

Note: Memory considerations: The mail data store and control structures are part of this class - they do not (themselves) allocate memory on the heap, both for the Mbed OS and underlying RTOS objects (static or dynamic RTOS memory pools are not being used).

Definition at line 63 of file Mail.h.

Constructor & Destructor Documentation

Mail ( )

Create and initialize Mail queue.

Note: You cannot call this function from ISR context.

Definition at line 69 of file Mail.h.

Member Function Documentation

T* alloc ( MBED_UNUSED uint32_t millisec = 0 )

Allocate a memory block of type T, without blocking.

Parameters

millisec Not used (see note).

Returns: Pointer to memory block that you can fill with mail or nullptr in case error.

Note: You may call this function from ISR context.; If blocking is required, use Mail::alloc_for or Mail::alloc_until

Definition at line 106 of file Mail.h.

T* alloc_for ( uint32_t millisec )

Allocate a memory block of type T, optionally blocking.

Parameters

millisec Timeout value, or osWaitForever.

Returns: Pointer to memory block that you can fill with mail or nullptr in case error.

Note: You may call this function from ISR context if the millisec parameter is set to 0.

Definition at line 119 of file Mail.h.

T* alloc_until ( uint64_t millisec )

Allocate a memory block of type T, blocking.

Parameters

millisec Absolute timeout time, referenced to Kernel::get_ms_count().

Returns: Pointer to memory block that you can fill with mail or nullptr in case error.

Note: You cannot call this function from ISR context.; the underlying RTOS may have a limit to the maximum wait time due to internal 32-bit computations, but this is guaranteed to work if the wait is <= 0x7fffffff milliseconds (~24 days). If the limit is exceeded, the wait will time out earlier than specified.

Definition at line 136 of file Mail.h.

T* calloc ( MBED_UNUSED uint32_t millisec = 0 )

Allocate a memory block of type T, and set memory block to zero.

Parameters

millisec Not used (see note).

Returns: Pointer to memory block that you can fill with mail or nullptr in case error.

Note: You may call this function from ISR context if the millisec parameter is set to 0.; If blocking is required, use Mail::calloc_for or Mail::calloc_until

Definition at line 150 of file Mail.h.

T* calloc_for ( uint32_t millisec )

Allocate a memory block of type T, optionally blocking, and set memory block to zero.

Parameters

millisec Timeout value, or osWaitForever.

Returns: Pointer to memory block that you can fill with mail or nullptr in case error.

Note: You may call this function from ISR context if the millisec parameter is set to 0.

Definition at line 163 of file Mail.h.

T* calloc_until ( uint64_t millisec )

Allocate a memory block of type T, blocking, and set memory block to zero.

Parameters

millisec Absolute timeout time, referenced to Kernel::get_ms_count().

Returns: Pointer to memory block that you can fill with mail or nullptr in case error.

Note: You cannot call this function from ISR context.; the underlying RTOS may have a limit to the maximum wait time due to internal 32-bit computations, but this is guaranteed to work if the wait is <= 0x7fffffff milliseconds (~24 days). If the limit is exceeded, the wait will time out earlier than specified.

Definition at line 180 of file Mail.h.

bool empty ( ) const

Check if the mail queue is empty.

Returns: State of queue.

Return values

true	Mail queue is empty.
false	Mail queue contains mail.

Note: You may call this function from ISR context.

Definition at line 79 of file Mail.h.

osStatus free ( T * mptr )

Free a memory block from a mail.

Parameters

mptr	Pointer to the memory block that was obtained with Mail::get.

Returns: Status code that indicates the execution status of the function (osOK on success).

Note: You may call this function from ISR context.

Definition at line 227 of file Mail.h.

bool full ( ) const

Check if the mail queue is full.

Returns: State of queue.

Return values

true	Mail queue is full.
false	Mail queue is not full.

Note: You may call this function from ISR context.

Definition at line 92 of file Mail.h.

osEvent get ( uint32_t millisec = osWaitForever )

Get a mail from the queue.

Parameters

millisec Timeout value (default: osWaitForever).

Returns: Event that contains mail information or error code.

Return values

osEventMessage	Message received.
osOK	No mail is available (and no timeout was specified).
osEventTimeout	No mail has arrived during the given timeout period.
osErrorParameter	A parameter is invalid or outside of a permitted range.

Note: You may call this function from ISR context if the millisec parameter is set to 0.

Definition at line 210 of file Mail.h.

osStatus put ( T * mptr )

Put a mail in the queue.

Parameters

mptr	Memory block previously allocated with Mail::alloc or Mail::calloc.

Returns: Status code that indicates the execution status of the function (osOK on success).

Note: You may call this function from ISR context.

Definition at line 193 of file Mail.h.

Public Member Functions

Detailed Description

template<typename T, uint32_t queue_sz> class rtos::Mail< T, queue_sz >

Constructor & Destructor Documentation

Member Function Documentation

Important Information for this Arm website

template<typename T, uint32_t queue_sz>
class rtos::Mail< T, queue_sz >