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Issue with RTOS example code for mail queue

Topic last updated 13 Jul 2015, by jim herd. 0 replies
jim herd
13 Jul 2015

RTOS MAIL

The example 'send_thread' task uses the following code to allocate a buffer

void send_thread (void const *args) {
    uint32_t i = 0;
    while (true) {
        i++; // fake data update
        mail_t *mail = mail_box.alloc();    ******
        mail->voltage = (i * 0.1) * 33;

The call to 'alloc' returns under all circumstances, e.g. when there are no buffers to be allocated. The result is that a fault occurs only when the buffer hits its limit.

void send_thread (void const *args) {
    uint32_t i = 0;
    while (true) {
        i++; // fake data update
        mail_t *mail = mail_box.alloc(osWaitForever);    ******
        mail->voltage = (i * 0.1) * 33;

will force the thread to wait until a buffer becomes available (assuming this is the effect you want).

The RTX documentation at Keil uses 'osWaitForever' in their example code.

Jim herd