Hi Michael, do you initialize the flags somewhere with cyg_flag_init() ? This initialisation needs to be made before the first access of the event flag variable.
Best Regards Richard www.itrgmbh.com > -----Ursprüngliche Nachricht----- > Von: ecos-discuss-ow...@ecos.sourceware.org [mailto:ecos-discuss- > ow...@ecos.sourceware.org] Im Auftrag von Michael W. Ellis > Gesendet: Freitag, 27. Mai 2016 15:31 > An: ecos-discuss@ecos.sourceware.org > Betreff: [ECOS] cyg_flag_timed_wait doesn't seem to work as expected > > I'm running an old version of eCos (2.0.98) from eCosCentric and I'm > attempting to use cyg_flag_timed_wait to periodically update a display (see > code, below). My event flag variable g_flags is initialized elsewhere before > this thread is created. Other threads access the same event flag but use their > own bits within the flag. > > My problem is with the timed wait behavior of the event flag. At startup I > see an initial wait of 30 seconds before the first display update occurs, but > the update occurs continually after the initial timeout. The local variable > flags always reads 0, indicating timeout has occurred. My understanding is > that calling cyg_flag_timed_wait at the top of the loop restarts the timer, but > this does not seem to be the case. What am I missing here? Is there > something I must do to clear the timeout event? > > Variable allocation and initialization: > static cyg_flag_t g_flags; // thread sync event flags > cyg_flag_init(&g_flags); // init thread sync flag > > > // ogDisplayThread - update display > static void ogDisplayThread(cyg_addrword_t data) { > diag_printf("Entering ogDisplayThread...\r\n"); > > cyg_flag_setbits(&g_flags, OG_FLAG_DISP_RDY); // say this > thread is ready > > while (1) > { > cyg_flag_value_t flags; > > flags = cyg_flag_timed_wait(&g_flags, // timed wait > OG_FLAG_DISP_EXIT, // wait for EXIT flag or > timeout > CYG_FLAG_WAITMODE_AND, > 3000); // 30 second timeout > > diag_printf("ogDisplayThread flag = %08X\r\n", flags); > > if (flags & OG_FLAG_DISP_EXIT) // if EXIT event > occurred > { > diag_printf("Exiting ogDisplayThread\r\n"); > > cyg_flag_maskbits(&g_flags, // say this thread is no > longer ready > OG_FLAG_DISP_RDY|OG_FLAG_DISP_EXIT); > > cyg_thread_exit(); // and exit thread > } > else if (!flags) // if timeout occurred (normal > condition) > { > diag_printf("ogDisplayThread sending data\r\n"); > ogp_msg_t *msg; > > // send IP address > if (NULL == (msg = malloc(sizeof(ogp_msg_t)))) // allocate a > message buffer > diag_printf("ogDisplayThread malloc error\r\n"); > else > { > msg->sync = htonl(OGP_SYNC_WORD); // build message > msg->src = LOCAL_CMD_SRC; > msg->dst = LOCAL_CMD_DST_SET_IPADDR; > msg->mtype = LOCAL_CMD_MTYPE; > api_eth_get_ip(msg->data, 16); // get IP address string > msg->len = htons(strlen(msg->data)+1); // set length > ogpPutTxQ(msg); // send message > } > } > else // should never get here > diag_printf("ogDisplayThread unexpected event flag\r\n"); > } > } > > Debug output (continual after 30 seconds): > ogDisplayThread flag = 00000000 > ogDisplayThread sending data > ogDisplayThread flag = 00000000 > ogDisplayThread sending data > ogDisplayThread flag = 00000000 > ogDisplayThread sending data > ogDisplayThread flag = 00000000 > ogDisplayThread sending data > ogDisplayThread flag = 00000000 > ogDisplayThread sending data > ogDisplayThread flag = 00000000 > ogDisplayThread sending data > ogDisplayThread flag = 00000000 > ogDisplayThread sending data > > > Thanks, > Michael > > > -- > Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos > and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss
