![](/media/cache/img/default_profile.jpg.50x50_q85.jpg)
Control of mbed using OSC. Based on code from the Make Controller. Right now you can turn the onboard LEDs on/off and toggle 8 digital out pins. More I/O will be done in the future.
Diff: lwip/lwIP/core/sys.c
- Revision:
- 0:439354122597
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/lwip/lwIP/core/sys.c Wed Mar 17 03:17:38 2010 +0000 @@ -0,0 +1,344 @@ +/** + * @file + * lwIP Operating System abstraction + * + */ + +/* + * Copyright (c) 2001-2004 Swedish Institute of Computer Science. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without modification, + * are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT + * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT + * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING + * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY + * OF SUCH DAMAGE. + * + * This file is part of the lwIP TCP/IP stack. + * + * Author: Adam Dunkels <adam@sics.se> + * + */ + +#include "lwip/opt.h" + +#if (NO_SYS == 0) /* don't build if not configured for use in lwipopts.h */ + +#include "lwip/sys.h" +#include "lwip/def.h" +#include "lwip/memp.h" +#include "lwip/tcpip.h" + +/** + * Struct used for sys_sem_wait_timeout() to tell wether the time + * has run out or the semaphore has really become available. + */ +struct sswt_cb +{ + s16_t timeflag; + sys_sem_t *psem; +}; + +/** + * Wait (forever) for a message to arrive in an mbox. + * While waiting, timeouts (for this thread) are processed. + * + * @param mbox the mbox to fetch the message from + * @param msg the place to store the message + */ +void +sys_mbox_fetch(sys_mbox_t mbox, void **msg) +{ + u32_t time_needed; + struct sys_timeouts *timeouts; + struct sys_timeo *tmptimeout; + sys_timeout_handler h; + void *arg; + + again: + timeouts = sys_arch_timeouts(); + + if (!timeouts || !timeouts->next) { + UNLOCK_TCPIP_CORE(); + time_needed = sys_arch_mbox_fetch(mbox, msg, 0); + LOCK_TCPIP_CORE(); + } else { + if (timeouts->next->time > 0) { + UNLOCK_TCPIP_CORE(); + time_needed = sys_arch_mbox_fetch(mbox, msg, timeouts->next->time); + LOCK_TCPIP_CORE(); + } else { + time_needed = SYS_ARCH_TIMEOUT; + } + + if (time_needed == SYS_ARCH_TIMEOUT) { + /* If time == SYS_ARCH_TIMEOUT, a timeout occured before a message + could be fetched. We should now call the timeout handler and + deallocate the memory allocated for the timeout. */ + tmptimeout = timeouts->next; + timeouts->next = tmptimeout->next; + h = tmptimeout->h; + arg = tmptimeout->arg; + memp_free(MEMP_SYS_TIMEOUT, tmptimeout); + if (h != NULL) { + LWIP_DEBUGF(SYS_DEBUG, ("smf calling h=%p(%p)\n", (void*)&h, arg)); + h(arg); + } + + /* We try again to fetch a message from the mbox. */ + goto again; + } else { + /* If time != SYS_ARCH_TIMEOUT, a message was received before the timeout + occured. The time variable is set to the number of + milliseconds we waited for the message. */ + if (time_needed < timeouts->next->time) { + timeouts->next->time -= time_needed; + } else { + timeouts->next->time = 0; + } + } + } +} + +/** + * Wait (forever) for a semaphore to become available. + * While waiting, timeouts (for this thread) are processed. + * + * @param sem semaphore to wait for + */ +void +sys_sem_wait(sys_sem_t sem) +{ + u32_t time_needed; + struct sys_timeouts *timeouts; + struct sys_timeo *tmptimeout; + sys_timeout_handler h; + void *arg; + + again: + + timeouts = sys_arch_timeouts(); + + if (!timeouts || !timeouts->next) { + sys_arch_sem_wait(sem, 0); + } else { + if (timeouts->next->time > 0) { + time_needed = sys_arch_sem_wait(sem, timeouts->next->time); + } else { + time_needed = SYS_ARCH_TIMEOUT; + } + + if (time_needed == SYS_ARCH_TIMEOUT) { + /* If time == SYS_ARCH_TIMEOUT, a timeout occured before a message + could be fetched. We should now call the timeout handler and + deallocate the memory allocated for the timeout. */ + tmptimeout = timeouts->next; + timeouts->next = tmptimeout->next; + h = tmptimeout->h; + arg = tmptimeout->arg; + memp_free(MEMP_SYS_TIMEOUT, tmptimeout); + if (h != NULL) { + LWIP_DEBUGF(SYS_DEBUG, ("ssw h=%p(%p)\n", (void*)&h, (void *)arg)); + h(arg); + } + + /* We try again to fetch a message from the mbox. */ + goto again; + } else { + /* If time != SYS_ARCH_TIMEOUT, a message was received before the timeout + occured. The time variable is set to the number of + milliseconds we waited for the message. */ + if (time_needed < timeouts->next->time) { + timeouts->next->time -= time_needed; + } else { + timeouts->next->time = 0; + } + } + } +} + +/** + * Create a one-shot timer (aka timeout). Timeouts are processed in the + * following cases: + * - while waiting for a message using sys_mbox_fetch() + * - while waiting for a semaphore using sys_sem_wait() or sys_sem_wait_timeout() + * - while sleeping using the inbuilt sys_msleep() + * + * @param msecs time in milliseconds after that the timer should expire + * @param h callback function to call when msecs have elapsed + * @param arg argument to pass to the callback function + */ +void +sys_timeout(u32_t msecs, sys_timeout_handler h, void *arg) +{ + struct sys_timeouts *timeouts; + struct sys_timeo *timeout, *t; + + timeout = memp_malloc(MEMP_SYS_TIMEOUT); + if (timeout == NULL) { + LWIP_ASSERT("sys_timeout: timeout != NULL", timeout != NULL); + return; + } + timeout->next = NULL; + timeout->h = h; + timeout->arg = arg; + timeout->time = msecs; + + timeouts = sys_arch_timeouts(); + + LWIP_DEBUGF(SYS_DEBUG, ("sys_timeout: %p msecs=%"U32_F" h=%p arg=%p\n", + (void *)timeout, msecs, (void*)&h, (void *)arg)); + + if (timeouts == NULL) { + LWIP_ASSERT("sys_timeout: timeouts != NULL", timeouts != NULL); + return; + } + + if (timeouts->next == NULL) { + timeouts->next = timeout; + return; + } + + if (timeouts->next->time > msecs) { + timeouts->next->time -= msecs; + timeout->next = timeouts->next; + timeouts->next = timeout; + } else { + for(t = timeouts->next; t != NULL; t = t->next) { + timeout->time -= t->time; + if (t->next == NULL || t->next->time > timeout->time) { + if (t->next != NULL) { + t->next->time -= timeout->time; + } + timeout->next = t->next; + t->next = timeout; + break; + } + } + } +} + +/** + * Go through timeout list (for this task only) and remove the first matching + * entry, even though the timeout has not triggered yet. + * + * @note This function only works as expected if there is only one timeout + * calling 'h' in the list of timeouts. + * + * @param h callback function that would be called by the timeout + * @param arg callback argument that would be passed to h +*/ +void +sys_untimeout(sys_timeout_handler h, void *arg) +{ + struct sys_timeouts *timeouts; + struct sys_timeo *prev_t, *t; + + timeouts = sys_arch_timeouts(); + + if (timeouts == NULL) { + LWIP_ASSERT("sys_untimeout: timeouts != NULL", timeouts != NULL); + return; + } + if (timeouts->next == NULL) { + return; + } + + for (t = timeouts->next, prev_t = NULL; t != NULL; prev_t = t, t = t->next) { + if ((t->h == h) && (t->arg == arg)) { + /* We have a match */ + /* Unlink from previous in list */ + if (prev_t == NULL) + timeouts->next = t->next; + else + prev_t->next = t->next; + /* If not the last one, add time of this one back to next */ + if (t->next != NULL) + t->next->time += t->time; + memp_free(MEMP_SYS_TIMEOUT, t); + return; + } + } + return; +} + +/** + * Timeout handler function for sys_sem_wait_timeout() + * + * @param arg struct sswt_cb* used to signal a semaphore and end waiting. + */ +static void +sswt_handler(void *arg) +{ + struct sswt_cb *sswt_cb = (struct sswt_cb *) arg; + + /* Timeout. Set flag to TRUE and signal semaphore */ + sswt_cb->timeflag = 1; + sys_sem_signal(*(sswt_cb->psem)); +} + +/** + * Wait for a semaphore with timeout (specified in ms) + * + * @param sem semaphore to wait + * @param timeout timeout in ms (0: wait forever) + * @return 0 on timeout, 1 otherwise + */ +int +sys_sem_wait_timeout(sys_sem_t sem, u32_t timeout) +{ + struct sswt_cb sswt_cb; + + sswt_cb.psem = &sem; + sswt_cb.timeflag = 0; + + /* If timeout is zero, then just wait forever */ + if (timeout > 0) { + /* Create a timer and pass it the address of our flag */ + sys_timeout(timeout, sswt_handler, &sswt_cb); + } + sys_sem_wait(sem); + /* Was it a timeout? */ + if (sswt_cb.timeflag) { + /* timeout */ + return 0; + } else { + /* Not a timeout. Remove timeout entry */ + sys_untimeout(sswt_handler, &sswt_cb); + return 1; + } +} + +/** + * Sleep for some ms. Timeouts are processed while sleeping. + * + * @param ms number of milliseconds to sleep + */ +void +sys_msleep(u32_t ms) +{ + sys_sem_t delaysem = sys_sem_new(0); + + sys_sem_wait_timeout(delaysem, ms); + + sys_sem_free(delaysem); +} + + +#endif /* NO_SYS */