diff --git a/fw/Makefile b/fw/Makefile index 8ada67c..c9fcb52 100644 --- a/fw/Makefile +++ b/fw/Makefile @@ -15,9 +15,12 @@ U8G2_SRC:=$(U8G2_DIR)/u8x8_d_$(DISPLAY).c $(filter-out $(U8G2_DIR)/u8x8_d_%.c, \ FRMATH_DIR:=fr_math FRMATH_SRC:=$(wildcard $(FRMATH_DIR)/*.c) -EXTRA_CFLAGS += -I$(U8G2_DIR) -I$(FRMATH_DIR) +# include protothreads +PT_DIR:=pt + +EXTRA_CFLAGS += -I$(U8G2_DIR) -I$(FRMATH_DIR) -I$(PT_DIR) ADDITIONAL_C_FILES += lib_i2c.c display.c sc7a20.c pd.c -HEADER_FILES := $(wildcard *.h) +HEADER_FILES := $(wildcard *.h) $(wildcard $(PT_DIR)/*.h) include ch32fun/ch32fun/ch32fun.mk diff --git a/fw/pt/lc-addrlabels.h b/fw/pt/lc-addrlabels.h new file mode 100644 index 0000000..3e6474e --- /dev/null +++ b/fw/pt/lc-addrlabels.h @@ -0,0 +1,85 @@ +/* + * Copyright (c) 2004-2005, 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. Neither the name of the Institute nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``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 INSTITUTE OR CONTRIBUTORS 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 Contiki operating system. + * + * Author: Adam Dunkels + * + * $Id: lc-addrlabels.h,v 1.4 2006/06/03 11:29:43 adam Exp $ + */ + +/** + * \addtogroup lc + * @{ + */ + +/** + * \file + * Implementation of local continuations based on the "Labels as + * values" feature of gcc + * \author + * Adam Dunkels + * + * This implementation of local continuations is based on a special + * feature of the GCC C compiler called "labels as values". This + * feature allows assigning pointers with the address of the code + * corresponding to a particular C label. + * + * For more information, see the GCC documentation: + * http://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html + * + */ + +#ifndef __LC_ADDRLABELS_H__ +#define __LC_ADDRLABELS_H__ + +/** \hideinitializer */ +typedef void * lc_t; + +#define LC_INIT(s) s = NULL + +#define LC_RESUME(s) \ + do { \ + if(s != NULL) { \ + goto *s; \ + } \ + } while(0) + +#define LC_CONCAT2(s1, s2) s1##s2 +#define LC_CONCAT(s1, s2) LC_CONCAT2(s1, s2) + +#define LC_SET(s) \ + do { \ + LC_CONCAT(LC_LABEL, __LINE__): \ + (s) = &&LC_CONCAT(LC_LABEL, __LINE__); \ + } while(0) + +#define LC_END(s) + +#endif /* __LC_ADDRLABELS_H__ */ +/** @} */ diff --git a/fw/pt/lc-switch.h b/fw/pt/lc-switch.h new file mode 100644 index 0000000..dbdde01 --- /dev/null +++ b/fw/pt/lc-switch.h @@ -0,0 +1,76 @@ +/* + * Copyright (c) 2004-2005, 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. Neither the name of the Institute nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``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 INSTITUTE OR CONTRIBUTORS 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 Contiki operating system. + * + * Author: Adam Dunkels + * + * $Id: lc-switch.h,v 1.4 2006/06/03 11:29:43 adam Exp $ + */ + +/** + * \addtogroup lc + * @{ + */ + +/** + * \file + * Implementation of local continuations based on switch() statment + * \author Adam Dunkels + * + * This implementation of local continuations uses the C switch() + * statement to resume execution of a function somewhere inside the + * function's body. The implementation is based on the fact that + * switch() statements are able to jump directly into the bodies of + * control structures such as if() or while() statmenets. + * + * This implementation borrows heavily from Simon Tatham's coroutines + * implementation in C: + * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html + */ + +#ifndef __LC_SWITCH_H__ +#define __LC_SWITCH_H__ + +/* WARNING! lc implementation using switch() does not work if an + LC_SET() is done within another switch() statement! */ + +/** \hideinitializer */ +typedef unsigned short lc_t; + +#define LC_INIT(s) s = 0; + +#define LC_RESUME(s) switch(s) { case 0: + +#define LC_SET(s) s = __LINE__; case __LINE__: + +#define LC_END(s) } + +#endif /* __LC_SWITCH_H__ */ + +/** @} */ diff --git a/fw/pt/lc.h b/fw/pt/lc.h new file mode 100644 index 0000000..a965956 --- /dev/null +++ b/fw/pt/lc.h @@ -0,0 +1,132 @@ +/* + * Copyright (c) 2004-2005, 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. Neither the name of the Institute nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``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 INSTITUTE OR CONTRIBUTORS 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 protothreads library. + * + * Author: Adam Dunkels + * + * $Id: lc.h,v 1.2 2005/02/24 10:36:59 adam Exp $ + */ + +/** + * \addtogroup pt + * @{ + */ + +/** + * \defgroup lc Local continuations + * @{ + * + * Local continuations form the basis for implementing protothreads. A + * local continuation can be set in a specific function to + * capture the state of the function. After a local continuation has + * been set can be resumed in order to restore the state of the + * function at the point where the local continuation was set. + * + * + */ + +/** + * \file lc.h + * Local continuations + * \author + * Adam Dunkels + * + */ + +#ifdef DOXYGEN +/** + * Initialize a local continuation. + * + * This operation initializes the local continuation, thereby + * unsetting any previously set continuation state. + * + * \hideinitializer + */ +#define LC_INIT(lc) + +/** + * Set a local continuation. + * + * The set operation saves the state of the function at the point + * where the operation is executed. As far as the set operation is + * concerned, the state of the function does not include the + * call-stack or local (automatic) variables, but only the program + * counter and such CPU registers that needs to be saved. + * + * \hideinitializer + */ +#define LC_SET(lc) + +/** + * Resume a local continuation. + * + * The resume operation resumes a previously set local continuation, thus + * restoring the state in which the function was when the local + * continuation was set. If the local continuation has not been + * previously set, the resume operation does nothing. + * + * \hideinitializer + */ +#define LC_RESUME(lc) + +/** + * Mark the end of local continuation usage. + * + * The end operation signifies that local continuations should not be + * used any more in the function. This operation is not needed for + * most implementations of local continuation, but is required by a + * few implementations. + * + * \hideinitializer + */ +#define LC_END(lc) + +/** + * \var typedef lc_t; + * + * The local continuation type. + * + * \hideinitializer + */ +#endif /* DOXYGEN */ + +#ifndef __LC_H__ +#define __LC_H__ + + +#ifdef LC_INCLUDE +#include LC_INCLUDE +#else +#include "lc-switch.h" +#endif /* LC_INCLUDE */ + +#endif /* __LC_H__ */ + +/** @} */ +/** @} */ diff --git a/fw/pt/pt-sem.h b/fw/pt/pt-sem.h new file mode 100644 index 0000000..98ae25d --- /dev/null +++ b/fw/pt/pt-sem.h @@ -0,0 +1,228 @@ +/* + * Copyright (c) 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. Neither the name of the Institute nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``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 INSTITUTE OR CONTRIBUTORS 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 protothreads library. + * + * Author: Adam Dunkels + * + * $Id: pt-sem.h,v 1.2 2005/02/24 10:36:59 adam Exp $ + */ + +/** + * \addtogroup pt + * @{ + */ + +/** + * \defgroup ptsem Protothread semaphores + * @{ + * + * This module implements counting semaphores on top of + * protothreads. Semaphores are a synchronization primitive that + * provide two operations: "wait" and "signal". The "wait" operation + * checks the semaphore counter and blocks the thread if the counter + * is zero. The "signal" operation increases the semaphore counter but + * does not block. If another thread has blocked waiting for the + * semaphore that is signalled, the blocked thread will become + * runnable again. + * + * Semaphores can be used to implement other, more structured, + * synchronization primitives such as monitors and message + * queues/bounded buffers (see below). + * + * The following example shows how the producer-consumer problem, also + * known as the bounded buffer problem, can be solved using + * protothreads and semaphores. Notes on the program follow after the + * example. + * + \code +#include "pt-sem.h" + +#define NUM_ITEMS 32 +#define BUFSIZE 8 + +static struct pt_sem mutex, full, empty; + +PT_THREAD(producer(struct pt *pt)) +{ + static int produced; + + PT_BEGIN(pt); + + for(produced = 0; produced < NUM_ITEMS; ++produced) { + + PT_SEM_WAIT(pt, &full); + + PT_SEM_WAIT(pt, &mutex); + add_to_buffer(produce_item()); + PT_SEM_SIGNAL(pt, &mutex); + + PT_SEM_SIGNAL(pt, &empty); + } + + PT_END(pt); +} + +PT_THREAD(consumer(struct pt *pt)) +{ + static int consumed; + + PT_BEGIN(pt); + + for(consumed = 0; consumed < NUM_ITEMS; ++consumed) { + + PT_SEM_WAIT(pt, &empty); + + PT_SEM_WAIT(pt, &mutex); + consume_item(get_from_buffer()); + PT_SEM_SIGNAL(pt, &mutex); + + PT_SEM_SIGNAL(pt, &full); + } + + PT_END(pt); +} + +PT_THREAD(driver_thread(struct pt *pt)) +{ + static struct pt pt_producer, pt_consumer; + + PT_BEGIN(pt); + + PT_SEM_INIT(&empty, 0); + PT_SEM_INIT(&full, BUFSIZE); + PT_SEM_INIT(&mutex, 1); + + PT_INIT(&pt_producer); + PT_INIT(&pt_consumer); + + PT_WAIT_THREAD(pt, producer(&pt_producer) & + consumer(&pt_consumer)); + + PT_END(pt); +} + \endcode + * + * The program uses three protothreads: one protothread that + * implements the consumer, one thread that implements the producer, + * and one protothread that drives the two other protothreads. The + * program uses three semaphores: "full", "empty" and "mutex". The + * "mutex" semaphore is used to provide mutual exclusion for the + * buffer, the "empty" semaphore is used to block the consumer is the + * buffer is empty, and the "full" semaphore is used to block the + * producer is the buffer is full. + * + * The "driver_thread" holds two protothread state variables, + * "pt_producer" and "pt_consumer". It is important to note that both + * these variables are declared as static. If the static + * keyword is not used, both variables are stored on the stack. Since + * protothreads do not store the stack, these variables may be + * overwritten during a protothread wait operation. Similarly, both + * the "consumer" and "producer" protothreads declare their local + * variables as static, to avoid them being stored on the stack. + * + * + */ + +/** + * \file + * Couting semaphores implemented on protothreads + * \author + * Adam Dunkels + * + */ + +#ifndef __PT_SEM_H__ +#define __PT_SEM_H__ + +#include "pt.h" + +struct pt_sem { + unsigned int count; +}; + +/** + * Initialize a semaphore + * + * This macro initializes a semaphore with a value for the + * counter. Internally, the semaphores use an "unsigned int" to + * represent the counter, and therefore the "count" argument should be + * within range of an unsigned int. + * + * \param s (struct pt_sem *) A pointer to the pt_sem struct + * representing the semaphore + * + * \param c (unsigned int) The initial count of the semaphore. + * \hideinitializer + */ +#define PT_SEM_INIT(s, c) (s)->count = c + +/** + * Wait for a semaphore + * + * This macro carries out the "wait" operation on the semaphore. The + * wait operation causes the protothread to block while the counter is + * zero. When the counter reaches a value larger than zero, the + * protothread will continue. + * + * \param pt (struct pt *) A pointer to the protothread (struct pt) in + * which the operation is executed. + * + * \param s (struct pt_sem *) A pointer to the pt_sem struct + * representing the semaphore + * + * \hideinitializer + */ +#define PT_SEM_WAIT(pt, s) \ + do { \ + PT_WAIT_UNTIL(pt, (s)->count > 0); \ + --(s)->count; \ + } while(0) + +/** + * Signal a semaphore + * + * This macro carries out the "signal" operation on the semaphore. The + * signal operation increments the counter inside the semaphore, which + * eventually will cause waiting protothreads to continue executing. + * + * \param pt (struct pt *) A pointer to the protothread (struct pt) in + * which the operation is executed. + * + * \param s (struct pt_sem *) A pointer to the pt_sem struct + * representing the semaphore + * + * \hideinitializer + */ +#define PT_SEM_SIGNAL(pt, s) ++(s)->count + +#endif /* __PT_SEM_H__ */ + +/** @} */ +/** @} */ + diff --git a/fw/pt/pt.h b/fw/pt/pt.h new file mode 100644 index 0000000..92856cb --- /dev/null +++ b/fw/pt/pt.h @@ -0,0 +1,323 @@ +/* + * Copyright (c) 2004-2005, 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. Neither the name of the Institute nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``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 INSTITUTE OR CONTRIBUTORS 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 Contiki operating system. + * + * Author: Adam Dunkels + * + * $Id: pt.h,v 1.7 2006/10/02 07:52:56 adam Exp $ + */ + +/** + * \addtogroup pt + * @{ + */ + +/** + * \file + * Protothreads implementation. + * \author + * Adam Dunkels + * + */ + +#ifndef __PT_H__ +#define __PT_H__ + +#include "lc.h" + +struct pt { + lc_t lc; +}; + +#define PT_WAITING 0 +#define PT_YIELDED 1 +#define PT_EXITED 2 +#define PT_ENDED 3 + +/** + * \name Initialization + * @{ + */ + +/** + * Initialize a protothread. + * + * Initializes a protothread. Initialization must be done prior to + * starting to execute the protothread. + * + * \param pt A pointer to the protothread control structure. + * + * \sa PT_SPAWN() + * + * \hideinitializer + */ +#define PT_INIT(pt) LC_INIT((pt)->lc) + +/** @} */ + +/** + * \name Declaration and definition + * @{ + */ + +/** + * Declaration of a protothread. + * + * This macro is used to declare a protothread. All protothreads must + * be declared with this macro. + * + * \param name_args The name and arguments of the C function + * implementing the protothread. + * + * \hideinitializer + */ +#define PT_THREAD(name_args) char name_args + +/** + * Declare the start of a protothread inside the C function + * implementing the protothread. + * + * This macro is used to declare the starting point of a + * protothread. It should be placed at the start of the function in + * which the protothread runs. All C statements above the PT_BEGIN() + * invokation will be executed each time the protothread is scheduled. + * + * \param pt A pointer to the protothread control structure. + * + * \hideinitializer + */ +#define PT_BEGIN(pt) { char PT_YIELD_FLAG = 1; LC_RESUME((pt)->lc) + +/** + * Declare the end of a protothread. + * + * This macro is used for declaring that a protothread ends. It must + * always be used together with a matching PT_BEGIN() macro. + * + * \param pt A pointer to the protothread control structure. + * + * \hideinitializer + */ +#define PT_END(pt) LC_END((pt)->lc); PT_YIELD_FLAG = 0; \ + PT_INIT(pt); return PT_ENDED; } + +/** @} */ + +/** + * \name Blocked wait + * @{ + */ + +/** + * Block and wait until condition is true. + * + * This macro blocks the protothread until the specified condition is + * true. + * + * \param pt A pointer to the protothread control structure. + * \param condition The condition. + * + * \hideinitializer + */ +#define PT_WAIT_UNTIL(pt, condition) \ + do { \ + LC_SET((pt)->lc); \ + if(!(condition)) { \ + return PT_WAITING; \ + } \ + } while(0) + +/** + * Block and wait while condition is true. + * + * This function blocks and waits while condition is true. See + * PT_WAIT_UNTIL(). + * + * \param pt A pointer to the protothread control structure. + * \param cond The condition. + * + * \hideinitializer + */ +#define PT_WAIT_WHILE(pt, cond) PT_WAIT_UNTIL((pt), !(cond)) + +/** @} */ + +/** + * \name Hierarchical protothreads + * @{ + */ + +/** + * Block and wait until a child protothread completes. + * + * This macro schedules a child protothread. The current protothread + * will block until the child protothread completes. + * + * \note The child protothread must be manually initialized with the + * PT_INIT() function before this function is used. + * + * \param pt A pointer to the protothread control structure. + * \param thread The child protothread with arguments + * + * \sa PT_SPAWN() + * + * \hideinitializer + */ +#define PT_WAIT_THREAD(pt, thread) PT_WAIT_WHILE((pt), PT_SCHEDULE(thread)) + +/** + * Spawn a child protothread and wait until it exits. + * + * This macro spawns a child protothread and waits until it exits. The + * macro can only be used within a protothread. + * + * \param pt A pointer to the protothread control structure. + * \param child A pointer to the child protothread's control structure. + * \param thread The child protothread with arguments + * + * \hideinitializer + */ +#define PT_SPAWN(pt, child, thread) \ + do { \ + PT_INIT((child)); \ + PT_WAIT_THREAD((pt), (thread)); \ + } while(0) + +/** @} */ + +/** + * \name Exiting and restarting + * @{ + */ + +/** + * Restart the protothread. + * + * This macro will block and cause the running protothread to restart + * its execution at the place of the PT_BEGIN() call. + * + * \param pt A pointer to the protothread control structure. + * + * \hideinitializer + */ +#define PT_RESTART(pt) \ + do { \ + PT_INIT(pt); \ + return PT_WAITING; \ + } while(0) + +/** + * Exit the protothread. + * + * This macro causes the protothread to exit. If the protothread was + * spawned by another protothread, the parent protothread will become + * unblocked and can continue to run. + * + * \param pt A pointer to the protothread control structure. + * + * \hideinitializer + */ +#define PT_EXIT(pt) \ + do { \ + PT_INIT(pt); \ + return PT_EXITED; \ + } while(0) + +/** @} */ + +/** + * \name Calling a protothread + * @{ + */ + +/** + * Schedule a protothread. + * + * This function shedules a protothread. The return value of the + * function is non-zero if the protothread is running or zero if the + * protothread has exited. + * + * \param f The call to the C function implementing the protothread to + * be scheduled + * + * \hideinitializer + */ +#define PT_SCHEDULE(f) ((f) < PT_EXITED) + +/** @} */ + +/** + * \name Yielding from a protothread + * @{ + */ + +/** + * Yield from the current protothread. + * + * This function will yield the protothread, thereby allowing other + * processing to take place in the system. + * + * \param pt A pointer to the protothread control structure. + * + * \hideinitializer + */ +#define PT_YIELD(pt) \ + do { \ + PT_YIELD_FLAG = 0; \ + LC_SET((pt)->lc); \ + if(PT_YIELD_FLAG == 0) { \ + return PT_YIELDED; \ + } \ + } while(0) + +/** + * \brief Yield from the protothread until a condition occurs. + * \param pt A pointer to the protothread control structure. + * \param cond The condition. + * + * This function will yield the protothread, until the + * specified condition evaluates to true. + * + * + * \hideinitializer + */ +#define PT_YIELD_UNTIL(pt, cond) \ + do { \ + PT_YIELD_FLAG = 0; \ + LC_SET((pt)->lc); \ + if((PT_YIELD_FLAG == 0) || !(cond)) { \ + return PT_YIELDED; \ + } \ + } while(0) + +/** @} */ + +#endif /* __PT_H__ */ + +/** @} */