| /**************************************************************************** |
| * examples/ostest/prioinherit.c |
| * |
| * Copyright (C) 2009, 2011 Gregory Nutt. All rights reserved. |
| * Author: Gregory Nutt <spudmonkey@racsa.co.cr> |
| * |
| * 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 NuttX 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 COPYRIGHT HOLDERS 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 |
| * COPYRIGHT OWNER 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. |
| * |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Included Files |
| ****************************************************************************/ |
| |
| #include <stdio.h> |
| #include <unistd.h> |
| #include <semaphore.h> |
| #include <pthread.h> |
| #include <errno.h> |
| |
| #ifdef CONFIG_ARCH_SIM |
| # include <nuttx/arch.h> |
| #endif |
| |
| #include "ostest.h" |
| |
| #if defined(CONFIG_PRIORITY_INHERITANCE) && !defined(CONFIG_DISABLE_SIGNALS) && !defined(CONFIG_DISABLE_PTHREAD) |
| |
| /**************************************************************************** |
| * Definitions |
| ****************************************************************************/ |
| |
| #ifndef CONFIG_SEM_PREALLOCHOLDERS |
| # define CONFIG_SEM_PREALLOCHOLDERS 0 |
| #endif |
| #define NLOWPRI_THREADS (CONFIG_SEM_PREALLOCHOLDERS+1) |
| |
| #ifndef CONFIG_SEM_NNESTPRIO |
| # define CONFIG_SEM_NNESTPRIO 0 |
| #endif |
| #define NHIGHPRI_THREADS (CONFIG_SEM_NNESTPRIO+1) |
| |
| /**************************************************************************** |
| * Private Data |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Private Functions |
| ****************************************************************************/ |
| |
| enum thstate_e |
| { |
| NOTSTARTED = 0, |
| RUNNING, |
| WAITING, |
| DONE |
| }; |
| |
| static sem_t g_sem; |
| static volatile enum thstate_e g_middlestate; |
| static volatile enum thstate_e g_highstate[NHIGHPRI_THREADS]; |
| static volatile enum thstate_e g_lowstate[NLOWPRI_THREADS]; |
| static int g_highpri; |
| static int g_medpri; |
| static int g_lowpri; |
| |
| /**************************************************************************** |
| * Name: nhighpri_waiting |
| ****************************************************************************/ |
| |
| static int nhighpri_waiting(void) |
| { |
| int n = 0; |
| int i; |
| |
| for (i = 0; i < NHIGHPRI_THREADS; i++) |
| { |
| if (g_highstate[i] == WAITING) |
| { |
| n++; |
| } |
| } |
| return n; |
| } |
| |
| /**************************************************************************** |
| * Name: nhighpri_running |
| ****************************************************************************/ |
| |
| static int nhighpri_running(void) |
| { |
| int n = 0; |
| int i; |
| |
| for (i = 0; i < NHIGHPRI_THREADS; i++) |
| { |
| if (g_highstate[i] != DONE) |
| { |
| n++; |
| } |
| } |
| return n; |
| } |
| |
| /**************************************************************************** |
| * Name: highpri_thread |
| ****************************************************************************/ |
| |
| static void *highpri_thread(void *parameter) |
| { |
| int threadno = (int)parameter; |
| int ret; |
| |
| g_highstate[threadno-1] = RUNNING; |
| |
| printf("highpri_thread-%d: Started\n", threadno); |
| FFLUSH(); |
| sleep(1); |
| |
| printf("highpri_thread-%d: Calling sem_wait()\n", threadno); |
| g_highstate[threadno-1] = WAITING; |
| ret = sem_wait(&g_sem); |
| g_highstate[threadno-1] = DONE; |
| |
| if (ret != 0) |
| { |
| printf("highpri_thread-%d: sem_take failed: %d\n", threadno, ret); |
| } |
| else if (g_middlestate == RUNNING) |
| { |
| printf("highpri_thread-%d: SUCCESS midpri_thread is still running!\n", threadno); |
| } |
| else |
| { |
| printf("highpri_thread-%d: ERROR -- midpri_thread has already exited!\n", threadno); |
| } |
| |
| sem_post(&g_sem); |
| printf("highpri_thread-%d: Okay... I'm done!\n", threadno); |
| FFLUSH(); |
| return NULL; |
| } |
| |
| /**************************************************************************** |
| * Name: hog_cpu |
| ****************************************************************************/ |
| |
| static inline void hog_cpu(void) |
| { |
| #ifdef CONFIG_ARCH_SIM |
| /* The simulator doesn't have any mechanism to do asynchronous pre-emption |
| * (basically because it doesn't have any interupts/asynchronous events). |
| * The simulator does "fake" a timer interrupt in up_idle() -- the idle |
| * thread that only executes when nothing else is running. In the simulator, |
| * we cannot suspend the middle priority task, or we wouldn't have the |
| * test that we want. So, we have no option but to pump the fake clock |
| * here by calling up_idle(). Sigh! |
| */ |
| |
| up_idle(); |
| #else |
| /* On real platforms with a real timer interrupt, we really can hog the |
| * CPU. When the sleep() goes off in priority_inheritance(), it will |
| * wake up and start the high priority thread. |
| */ |
| |
| volatile int i; |
| for (i = 0; i < INT_MAX; i++); |
| #endif |
| } |
| |
| /**************************************************************************** |
| * Name: medpri_thread |
| ****************************************************************************/ |
| |
| static void *medpri_thread(void *parameter) |
| { |
| printf("medpri_thread: Started ... I won't let go of the CPU!\n"); |
| g_middlestate = RUNNING; |
| FFLUSH(); |
| |
| /* The following loop will completely block lowpri_thread from running. |
| * UNLESS priority inheritance is working. In that case, its priority |
| * will be boosted. |
| */ |
| |
| while (nhighpri_running() > 0) |
| { |
| hog_cpu(); |
| } |
| |
| printf("medpri_thread: Okay... I'm done!\n"); |
| FFLUSH(); |
| g_middlestate = DONE; |
| return NULL; |
| } |
| |
| /**************************************************************************** |
| * Name: lowpri_thread |
| ****************************************************************************/ |
| |
| static void *lowpri_thread(void *parameter) |
| { |
| void *retval = (void*)-1; |
| struct sched_param sparam; |
| int threadno = (int)parameter; |
| int expected; |
| int count; |
| int policy; |
| int ret; |
| int nwaiting; |
| int i; |
| |
| g_lowstate[threadno-1] = RUNNING; |
| printf("lowpri_thread-%d: Started\n", threadno); |
| |
| ret = pthread_getschedparam(pthread_self(), &policy, &sparam); |
| if (ret != 0) |
| { |
| printf("lowpri_thread-%d: ERROR pthread_getschedparam failed: %d\n", threadno, ret); |
| } |
| else |
| { |
| printf("lowpri_thread-%d: initial priority: %d\n", threadno, sparam.sched_priority); |
| if (sparam.sched_priority != g_lowpri) |
| { |
| printf(" ERROR should have been %d\n", g_lowpri); |
| } |
| } |
| |
| g_lowstate[threadno-1] = WAITING; |
| ret = sem_wait(&g_sem); |
| if (ret != 0) |
| { |
| printf("lowpri_thread-%d: sem_take failed: %d\n", threadno, ret); |
| } |
| else |
| { |
| /* Hang on to the thread until the middle priority thread runs */ |
| |
| while (g_middlestate == NOTSTARTED && nhighpri_waiting() < NHIGHPRI_THREADS) |
| { |
| printf("lowpri_thread-%d: Waiting for the midle pri task to run\n", threadno); |
| printf(" g_middlestate: %d\n", (int)g_middlestate); |
| for (i = 0; i < NHIGHPRI_THREADS; i++) |
| { |
| printf(" g_highstate[%d]: %d\n", i, (int)g_highstate[i]); |
| } |
| printf(" I still have a count on the semaphore\n"); |
| sem_enumholders(&g_sem); |
| FFLUSH(); |
| sleep(1); |
| } |
| |
| /* Account for all of the semaphore counts. At any given time if there are 'n' |
| * running hight prioity tasks, then the semaphore count should be '-n' |
| */ |
| |
| sched_lock(); /* Needs to be atomic */ |
| ret = sem_getvalue(&g_sem, &count); |
| nwaiting = nhighpri_waiting(); |
| sched_unlock(); |
| |
| if (ret < 0) |
| { |
| printf("lowpri_thread-%d: ERROR sem_getvalue failed: %d\n", threadno, errno); |
| } |
| printf("lowpri_thread-%d: Sem count: %d, No. highpri thread: %d\n", threadno, count, nwaiting); |
| |
| /* The middle priority task is running, let go of the semaphore */ |
| |
| if (g_middlestate == RUNNING && nwaiting == -count) |
| { |
| /* Good.. the middle priority task is still running and the counts are okay. */ |
| |
| retval = NULL; |
| } |
| else |
| { |
| /* If the sem count is positive, then there all of the higher priority threads |
| * should have already completed. |
| */ |
| |
| printf("lowpri_thread-%d: %s the middle priority task has already exitted!\n", |
| threadno, count >= 0 ? "SUCCESS" : "ERROR" ); |
| printf(" g_middlestate: %d sem count=%d\n", (int)g_middlestate, count); |
| for (i = 0; i < NHIGHPRI_THREADS; i++) |
| { |
| printf(" g_highstate[%d]: %d\n", i, (int)g_highstate[i]); |
| } |
| } |
| } |
| |
| ret = pthread_getschedparam(pthread_self(), &policy, &sparam); |
| sem_enumholders(&g_sem); |
| sem_post(&g_sem); |
| if (ret != 0) |
| { |
| printf("lowpri_thread-%d: ERROR pthread_getschedparam failed: %d\n", threadno, ret); |
| } |
| else |
| { |
| if (nwaiting > 0) |
| { |
| expected = g_highpri; |
| } |
| else |
| { |
| expected = g_lowpri; |
| } |
| |
| printf("lowpri_thread-%d: %s priority before sem_post: %d\n", |
| threadno, |
| sparam.sched_priority != expected ? "ERROR" : "SUCCESS", |
| sparam.sched_priority); |
| |
| if (sparam.sched_priority != expected) |
| { |
| printf(" ERROR should have been %d\n", expected); |
| } |
| } |
| |
| ret = pthread_getschedparam(pthread_self(), &policy, &sparam); |
| if (ret != 0) |
| { |
| printf("lowpri_thread-%d: ERROR pthread_getschedparam failed: %d\n", threadno, ret); |
| } |
| else |
| { |
| printf("lowpri_thread-%d: %s final priority: %d\n", |
| threadno, |
| sparam.sched_priority != g_lowpri ? "ERROR" : "SUCCESS", |
| sparam.sched_priority); |
| |
| if (sparam.sched_priority != g_lowpri) |
| { |
| printf(" ERROR should have been %d\n", g_lowpri); |
| } |
| } |
| sem_enumholders(&g_sem); |
| |
| printf("lowpri_thread-%d: Okay... I'm done!\n", threadno); |
| FFLUSH(); |
| g_lowstate[threadno-1] = DONE; |
| return retval; |
| } |
| #endif /* CONFIG_PRIORITY_INHERITANCE && !CONFIG_DISABLE_SIGNALS && !CONFIG_DISABLE_PTHREAD */ |
| |
| /**************************************************************************** |
| * Public Functions |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Name: priority_inheritance |
| ****************************************************************************/ |
| |
| void priority_inheritance(void) |
| { |
| #if defined(CONFIG_PRIORITY_INHERITANCE) && !defined(CONFIG_DISABLE_SIGNALS) && !defined(CONFIG_DISABLE_PTHREAD) |
| pthread_t lowpri[NLOWPRI_THREADS]; |
| pthread_t medpri; |
| pthread_t highpri[NHIGHPRI_THREADS]; |
| pthread_addr_t result; |
| pthread_attr_t attr; |
| struct sched_param sparam; |
| int my_pri; |
| int status; |
| int i; |
| |
| printf("priority_inheritance: Started\n"); |
| |
| g_middlestate = NOTSTARTED; |
| for (i = 0; i < NHIGHPRI_THREADS; i++) g_highstate[i] = NOTSTARTED; |
| for (i = 0; i < NLOWPRI_THREADS; i++) g_lowstate[i] = NOTSTARTED; |
| |
| status = sched_getparam (getpid(), &sparam); |
| if (status != 0) |
| { |
| printf("priority_inheritance: sched_getparam failed\n"); |
| sparam.sched_priority = PTHREAD_DEFAULT_PRIORITY; |
| } |
| my_pri = sparam.sched_priority; |
| |
| g_highpri = sched_get_priority_max(SCHED_FIFO); |
| g_lowpri = sched_get_priority_min(SCHED_FIFO); |
| g_medpri = my_pri - 1; |
| |
| sem_init(&g_sem, 0, NLOWPRI_THREADS); |
| dump_nfreeholders("priority_inheritance:"); |
| |
| /* Start the low priority threads */ |
| |
| for (i = 0; i < NLOWPRI_THREADS; i++) |
| { |
| int threadno = i+1; |
| printf("priority_inheritance: Starting lowpri_thread-%d (of %d) at %d\n", |
| threadno, NLOWPRI_THREADS, g_lowpri); |
| status = pthread_attr_init(&attr); |
| if (status != 0) |
| { |
| printf("priority_inheritance: pthread_attr_init failed, status=%d\n", status); |
| } |
| sparam.sched_priority = g_lowpri; |
| status = pthread_attr_setschedparam(&attr,& sparam); |
| if (status != OK) |
| { |
| printf("priority_inheritance: pthread_attr_setschedparam failed, status=%d\n", status); |
| } |
| else |
| { |
| printf("priority_inheritance: Set lowpri_thread-%d priority to %d\n", |
| threadno, sparam.sched_priority); |
| } |
| |
| status = pthread_create(&lowpri[i], &attr, lowpri_thread, (void*)threadno); |
| if (status != 0) |
| { |
| printf("priority_inheritance: pthread_create failed, status=%d\n", status); |
| } |
| } |
| printf("priority_inheritance: Waiting...\n"); |
| sleep(2); |
| dump_nfreeholders("priority_inheritance:"); |
| |
| /* Start the medium priority thread */ |
| |
| printf("priority_inheritance: Starting medpri_thread at %d\n", g_medpri); |
| status = pthread_attr_init(&attr); |
| if (status != 0) |
| { |
| printf("priority_inheritance: pthread_attr_init failed, status=%d\n", status); |
| } |
| |
| sparam.sched_priority = g_medpri; |
| status = pthread_attr_setschedparam(&attr,& sparam); |
| if (status != OK) |
| { |
| printf("priority_inheritance: pthread_attr_setschedparam failed, status=%d\n", status); |
| } |
| else |
| { |
| printf("priority_inheritance: Set medpri_thread priority to %d\n", sparam.sched_priority); |
| } |
| FFLUSH(); |
| |
| status = pthread_create(&medpri, &attr, medpri_thread, NULL); |
| if (status != 0) |
| { |
| printf("priority_inheritance: pthread_create failed, status=%d\n", status); |
| } |
| printf("priority_inheritance: Waiting...\n"); |
| sleep(1); |
| dump_nfreeholders("priority_inheritance:"); |
| |
| /* Start the high priority threads */ |
| |
| for (i = 0; i < NHIGHPRI_THREADS; i++) |
| { |
| int threadno = i+1; |
| printf("priority_inheritance: Starting highpri_thread-%d (of %d) at %d\n", |
| threadno, NHIGHPRI_THREADS, g_highpri); |
| status = pthread_attr_init(&attr); |
| if (status != 0) |
| { |
| printf("priority_inheritance: pthread_attr_init failed, status=%d\n", status); |
| } |
| |
| sparam.sched_priority = g_highpri - i; |
| status = pthread_attr_setschedparam(&attr,& sparam); |
| if (status != OK) |
| { |
| printf("priority_inheritance: pthread_attr_setschedparam failed, status=%d\n", status); |
| } |
| else |
| { |
| printf("priority_inheritance: Set highpri_thread-%d priority to %d\n", |
| threadno, sparam.sched_priority); |
| } |
| FFLUSH(); |
| |
| status = pthread_create(&highpri[i], &attr, highpri_thread, (void*)threadno); |
| if (status != 0) |
| { |
| printf("priority_inheritance: pthread_create failed, status=%d\n", status); |
| } |
| } |
| dump_nfreeholders("priority_inheritance:"); |
| FFLUSH(); |
| |
| /* Wait for all thread instances to complete */ |
| |
| for (i = 0; i < NHIGHPRI_THREADS; i++) |
| { |
| printf("priority_inheritance: Waiting for highpri_thread-%d to complete\n", i+1); |
| FFLUSH(); |
| (void)pthread_join(highpri[i], &result); |
| dump_nfreeholders("priority_inheritance:"); |
| } |
| printf("priority_inheritance: Waiting for medpri_thread to complete\n"); |
| FFLUSH(); |
| (void)pthread_join(medpri, &result); |
| dump_nfreeholders("priority_inheritance:"); |
| for (i = 0; i < NLOWPRI_THREADS; i++) |
| { |
| printf("priority_inheritance: Waiting for lowpri_thread-%d to complete\n", i+1); |
| FFLUSH(); |
| (void)pthread_join(lowpri[i], &result); |
| dump_nfreeholders("priority_inheritance:"); |
| } |
| |
| printf("priority_inheritance: Finished\n"); |
| sem_destroy(&g_sem); |
| dump_nfreeholders("priority_inheritance:"); |
| FFLUSH(); |
| #endif /* CONFIG_PRIORITY_INHERITANCE && !CONFIG_DISABLE_SIGNALS && !CONFIG_DISABLE_PTHREAD */ |
| } |