生産者消費者に関する注記

notes/生産者消費者/pthread_cc

@@ -0,0 +1,31 @@
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define NUM_THREADS     5
+
+void *PrintHello(void *threadid)
+{
+   long tid;
+   tid = (long)threadid;
+   printf("Hello World! It's me, thread #%ld!\n", tid);
+   pthread_exit(NULL);
+}
+
+int main (int argc, char *argv[])
+{
+   pthread_t threads[NUM_THREADS];
+   int rc;
+   long t;
+   for(t=0; t<NUM_THREADS; t++){
+      printf("In main: creating thread %ld\n", t);
+      rc = pthread_create(&threads[t], NULL, PrintHello, (void *)t);
+      if (rc){
+         printf("ERROR; return code from pthread_create() is %d\n", rc);
+         exit(-1);
+      }
+   }
+
+   /* Last thing that main() should do */
+   pthread_exit(NULL);
+}

notes/生産者消費者/生産者消費者コード

@@ -0,0 +1,191 @@
+#include<iostream>
+#include<semaphore.h>
+#include<stdio.h>
+#include<iomanip>
+#include<pthread.h>
+#include<stdlib.h>
+#include<unistd.h>
+
+
+
+#define Producer_Steps 5//producer thread iterations
+#define Consumer_Steps 5 //consumer thread iterations
+#define NUM_THREADS 4 //count of threads
+#define BUFFER_SIZE 10 //max capacity of buffer
+
+
+void * Produce(void *threadIn);
+void * Consume(void *ThreadIn);
+void Insert(int threadIn);
+void Remove(int threadIn);
+
+sem_t full;
+sem_t empty;
+int cookieCount;
+
+pthread_mutex_t mutex;
+
+// Main 
+// executes thread code from codeIn 
+//error checks for proper input
+int main(int argc, char *argv[]){
+    int ret_creats;
+
+    //check semaphore containments for max and empty
+    sem_init(&full, 0, BUFFER_SIZE);
+    sem_init(&empty, 0, 0);
+
+    //make the consumer and produce array for threads
+    pthread_t Consumer[NUM_THREADS];
+    pthread_t Producer[NUM_THREADS];
+
+    //define the mutex
+    pthread_mutex_init(&mutex,NULL);
+
+    long c = 0;
+	while (c < NUM_THREADS){	
+		ret_creats = pthread_create(&Consumer[c], NULL, Consume, (void *) c);	
+		if(ret_creats){	
+            //error check for test case
+			std::cerr << "Error in Consumer create" << std::endl;
+			exit(-1);
+		}
+        c++;
+	}
+
+        long p = 0;
+	while (p < NUM_THREADS){	
+		ret_creats = pthread_create(&Producer[p], NULL, Produce, (void *) p);
+		if(ret_creats){	
+            //error check for test case
+			std::cerr << "Error in producer create" << std::endl;
+			exit(-1);
+		}
+        p++;
+	}
+
+    //this deletes the total number of threads
+    //once the endpoint of Consumer is reached
+    int k = 0;    
+	while (k < NUM_THREADS){	
+		pthread_join(Consumer[k], NULL);
+        k++;
+	}
+
+    //this deletes the total number of threads
+    //one the endpoint of Producer is reaches
+    int l = 0;
+	while(l < NUM_THREADS){	
+		pthread_join(Producer[l], NULL);
+        l++;
+	}
+
+    //end print statement
+    std::cout << "All threads are done." << std::endl;
+	std::cout << "Resources cleaned up." << std::endl;
+
+    pthread_mutex_destroy(&mutex);
+	pthread_exit(NULL);
+
+	// delete the semaphores.
+	sem_destroy(&full);	
+	sem_destroy(&empty);	
+
+	return 0;
+}
+
+
+//this function inserts, adds, and configures
+// threads to add one 
+void Insert(int threadIn){
+    int codeIn;
+    //attempt mutex lock
+    codeIn = pthread_mutex_lock(&mutex);
+
+    //error check #1
+    if(codeIn !=0){
+        std::cerr << "producer #" << threadIn << "Error in the lock" << std::endl;
+        exit(-1);
+    }
+    else{
+        cookieCount++;
+        std::cerr <<"producer #" << threadIn << " inserted a cookie." << " Total: " << cookieCount << std::endl;
+    }
+
+    //this step unlocks the mutex
+    codeIn = pthread_mutex_unlock(&mutex);
+
+    //if error then halt the program and quit
+    //otherwise just disregard
+    if(codeIn != 0){
+        std::cerr << "producer #" << threadIn << " Error in the Unlock" << std::endl;
+    }
+
+}
+
+//this function will take the cookieCount out
+// of the counter and lock and relock & repeat
+void Remove(int threadIn) {
+    //placeholder for the pthread_mutex
+    //and lock
+    int codeIn = pthread_mutex_lock(&mutex);
+    //error check for lock
+    if (codeIn != 0) {
+        std::cerr <<"consumer #" << threadIn << ": Failed in Remove: lock" << std::endl;
+        exit(-1);
+    }
+    else {
+        //decrement the counter
+        cookieCount--;
+        std::cerr << "consumer #" << threadIn << " removed a cookie. " << "Total: " << cookieCount << std::endl; 
+    }
+
+    //this unlocks the mutex when the function is being called
+    codeIn = pthread_mutex_unlock(&mutex);
+
+    //error check for unlock
+    if (codeIn != 0) {
+        std::cerr << "consumer: #" << threadIn << ": Failed in Remove Unlock" << std::endl;
+        exit(-1);
+    }
+}
+
+//producer thread will alternate between inserting 
+//an item and sleeping for 1 second. It will do so for 5 
+//times. Call sleep(1) to sleep for 1 second between iterations.
+
+void * Produce(void *threadIn) {
+    long temp = (long)threadIn;
+
+    int i = 0;
+    while (i < Producer_Steps) {
+        sem_wait(&full);
+        Insert(temp);
+        sem_post(&empty);
+        //sleep and increment
+        sleep(1);
+        i++;
+    }
+    //finish
+    pthread_exit(NULL);
+}
+
+//cosumer thread runs eacdh thread to delete int
+//countwidbuffer
+
+void * Consume(void * threadIn){
+    //convert value to int
+    long temp = (long)threadIn;
+
+    int i = 0;
+    while (i < Consumer_Steps) {
+        sem_wait(&empty);
+        Remove(temp);
+        sem_post(&full);
+        //sleep and increment
+        sleep(1);
+        i++;
+    }
+    //finish
+    pthread_exit(NULL);
+}