aboutsummaryrefslogtreecommitdiff
path: root/linuxthreads/Examples/ex5.c
diff options
context:
space:
mode:
Diffstat (limited to 'linuxthreads/Examples/ex5.c')
-rw-r--r--linuxthreads/Examples/ex5.c114
1 files changed, 0 insertions, 114 deletions
diff --git a/linuxthreads/Examples/ex5.c b/linuxthreads/Examples/ex5.c
deleted file mode 100644
index d39d487603..0000000000
--- a/linuxthreads/Examples/ex5.c
+++ /dev/null
@@ -1,114 +0,0 @@
-/* The classic producer-consumer example, implemented with semaphores.
- All integers between 0 and 9999 should be printed exactly twice,
- once to the right of the arrow and once to the left. */
-
-#include <stdio.h>
-#include "pthread.h"
-#include "semaphore.h"
-
-#define BUFFER_SIZE 16
-
-/* Circular buffer of integers. */
-
-struct prodcons
-{
- int buffer[BUFFER_SIZE]; /* the actual data */
- int readpos, writepos; /* positions for reading and writing */
- sem_t sem_read; /* number of elements available for reading */
- sem_t sem_write; /* number of locations available for writing */
-};
-
-/* Initialize a buffer */
-
-static void
-init (struct prodcons *b)
-{
- sem_init (&b->sem_write, 0, BUFFER_SIZE - 1);
- sem_init (&b->sem_read, 0, 0);
- b->readpos = 0;
- b->writepos = 0;
-}
-
-/* Store an integer in the buffer */
-
-static void
-put (struct prodcons *b, int data)
-{
- /* Wait until buffer is not full */
- sem_wait (&b->sem_write);
- /* Write the data and advance write pointer */
- b->buffer[b->writepos] = data;
- b->writepos++;
- if (b->writepos >= BUFFER_SIZE)
- b->writepos = 0;
- /* Signal that the buffer contains one more element for reading */
- sem_post (&b->sem_read);
-}
-
-/* Read and remove an integer from the buffer */
-
-static int
-get (struct prodcons *b)
-{
- int data;
- /* Wait until buffer is not empty */
- sem_wait (&b->sem_read);
- /* Read the data and advance read pointer */
- data = b->buffer[b->readpos];
- b->readpos++;
- if (b->readpos >= BUFFER_SIZE)
- b->readpos = 0;
- /* Signal that the buffer has now one more location for writing */
- sem_post (&b->sem_write);
- return data;
-}
-
-/* A test program: one thread inserts integers from 1 to 10000,
- the other reads them and prints them. */
-
-#define OVER (-1)
-
-struct prodcons buffer;
-
-static void *
-producer (void *data)
-{
- int n;
- for (n = 0; n < 10000; n++)
- {
- printf ("%d --->\n", n);
- put (&buffer, n);
- }
- put (&buffer, OVER);
- return NULL;
-}
-
-static void *
-consumer (void *data)
-{
- int d;
- while (1)
- {
- d = get (&buffer);
- if (d == OVER)
- break;
- printf ("---> %d\n", d);
- }
- return NULL;
-}
-
-int
-main (void)
-{
- pthread_t th_a, th_b;
- void *retval;
-
- init (&buffer);
- /* Create the threads */
- pthread_create (&th_a, NULL, producer, 0);
- pthread_create (&th_b, NULL, consumer, 0);
- /* Wait until producer and consumer finish. */
- pthread_join (th_a, &retval);
- pthread_join (th_b, &retval);
- return 0;
-}