1 files changed, 153 insertions, 0 deletions
diff --git a/notxv6/ph.c b/notxv6/ph.c
new file mode 100644
index 0000000..db8a630
--- /dev/null
+++ b/notxv6/ph.c
@@ -0,0 +1,153 @@
+#include <stdlib.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <assert.h>
+#include <pthread.h>
+#include <sys/time.h>
+
+#define NBUCKET 5
+#define NKEYS 100000
+
+struct entry {
+  int key;
+  int value;
+  struct entry *next;
+};
+struct entry *table[NBUCKET];
+int keys[NKEYS];
+int nthread = 1;
+pthread_mutex_t lock[NBUCKET];
+
+double
+now()
+{
+ struct timeval tv;
+ gettimeofday(&tv, 0);
+ return tv.tv_sec + tv.tv_usec / 1000000.0;
+}
+
+static void 
+insert(int key, int value, struct entry **p, struct entry *n)
+{
+  struct entry *e = malloc(sizeof(struct entry));
+  e->key = key;
+  e->value = value;
+  e->next = n;
+  *p = e;
+}
+
+static 
+void put(int key, int value)
+{
+  int i = key % NBUCKET;
+
+  // is the key already present?
+  struct entry *e = 0;
+  for (e = table[i]; e != 0; e = e->next) {
+    if (e->key == key)
+      break;
+  }
+  pthread_mutex_lock(&lock[i]);
+  if(e){
+    // update the existing key.
+    e->value = value;
+  } else {
+    // the new is new.
+    insert(key, value, &table[i], table[i]);
+  }
+  pthread_mutex_unlock(&lock[i]);
+}
+
+static struct entry*
+get(int key)
+{
+  int i = key % NBUCKET;
+
+
+  struct entry *e = 0;
+  for (e = table[i]; e != 0; e = e->next) {
+    if (e->key == key) break;
+  }
+  return e;
+}
+
+static void *
+put_thread(void *xa)
+{
+  int n = (int) (long) xa; // thread number
+  int b = NKEYS/nthread;
+
+  for (int i = 0; i < b; i++) {
+    put(keys[b*n + i], n);
+  }
+
+  return NULL;
+}
+
+static void *
+get_thread(void *xa)
+{
+  int n = (int) (long) xa; // thread number
+  int missing = 0;
+
+  for (int i = 0; i < NKEYS; i++) {
+    struct entry *e = get(keys[i]);
+    if (e == 0) missing++;
+  }
+  printf("%d: %d keys missing\n", n, missing);
+  return NULL;
+}
+
+int
+main(int argc, char *argv[])
+{
+  pthread_t *tha;
+  void *value;
+  double t1, t0;
+
+
+  if (argc < 2) {
+    fprintf(stderr, "Usage: %s nthreads\n", argv[0]);
+    exit(-1);
+  }
+  nthread = atoi(argv[1]);
+  tha = malloc(sizeof(pthread_t) * nthread);
+  srandom(0);
+  for (int i = 0; i < NBUCKET; i++) {
+    pthread_mutex_init(&lock[i], NULL);
+  }
+  assert(NKEYS % nthread == 0);
+  for (int i = 0; i < NKEYS; i++) {
+    keys[i] = random();
+  }
+
+  //
+  // first the puts
+  //
+  t0 = now();
+  for(int i = 0; i < nthread; i++) {
+    assert(pthread_create(&tha[i], NULL, put_thread, (void *) (long) i) == 0);
+  }
+  for(int i = 0; i < nthread; i++) {
+    assert(pthread_join(tha[i], &value) == 0);
+  }
+  t1 = now();
+
+  printf("%d puts, %.3f seconds, %.0f puts/second\n",
+         NKEYS, t1 - t0, NKEYS / (t1 - t0));
+
+  //
+  // now the gets
+  //
+  t0 = now();
+  for(int i = 0; i < nthread; i++) {
+    assert(pthread_create(&tha[i], NULL, get_thread, (void *) (long) i) == 0);
+  }
+  for(int i = 0; i < nthread; i++) {
+    assert(pthread_join(tha[i], &value) == 0);
+  }
+  t1 = now();
+
+  printf("%d gets, %.3f seconds, %.0f gets/second\n",
+         NKEYS*nthread, t1 - t0, (NKEYS*nthread) / (t1 - t0));
+}