added multithreading sync/memory examples

6 files changed, 432 insertions, 0 deletions

diff --git a/parallel/.gitignore b/parallel/.gitignore
new file mode 100644
index 0000000..6b468b6
--- /dev/null
+++ b/parallel/.gitignore
@@ -0,0 +1 @@
+*.class
diff --git a/parallel/Atomic.java b/parallel/Atomic.java
new file mode 100644
index 0000000..d091e0a
--- /dev/null
+++ b/parallel/Atomic.java
@@ -0,0 +1,18 @@
+public class Main {
+
+	public static volatile boolean running = true;
+	public static int cnt = 0;
+
+public static void main(String[] args) throws InterruptedException {
+	System.out.println("start");
+	Thread t = new Thread( () -> { System.out.println("Ich bin ein Thread"); while (running) { cnt++; }; } );
+	t.start();
+	Thread.sleep(1000);
+	running = false;
+	t.join();
+	System.out.println("ende");
+	System.out.println("ausgefuhrt: " + cnt);
+	System.err.println(cnt);
+}
+
+}
diff --git a/parallel/cig_smoker_problem.c b/parallel/cig_smoker_problem.c
new file mode 100644
index 0000000..9d0928b
--- /dev/null
+++ b/parallel/cig_smoker_problem.c
@@ -0,0 +1,123 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <pthread.h>
+#include <semaphore.h>
+
+#include <assert.h>
+
+
+enum thrd_ids {
+  AGENT_A = 0,
+  AGENT_B,
+  AGENT_C,
+  SMOKER_T,
+  SMOKER_P,
+  SMOKER_M,
+  THRD_MAX
+};
+
+static pthread_t thrds[THRD_MAX];
+
+enum sem_ids {
+  AGENTSEM = 0,
+  TOBACCO,
+  PAPER,
+  MATCH,
+  SEM_MAX
+};
+
+static sem_t sems[SEM_MAX];
+
+
+static void *agenta_thread(void *args)
+{
+  while (1) {
+    sem_wait(&sems[AGENTSEM]);
+    sem_post(&sems[TOBACCO]);
+    sem_post(&sems[PAPER]);
+    printf("AGENT_A: +1 TOBACCO , +1 PAPER\n");
+  }
+  return NULL;
+}
+
+static void *agentb_thread(void *args)
+{
+  while (1) {
+    sem_wait(&sems[AGENTSEM]);
+    sem_post(&sems[PAPER]);
+    sem_post(&sems[MATCH]);
+    printf("AGENT_B: +1 PAPER, +1 MATCH\n");
+  }
+  return NULL;
+}
+
+static void *agentc_thread(void *args)
+{
+  while (1) {
+    sem_wait(&sems[AGENTSEM]);
+    sem_post(&sems[TOBACCO]);
+    sem_post(&sems[MATCH]);
+    printf("AGENT_C: +1 TOBACCO, +1 MATCH\n");
+  }
+  return NULL;
+}
+
+static void *smokerm_thread(void *args)
+{
+  while (1) {
+    sem_wait(&sems[TOBACCO]);
+    sem_wait(&sems[PAPER]);
+    sem_post(&sems[AGENTSEM]);
+    printf("SMOKER_M: +1 PAPER , \n");
+  }
+  return NULL;
+}
+
+static void *smokert_thread(void *args)
+{
+  while (1) {
+    sem_wait(&sems[PAPER]);
+    sem_wait(&sems[MATCH]);
+    sem_post(&sems[AGENTSEM]);
+    printf("SMOKER_T\n");
+  }
+  return NULL;
+}
+
+static void *smokerp_thread(void *args)
+{
+  while (1) {
+    sem_wait(&sems[TOBACCO]);
+    sem_wait(&sems[MATCH]);
+    sem_post(&sems[AGENTSEM]);
+    printf("SMOKER_P\n");
+  }
+  return NULL;
+}
+
+int
+main(int argc, char *argv[])
+{
+  int i;
+
+  for (i = 0; i < SEM_MAX; i++) {
+    assert( sem_init(&sems[i], 0, 0) == 0 );
+  }
+
+  assert( pthread_create(&thrds[AGENT_A], NULL, agenta_thread, NULL) == 0 );
+  assert( pthread_create(&thrds[AGENT_B], NULL, agentb_thread, NULL) == 0 );
+  assert( pthread_create(&thrds[AGENT_C], NULL, agentc_thread, NULL) == 0 );
+  assert( pthread_create(&thrds[SMOKER_M], NULL, smokerm_thread, NULL) == 0 );
+  assert( pthread_create(&thrds[SMOKER_T], NULL, smokert_thread, NULL) == 0 );
+  assert( pthread_create(&thrds[SMOKER_P], NULL, smokerp_thread, NULL) == 0 );
+
+  while (1) {
+    sleep( random() % 5 );
+    sem_post(&sems[AGENTSEM]);
+  }
+  return 0;
+}
+
+
diff --git a/parallel/cig_smoker_problem_stm.c b/parallel/cig_smoker_problem_stm.c
new file mode 100644
index 0000000..a167789
--- /dev/null
+++ b/parallel/cig_smoker_problem_stm.c
@@ -0,0 +1,151 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <pthread.h>
+#include <immintrin.h>
+
+#include <assert.h>
+
+
+enum thrd_ids {
+  AGENT_A = 0,
+  AGENT_B,
+  AGENT_C,
+  SMOKER_T,
+  SMOKER_P,
+  SMOKER_M,
+  THRD_MAX
+};
+
+static pthread_t thrds[THRD_MAX];
+
+/* memory shared by all threads */
+/* only atomic operations are allowed */
+static unsigned int agent_tasks = 0;
+static unsigned int tobacco = 0;
+static unsigned int paper = 0;
+static unsigned int match = 0;
+
+
+static void *agenta_thread(void *args)
+{
+  while (1) {
+    __transaction_atomic {
+      if (agent_tasks > 0) {
+        agent_tasks--;
+        tobacco++; paper++;
+      }
+    }
+    printf("AGENT_A: +1 TOBACCO , +1 PAPER\n");
+    sleep( random() % 5 );
+  }
+  return NULL;
+}
+
+static void *agentb_thread(void *args)
+{
+  while (1) {
+    __transaction_atomic {
+      if (agent_tasks > 0) {
+        agent_tasks--;
+        paper++; match++;
+      }
+    }
+    printf("AGENT_B: +1 PAPER, +1 MATCH\n");
+    sleep( random() % 5 );
+  }
+  return NULL;
+}
+
+static void *agentc_thread(void *args)
+{
+  while (1) {
+    __transaction_atomic {
+      if (agent_tasks > 0) {
+        agent_tasks--;
+        tobacco++; match++;
+      }
+    }
+    printf("AGENT_C: +1 TOBACCO, +1 MATCH\n");
+    sleep( random() % 5 );
+  }
+  return NULL;
+}
+
+static void *smokerm_thread(void *args)
+{
+  while (1) {
+    __transaction_atomic {
+      if (tobacco > 0 && paper > 0) {
+        agent_tasks++;
+        tobacco--; paper--;
+      }
+    }
+    printf("SMOKER_M: -1 TOBACCO, -1 PAPER\n");
+    sleep( random() % 5 );
+  }
+  return NULL;
+}
+
+static void *smokert_thread(void *args)
+{
+  while (1) {
+    __transaction_atomic {
+      if (paper > 0 && match > 0) {
+        agent_tasks++;
+        paper--; match--;
+      }
+    }
+    printf("SMOKER_T: -1 PAPER, -1 MATCH\n");
+    sleep( random() % 5 );
+  }
+  return NULL;
+}
+
+static void *smokerp_thread(void *args)
+{
+  while (1) {
+    __transaction_atomic {
+      if (tobacco > 0 && match > 0) {
+        agent_tasks++;
+        tobacco--; match--;
+      }
+    }
+    printf("SMOKER_P: -1 TOBACCO, -1 MATCH\n");
+    sleep( random() % 5 );
+  }
+  return NULL;
+}
+
+int
+main(int argc, char *argv[])
+{
+  assert( pthread_create(&thrds[AGENT_A], NULL, agenta_thread, NULL) == 0 );
+  assert( pthread_create(&thrds[AGENT_B], NULL, agentb_thread, NULL) == 0 );
+  assert( pthread_create(&thrds[AGENT_C], NULL, agentc_thread, NULL) == 0 );
+  assert( pthread_create(&thrds[SMOKER_M], NULL, smokerm_thread, NULL) == 0 );
+  assert( pthread_create(&thrds[SMOKER_T], NULL, smokert_thread, NULL) == 0 );
+  assert( pthread_create(&thrds[SMOKER_P], NULL, smokerp_thread, NULL) == 0 );
+
+  while (1) {
+    unsigned char succ = 0;
+    unsigned int t_tasks, t_tobacco, t_paper, t_match;
+    sleep(1);
+    __transaction_atomic {
+      t_tasks = agent_tasks;
+      t_tobacco = tobacco;
+      t_paper = paper;
+      t_match = match;
+      succ = 1;
+    }
+    if (succ == 1) {
+      printf("*** STATUS: %u agent_tasks , %u tobacco , %u paper , %u matches\n", t_tasks, t_tobacco, t_paper, t_match);
+    } else {
+      printf("*** ATOMIC OPERATIONS NOT EXECUTED ***\n");
+    }
+  }
+  return 0;
+}
+
+
diff --git a/parallel/nosync.c b/parallel/nosync.c
new file mode 100644
index 0000000..9ddc5a3
--- /dev/null
+++ b/parallel/nosync.c
@@ -0,0 +1,68 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <pthread.h>
+
+#include <assert.h>
+
+
+struct thread_data {
+  pthread_t thrd;
+  int id;
+  int result;
+};
+  
+
+#define NTHREADS 8
+static const unsigned int nthreads = NTHREADS;
+static const unsigned int iterations = 4000;
+static struct thread_data thrds[NTHREADS];
+
+/* r/w by threads */
+static int sum = 0;
+
+
+void *
+thread_func(void *arg)
+{
+  int i;
+  int s;
+  struct thread_data *td = (struct thread_data *) arg;
+
+  printf("Thread %d started ..\n", td->id);
+
+  /* critical section - no sync */
+  s = sum; // READ
+  for (i = 0; i < iterations; i++) {
+    s++;
+  }
+  sum = s; // WRITE
+
+  return NULL;
+}
+
+int
+main(int argc, char *argv[])
+{
+  int i;
+
+  for (i = 0; i < nthreads; i++) {
+    thrds[i].id = i;
+    thrds[i].result = 0;
+    assert( pthread_create( &(thrds[i].thrd), NULL, thread_func, (void*)&thrds[i] ) == 0 );
+  }
+
+  for (i = 0; i < nthreads; i++) {
+    assert( pthread_join(thrds[i].thrd, NULL) == 0 );
+  }
+
+  printf("Expected result: sum == %d\n", iterations*nthreads);
+  if (sum == iterations*nthreads) {
+    printf("It worked randomly, lucky dude ..\n");
+  } else {
+    printf("This should be the common occasion: sum == %d\n", sum);
+  }
+
+  return 0;
+}
diff --git a/parallel/stm.c b/parallel/stm.c
new file mode 100644
index 0000000..15f5bbf
--- /dev/null
+++ b/parallel/stm.c
@@ -0,0 +1,71 @@
+/*
+ * compile with: gcc -Wall -fgnu-tm -O2 -s stm.c -o stm
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <pthread.h>
+#include <immintrin.h>
+
+
+#include <assert.h>
+
+
+struct thread_data {
+  pthread_t thrd;
+  int id;
+  int result;
+};
+  
+
+#define NTHREADS 8
+static const unsigned int nthreads = NTHREADS;
+static const unsigned int iterations = 4000;
+static struct thread_data thrds[NTHREADS];
+
+/* r/w by threads */
+static int sum = 0;
+
+
+void *
+thread_func(void *arg)
+{
+  int i;
+  struct thread_data *td = (struct thread_data *) arg;
+
+  printf("Thread %d started ..\n", td->id);
+
+  /* critical section - stm */
+  for (i = 0; i < iterations; i++) {
+    __transaction_atomic { sum++; }
+  }
+
+  return NULL;
+}
+
+int
+main(int argc, char *argv[])
+{
+  int i;
+
+  for (i = 0; i < nthreads; i++) {
+    thrds[i].id = i;
+    thrds[i].result = 0;
+    assert( pthread_create( &(thrds[i].thrd), NULL, thread_func, (void*)&thrds[i] ) == 0 );
+  }
+
+  for (i = 0; i < nthreads; i++) {
+    assert( pthread_join(thrds[i].thrd, NULL) == 0 );
+  }
+
+  printf("Expected result: sum == %d\n", iterations*nthreads);
+  if (sum == iterations*nthreads) {
+    printf("STM worked! sum == %d\n", sum);
+  } else {
+    printf("Wrong result? Maybe your GNU-STM does not work. (sum == %d)\n", sum);
+  }
+
+  return 0;
+}