[examples] add s4u-synchro-semaphore

[simgrid.git] / examples / s4u / synchro-semaphore / s4u-synchro-semaphore.cpp

diff --git a/examples/s4u/synchro-semaphore/s4u-synchro-semaphore.cpp b/examples/s4u/synchro-semaphore/s4u-synchro-semaphore.cpp
new file mode 100644 (file)
index 0000000..8c96391
--- /dev/null
+++ b/examples/s4u/synchro-semaphore/s4u-synchro-semaphore.cpp
@@ -0,0 +1,67 @@
+/* Copyright (c) 2006-2018. The SimGrid Team. All rights reserved.          */
+
+/* This program is free software; you can redistribute it and/or modify it
+ * under the terms of the license (GNU LGPL) which comes with this package. */
+
+#include "simgrid/s4u.hpp"
+
+#include <memory>
+
+XBT_LOG_NEW_DEFAULT_CATEGORY(s4u_test, "a sample log category");
+
+// This example implements a one-time use barrier with 1 semaphore and 1 mutex.
+
+static void worker(simgrid::s4u::SemaphorePtr semaphore, simgrid::s4u::MutexPtr mutex, int process_count, std::shared_ptr<int> count)
+{
+  mutex->lock();
+  XBT_INFO("Got mutex. Incrementing count.");
+  XBT_INFO("Count is %d", *count);
+  *count = (*count) + 1;
+  XBT_INFO("Count is now %d. Process count is %d.", *count, process_count);
+
+  if (*count == process_count) {
+    XBT_INFO("Releasing the semaphore %d times.", process_count-1);
+    for (int i = 0; i < process_count-1; i++) {
+      semaphore->release();
+    }
+
+    XBT_INFO("Releasing mutex.");
+    mutex->unlock();
+  }
+  else {
+    XBT_INFO("Releasing mutex.");
+    mutex->unlock();
+    XBT_INFO("Acquiring semaphore.");
+    semaphore->acquire();
+  }
+
+  XBT_INFO("Bye!");
+}
+
+static void master(unsigned int process_count)
+{
+  simgrid::s4u::SemaphorePtr semaphore = simgrid::s4u::Semaphore::create(0);
+  simgrid::s4u::MutexPtr mutex = simgrid::s4u::Mutex::create();
+  std::shared_ptr<int> count(new int);
+  *count = 0;
+
+  XBT_INFO("Spawning %d workers", process_count);
+  for (unsigned int i = 0; i < process_count; i++) {
+    simgrid::s4u::Actor::create("worker", simgrid::s4u::Host::by_name("Jupiter"), worker, semaphore, mutex, process_count, count);
+  }
+}
+
+int main(int argc, char **argv)
+{
+  // Parameter: Number of processes in the barrier
+  xbt_assert(argc >= 2, "Usage: %s <process-count>\n", argv[0]);
+  unsigned int process_count = std::stoi(argv[1]);
+  xbt_assert(process_count > 0, "<process-count> must be greater than 0");
+
+  simgrid::s4u::Engine e(&argc, argv);
+  e.load_platform("../../platforms/two_hosts.xml");
+  simgrid::s4u::Actor::create("master", simgrid::s4u::Host::by_name("Tremblay"), master, process_count);
+  e.run();
+
+  return 0;
+}