Workers

core/platform.h

@@ -90,6 +90,11 @@ typedef _microstep_t microstep_t;
 
 #ifdef NUMBER_OF_WORKERS
 
+/**
+ * @brief Get the number of cores on the host machine.
+ */
+extern int lf_host_cores();
+
 /**
  * Create a new thread, starting with execution of lf_thread
  * getting passed arguments. The new handle is stored in thread_id.

core/platform/lf_linux_support.c

@@ -41,6 +41,7 @@ THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #endif
 
 #include "lf_unix_clock_support.c"
+#include "lf_unix_syscall_support.c"
 
 /**
  * Pause execution for a number of nanoseconds.

core/platform/lf_macos_support.c

@@ -41,6 +41,7 @@ THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #endif
 
 #include "lf_unix_clock_support.c"
+#include "lf_unix_syscall_support.c"
 
 /**
  * Pause execution for a number of nanoseconds.

core/platform/lf_unix_syscall_support.c

@@ -0,0 +1,19 @@
+/**
+ * @file lf_unix_syscall_support.c
+ * @author Soroush Bateni ([email protected])
+ * @brief Platform support for syscalls in Unix-like systems.
+ * @version 0.1
+ * @date 2022-03-09
+ * 
+ * @copyright Copyright (c) 2022 The University of Texas at Dallas
+ * 
+ */
+
+#include <unistd.h>
+
+/**
+ * @brief Get the number of cores on the host machine.
+ */
+int lf_host_cores() {
+    return (int)sysconf(_SC_NPROCESSORS_ONLN);
+}

core/platform/lf_windows_support.c

@@ -35,6 +35,7 @@ THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include <windows.h>
 #include <process.h>
+#include <sysinfoapi.h>
 #include <errno.h>
 #include "lf_windows_support.h"
 #include "../platform.h"
@@ -56,6 +57,15 @@ double _lf_frequency_to_ns = 1.0;
 #define BILLION 1000000000
 
 #ifdef NUMBER_OF_WORKERS
+/**
+ * @brief Get the number of cores on the host machine.
+ */
+int lf_host_cores() {
+    SYSTEM_INFO sysinfo;
+    GetSystemInfo(&sysinfo);
+    return sysinfo.dwNumberOfProcessors;
+}
+
 #if __STDC_VERSION__ < 201112L || defined (__STDC_NO_THREADS__) // (Not C++11 or later) or no threads support
 
 /**

core/threaded/reactor_threaded.c

@@ -1137,8 +1137,23 @@ int lf_reactor_c_main(int argc, char* argv[]) {
 
     if (process_args(default_argc, default_argv)
             && process_args(argc, argv)) {
-        lf_mutex_lock(&mutex); // Sets start_time
-        initialize();
+
+        // If _lf_number_of_threads is 0, it means that it was not provided on
+        // the command-line using the --threads argument.
+        if (_lf_number_of_threads == 0u) {
+            #if !defined(NUMBER_OF_WORKERS) || NUMBER_OF_WORKERS == 0
+            // Use the number of cores on the host machine.
+            _lf_number_of_threads = lf_host_cores();
+            #else
+            // Use the provided number of workers by the user
+            _lf_number_of_threads = NUMBER_OF_WORKERS;
+            #endif
+        }
+
+        lf_mutex_lock(&mutex);
+        initialize(); // Sets start_time
+
+        info_print("---- Using %d workers.", _lf_number_of_threads);
 
         // Initialize the scheduler
         lf_sched_init(