Get threads to deal with exit conditions, create timestamps

[matches/MCTX3420.git] / server / thread.c

diff --git a/server/thread.c b/server/thread.c
new file mode 100644 (file)
index 0000000..57473ea
--- /dev/null
+++ b/server/thread.c
@@ -0,0 +1,62 @@
+/**
+ * @file thread.c
+ * @purpose Implementation of thread control
+ */
+
+#include "thread.h"
+#include "options.h"
+
+pthread_mutex_t mutex_runstate = PTHREAD_MUTEX_INITIALIZER;
+Runstate runstate = RUNNING;
+
+/**
+ * Set the runstate, causing all threads to exit when they next check Thread_Runstate
+ * Repeated calls to this function have no effect on the runstate.
+ * @param error - Set to true to indicate an error occured
+ */
+void Thread_QuitProgram(bool error)
+{
+       if (runstate != RUNNING)
+       {
+               Log(LOGNOTE, "Called when program is not running; runstate = %d", runstate);
+               return;
+       }
+
+
+       Log(LOGNOTE, "Program will quit; error = %d", (int)error);
+
+       //CRITICAL SECTION - We do NOT want multiple threads editing the runstate at the same time!
+       pthread_mutex_lock(&mutex_runstate);
+       if (error)
+               runstate = QUIT_ERROR;
+       else
+               runstate = QUIT;
+       
+       gettimeofday(&g_options.end_time, NULL);
+       pthread_mutex_unlock(&mutex_runstate);
+       // End critical section
+}
+
+/**
+ * Check the runstate; to be called periodically by all threads.
+ * This function will call Thread_QuitProgram and change the Runstate there is an exit condition detected.
+ */
+Runstate Thread_Runstate()
+{
+       //TODO: Add real exit conditions; for testing purposes, set a timeout
+       /*
+       struct timeval time;
+       gettimeofday(&time, NULL);
+       Log(LOGDEBUG, "It has been %d seconds since program started.", time.tv_sec - g_options.start_time.tv_sec);
+       if (time.tv_sec - g_options.start_time.tv_sec > 3)
+       {
+               Thread_QuitProgram(false);
+       }
+       */
+       
+       // Just reading the runstate doesn't really require a mutex
+       // The worst case: Another thread alters the runstate before this thread gets the result; this thread thinks the program is still running
+       // In that case, the thread will run an extra cycle of its loop and *then* exit. Since the runstate can only be changed once.
+       // We could put a mutex here anyway, but it will have an impact on how fast the loops can run.
+       return runstate;
+}