initial import

from
http://www.informit.com/store/programming-with-posix-threads-9780201633924

alarm_thread.c

@@ -0,0 +1,59 @@
+/*
+ * alarm_fork.c
+ *
+ * This version of alarm.c uses pthread_create to create a
+ * separate thread to wait for each alarm to expire.
+ */
+#include <pthread.h>
+#include "errors.h"
+
+typedef struct alarm_tag {
+    int         seconds;
+    char        message[64];
+} alarm_t;
+
+void *alarm_thread (void *arg)
+{
+    alarm_t *alarm = (alarm_t*)arg;
+    int status;
+
+    status = pthread_detach (pthread_self ());
+    if (status != 0)
+        err_abort (status, "Detach thread");
+    sleep (alarm->seconds);
+    printf ("(%d) %s\n", alarm->seconds, alarm->message);
+    free (alarm);
+    return NULL;
+}
+int main (int argc, char *argv[])
+{
+    int status;
+    char line[128];
+    alarm_t *alarm;
+    pthread_t thread;
+
+    while (1) {
+        printf ("Alarm> ");
+        if (fgets (line, sizeof (line), stdin) == NULL) exit (0);
+        if (strlen (line) <= 1) continue;
+        alarm = (alarm_t*)malloc (sizeof (alarm_t));
+        if (alarm == NULL)
+            errno_abort ("Allocate alarm");
+
+        /*
+         * Parse input line into seconds (%d) and a message
+         * (%64[^\n]), consisting of up to 64 characters
+         * separated from the seconds by whitespace.
+         */
+        if (sscanf (line, "%d %64[^\n]", 
+            &alarm->seconds, alarm->message) < 2) {
+            fprintf (stderr, "Bad command\n");
+            free (alarm);
+        } else {
+            status = pthread_create (
+                &thread, NULL, alarm_thread, alarm);
+            if (status != 0)
+                err_abort (status, "Create alarm thread");
+        }
+    }
+}