- example multi-thread app: change to use boinc_init_parallel().

It's way simpler now.


svn path=/trunk/boinc/; revision=20058

checkin_notes

@@ -10796,3 +10796,9 @@ David  31 Dec 2009
         graphics_lib.cpp
     lib/
         win_util.cpp
+
+David  31 Dec 2009
+    - example multi-thread app: change to use boinc_init_parallel().
+        It's way simpler now.
+    samples/multi_thread/
+        multi_thread.cpp

samples/multi_thread/multi_thread.cpp

@@ -20,28 +20,6 @@
 // It divides this among N "worker" threads.
 // N is passed in the command line, and defaults to 1.
 //
-// The main issue is how to suspend/resume the threads.
-// The standard BOINC API doesn't work - it assumes that
-// the initial thread is the only one.
-// On Linux, there's no API to suspend/resume threads.
-// All you can do is SIGSTOP/SIGCONT, which affects the whole process.
-// So we use the following process/thread structure:
-//
-// Windows:
-// Initial thread:
-//  - launches worker threads,
-//  - in polling loop, checks for suspend/resume messages
-//    from the BOINC client, and handles them itself.
-// Unix:
-//  Initial process
-//    - forks worker process
-//    - in polling loop, checks for worker process completion
-//    - doesn't send status msgs
-//  Worker process
-//    Initial thread:
-//    - forks worker threads, wait for them to finish, exit
-//    - uses BOINC runtime to send status messages (frac done, CPU time)
-//
 // Doesn't do checkpointing.
 
 #include <stdio.h>
@@ -61,8 +39,8 @@
 
 using std::vector;
 
-#define DEFAULT_NTHREADS 1
-#define TOTAL_UNITS 64
+#define DEFAULT_NTHREADS 4
+#define TOTAL_UNITS 16
 
 int units_per_thread;
 
@@ -110,29 +88,10 @@ struct THREAD {
         }
 #endif
     }
-
-#ifdef _WIN32
-    void suspend(bool if_susp) {
-        if (if_susp) {
-            SuspendThread(id);
-        } else {
-            ResumeThread(id);
-        }
-    }
-#endif
 };
 
 struct THREAD_SET {
     vector<THREAD*> threads;
-#ifdef _WIN32
-    void suspend(bool if_susp) {
-        for (unsigned int i=0; i<threads.size(); i++) {
-            THREAD* t = threads[i];
-            if (t->id != THREAD_ID_NULL) t->suspend(if_susp);
-        }
-        fprintf(stderr, "%s suspended all\n", boinc_msg_prefix());
-    }
-#endif
     bool all_done() {
         for (unsigned int i=0; i<threads.size(); i++) {
             if (threads[i]->id != THREAD_ID_NULL) return false;
@@ -182,44 +141,13 @@ void* worker(void* p) {
 #endif
 }
 
-void main_thread(int nthreads) {
-    int i;
-#ifdef _WIN32
-    static BOINC_STATUS status;
-#endif
-    THREAD_SET thread_set;
-    for (i=0; i<nthreads; i++) {
-        thread_set.threads.push_back(new THREAD(worker, i));
-    }
-    while (1) {
-        double f = thread_set.units_done()/((double)TOTAL_UNITS);
-        boinc_fraction_done(f);
-        if (thread_set.all_done()) break;
-#ifdef _WIN32
-        int old_susp = status.suspended;
-        boinc_get_status(&status);
-        if (status.quit_request || status.abort_request || status.no_heartbeat) {
-            exit(0);
-        }
-        if (status.suspended != old_susp) {
-            thread_set.suspend(status.suspended != 0);
-        }
-        boinc_sleep(0.1);
-#else
-        boinc_sleep(1.0);
-#endif
-    }
-}
-
 int main(int argc, char** argv) {
-    BOINC_OPTIONS options;
-    int nthreads = DEFAULT_NTHREADS;
+    int i, nthreads = DEFAULT_NTHREADS;
     double start_time = dtime();
 
-    boinc_options_defaults(options);
-    options.direct_process_action = 0;
+    boinc_init_parallel();
 
-    for (int i=1; i<argc; i++) {
+    for (i=1; i<argc; i++) {
         if (!strcmp(argv[i], "--nthreads")) {
             nthreads = atoi(argv[++i]);
         } else {
@@ -231,39 +159,16 @@ int main(int argc, char** argv) {
 
     units_per_thread = TOTAL_UNITS/nthreads;
 
-#ifdef _WIN32
-    boinc_init_options(&options);
-    main_thread(nthreads);
-#else
-    options.send_status_msgs = 0;
-    boinc_init_options(&options);
-    int pid = fork();
-    if (pid) {          // parent
-        BOINC_STATUS status;
-        boinc_get_status(&status);
-        int exit_status;
-        while (1) {
-            bool old_susp = status.suspended;
-            boinc_get_status(&status);
-            if (status.quit_request || status.abort_request || status.no_heartbeat) {
-                kill(pid, SIGKILL);
-                exit(0);
-            }
-            if (status.suspended != old_susp) {
-                kill(pid, status.suspended?SIGSTOP:SIGCONT);
-            }
-            if (waitpid(pid, &exit_status, WNOHANG) == pid) {
-                break;
-            }
-            boinc_sleep(0.1);
-        }
-    } else {            // child (worker)
-        memset(&options, 0, sizeof(options));
-        options.send_status_msgs = 1;
-        boinc_init_options(&options);
-        main_thread(nthreads);
+    THREAD_SET thread_set;
+    for (i=0; i<nthreads; i++) {
+        thread_set.threads.push_back(new THREAD(worker, i));
+    }
+    while (1) {
+        double f = thread_set.units_done()/((double)TOTAL_UNITS);
+        boinc_fraction_done(f);
+        if (thread_set.all_done()) break;
+        boinc_sleep(1.0);
     }
-#endif
 
     double elapsed_time = dtime()-start_time;
     fprintf(stderr,