examples: Address issues reported by Markus Elfring

  * Use sig_atomic_t as data type for variable do_exit
  * Use async-safe function within signal handler

Closes #34

Signed-off-by: Chris Dickens <christopher.a.dickens@gmail.com>

diff --git a/examples/dpfp_threaded.c b/examples/dpfp_threaded.c
index 771e2ec..a7502a4 100644 (file)
--- a/examples/dpfp_threaded.c
+++ b/examples/dpfp_threaded.c
@@ -23,6 +23,7 @@
 
 #include <errno.h>
 #include <pthread.h>
+#include <semaphore.h>
 #include <signal.h>
 #include <string.h>
 #include <stdio.h>
@@ -64,16 +65,15 @@ static unsigned char irqbuf[INTR_LENGTH];
 static struct libusb_transfer *img_transfer = NULL;
 static struct libusb_transfer *irq_transfer = NULL;
 static int img_idx = 0;
-static int do_exit = 0;
+static volatile sig_atomic_t do_exit = 0;
 
 static pthread_t poll_thread;
-static pthread_cond_t exit_cond = PTHREAD_COND_INITIALIZER;
-static pthread_mutex_t exit_cond_lock = PTHREAD_MUTEX_INITIALIZER;
+static sem_t exit_sem;
 
-static void request_exit(int code)
+static void request_exit(sig_atomic_t code)
 {
        do_exit = code;
-       pthread_cond_signal(&exit_cond);
+       sem_post(&exit_sem);
 }
 
 static void *poll_thread_main(void *arg)
@@ -446,9 +446,16 @@ int main(void)
        struct sigaction sigact;
        int r = 1;
 
+       r = sem_init(&exit_sem, 0, 0);
+       if (r) {
+               fprintf(stderr, "failed to initialise semaphore error %d", errno);
+               exit(1);
+       }
+
        r = libusb_init(NULL);
        if (r < 0) {
                fprintf(stderr, "failed to initialise libusb\n");
+               sem_destroy(&exit_sem);
                exit(1);
        }
 
@@ -500,11 +507,8 @@ int main(void)
                goto out_deinit;
        }
 
-       while (!do_exit) {
-               pthread_mutex_lock(&exit_cond_lock);
-               pthread_cond_wait(&exit_cond, &exit_cond_lock);
-               pthread_mutex_unlock(&exit_cond_lock);
-       }
+       while (!do_exit)
+               sem_wait(&exit_sem);
 
        printf("shutting down...\n");
        pthread_join(poll_thread, NULL);
@@ -540,5 +544,6 @@ out_release:
 out:
        libusb_close(devh);
        libusb_exit(NULL);
+       sem_destroy(&exit_sem);
        return r >= 0 ? r : -r;
 }

diff --git a/libusb/version_nano.h b/libusb/version_nano.h
index 97ba0ff..bfafef7 100644 (file)
--- a/libusb/version_nano.h
+++ b/libusb/version_nano.h
@@ -1 +1 @@
-#define LIBUSB_NANO 10979
+#define LIBUSB_NANO 10980