ipc.c: Improve para_semop().

It's kind of silly to retry the semop 500 times. Just check if sempop()
was interrupted and retry in this case. Otherwise, error out.

diff --git a/ipc.c b/ipc.c
index 833ba1a43aed86e183d52b68c2e718b30c5468dd..debf9d11be254ed6cf07d7dc390763cbc0f5fb8d 100644 (file)
--- a/ipc.c
+++ b/ipc.c
@@ -13,9 +13,6 @@
 #include <sys/shm.h>
 #include <sys/sem.h>
 
 #include <sys/shm.h>
 #include <sys/sem.h>
 

-/** abort if semget() failed that many times */
-#define MAX_SEMOP_RETRIES 500
-

 /**
  * define a new mutex
  *
 /**
  * define a new mutex
  *


@@ -45,14 +42,17 @@ int mutex_destroy(int id)
        return ret < 0? -E_SEM_REMOVE : 1;
 }
 
        return ret < 0? -E_SEM_REMOVE : 1;
 }
 

-static void para_semop(int id, struct sembuf *sops, unsigned num)
+static void para_semop(int id, struct sembuf *sops, int num)

 {
 {

-       int i;
-
-       for (i = 0; i < MAX_SEMOP_RETRIES; i++)
+       do {

                if (semop(id, sops, num) >= 0)
                        return;
                if (semop(id, sops, num) >= 0)
                        return;

-       PARA_EMERG_LOG("semop failed %d times, aborting\n", MAX_SEMOP_RETRIES);
+       } while (errno == EINTR);
+       if (errno == EIDRM) {
+               PARA_NOTICE_LOG("semaphore set %d was removed\n", id);
+               return;
+       }
+       PARA_EMERG_LOG("fatal semop error %s: pid %d\n", strerror(errno), getpid());

        exit(EXIT_FAILURE);
 }
 
        exit(EXIT_FAILURE);
 }