paraslash 0.7.3

[paraslash.git] / ipc.c

diff --git a/ipc.c b/ipc.c
index 576bfe5bcd815ee296da0b56d49a7f3ea5d97e4e..8e9dd51a2369e7e60ebd4bda3fa889eaed892248 100644 (file)
--- a/ipc.c
+++ b/ipc.c
@@ -1,8 +1,4 @@
-/*
- * Copyright (C) 2006-2011 Andre Noll <maan@systemlinux.org>
- *
- * Licensed under the GPL v2. For licencing details see COPYING.
- */
+/* Copyright (C) 2006 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
 
 /** \file ipc.c Inter-process communication and shared memory helpers. */
 
@@ -11,7 +7,6 @@
 #include "ipc.h"
 #include <sys/types.h>
 #include <sys/param.h>
-#include <sys/sysctl.h>
 
 #include <sys/ipc.h>
 #include <sys/shm.h>
@@ -68,7 +63,7 @@ static void para_semop(int id, struct sembuf *sops, int num)
  *
  * This function either succeeds or aborts.
  *
- * \sa semop(2), struct misc_meta_data.
+ * \sa semop(2), struct \ref misc_meta_data.
  */
 void mutex_lock(int id)
 {
@@ -94,7 +89,7 @@ void mutex_lock(int id)
  *
  * This function either succeeds or aborts.
  *
- * \sa semop(2), struct misc_meta_data.
+ * \sa semop(2), struct \ref misc_meta_data.
  */
 void mutex_unlock(int id)
 {
@@ -161,6 +156,27 @@ int shm_attach(int id, enum shm_attach_mode mode, void **result)
        return *result == (void *) -1? -ERRNO_TO_PARA_ERROR(errno) : 1;
 }
 
+/**
+ * Get the size of a shared memory segment.
+ *
+ * \param id The shared memory segment identifier.
+ * \param result Size in bytes is returned here, zero on errors.
+ *
+ * \return Standard.
+ *
+ * \sa shmctl(2).
+ */
+int shm_size(int id, size_t *result)
+{
+       struct shmid_ds ds; /* data structure */
+
+       *result = 0;
+       if (shmctl(id, IPC_STAT, &ds) < 0)
+               return -ERRNO_TO_PARA_ERROR(errno);
+       *result = ds.shm_segsz;
+       return 1;
+}
+
 /**
  * Detach a shared memory segment.
  *
@@ -177,9 +193,8 @@ int shm_detach(void *addr)
 }
 
 # if defined __FreeBSD__ || defined __NetBSD__
+#include <sys/sysctl.h>
 #      define SYSCTL_SHMMAX_VARIABLE "kern.ipc.shmmax"
-# elif defined __APPLE__
-#      define SYSCTL_SHMMAX_VARIABLE "kern.sysv.shmmax"
 # else
 #      undef SYSCTL_SHMMAX_VARIABLE
 # endif
@@ -209,6 +224,7 @@ size_t shm_get_shmmax(void)
                                buf[ret] = '\0';
                                shmmax = strtoul(buf, NULL, 10);
                        }
+                       close(fd);
                }
        }
 #elif defined SYSCTL_SHMMAX_VARIABLE
@@ -221,7 +237,7 @@ size_t shm_get_shmmax(void)
 #endif
        if (shmmax == 0) {
                PARA_WARNING_LOG("unable to determine shmmax\n");
-               shmmax = 65535; /* last ressort */
+               shmmax = 65535; /* last resort */
        }
        PARA_INFO_LOG("shmmax: %zu\n", shmmax);
        return shmmax;