--- a
+++ b/src/sysvshm.h
@@ -0,0 +1,70 @@
+/* Copyright (C) 2017-2018 J.F.Dockes
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the
+ * Free Software Foundation, Inc.,
+ * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#ifndef _SYSVIPC_H_INCLUDED_
+#define _SYSVIPC_H_INCLUDED_
+
+#include <sys/types.h>
+#include <sys/ipc.h>
+#include <sys/msg.h>
+#include <sys/sem.h>
+#include <sys/shm.h>
+
+class ShmSeg {
+public:
+ ShmSeg(key_t ky, size_t size, bool create = false, int perms = 0600);
+ ShmSeg(const char*pathname, int proj_id, size_t size, bool create = false, int perms = 0600);
+ ShmSeg(int size) : ShmSeg(IPC_PRIVATE, size) {}
+ virtual ~ShmSeg();
+ virtual void setremove(bool onoff = true);
+ virtual void *getseg();
+ virtual size_t getsize();
+ virtual bool ok();
+
+ class Internal;
+protected:
+ Internal *m;
+};
+
+// Shm segment with integrated lock. Note that the lock initialization
+// is not protected, and that an external method is needed for the
+// creating process to be left alone while it is creating the segment
+// and initializing the lock.
+//
+// You need to use an Accessor object to get to the segment. This
+// takes the lock on construction and releases it on deletion
+class LockableShmSeg : public ShmSeg {
+public:
+ LockableShmSeg(key_t ky, size_t size, bool create = false, int perms = 0600);
+ LockableShmSeg(const char*pathname, int proj_id, size_t size,
+ bool create = false, int perms = 0600);
+ LockableShmSeg(int size) : LockableShmSeg(IPC_PRIVATE, size) {}
+ virtual ~LockableShmSeg();
+ class Accessor {
+ public:
+ Accessor(LockableShmSeg&);
+ ~Accessor();
+ void *getseg();
+ private:
+ LockableShmSeg& lss;
+ };
+ friend class Accessor;
+private:
+ virtual void *getseg();
+};
+
+#endif /* _SYSVIPC_H_INCLUDED_ */