Initial import of the CDE 2.1.30 sources from the Open Group.

cde/programs/dtmail/include/utils/MemUtils.hh

@@ -0,0 +1,175 @@
+/* $TOG: MemUtils.hh /main/5 1998/04/06 13:25:12 mgreess $ */
+/*
+ *+SNOTICE
+ *
+ *	RESTRICTED CONFIDENTIAL INFORMATION:
+ *	
+ *	The information in this document is subject to special
+ *	restrictions in a confidential disclosure agreement bertween
+ *	HP, IBM, Sun, USL, SCO and Univel.  Do not distribute this
+ *	document outside HP, IBM, Sun, USL, SCO, or Univel wihtout
+ *	Sun's specific written approval.  This documment and all copies
+ *	and derivative works thereof must be returned or destroyed at
+ *	Sun's request.
+ *
+ *	Copyright 1993 Sun Microsystems, Inc.  All rights reserved.
+ *
+ *+ENOTICE
+ */
+
+#ifndef _MEMUTILS_HH
+#define _MEMUTILS_HH
+
+#include <string.h>
+
+// The FORCE_SEGV_DECL macro is used to declare pointers on the stack. It
+// will initialize the pointer in such a way as to force SEGV if it is
+// used before set, and created detectable errors if it is freed before
+// set. This macro should be used any time an uninitialized pointer would
+// be created.
+//
+// Usage:
+//	Instead of:
+//		char * a_string;
+//
+//	Do:
+//		FORCE_SEGV_DECL(char, a_string);
+//
+//	Note that the * is not specified on the type or variable name.
+//
+#ifdef DEBUG
+#define FORCE_SEGV_CONST	(0x13)
+#define FORCE_SEGV_DECL(a, b)	a *b = (a *)FORCE_SEGV_CONST
+#else
+#define FORCE_SEGV_CONST	(0)
+#define FORCE_SEGV_DECL(a, b)	a *b = (a *)FORCE_SEGV_CONST
+#endif
+
+// The strdup_n function replaces the functionality of strdup(3C), but uses
+// the C++ new operator. This is provided to allow consistent use of
+// the delete operator when handling strings.
+//
+inline
+char *
+strdup_n(const char * old_str)
+{
+    char * new_str = (char *) NULL;
+    
+    if (old_str) new_str = new char[strlen(old_str) + 1];
+    return(new_str ? strcpy(new_str, old_str) : (char*) NULL);
+}
+
+// The grow_region function provides the functionality of realloc(3C) for
+// memory that has been allocated with new. This is provided to allow
+// consistent use of the delete operator for memory regions that must
+// be resized.
+//
+inline
+void *
+grow_region(void * old_region, const int old_size, const int new_size)
+{
+    void * new_region = new unsigned char[new_size];
+    if (new_region) {
+	memcpy(new_region, old_region, old_size);
+    }
+    delete old_region;
+    return(new_region);
+}
+
+// The StackProbe class is used to debug stack over runs. It works by
+// allocating two pages on the stack, and mprotecting one of the pages.
+// The reason two pages are used is mprotect must protect entire pages.
+// The top of the stack in any given routine will most likely not be
+// on an even page boundary, so two pages are allocated to get one that
+// can be protected.
+//
+#if defined(DEBUG) && defined(STACK_PROBE)
+
+#ifndef STACK_PAGE_SIZE
+#define STACK_PAGE_SIZE		4096
+#endif
+
+#include <sys/mman.h>
+
+class StackProbe {
+  public:
+    StackProbe(void) {
+	caddr_t page_start = &region[((int)&region % STACK_PAGE_SIZE)];
+	mprotect(page_start, STACK_PAGE_SIZE, PROT_NONE);
+    }
+
+    ~StackProbe(void) {
+	caddr_t page_start = &region[((int)&region % STACK_PAGE_SIZE)];
+	mprotect(page_start, STACK_PAGE_SIZE, PROT_READ | PROT_WRITE);
+    }
+
+  private:
+    char	region[STACK_PAGE_SIZE * 2];
+};
+
+#define INSERT_STACK_PROBE	StackProbe _stack_probe;
+#endif
+
+#ifndef INSERT_STACK_PROBE
+#define INSERT_STACK_PROBE
+#endif
+
+#if defined(SENTINEL) && defined(DEBUG)
+
+#include <stdio.h>
+#include <sentinel.h>
+
+inline
+void
+MdbgAddWatchPoint(const void * ptr, const size_t len)
+{
+    SeAddWatchPoint((void *)ptr, (size_t)len, "check");
+}
+
+inline
+void
+MdbgChainCheck(void)
+{
+    SeChainCheck(1);
+}
+
+inline
+void
+MdbgCheckData(const void * ptr, const int len)
+{
+    SeCheckData(SE_READ, (char *)ptr, (int)len, 1);
+}
+
+inline
+void
+MdbgCheckString(const char * str)
+{
+    SeCheckString((char *)str, 1);
+}
+
+inline
+void
+MdbgCheckWatchPoints(void)
+{
+    SeCheckWatchPoints();
+}
+
+inline
+void
+MdbgRemoveWatchPoint(const void * ptr)
+{
+    SeRemoveWatchPoint((void *)ptr);
+}
+
+#else /* Sentinel */
+
+inline void MdbgAddWatchPoint(const void *, const size_t) {}
+inline void MdbgChainCheck(void) {}
+inline void MdbgCheckData(const void *, const int) {}
+inline void MdbgCheckString(const char *) {}
+inline void MdbgCheckWatchPoints(void) {}
+inline void MdbgRemoveWatchPoint(const void *) {}
+
+#endif /* Sentinel */
+
+#endif