1 files changed, 146 insertions, 0 deletions
diff --git a/innobase/os/os0shm.c b/innobase/os/os0shm.c
new file mode 100644
index 00000000000..e03440cd4f4
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+++ b/innobase/os/os0shm.c
@@ -0,0 +1,146 @@
+/******************************************************
+The interface to the operating system
+shared memory primitives
+
+(c) 1995 Innobase Oy
+
+Created 9/23/1995 Heikki Tuuri
+*******************************************************/
+
+#include "os0shm.h"
+#ifdef UNIV_NONINL
+#include "os0shm.ic"
+#endif
+
+#ifdef __WIN__
+#include "windows.h"
+
+typedef	HANDLE	os_shm_t;
+#endif
+
+/********************************************************************
+Creates an area of shared memory. It can be named so that
+different processes may access it in the same computer.
+If an area with the same name already exists, returns
+a handle to that area (where the size of the area is
+not changed even if this call requests a different size).
+To use the area, it first has to be mapped to the process
+address space by os_shm_map. */
+
+os_shm_t
+os_shm_create(
+/*==========*/
+			/* out, own: handle to the shared
+			memory area, NULL if error */
+	ulint	size,	/* in: area size < 4 GB */
+	char*	name)	/* in: name of the area as a null-terminated
+			string */
+{
+#ifdef __WIN__
+	os_shm_t	shm;
+
+	ut_a(name);
+	ut_a(size > 0);
+	ut_a(size < 0xFFFFFFFF);
+
+	/* In Windows NT shared memory is created as a memory mapped
+	file */
+	shm = CreateFileMapping((HANDLE)0xFFFFFFFF, /* use operating system
+						    swap file as the backing
+						    file */
+				NULL,		    /* default security
+						    descriptor */
+				PAGE_READWRITE,	    /* allow reading and
+						    writing */
+				0,		    /* size must be less
+						    than 4 GB */
+				(DWORD)size,	
+				name);			
+	return(shm);
+#else
+	UT_NOT_USED(size);
+	UT_NOT_USED(name);
+
+	return(NULL);
+#endif
+}
+
+/***************************************************************************
+Frees a shared memory area. The area can be freed only after it
+has been unmapped in all the processes where it was mapped. */
+
+ibool
+os_shm_free(
+/*========*/
+				/* out: TRUE if success */
+	os_shm_t	shm)	/* in, own: handle to a shared memory area */
+{
+#ifdef __WIN__
+
+	BOOL	ret;
+
+	ut_a(shm);
+
+	ret = CloseHandle(shm);
+
+	if (ret) {
+		return(TRUE);
+	} else {
+		return(FALSE);
+	}
+#else
+	UT_NOT_USED(shm);
+#endif
+}
+
+/***************************************************************************
+Maps a shared memory area in the address space of a process. */
+
+void*
+os_shm_map(
+/*=======*/
+				/* out: address of the area, NULL if error */
+	os_shm_t	shm)	/* in: handle to a shared memory area */
+{
+#ifdef __WIN__
+	void*	mem;
+
+	ut_a(shm);
+
+	mem = MapViewOfFile(shm,
+			    FILE_MAP_ALL_ACCESS,  /* read and write access
+			    			  allowed */
+			    0,			  /* map from start of */
+			    0,			  /* area */
+			    0);			  /* map the whole area */
+	return(mem);
+#else
+	UT_NOT_USED(shm);
+#endif
+}
+		
+/***************************************************************************
+Unmaps a shared memory area from the address space of a process. */
+
+ibool
+os_shm_unmap(
+/*=========*/
+			/* out: TRUE if succeed */
+	void*	addr)	/* in: address of the area */
+{
+#ifdef __WIN__
+	BOOL	ret;
+
+	ut_a(addr);
+
+	ret = UnmapViewOfFile(addr);
+
+	if (ret) {
+		return(TRUE);
+	} else {
+		return(FALSE);
+	}
+#else
+	UT_NOT_USED(addr);
+#endif
+}