[gimp] libgimp: forgot to actually add gimp-shm.[ch]

[Michael Natterer <mitch src gnome org>]

commit 1c317a739ba8755382cac9455dd23b0d7bcd2332
Author: Michael Natterer <mitch gimp org>
Date:   Sun Aug 4 20:18:10 2019 +0200

    libgimp: forgot to actually add gimp-shm.[ch]

 libgimp/gimp-shm.c | 196 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 libgimp/gimp-shm.h |  35 ++++++++++
 2 files changed, 231 insertions(+)
---
diff --git a/libgimp/gimp-shm.c b/libgimp/gimp-shm.c
new file mode 100644
index 0000000000..4b78909b94
--- /dev/null
+++ b/libgimp/gimp-shm.c
@@ -0,0 +1,196 @@
+/* LIBGIMP - The GIMP Library
+ * Copyright (C) 1995-1997 Peter Mattis and Spencer Kimball
+ *
+ * gimp-shm.c
+ *
+ * This library is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library.  If not, see
+ * <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <errno.h>
+
+#if defined(USE_SYSV_SHM)
+
+#ifdef HAVE_IPC_H
+#include <sys/ipc.h>
+#endif
+
+#ifdef HAVE_SHM_H
+#include <sys/shm.h>
+#endif
+
+#elif defined(USE_POSIX_SHM)
+
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+#include <fcntl.h>
+#include <sys/mman.h>
+
+#endif /* USE_POSIX_SHM */
+
+#include <glib.h>
+
+#if defined(G_OS_WIN32) || defined(G_WITH_CYGWIN)
+#  ifdef STRICT
+#  undef STRICT
+#  endif
+#  define STRICT
+
+#  ifdef _WIN32_WINNT
+#  undef _WIN32_WINNT
+#  endif
+#  define _WIN32_WINNT 0x0601
+
+#  include <windows.h>
+#  include <tlhelp32.h>
+#  undef RGB
+#  define USE_WIN32_SHM 1
+#endif
+
+#include "gimp.h"
+#include "gimp-shm.h"
+
+
+#define TILE_MAP_SIZE     (_tile_width * _tile_height * 32)
+#define ERRMSG_SHM_FAILED "Could not attach to gimp shared memory segment"
+
+
+#ifdef USE_WIN32_SHM
+static HANDLE  _shm_handle;
+#endif
+
+static gint    _shm_ID   = -1;
+static guchar *_shm_addr = NULL;
+
+
+guchar *
+_gimp_shm_addr (void)
+{
+  return _shm_addr;
+}
+
+void
+_gimp_shm_open (gint shm_ID)
+{
+  _shm_ID = shm_ID;
+
+  if (_shm_ID != -1)
+    {
+#if defined(USE_SYSV_SHM)
+
+      /* Use SysV shared memory mechanisms for transferring tile data. */
+
+      _shm_addr = (guchar *) shmat (_shm_ID, NULL, 0);
+
+      if (_shm_addr == (guchar *) -1)
+        {
+          g_error ("shmat() failed: %s\n" ERRMSG_SHM_FAILED,
+                   g_strerror (errno));
+        }
+
+#elif defined(USE_WIN32_SHM)
+
+      /* Use Win32 shared memory mechanisms for transferring tile data. */
+
+      gchar fileMapName[128];
+
+      /* From the id, derive the file map name */
+      g_snprintf (fileMapName, sizeof (fileMapName), "GIMP%d.SHM", _shm_ID);
+
+      /* Open the file mapping */
+      shm_handle = OpenFileMapping (FILE_MAP_ALL_ACCESS,
+                                    0, fileMapName);
+      if (shm_handle)
+        {
+          /* Map the shared memory into our address space for use */
+          _shm_addr = (guchar *) MapViewOfFile (shm_handle,
+                                                FILE_MAP_ALL_ACCESS,
+                                                0, 0, TILE_MAP_SIZE);
+
+          /* Verify that we mapped our view */
+          if (!_shm_addr)
+            {
+              g_error ("MapViewOfFile error: %lu... " ERRMSG_SHM_FAILED,
+                       GetLastError ());
+            }
+        }
+      else
+        {
+          g_error ("OpenFileMapping error: %lu... " ERRMSG_SHM_FAILED,
+                   GetLastError ());
+        }
+
+#elif defined(USE_POSIX_SHM)
+
+      /* Use POSIX shared memory mechanisms for transferring tile data. */
+
+      gchar map_file[32];
+      gint  shm_fd;
+
+      /* From the id, derive the file map name */
+      g_snprintf (map_file, sizeof (map_file), "/gimp-shm-%d", _shm_ID);
+
+      /* Open the file mapping */
+      shm_fd = shm_open (map_file, O_RDWR, 0600);
+
+      if (shm_fd != -1)
+        {
+          /* Map the shared memory into our address space for use */
+          _shm_addr = (guchar *) mmap (NULL, TILE_MAP_SIZE,
+                                       PROT_READ | PROT_WRITE, MAP_SHARED,
+                                       shm_fd, 0);
+
+          /* Verify that we mapped our view */
+          if (_shm_addr == MAP_FAILED)
+            {
+              g_error ("mmap() failed: %s\n" ERRMSG_SHM_FAILED,
+                       g_strerror (errno));
+            }
+
+          close (shm_fd);
+        }
+      else
+        {
+          g_error ("shm_open() failed: %s\n" ERRMSG_SHM_FAILED,
+                   g_strerror (errno));
+        }
+
+#endif
+    }
+}
+
+void
+_gimp_shm_close (void)
+{
+#if defined(USE_SYSV_SHM)
+
+  if ((_shm_ID != -1) && _shm_addr)
+    shmdt ((char *) _shm_addr);
+
+#elif defined(USE_WIN32_SHM)
+
+  if (shm_handle)
+    CloseHandle (shm_handle);
+
+#elif defined(USE_POSIX_SHM)
+
+  if ((_shm_ID != -1) && (_shm_addr != MAP_FAILED))
+    munmap (_shm_addr, TILE_MAP_SIZE);
+
+#endif
+}
diff --git a/libgimp/gimp-shm.h b/libgimp/gimp-shm.h
new file mode 100644
index 0000000000..f81437c719
--- /dev/null
+++ b/libgimp/gimp-shm.h
@@ -0,0 +1,35 @@
+/* LIBGIMP - The GIMP Library
+ * Copyright (C) 1995-1997 Peter Mattis and Spencer Kimball
+ *
+ * gimp-shm.h
+ *
+ * This library is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library.  If not, see
+ * <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_SHM_H__
+#define __GIMP_SHM_H__
+
+G_BEGIN_DECLS
+
+
+guchar * _gimp_shm_addr  (void);
+
+void     _gimp_shm_open  (gint shm_ID);
+void     _gimp_shm_close (void);
+
+
+G_END_DECLS
+
+#endif /* __GIMP_SHM_H__ */