[Change] Removed the memory mapped file.

Using the system paging file to implement COW.

msvs/setups/documentation/redis.windows-service.conf

@@ -422,47 +422,17 @@ slave-priority 100
 # mechanism, the master-slave synchronization and clustering features are
 # dependent on this behavior of fork(). In order for the Windows version to
 # perform like the Linux version we had to simulate this aspect of fork().
-# Doing so meant moving the Redis heap into a memory mapped file that can
-# be shared with a child process.
-#
-# *** There must be disk space available for this file in order for Redis
-# to launch. *** The default configuration places this file in the local
-# appdata directory. If you wish to move this file to another local disk,
-# use the heapdir flag as described below.
-#
-# The maxheap flag controls the maximum size of this memory mapped file,
-# as well as the total usable space for the Redis heap. Running Redis
-# without either maxheap or maxmemory will result in a memory mapped file
-# being created that is equal to the size of physical memory. During
-# fork() operations the total page file commit will max out at around:
-#
-#    (size of physical memory) + (2 * size of maxheap)
-#
-# For instance, on a machine with 8GB of physical RAM, the max page file
-# commit with the default maxheap size will be (8)+(2*8) GB , or 24GB. The
-# default page file sizing of Windows will allow for this without having
-# to reconfigure the system. Larger heap sizes are possible, but the maximum
-# page file size will have to be increased accordingly.
-#
-# The Redis heap must be larger than the value specified by the maxmemory
-# flag, as the heap allocator has its own memory requirements and
-# fragmentation of the heap is inevitable. If only the maxmemory flag is
-# specified, maxheap will be set at 1.5*maxmemory. If the maxheap flag is
-# specified along with maxmemory, the maxheap flag will be automatically
-# increased if it is smaller than 1.5*maxmemory.
+# The system paging file is used to share memory between the parent process
+# and the child (aka forked) process.
 #
-# maxheap <bytes>
-
-# The heap memory mapped file must reside on a local path for heap sharing
-# between processes to work. A UNC path will not suffice here. For maximum
-# performance this should be located on the fastest local drive available.
-# This value defaults to the local application data folder(e.g.,
-# "%USERPROFILE%\AppData\Local"). Since this file can be very large, you
-# may wish to place this on a drive other than the one the operating system
-# is installed on.
+# The maxheap flag controls the total usable space for the Redis heap.
+# Running Redis without either maxheap or maxmemory will result in a max
+# usable heap equal to 1.5 * physical memory. If only the maxmemory flag is
+# specified, maxheap will be set at 1.5 * maxmemory.
+# If the maxheap flag is specified along with maxmemory, the maxheap flag
+# will be automatically increased if it is smaller than 1.5*maxmemory.
 #
-# Note that you must specify a directory here, not a file name.
-# heapdir <directory path(absolute or relative)>
+# maxheap <bytes>
 
 # If Redis is to be used as an in-memory-only cache without any kind of
 # persistence, then the fork() mechanism used by the background AOF/RDB

msvs/setups/documentation/redis.windows.conf

@@ -419,50 +419,20 @@ slave-priority 100
 
 # The Linux version of Redis relies on the system call fork() to perform
 # point-in-time snapshots of the heap. In addition to the AOF and RDB backup
-# mechanism, the master-slave synchronization and clustering features are 
-# dependent on this behavior of fork(). In order for the Windows version to 
+# mechanism, the master-slave synchronization and clustering features are
+# dependent on this behavior of fork(). In order for the Windows version to
 # perform like the Linux version we had to simulate this aspect of fork().
-# Doing so meant moving the Redis heap into a memory mapped file that can
-# be shared with a child process. 
-#
-# *** There must be disk space available for this file in order for Redis 
-# to launch. *** The default configuration places this file in the local 
-# appdata directory. If you wish to move this file to another local disk,
-# use the heapdir flag as described below.
-#
-# The maxheap flag controls the maximum size of this memory mapped file,
-# as well as the total usable space for the Redis heap. Running Redis
-# without either maxheap or maxmemory will result in a memory mapped file 
-# being created that is equal to the size of physical memory. During 
-# fork() operations the total page file commit will max out at around:
-#
-#    (size of physical memory) + (2 * size of maxheap)
-#
-# For instance, on a machine with 8GB of physical RAM, the max page file 
-# commit with the default maxheap size will be (8)+(2*8) GB , or 24GB. The
-# default page file sizing of Windows will allow for this without having 
-# to reconfigure the system. Larger heap sizes are possible, but the maximum
-# page file size will have to be increased accordingly.
-# 
-# The Redis heap must be larger than the value specified by the maxmemory 
-# flag, as the heap allocator has its own memory requirements and 
-# fragmentation of the heap is inevitable. If only the maxmemory flag is 
-# specified, maxheap will be set at 1.5*maxmemory. If the maxheap flag is 
-# specified along with maxmemory, the maxheap flag will be automatically 
-# increased if it is smaller than 1.5*maxmemory. 
-#  
-# maxheap <bytes>
-
-# The heap memory mapped file must reside on a local path for heap sharing 
-# between processes to work. A UNC path will not suffice here. For maximum 
-# performance this should be located on the fastest local drive available.
-# This value defaults to the local application data folder(e.g.,
-# "%USERPROFILE%\AppData\Local"). Since this file can be very large, you
-# may wish to place this on a drive other than the one the operating system  
-# is installed on.
+# The system paging file is used to share memory between the parent process
+# and the child (aka forked) process.
 #
-# Note that you must specify a directory here, not a file name.
-# heapdir <directory path(absolute or relative)>
+# The maxheap flag controls the total usable space for the Redis heap.
+# Running Redis without either maxheap or maxmemory will result in a max
+# usable heap equal to 1.5 * physical memory. If only the maxmemory flag is
+# specified, maxheap will be set at 1.5 * maxmemory.
+# If the maxheap flag is specified along with maxmemory, the maxheap flag
+# will be automatically increased if it is smaller than 1.5*maxmemory.
+#
+# maxheap <bytes>
 
 # If Redis is to be used as an in-memory-only cache without any kind of 
 # persistence, then the fork() mechanism used by the background AOF/RDB 

src/Win32_Interop/Win32_CommandLine.cpp

@@ -351,7 +351,6 @@ static RedisParamterMapper g_redisArgMap =
     // QFork flags
     { cQFork,                           &fp2 },    // qfork [QForkControlMemoryMap handle] [parent process id]
     { cMaxHeap,                         &fp1 },    // maxheap [number]
-    { cHeapDir,                         &fp1 },    // heapdir [path]
     { cPersistenceAvailable,            &fp1 },    // persistence-available [yes/no]
 
     // service commands

src/Win32_Interop/Win32_CommandLine.h

@@ -52,7 +52,6 @@ const string cSyslogIdent= "syslog-ident";
 const string cLogfile = "logfile";
 const string cInclude = "include";
 const string cDir = "dir";
-const string cHeapDir = "heapdir";
 const string cPersistenceAvailable = "persistence-available";
 
 const string cMaxHeap = "maxheap";