Add --malloc-lib=LIB option to mysqld_safe to LD_PRELOAD a shared library for mysqld

scripts/mysql_config.sh

@@ -167,6 +167,10 @@ Options:
         --port           [$port]
         --version        [$version]
         --libmysqld-libs [$embedded_libs]
+        --variable=VAR   VAR is one of:
+                pkgincludedir [$pkgincludedir]
+                pkglibdir     [$pkglibdir]
+                plugindir     [$plugindir]
 EOF
         exit 1
 }
@@ -184,6 +188,15 @@ while test $# -gt 0; do
         --port)    echo "$port" ;;
         --version) echo "$version" ;;
         --embedded-libs | --embedded | --libmysqld-libs) echo "$embedded_libs" ;;
+        --variable=*)
+          var=`echo "$1" | sed 's,^[^=]*=,,'`
+          case "$var" in
+            pkgincludedir) echo "$pkgincludedir" ;;
+            pkglibdir) echo "$pkglibdir" ;;
+            plugindir) echo "$plugindir" ;;
+            *) usage ;;
+          esac
+          ;;
         *)         usage ;;
         esac
 

scripts/mysqld_safe.sh

@@ -11,9 +11,13 @@
 # mysql.server works by first doing a cd to the base directory and from there
 # executing mysqld_safe
 
+# Initialize script globals
 KILL_MYSQLD=1;
 MYSQLD=
 niceness=0
+mysqld_ld_preload=
+mysqld_ld_library_path=
+
 # Initial logging status: error log is not open, and not using syslog
 logging=init
 want_syslog=0
@@ -46,6 +50,7 @@ Usage: $0 [OPTIONS]
   --open-files-limit=LIMIT   Limit the number of open files
   --core-file-size=LIMIT     Limit core files to the specified size
   --timezone=TZ              Set the system timezone
+  --malloc-lib=LIB           Preload shared library LIB if available
   --mysqld=FILE              Use the specified file as mysqld
   --mysqld-version=VERSION   Use "mysqld-VERSION" as mysqld
   --nice=NICE                Set the scheduling priority of mysqld
@@ -172,6 +177,7 @@ parse_arguments() {
       # mysqld_safe-specific options - must be set in my.cnf ([mysqld_safe])!
       --core-file-size=*) core_file_size="$val" ;;
       --ledir=*) ledir="$val" ;;
+      --malloc-lib=*) set_malloc_lib "$val" ;;
       --mysqld=*) MYSQLD="$val" ;;
       --mysqld-version=*)
         if test -n "$val"
@@ -202,6 +208,131 @@ parse_arguments() {
 }
 
 
+# Add a single shared library to the list of libraries which will be added to
+# LD_PRELOAD for mysqld
+#
+# Since LD_PRELOAD is a space-separated value (for historical reasons), if a
+# shared lib's path contains spaces, that path will be prepended to
+# LD_LIBRARY_PATH and stripped from the lib value.
+add_mysqld_ld_preload() {
+  lib_to_add="$1"
+  log_notice "Adding '$lib_to_add' to LD_PRELOAD for mysqld"
+
+  case "$lib_to_add" in
+    *' '*)
+      # Must strip path from lib, and add it to LD_LIBRARY_PATH
+      lib_file=`basename "$lib_to_add"`
+      case "$lib_file" in
+        *' '*)
+          # The lib file itself has a space in its name, and can't
+          # be used in LD_PRELOAD
+          log_error "library name '$lib_to_add' contains spaces and can not be used with LD_PRELOAD"
+          exit 1
+          ;;
+      esac
+      lib_path=`dirname "$lib_to_add"`
+      lib_to_add="$lib_file"
+      [ -n "$mysqld_ld_library_path" ] && mysqld_ld_library_path="$mysqld_ld_library_path:"
+      mysqld_ld_library_path="$mysqld_ld_library_path$lib_path"
+      ;;
+  esac
+
+  # LD_PRELOAD is a space-separated
+  [ -n "$mysqld_ld_preload" ] && mysqld_ld_preload="$mysqld_ld_preload "
+  mysqld_ld_preload="${mysqld_ld_preload}$lib_to_add"
+}
+
+
+# Returns LD_PRELOAD (and LD_LIBRARY_PATH, if needed) text, quoted to be
+# suitable for use in the eval that calls mysqld.
+#
+# All values in mysqld_ld_preload are prepended to LD_PRELOAD.
+mysqld_ld_preload_text() {
+  text=
+
+  if [ -n "$mysqld_ld_preload" ]; then
+    new_text="$mysqld_ld_preload"
+    [ -n "$LD_PRELOAD" ] && new_text="$new_text $LD_PRELOAD"
+    text="${text}LD_PRELOAD="`shell_quote_string "$new_text"`' '
+  fi
+
+  if [ -n "$mysqld_ld_library_path" ]; then
+    new_text="$mysqld_ld_library_path"
+    [ -n "$LD_LIBRARY_PATH" ] && new_text="$new_text:$LD_LIBRARY_PATH"
+    text="${text}LD_LIBRARY_PATH="`shell_quote_string "$new_text"`' '
+  fi
+
+  echo "$text"
+}
+
+
+mysql_config=
+get_mysql_config() {
+  if [ -z "$mysql_config" ]; then
+    mysql_config=`echo "$0" | sed 's,/[^/][^/]*$,/mysql_config,'`
+    if [ ! -x "$mysql_config" ]; then
+      log_error "Can not run mysql_config $@ from '$mysql_config'"
+      exit 1
+    fi
+  fi
+
+  "$mysql_config" "$@"
+}
+
+
+# set_malloc_lib LIB
+# - If LIB is empty, do nothing and return
+# - If LIB is 'tcmalloc', look for tcmalloc shared library in /usr/lib
+#   then pkglibdir.  tcmalloc is part of the Google perftools project.
+# - If LIB is an absolute path, assume it is a malloc shared library
+#
+# Put LIB in mysqld_ld_preload, which will be added to LD_PRELOAD when
+# running mysqld.  See ld.so for details.
+set_malloc_lib() {
+  malloc_lib="$1"
+
+  if [ "$malloc_lib" = tcmalloc ]; then
+    pkglibdir=`get_mysql_config --variable=pkglibdir`
+    malloc_lib=
+    # This list is kept intentionally simple.  Simply set --malloc-lib
+    # to a full path if another location is desired.
+    for libdir in /usr/lib "$pkglibdir"; do
+      for flavor in _minimal '' _and_profiler _debug; do
+        tmp="$libdir/libtcmalloc$flavor.so"
+        #log_notice "DEBUG: Checking for malloc lib '$tmp'"
+        [ -r "$tmp" ] || continue
+        malloc_lib="$tmp"
+        break 2
+      done
+    done
+
+    if [ -z "$malloc_lib" ]; then
+      log_error "no shared library for --malloc-lib=tcmalloc found in /usr/lib or $pkglibdir"
+      exit 1
+    fi
+  fi
+
+  # Allow --malloc-lib='' to override other settings
+  [ -z  "$malloc_lib" ] && return
+
+  case "$malloc_lib" in
+    /*)
+      if [ ! -r "$malloc_lib" ]; then
+        log_error "--malloc-lib '$malloc_lib' can not be read and will not be used"
+        exit 1
+      fi
+      ;;
+    *)
+      log_error "--malloc-lib must be an absolute path or 'tcmalloc'; " \
+        "ignoring value '$malloc_lib'"
+      exit 1
+      ;;
+  esac
+
+  add_mysqld_ld_preload "$malloc_lib"
+}
+
+
 #
 # First, try to find BASEDIR and ledir (where mysqld is)
 #
@@ -549,7 +680,7 @@ fi
 #  ulimit -n 256 > /dev/null 2>&1		# Fix for BSD and FreeBSD systems
 #fi
 
-cmd="$NOHUP_NICENESS"
+cmd="`mysqld_ld_preload_text`$NOHUP_NICENESS"
 
 for i in  "$ledir/$MYSQLD" "$defaults" "--basedir=$MY_BASEDIR_VERSION" \
   "--datadir=$DATADIR" "$USER_OPTION"