Add C version of safe_process

BitKeeper/etc/ignore:
  Added mysql-test/lib/My/SafeProcess/my_safe_process to the ignore list
configure.in:
  Add Makefile to build safe_process
mysql-test/Makefile.am:
  Build lib/My/SafeProcess
mysql-test/lib/My/SafeProcess.pm:
  Use C version of safe_process
mysql-test/lib/t/SafeProcessStress.pl:
  Decrease number of loops
mysql-test/lib/My/SafeProcess/Makefile.am:
  New BitKeeper file ``mysql-test/lib/My/SafeProcess/Makefile.am''
mysql-test/lib/My/SafeProcess/safe_process.cc:
  New BitKeeper file ``mysql-test/lib/My/SafeProcess/safe_process.cc''

.bzrignore

@@ -3005,3 +3005,4 @@ win/vs71cache.txt
 win/vs8cache.txt
 zlib/*.ds?
 zlib/*.vcproj
+mysql-test/lib/My/SafeProcess/my_safe_process

configure.in

@@ -2680,7 +2680,7 @@ AC_CONFIG_FILES(Makefile extra/Makefile mysys/Makefile dnl
  server-tools/Makefile server-tools/instance-manager/Makefile dnl
  cmd-line-utils/Makefile cmd-line-utils/libedit/Makefile dnl
  libmysqld/Makefile libmysqld/examples/Makefile dnl
- mysql-test/Makefile dnl
+ mysql-test/Makefile mysql-test/lib/My/SafeProcess/Makefile dnl
  netware/Makefile sql-bench/Makefile dnl
  include/mysql_version.h plugin/Makefile win/Makefile)
 

mysql-test/Makefile.am

@@ -29,6 +29,8 @@ EXTRA_DIST =		README \
 test_SCRIPTS =		mtr mysql-test-run
 CLEANFILES =		$(test_SCRIPTS)
 
+SUBDIRS =               lib/My/SafeProcess
+
 
 # Install all files and files in directories listed in EXTRA_DIST
 install-data-local:

mysql-test/lib/My/SafeProcess.pm

@@ -90,22 +90,35 @@ my @safe_process_cmd;
 my $safe_kill;
 if (IS_WIN32PERL or IS_CYGWIN){
   # Use my_safe_process.exe
-  my $exe= my_find_bin(".", "lib/My/SafeProcess", "my_safe_process.exe");
-  die "Could not find my_safe_process.exe" unless $exe;
+  my $exe= my_find_bin(".", ["lib/My/SafeProcess", "My/SafeProcess"],
+		       "my_safe_process");
+  die "Could not find my_safe_process" unless $exe;
   push(@safe_process_cmd, $exe);
 
   # Use my_safe_kill.exe
   my $safe_kill= my_find_bin(".", "lib/My/SafeProcess", "my_safe_kill");
-  die "Could not find my_safe_kill.exe" unless $safe_kill;
+  die "Could not find my_safe_kill" unless $safe_kill;
 }
-else {
-  # Use safe_process.pl
-  my $script=  "lib/My/SafeProcess/safe_process.pl";
-  $script= "../$script" unless -f $script;
-  die "Could not find safe_process.pl" unless -f $script;
-
-  # Call $script with Perl interpreter
-  push(@safe_process_cmd, $^X, $script);
+else
+{
+  my $use_safe_process_binary= 1;
+  if ($use_safe_process_binary) {
+    # Use my_safe_process
+    my $exe= my_find_bin(".", ["lib/My/SafeProcess", "My/SafeProcess"],
+			 "my_safe_process");
+    die "Could not find my_safe_process" unless $exe;
+    push(@safe_process_cmd, $exe);
+  }
+  else
+  {
+    # Use safe_process.pl
+    my $script=  "lib/My/SafeProcess/safe_process.pl";
+    $script= "../$script" unless -f $script;
+    die "Could not find safe_process.pl" unless -f $script;
+
+    # Call $script with Perl interpreter
+    push(@safe_process_cmd, $^X, $script);
+  }
 }
 
 

mysql-test/lib/My/SafeProcess/Makefile.am

+# Copyright (C) 2000-2006 MySQL AB
+# 
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; version 2 of the License.
+# 
+# This program 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 General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+bin_PROGRAMS =		my_safe_process
+
+my_safe_process_SOURCES = safe_process.cc
+
+# Don't update the files from bitkeeper
+%::SCCS/s.%

mysql-test/lib/My/SafeProcess/safe_process.cc

+/* Copyright (C) 2008 MySQL AB
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
+
+
+/*
+  Utility program that encapsulates process creation, monitoring
+  and bulletproof process cleanup
+
+  Usage:
+    safe_process [options to safe_process] -- progname arg1 ... argn
+
+  To safeguard mysqld you would invoke safe_process with a few options
+  for safe_process itself followed by a double dash to indicate start
+  of the command line for the program you really want to start
+
+  $> safe_process --output=output.log -- mysqld --datadir=var/data1 ...
+
+  This would redirect output to output.log and then start mysqld,
+  once it has done that it will continue to monitor the child as well
+  as the parent.
+
+  The safe_process then checks the follwing things:
+  1. Child exits, propagate the childs return code to the parent
+     by exiting with the same return code as the child.
+
+  2. Parent dies, immediately kill the child and exit, thus the
+     parent does not need to properly cleanup any child, it is handled
+     automatically.
+
+  3. Signal's recieced by the process will trigger same action as 2)
+
+*/
+
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <string.h>
+#include <errno.h>
+
+int verbose= 0;
+int terminated= 0;
+pid_t child_pid= -1;
+char safe_process_name[32]= {0};
+
+
+static void message(const char* fmt, ...)
+{
+  if (!verbose)
+    return;
+  va_list args;
+  fprintf(stderr, "%s: ", safe_process_name);
+  va_start(args, fmt);
+  vfprintf(stderr, fmt, args);
+  fprintf(stderr, "\n");
+  va_end(args);
+  fflush(stderr);
+}
+
+
+static void die(const char* fmt, ...)
+{
+  va_list args;
+  fprintf(stderr, "%s: FATAL ERROR, ", safe_process_name);
+  va_start(args, fmt);
+  vfprintf(stderr, fmt, args);
+  fprintf(stderr, "\n");
+  va_end(args);
+  if (int last_err= errno)
+    fprintf(stderr, "error: %d, %s\n", last_err, strerror(last_err));
+  exit(1);
+}
+
+
+static void kill_child (void)
+{
+  int exit_code= 1;
+  int status= 0;
+
+  message("Killing child: %d", child_pid);
+  // Terminate whole process group
+  kill(-child_pid, SIGKILL);
+
+  pid_t ret_pid= waitpid(child_pid, &status, 0);
+  if (ret_pid == child_pid)
+  {
+    if (WIFEXITED(status))
+    {
+      // Process has exited, collect return status
+      exit_code= WEXITSTATUS(status);
+      message("Child exit: %d", exit_code);
+      // Exit with exit status of the child
+      exit(exit_code);
+    }
+
+    if (WIFSIGNALED(status))
+      message("Child killed by signal: %d", WTERMSIG(status));
+
+    exit(exit_code);
+  }
+  exit(exit_code);
+}
+
+
+static void handle_signal (int sig)
+{
+  message("Got signal %d, child_pid: %d", sig, child_pid);
+  terminated= 1;
+
+  // Ignore further signals
+  signal(SIGTERM, SIG_IGN);
+  signal(SIGINT,  SIG_IGN);
+  signal(SIGCHLD, SIG_IGN);
+
+  if (child_pid > 0)
+    kill_child();
+
+  // Continune execution, allow the child to be started and
+  // finally terminated by monitor loop
+}
+
+
+int main(int argc, char* const argv[] )
+{
+  char* const* child_argv= 0;
+  pid_t own_pid= getpid();
+  pid_t parent_pid= getppid();
+
+  /* Install signal handlers */
+  signal(SIGTERM, handle_signal);
+  signal(SIGINT,  handle_signal);
+  signal(SIGCHLD, handle_signal);
+
+  sprintf(safe_process_name, "safe_process[%d]", own_pid);
+
+  message("Started");
+
+  /* Parse arguments */
+  for (int i= 1; i < argc; i++) {
+    const char* arg= argv[i];
+    if (strcmp(arg, "--") == 0 && strlen(arg) == 2) {
+      /* Got the "--" delimiter */
+      if (i >= argc)
+        die("No real args -> nothing to do");
+      child_argv= &argv[i+1];
+      break;
+    } else {
+      if ( strcmp(arg, "--verbose") == 0 )
+        verbose++;
+      else if ( strncmp(arg, "--parent-pid", 10) == 0 )
+      {
+        /* Override parent_pid with a value provided by user */
+        const char* start;
+        if ((start= strstr(arg, "=")) == NULL)
+          die("Could not find start of option value in '%s'", arg);
+        start++; /* Step past = */
+        if ((parent_pid= atoi(start)) == 0)
+          die("Invalid value '%s' passed to --parent-id", start);
+      }
+      else
+        die("Unknown option: %s", arg);
+    }
+  }
+  if (!child_argv || *child_argv == 0)
+    die("nothing to do");
+
+  message("parent_pid: %d", parent_pid);
+  if (parent_pid == own_pid)
+    die("parent_pid is equal to own pid!");
+
+  char buf;
+  int pfd[2];
+  if (pipe(pfd) == -1)
+    die("Failed to create pipe");
+
+  /* Create the child process */
+  while((child_pid= fork()) == -1)
+  {
+    message("fork failed");
+    sleep(1);
+  }
+
+  if (child_pid == 0)
+  {
+    close(pfd[0]); // Close unused read end
+
+    // Use default signal handlers in child
+    signal(SIGTERM, SIG_DFL);
+    signal(SIGINT,  SIG_DFL);
+    signal(SIGCHLD, SIG_DFL);
+
+    // Make this process it's own process group to be able to kill
+    // it and any childs(that hasn't changed group themself)
+    setpgid(0, 0);
+
+    // Signal that child is ready
+    buf= 37;
+    write(pfd[1], &buf, 1);
+    // Close write end
+    close(pfd[1]);
+
+    if (execvp(child_argv[0], child_argv) < 0)
+      die("Failed to exec child");
+  }
+
+  close(pfd[1]); // Close unused write end
+
+  // Wait for child to signal it's ready
+  read(pfd[0], &buf, 1);
+  if(buf != 37)
+    die("Didn't get 37 from pipe");
+  close(pfd[0]); // Close read end
+
+  /* Monitor loop */
+  message("Started child %d, terminated: %d", child_pid, terminated);
+
+  while(!terminated)
+  {
+    // Check if parent is still alive
+    if (kill(parent_pid, 0) != 0){
+      message("Parent is not alive anymore");
+      break;
+    }
+
+    // Check if child has exited, normally this wil be
+    // detected immediately with SIGCHLD handler
+    int status= 0;
+    pid_t ret_pid= waitpid(child_pid, &status, WNOHANG);
+    if (ret_pid == child_pid)
+    {
+      int ret_code= 2;
+      if (WIFEXITED(status))
+      {
+        // Process has exited, collect return status
+        int ret_code= WEXITSTATUS(status);
+        message("Child exit: %d", ret_code);
+        // Exit with exit status of the child
+        exit(ret_code);
+      }
+
+      if (WIFSIGNALED(status))
+        message("Child killed by signal: %d", WTERMSIG(status));
+
+      exit(ret_code);
+    }
+    sleep(1);
+  }
+  kill_child();
+
+  exit(1);
+}
+

mysql-test/lib/t/SafeProcessStress.pl

@@ -11,7 +11,7 @@ use My::SafeProcess;
 
 my $perl_path= $^X;
 my $verbose= 0;
-my $loops= 1000;
+my $loops= 100;
 
 print "kill one and wait for one\n";
 for (1...$loops){
@@ -33,7 +33,7 @@ for (1...$loops){
 
   foreach my $proc (@procs) {
     $proc->kill();
-    # dummyd will always be kiled and thus
+    # dummyd will always be killed and thus
     # exit_status should have been set to 1
     die "oops, exit_status: ", $proc->exit_status()
       unless $proc->exit_status() == 1;