hphp/util/light-process.h

   1 /*
   2    +----------------------------------------------------------------------+
   3    | HipHop for PHP                                                       |
   4    +----------------------------------------------------------------------+
   5    | Copyright (c) 2010-present Facebook, Inc. (http://www.facebook.com)  |
   6    +----------------------------------------------------------------------+
   7    | This source file is subject to version 3.01 of the PHP license,      |
   8    | that is bundled with this package in the file LICENSE, and is        |
   9    | available through the world-wide-web at the following url:           |
  10    | http://www.php.net/license/3_01.txt                                  |
  11    | If you did not receive a copy of the PHP license and are unable to   |
  12    | obtain it through the world-wide-web, please send a note to          |
  13    | license@php.net so we can mail you a copy immediately.               |
  14    +----------------------------------------------------------------------+
  15 */
  16
  17 #pragma once
  18
  19 #ifdef _MSC_VER
  20 # error LightProcess is not supported under MSVC!
  21 #endif
  22
  23 #include <string>
  24 #include <vector>
  25 #include <cstdio>
  26 #include <cstdlib>
  27 #include <map>
  28
  29 #include <signal.h>
  30 #include <unistd.h>
  31
  32 #include "hphp/util/process.h"
  33 #include "hphp/util/lock.h"
  34
  35 namespace HPHP {
  36 ///////////////////////////////////////////////////////////////////////////////
  37 // light-weight process
  38
  39 struct LightProcess {
  40   LightProcess();
  41   ~LightProcess();
  42
  43   Mutex& mutex() { return m_procMutex; }
  44
  45   static void Close();
  46   static bool Available();
  47   static void Initialize(const std::string &prefix, int count,
  48                          bool trackProcessTimes,
  49                          const std::vector<int> &inherited_fds);
  50   static void ChangeUser(const std::string &username);
  51   static void ChangeUser(int afdt, const std::string &username);
  52
  53   typedef std::function<void(pid_t)> LostChildHandler;
  54   static void SetLostChildHandler(const LostChildHandler& handler);
  55
  56   static FILE *popen(const char *cmd, const char *type,
  57                      const char *cwd = nullptr);
  58   static int pclose(FILE *f);
  59
  60   /** Opens a process with the given arguments, environment, working directory,
  61    * and file descriptors.
  62    *
  63    * See Process::ForkAndExecve for details.
  64    */
  65   static pid_t ForkAndExecve(
  66     const std::string& path,
  67     const std::vector<std::string>& argv,
  68     const std::vector<std::string>& envp,
  69     const std::string& cwd,
  70     const std::map<int, int>& fds,
  71     int flags = Process::FORK_AND_EXECVE_FLAG_NONE,
  72     pid_t pgid = 0
  73   );
  74
  75   /**
  76    * Opens a process with given cwd and environment variables, using the shell.
  77    *
  78    * The parameters "created" and "desired" describe the pipes that need to
  79    * be setup for the child process: "created" contains created fd for child,
  80    * and "desired" contains desired fd in child.
  81    *
  82    * The parameter env contains strings of the form <name>=<content>.
  83    */
  84   static pid_t proc_open(const char *cmd, const std::vector<int> &created,
  85                          const std::vector<int> &desired,
  86                          const char *cwd, const std::vector<std::string> &env);
  87
  88   /**
  89    * The main process is not the (direct) parent of the worker process,
  90    * and therefore it has to delegate to the shadow process to do waitpid.
  91    * There can be a timeout (in seconds), after which SIGKILL is sent to
  92    * the child process.
  93    */
  94   static pid_t waitpid(pid_t pid, int *stat_loc, int options, int timeout = 0);
  95
  96   static pid_t pcntl_waitpid(pid_t pid, int *stat_loc, int options);
  97
  98   /**
  99    * When running a CLI server, the requests executed on behalf of local
 100    * processes will delegate to a light process pool run by the client.
 101    */
 102   static int createDelegate();
 103
 104   static std::unique_ptr<LightProcess> setThreadLocalAfdtOverride(int fd);
 105   static std::unique_ptr<LightProcess> setThreadLocalAfdtOverride(
 106     std::unique_ptr<LightProcess> p
 107   );
 108
 109 private:
 110   static void SigChldHandler(int sig, siginfo_t* info, void* ctx);
 111
 112   bool initShadow(int afdt_listen,
 113                   const std::string& afdt_filename, int id,
 114                   const std::vector<int> &inherited_fds);
 115   static void runShadow(int afdt_fd);
 116   void closeShadow();
 117
 118   /**
 119    * For later light processes to close their pipes to previous ones.
 120    */
 121   void closeFiles();
 122
 123   static FILE *LightPopenImpl(const char *cmd, const char *type,
 124                               const char *cwd);
 125   static FILE *HeavyPopenImpl(const char *cmd, const char *type,
 126                               const char *cwd);
 127
 128   pid_t m_shadowProcess;
 129   Mutex m_procMutex;
 130   int m_afdt_fd;
 131   std::map<FILE*, pid_t> m_popenMap;
 132
 133  public:
 134   // whether to abort when user change fails.
 135   static bool g_strictUser;
 136 };
 137
 138 ///////////////////////////////////////////////////////////////////////////////
 139 }