hphp/util/light-process.h

   1 /*
   2    +----------------------------------------------------------------------+
   3    | HipHop for PHP                                                       |
   4    +----------------------------------------------------------------------+
   5    | Copyright (c) 2010-2014 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 #ifndef incl_HPHP_LIGHT_PROCESS_H_
  18 #define incl_HPHP_LIGHT_PROCESS_H_
  19
  20 #include <string>
  21 #include <vector>
  22 #include <cstdio>
  23 #include <cstdlib>
  24 #include <map>
  25
  26 #include <signal.h>
  27 #include <unistd.h>
  28
  29 #include "hphp/util/process.h"
  30 #include "hphp/util/lock.h"
  31
  32 namespace HPHP {
  33 ///////////////////////////////////////////////////////////////////////////////
  34 // light-weight process
  35
  36 class LightProcess {
  37 public:
  38   LightProcess();
  39   ~LightProcess();
  40
  41   static void Close();
  42   static bool Available();
  43   static void Initialize(const std::string &prefix, int count,
  44                          const std::vector<int> &inherited_fds);
  45   static void ChangeUser(const std::string &username);
  46
  47   typedef std::function<void(pid_t)> LostChildHandler;
  48   static void SetLostChildHandler(const LostChildHandler& handler);
  49
  50   static FILE *popen(const char *cmd, const char *type,
  51                      const char *cwd = nullptr);
  52   static int pclose(FILE *f);
  53
  54   /**
  55    * Opens a process with given cwd and environment variables.
  56    *
  57    * The parameters "created" and "desired" describe the pipes that need to
  58    * be setup for the child process: "created" contains created fd for child,
  59    * and "desired" contains desired fd in child.
  60    *
  61    * The parameter env contains strings of the form <name>=<content>.
  62    */
  63   static pid_t proc_open(const char *cmd, const std::vector<int> &created,
  64                          const std::vector<int> &desired,
  65                          const char *cwd, const std::vector<std::string> &env);
  66
  67   /**
  68    * The main process is not the (direct) parent of the worker process,
  69    * and therefore it has to delegate to the shadow process to do waitpid.
  70    * There can be a timeout (in seconds), after which SIGKILL is sent to
  71    * the child process.
  72    */
  73   static pid_t waitpid(pid_t pid, int *stat_loc, int options, int timeout = 0);
  74
  75   static pid_t pcntl_waitpid(pid_t pid, int *stat_loc, int options);
  76
  77 private:
  78   static int GetId();
  79   static void SigChldHandler(int sig, siginfo_t* info, void* ctx);
  80
  81   bool initShadow(const std::string &prefix, int id,
  82                   const std::vector<int> &inherited_fds);
  83   void runShadow(int fdin, int fdout);
  84   void closeShadow();
  85
  86   /**
  87    * For later light processes to close their pipes to previous ones.
  88    */
  89   void closeFiles();
  90
  91   static FILE *LightPopenImpl(const char *cmd, const char *type,
  92                               const char *cwd);
  93   static FILE *HeavyPopenImpl(const char *cmd, const char *type,
  94                               const char *cwd);
  95
  96   static Mutex s_mutex;
  97   pid_t m_shadowProcess;
  98   FILE *m_fin;   // the pipe to read from the child
  99   FILE *m_fout;  // the pipe to write to the child
 100   Mutex m_procMutex;
 101   std::string m_afdtFilename;
 102   int m_afdt_fd;
 103   int m_afdt_lfd;
 104   std::map<int64_t, int64_t> m_popenMap;
 105 };
 106
 107 ///////////////////////////////////////////////////////////////////////////////
 108 }
 109
 110 #endif // incl_HPHP_LIGHT_PROCESS_H_