00001 #ifndef __XRD_POLL_H__ 00002 #define __XRD_POLL_H__ 00003 /******************************************************************************/ 00004 /* */ 00005 /* X r d P o l l . h h */ 00006 /* */ 00007 /* (c) 2004 by the Board of Trustees of the Leland Stanford, Jr., University */ 00008 /* Produced by Andrew Hanushevsky for Stanford University under contract */ 00009 /* DE-AC02-76-SFO0515 with the Department of Energy */ 00010 /* */ 00011 /* This file is part of the XRootD software suite. */ 00012 /* */ 00013 /* XRootD is free software: you can redistribute it and/or modify it under */ 00014 /* the terms of the GNU Lesser General Public License as published by the */ 00015 /* Free Software Foundation, either version 3 of the License, or (at your */ 00016 /* option) any later version. */ 00017 /* */ 00018 /* XRootD is distributed in the hope that it will be useful, but WITHOUT */ 00019 /* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or */ 00020 /* FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public */ 00021 /* License for more details. */ 00022 /* */ 00023 /* You should have received a copy of the GNU Lesser General Public License */ 00024 /* along with XRootD in a file called COPYING.LESSER (LGPL license) and file */ 00025 /* COPYING (GPL license). If not, see <http://www.gnu.org/licenses/>. */ 00026 /* */ 00027 /* The copyright holder's institutional names and contributor's names may not */ 00028 /* be used to endorse or promote products derived from this software without */ 00029 /* specific prior written permission of the institution or contributor. */ 00030 /******************************************************************************/ 00031 00032 #include <sys/poll.h> 00033 #include "XrdSys/XrdSysPthread.hh" 00034 00035 #define XRD_NUMPOLLERS 3 00036 00037 class XrdOucTrace; 00038 class XrdSysError; 00039 class XrdLink; 00040 class XrdScheduler; 00041 class XrdSysSemaphore; 00042 00043 class XrdPoll 00044 { 00045 public: 00046 00047 // Attach() is called when a new link needs to be assigned to a poller 00048 // 00049 static int Attach(XrdLink *lp); // Implementation supplied 00050 00051 // Detach() is called when a link is being discarded 00052 // 00053 static void Detach(XrdLink *lp); // Implementation supplied 00054 00055 // Disable() is called when we need to mask interrupts from a link 00056 // 00057 virtual void Disable(XrdLink *lp, const char *etxt=0) = 0; 00058 00059 // Enable() is called when we want to receive interrupts from a link 00060 // 00061 virtual int Enable(XrdLink *lp) = 0; 00062 00063 // Finish() is called to allow a link to gracefully terminate when scheduled 00064 // 00065 static int Finish(XrdLink *lp, const char *etxt=0); //Implementation supplied 00066 00067 // Init() is called to set pointers to external interfaces at config time. 00068 // 00069 static void Init(XrdSysError *eP, XrdOucTrace *tP, XrdScheduler *sP) 00070 {XrdLog = eP; XrdTrace = tP; XrdSched = sP;} 00071 00072 // Poll2Text() converts bits in an revents item to text 00073 // 00074 static char *Poll2Text(short events); // Implementation supplied 00075 00076 // Setup() is called at config time to perform poller configuration 00077 // 00078 static int Setup(int numfd); // Implementation supplied 00079 00080 // Start() is called via a thread for each poller that was created 00081 // 00082 virtual void Start(XrdSysSemaphore *syncp, int &rc) = 0; 00083 00084 // Stats() is called to provide statistics on polling 00085 // 00086 static int Stats(char *buff, int blen, int do_sync=0); 00087 00088 // Identification of the thread handling this object 00089 // 00090 int PID; // Poller ID 00091 pthread_t TID; // Thread ID 00092 00093 // The following table reference the pollers in effect 00094 // 00095 static XrdPoll *Pollers[XRD_NUMPOLLERS]; 00096 00097 XrdPoll(); 00098 virtual ~XrdPoll() {} 00099 00100 protected: 00101 00102 static const char *TraceID; // For tracing 00103 static XrdOucTrace *XrdTrace; 00104 static XrdSysError *XrdLog; 00105 static XrdScheduler *XrdSched; 00106 00107 // Gets the next request on the poll pipe. This is common to all implentations. 00108 // 00109 int getRequest(); // Implementation supplied 00110 00111 // Exclude() called to exclude a link from a poll set 00112 // 00113 virtual void Exclude(XrdLink *lp) = 0; 00114 00115 // Include() called to include a link in a poll set 00116 // 00117 virtual int Include(XrdLink *lp) = 0; 00118 00119 // newPoller() called to get a new poll object at initialization time 00120 // Even though static, an implementation must be supplied. 00121 // 00122 static XrdPoll *newPoller(int pollid, int numfd) /* = 0 */; 00123 00124 // The following is common to all implementations 00125 // 00126 XrdSysMutex PollPipe; 00127 struct pollfd PipePoll; 00128 int CmdFD; // FD to send PipeData commands 00129 int ReqFD; // FD to recv PipeData requests 00130 struct PipeData {union {XrdSysSemaphore *theSem; 00131 struct {int fd; 00132 int ent;} Arg; 00133 } Parms; 00134 enum cmd {EnFD, DiFD, RmFD, Post}; 00135 cmd req; 00136 }; 00137 PipeData ReqBuff; 00138 char *PipeBuff; 00139 int PipeBlen; 00140 00141 // The following are statistical counters each implementation must maintain 00142 // 00143 int numEnabled; // Count of Enable() calls 00144 int numEvents; // Count of poll fd's dispatched 00145 int numInterrupts; // Number of interrupts (e.g., signals) 00146 00147 private: 00148 00149 static XrdSysMutex doingAttach; 00150 int numAttached; // Number of fd's attached to poller 00151 }; 00152 #endif