posix/JackPosixSemaphore.cpp

   1 /*
   2 Copyright (C) 2004-2008 Grame
   3
   4 This program is free software; you can redistribute it and/or modify
   5 it under the terms of the GNU Lesser General Public License as published by
   6 the Free Software Foundation; either version 2.1 of the License, or
   7 (at your option) any later version.
   8
   9 This program is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 GNU Lesser General Public License for more details.
  13
  14 You should have received a copy of the GNU Lesser General Public License
  15 along with this program; if not, write to the Free Software
  16 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  17
  18 */
  19
  20 #include "JackPosixSemaphore.h"
  21 #include "JackTools.h"
  22 #include "JackConstants.h"
  23 #include "JackError.h"
  24 #include <fcntl.h>
  25 #include <stdio.h>
  26 #include <sys/time.h>
  27 #ifdef __linux__
  28 #include "promiscuous.h"
  29 #endif
  30
  31 namespace Jack
  32 {
  33
  34 JackPosixSemaphore::JackPosixSemaphore() : JackSynchro(), fSemaphore(NULL)
  35 {
  36     const char* promiscuous = getenv("JACK_PROMISCUOUS_SERVER");
  37     fPromiscuous = (promiscuous != NULL);
  38 #ifdef __linux__
  39     fPromiscuousGid = jack_group2gid(promiscuous);
  40 #endif
  41 }
  42
  43 void JackPosixSemaphore::BuildName(const char* client_name, const char* server_name, char* res, int size)
  44 {
  45     char ext_client_name[SYNC_MAX_NAME_SIZE + 1];
  46     JackTools::RewriteName(client_name, ext_client_name);
  47 #if __APPLE__  // POSIX semaphore names are limited to 32 characters...
  48     snprintf(res, 32, "js_%s", ext_client_name);
  49 #else
  50     if (fPromiscuous) {
  51         snprintf(res, size, "jack_sem.%s_%s", server_name, ext_client_name);
  52     } else {
  53         snprintf(res, size, "jack_sem.%d_%s_%s", JackTools::GetUID(), server_name, ext_client_name);
  54     }
  55 #endif
  56 }
  57
  58 bool JackPosixSemaphore::Signal()
  59 {
  60     int res;
  61
  62     if (!fSemaphore) {
  63         jack_error("JackPosixSemaphore::Signal name = %s already deallocated!!", fName);
  64         return false;
  65     }
  66
  67     if (fFlush) {
  68         return true;
  69     }
  70
  71     if ((res = sem_post(fSemaphore)) != 0) {
  72         jack_error("JackPosixSemaphore::Signal name = %s err = %s", fName, strerror(errno));
  73     }
  74     return (res == 0);
  75 }
  76
  77 bool JackPosixSemaphore::SignalAll()
  78 {
  79     int res;
  80
  81     if (!fSemaphore) {
  82         jack_error("JackPosixSemaphore::SignalAll name = %s already deallocated!!", fName);
  83         return false;
  84     }
  85
  86     if (fFlush) {
  87         return true;
  88     }
  89
  90     if ((res = sem_post(fSemaphore)) != 0) {
  91         jack_error("JackPosixSemaphore::SignalAll name = %s err = %s", fName, strerror(errno));
  92     }
  93     return (res == 0);
  94 }
  95
  96 bool JackPosixSemaphore::Wait()
  97 {
  98     int res;
  99
 100     if (!fSemaphore) {
 101         jack_error("JackPosixSemaphore::Wait name = %s already deallocated!!", fName);
 102         return false;
 103     }
 104
 105     while ((res = sem_wait(fSemaphore) < 0)) {
 106         jack_error("JackPosixSemaphore::Wait name = %s err = %s", fName, strerror(errno));
 107         if (errno != EINTR) {
 108             break;
 109         }
 110     }
 111     return (res == 0);
 112 }
 113
 114 #if (_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600) // glibc feature test
 115
 116 bool JackPosixSemaphore::TimedWait(long usec)
 117 {
 118         int res;
 119         struct timeval now;
 120         timespec time;
 121
 122         if (!fSemaphore) {
 123                 jack_error("JackPosixSemaphore::TimedWait name = %s already deallocated!!", fName);
 124                 return false;
 125         }
 126         gettimeofday(&now, 0);
 127         time.tv_sec = now.tv_sec + usec / 1000000;
 128     long tv_usec = (now.tv_usec + (usec % 1000000));
 129     time.tv_sec += tv_usec / 1000000;
 130     time.tv_nsec = (tv_usec % 1000000) * 1000;
 131
 132     while ((res = sem_timedwait(fSemaphore, &time)) < 0) {
 133         jack_error("JackPosixSemaphore::TimedWait err = %s", strerror(errno));
 134         jack_log("JackPosixSemaphore::TimedWait now : %ld %ld ", now.tv_sec, now.tv_usec);
 135         jack_log("JackPosixSemaphore::TimedWait next : %ld %ld ", time.tv_sec, time.tv_nsec/1000);
 136         if (errno != EINTR) {
 137             break;
 138         }
 139     }
 140     return (res == 0);
 141 }
 142
 143 #else
 144 #warning "JackPosixSemaphore::TimedWait is not supported: Jack in SYNC mode with JackPosixSemaphore will not run properly !!"
 145
 146 bool JackPosixSemaphore::TimedWait(long usec)
 147 {
 148         return Wait();
 149 }
 150 #endif
 151
 152 // Server side : publish the semaphore in the global namespace
 153 bool JackPosixSemaphore::Allocate(const char* name, const char* server_name, int value)
 154 {
 155     BuildName(name, server_name, fName, sizeof(fName));
 156     jack_log("JackPosixSemaphore::Allocate name = %s val = %ld", fName, value);
 157
 158     if ((fSemaphore = sem_open(fName, O_CREAT | O_RDWR, 0777, value)) == (sem_t*)SEM_FAILED) {
 159         jack_error("Allocate: can't check in named semaphore name = %s err = %s", fName, strerror(errno));
 160         return false;
 161     } else {
 162 #ifdef __linux__
 163         if (fPromiscuous) {
 164             char sempath[SYNC_MAX_NAME_SIZE+13];
 165             snprintf(sempath, sizeof(sempath), "/dev/shm/sem.%s", fName);
 166             if (jack_promiscuous_perms(-1, sempath, fPromiscuousGid) < 0)
 167                 return false;
 168         }
 169 #endif
 170         return true;
 171     }
 172 }
 173
 174 // Client side : get the published semaphore from server
 175 bool JackPosixSemaphore::ConnectInput(const char* name, const char* server_name)
 176 {
 177     BuildName(name, server_name, fName, sizeof(fName));
 178     jack_log("JackPosixSemaphore::Connect name = %s", fName);
 179
 180     // Temporary...
 181     if (fSemaphore) {
 182         jack_log("Already connected name = %s", name);
 183         return true;
 184     }
 185
 186     if ((fSemaphore = sem_open(fName, O_RDWR)) == (sem_t*)SEM_FAILED) {
 187         jack_error("Connect: can't connect named semaphore name = %s err = %s", fName, strerror(errno));
 188         return false;
 189     } else if (fSemaphore) {
 190         int val = 0;
 191         sem_getvalue(fSemaphore, &val);
 192         jack_log("JackPosixSemaphore::Connect sem_getvalue %ld", val);
 193         return true;
 194     } else {
 195         jack_error("Connect: fSemaphore not initialized!");
 196         return false;
 197     }
 198 }
 199
 200 bool JackPosixSemaphore::Connect(const char* name, const char* server_name)
 201 {
 202     return ConnectInput(name, server_name);
 203 }
 204
 205 bool JackPosixSemaphore::ConnectOutput(const char* name, const char* server_name)
 206 {
 207     return ConnectInput(name, server_name);
 208 }
 209
 210 bool JackPosixSemaphore::Disconnect()
 211 {
 212     if (fSemaphore) {
 213         jack_log("JackPosixSemaphore::Disconnect name = %s", fName);
 214         if (sem_close(fSemaphore) != 0) {
 215             jack_error("Disconnect: can't disconnect named semaphore name = %s err = %s", fName, strerror(errno));
 216             return false;
 217         } else {
 218             fSemaphore = NULL;
 219             return true;
 220         }
 221     } else {
 222         return true;
 223     }
 224 }
 225
 226 // Server side : destroy the semaphore
 227 void JackPosixSemaphore::Destroy()
 228 {
 229     if (fSemaphore != NULL) {
 230         jack_log("JackPosixSemaphore::Destroy name = %s", fName);
 231         sem_unlink(fName);
 232         if (sem_close(fSemaphore) != 0) {
 233             jack_error("Destroy: can't destroy semaphore name = %s err = %s", fName, strerror(errno));
 234         }
 235         fSemaphore = NULL;
 236     } else {
 237         jack_error("JackPosixSemaphore::Destroy semaphore == NULL");
 238     }
 239 }
 240
 241 } // end of namespace
 242