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 #define _POSIX_C_SOURCE 200112L
  21
  22 #include "JackPosixSemaphore.h"
  23 #include "JackTools.h"
  24 #include "JackConstants.h"
  25 #include "JackError.h"
  26 #include <fcntl.h>
  27 #include <stdio.h>
  28 #include <sys/time.h>
  29 #ifdef __linux__
  30 #include "promiscuous.h"
  31 #endif
  32
  33 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
  34 #define JACK_SEM_PREFIX "/jack_sem"
  35 #define SEM_DEFAULT_O 0
  36 #else
  37 #define JACK_SEM_PREFIX "jack_sem"
  38 #define SEM_DEFAULT_O O_RDWR
  39 #endif
  40
  41 namespace Jack
  42 {
  43
  44 JackPosixSemaphore::JackPosixSemaphore() : JackSynchro(), fSemaphore(NULL)
  45 {
  46     const char* promiscuous = getenv("JACK_PROMISCUOUS_SERVER");
  47     fPromiscuous = (promiscuous != NULL);
  48 #ifdef __linux__
  49     fPromiscuousGid = jack_group2gid(promiscuous);
  50 #endif
  51 }
  52
  53 void JackPosixSemaphore::BuildName(const char* client_name, const char* server_name, char* res, int size)
  54 {
  55     char ext_client_name[SYNC_MAX_NAME_SIZE + 1];
  56     JackTools::RewriteName(client_name, ext_client_name);
  57 #if __APPLE__  // POSIX semaphore names are limited to 32 characters...
  58     snprintf(res, 32, "js_%s", ext_client_name);
  59 #else
  60     if (fPromiscuous) {
  61         snprintf(res, size, JACK_SEM_PREFIX ".%s_%s", server_name, ext_client_name);
  62     } else {
  63         snprintf(res, size, JACK_SEM_PREFIX ".%d_%s_%s", JackTools::GetUID(), server_name, ext_client_name);
  64     }
  65 #endif
  66 }
  67
  68 bool JackPosixSemaphore::Signal()
  69 {
  70     int res;
  71
  72     if (!fSemaphore) {
  73         jack_error("JackPosixSemaphore::Signal name = %s already deallocated!!", fName);
  74         return false;
  75     }
  76
  77     if (fFlush) {
  78         return true;
  79     }
  80
  81     if ((res = sem_post(fSemaphore)) != 0) {
  82         jack_error("JackPosixSemaphore::Signal name = %s err = %s", fName, strerror(errno));
  83     }
  84     return (res == 0);
  85 }
  86
  87 bool JackPosixSemaphore::SignalAll()
  88 {
  89     int res;
  90
  91     if (!fSemaphore) {
  92         jack_error("JackPosixSemaphore::SignalAll name = %s already deallocated!!", fName);
  93         return false;
  94     }
  95
  96     if (fFlush) {
  97         return true;
  98     }
  99
 100     if ((res = sem_post(fSemaphore)) != 0) {
 101         jack_error("JackPosixSemaphore::SignalAll name = %s err = %s", fName, strerror(errno));
 102     }
 103     return (res == 0);
 104 }
 105
 106 bool JackPosixSemaphore::Wait()
 107 {
 108     int res;
 109
 110     if (!fSemaphore) {
 111         jack_error("JackPosixSemaphore::Wait name = %s already deallocated!!", fName);
 112         return false;
 113     }
 114
 115     while ((res = sem_wait(fSemaphore) < 0)) {
 116         jack_error("JackPosixSemaphore::Wait name = %s err = %s", fName, strerror(errno));
 117         if (errno != EINTR) {
 118             break;
 119         }
 120     }
 121     return (res == 0);
 122 }
 123
 124 bool JackPosixSemaphore::TimedWait(long usec)
 125 {
 126         int res;
 127         struct timeval now;
 128         timespec time;
 129
 130         if (!fSemaphore) {
 131                 jack_error("JackPosixSemaphore::TimedWait name = %s already deallocated!!", fName);
 132                 return false;
 133         }
 134         gettimeofday(&now, 0);
 135         time.tv_sec = now.tv_sec + usec / 1000000;
 136     long tv_usec = (now.tv_usec + (usec % 1000000));
 137     time.tv_sec += tv_usec / 1000000;
 138     time.tv_nsec = (tv_usec % 1000000) * 1000;
 139
 140     while ((res = sem_timedwait(fSemaphore, &time)) < 0) {
 141         jack_error("JackPosixSemaphore::TimedWait err = %s", strerror(errno));
 142         jack_log("JackPosixSemaphore::TimedWait now : %ld %ld ", now.tv_sec, now.tv_usec);
 143         jack_log("JackPosixSemaphore::TimedWait next : %ld %ld ", time.tv_sec, time.tv_nsec/1000);
 144         if (errno != EINTR) {
 145             break;
 146         }
 147     }
 148     return (res == 0);
 149 }
 150
 151 // Server side : publish the semaphore in the global namespace
 152 bool JackPosixSemaphore::Allocate(const char* name, const char* server_name, int value)
 153 {
 154     BuildName(name, server_name, fName, sizeof(fName));
 155     jack_log("JackPosixSemaphore::Allocate name = %s val = %ld", fName, value);
 156
 157     if ((fSemaphore = sem_open(fName, O_CREAT | SEM_DEFAULT_O, 0777, value)) == (sem_t*)SEM_FAILED) {
 158         jack_error("Allocate: can't check in named semaphore name = %s err = %s", fName, strerror(errno));
 159         return false;
 160     } else {
 161 #ifdef __linux__
 162         if (fPromiscuous) {
 163             char sempath[SYNC_MAX_NAME_SIZE+13];
 164             snprintf(sempath, sizeof(sempath), "/dev/shm/sem.%s", fName);
 165             if (jack_promiscuous_perms(-1, sempath, fPromiscuousGid) < 0)
 166                 return false;
 167         }
 168 #endif
 169         return true;
 170     }
 171 }
 172
 173 // Client side : get the published semaphore from server
 174 bool JackPosixSemaphore::ConnectInput(const char* name, const char* server_name)
 175 {
 176     BuildName(name, server_name, fName, sizeof(fName));
 177     jack_log("JackPosixSemaphore::Connect name = %s", fName);
 178
 179     // Temporary...
 180     if (fSemaphore) {
 181         jack_log("Already connected name = %s", name);
 182         return true;
 183     }
 184
 185     if ((fSemaphore = sem_open(fName, SEM_DEFAULT_O)) == (sem_t*)SEM_FAILED) {
 186         jack_error("Connect: can't connect named semaphore name = %s err = %s", fName, strerror(errno));
 187         return false;
 188     } else if (fSemaphore) {
 189         int val = 0;
 190         sem_getvalue(fSemaphore, &val);
 191         jack_log("JackPosixSemaphore::Connect sem_getvalue %ld", val);
 192         return true;
 193     } else {
 194         jack_error("Connect: fSemaphore not initialized!");
 195         return false;
 196     }
 197 }
 198
 199 bool JackPosixSemaphore::Connect(const char* name, const char* server_name)
 200 {
 201     return ConnectInput(name, server_name);
 202 }
 203
 204 bool JackPosixSemaphore::ConnectOutput(const char* name, const char* server_name)
 205 {
 206     return ConnectInput(name, server_name);
 207 }
 208
 209 bool JackPosixSemaphore::Disconnect()
 210 {
 211     if (fSemaphore) {
 212         jack_log("JackPosixSemaphore::Disconnect name = %s", fName);
 213         if (sem_close(fSemaphore) != 0) {
 214             jack_error("Disconnect: can't disconnect named semaphore name = %s err = %s", fName, strerror(errno));
 215             return false;
 216         } else {
 217             fSemaphore = NULL;
 218             return true;
 219         }
 220     } else {
 221         return true;
 222     }
 223 }
 224
 225 // Server side : destroy the semaphore
 226 void JackPosixSemaphore::Destroy()
 227 {
 228     if (fSemaphore != NULL) {
 229         jack_log("JackPosixSemaphore::Destroy name = %s", fName);
 230         sem_unlink(fName);
 231         if (sem_close(fSemaphore) != 0) {
 232             jack_error("Destroy: can't destroy semaphore name = %s err = %s", fName, strerror(errno));
 233         }
 234         fSemaphore = NULL;
 235     } else {
 236         jack_error("JackPosixSemaphore::Destroy semaphore == NULL");
 237     }
 238 }
 239
 240 } // end of namespace
 241