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