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 <ctype.h>
  29 #include <sys/time.h>
  30 #ifdef __linux__
  31 #include "promiscuous.h"
  32 #endif
  33
  34 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
  35 #define JACK_SEM_PREFIX "/jack_sem"
  36 #define SEM_DEFAULT_O 0
  37 #else
  38 #define JACK_SEM_PREFIX "jack_sem"
  39 #define SEM_DEFAULT_O O_RDWR
  40 #endif
  41
  42 namespace Jack
  43 {
  44
  45 JackPosixSemaphore::JackPosixSemaphore() : JackSynchro(), fSemaphore(NULL)
  46 {
  47     const char* promiscuous = getenv("JACK_PROMISCUOUS_SERVER");
  48     fPromiscuous = (promiscuous != NULL);
  49 #ifdef __linux__
  50     fPromiscuousGid = jack_group2gid(promiscuous);
  51 #endif
  52 }
  53
  54 void JackPosixSemaphore::BuildName(const char* client_name, const char* server_name, char* res, int size)
  55 {
  56     char ext_client_name[SYNC_MAX_NAME_SIZE + 1];
  57     JackTools::RewriteName(client_name, ext_client_name);
  58 #if __APPLE__  // POSIX semaphore names are limited to 32 characters...
  59     snprintf(res, 32, "js_%s", ext_client_name);
  60 #else
  61     if (fPromiscuous) {
  62         snprintf(res, size, JACK_SEM_PREFIX ".%s_%s", server_name, ext_client_name);
  63     } else {
  64         snprintf(res, size, JACK_SEM_PREFIX ".%d_%s_%s", JackTools::GetUID(), server_name, ext_client_name);
  65     }
  66 #endif
  67 }
  68
  69 bool JackPosixSemaphore::Signal()
  70 {
  71     int res;
  72
  73     if (!fSemaphore) {
  74         jack_error("JackPosixSemaphore::Signal name = %s already deallocated!!", fName);
  75         return false;
  76     }
  77
  78     if (fFlush) {
  79         return true;
  80     }
  81
  82     if ((res = sem_post(fSemaphore)) != 0) {
  83         jack_error("JackPosixSemaphore::Signal name = %s err = %s", fName, strerror(errno));
  84     }
  85     return (res == 0);
  86 }
  87
  88 bool JackPosixSemaphore::SignalAll()
  89 {
  90     int res;
  91
  92     if (!fSemaphore) {
  93         jack_error("JackPosixSemaphore::SignalAll name = %s already deallocated!!", fName);
  94         return false;
  95     }
  96
  97     if (fFlush) {
  98         return true;
  99     }
 100
 101     if ((res = sem_post(fSemaphore)) != 0) {
 102         jack_error("JackPosixSemaphore::SignalAll name = %s err = %s", fName, strerror(errno));
 103     }
 104     return (res == 0);
 105 }
 106
 107 bool JackPosixSemaphore::Wait()
 108 {
 109     int res;
 110
 111     if (!fSemaphore) {
 112         jack_error("JackPosixSemaphore::Wait name = %s already deallocated!!", fName);
 113         return false;
 114     }
 115
 116     while ((res = sem_wait(fSemaphore) < 0)) {
 117         jack_error("JackPosixSemaphore::Wait name = %s err = %s", fName, strerror(errno));
 118         if (errno != EINTR) {
 119             break;
 120         }
 121     }
 122     return (res == 0);
 123 }
 124
 125 bool JackPosixSemaphore::TimedWait(long usec)
 126 {
 127         int res;
 128         struct timeval now;
 129         timespec time;
 130
 131         if (!fSemaphore) {
 132                 jack_error("JackPosixSemaphore::TimedWait name = %s already deallocated!!", fName);
 133                 return false;
 134         }
 135         gettimeofday(&now, 0);
 136         time.tv_sec = now.tv_sec + usec / 1000000;
 137     long tv_usec = (now.tv_usec + (usec % 1000000));
 138     time.tv_sec += tv_usec / 1000000;
 139     time.tv_nsec = (tv_usec % 1000000) * 1000;
 140
 141     while ((res = sem_timedwait(fSemaphore, &time)) < 0) {
 142         jack_error("JackPosixSemaphore::TimedWait err = %s", strerror(errno));
 143         jack_log("JackPosixSemaphore::TimedWait now : %ld %ld ", now.tv_sec, now.tv_usec);
 144         jack_log("JackPosixSemaphore::TimedWait next : %ld %ld ", time.tv_sec, time.tv_nsec/1000);
 145         if (errno != EINTR) {
 146             break;
 147         }
 148     }
 149     return (res == 0);
 150 }
 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 | SEM_DEFAULT_O, 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, SEM_DEFAULT_O)) == (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