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
  28 namespace Jack
  29 {
  30
  31 void JackPosixSemaphore::BuildName(const char* client_name, const char* server_name, char* res)
  32 {
  33     char ext_client_name[JACK_CLIENT_NAME_SIZE + 1];
  34     JackTools::RewriteName(client_name, ext_client_name);
  35     sprintf(res, "jack_sem.%d_%s_%s", JackTools::GetUID(), server_name, ext_client_name);
  36 }
  37
  38 bool JackPosixSemaphore::Signal()
  39 {
  40     int res;
  41
  42     if (!fSemaphore) {
  43         jack_error("JackPosixSemaphore::Signal name = %s already desallocated!!", fName);
  44         return false;
  45     }
  46
  47     if (fFlush)
  48         return true;
  49
  50     if ((res = sem_post(fSemaphore)) != 0) {
  51         jack_error("JackPosixSemaphore::Signal name = %s err = %s", fName, strerror(errno));
  52     }
  53     return (res == 0);
  54 }
  55
  56 bool JackPosixSemaphore::SignalAll()
  57 {
  58     int res;
  59
  60     if (!fSemaphore) {
  61         jack_error("JackPosixSemaphore::SignalAll name = %s already desallocated!!", fName);
  62         return false;
  63     }
  64
  65     if (fFlush)
  66         return true;
  67
  68     if ((res = sem_post(fSemaphore)) != 0) {
  69         jack_error("JackPosixSemaphore::SignalAll name = %s err = %s", fName, strerror(errno));
  70     }
  71     return (res == 0);
  72 }
  73
  74 /*
  75 bool JackPosixSemaphore::Wait()
  76 {
  77     int res;
  78
  79     if (!fSemaphore) {
  80         jack_error("JackPosixSemaphore::Wait name = %s already desallocated!!", fName);
  81         return false;
  82     }
  83
  84     if ((res = sem_wait(fSemaphore)) != 0) {
  85         jack_error("JackPosixSemaphore::Wait name = %s err = %s", fName, strerror(errno));
  86     }
  87     return (res == 0);
  88 }
  89 */
  90
  91 bool JackPosixSemaphore::Wait()
  92 {
  93     int res;
  94
  95     while ((res = sem_wait(fSemaphore) < 0)) {
  96         jack_error("JackPosixSemaphore::Wait name = %s err = %s", fName, strerror(errno));
  97         if (errno != EINTR)
  98             break;
  99     }
 100     return (res == 0);
 101 }
 102
 103 #if (_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600) // glibc feature test
 104
 105 bool JackPosixSemaphore::TimedWait(long usec)
 106 {
 107         int res;
 108         struct timeval now;
 109         timespec time;
 110
 111         if (!fSemaphore) {
 112                 jack_error("JackPosixSemaphore::TimedWait name = %s already desallocated!!", fName);
 113                 return false;
 114         }
 115         gettimeofday(&now, 0);
 116         time.tv_sec = now.tv_sec + usec / 1000000;
 117     long tv_usec = (now.tv_usec + (usec % 1000000));
 118     time.tv_sec += tv_usec / 1000000;
 119     time.tv_nsec = (tv_usec % 1000000) * 1000;
 120
 121     if ((res = sem_timedwait(fSemaphore, &time)) != 0) {
 122         jack_error("JackPosixSemaphore::TimedWait err = %s", strerror(errno));
 123         jack_log("now %ld %ld ", now.tv_sec, now.tv_usec);
 124         jack_log("next %ld %ld ", time.tv_sec, time.tv_nsec/1000);
 125     }
 126     return (res == 0);
 127 }
 128
 129 #else
 130 #warning "JackPosixSemaphore::TimedWait is not supported: Jack in SYNC mode with JackPosixSemaphore will not run properly !!"
 131
 132 bool JackPosixSemaphore::TimedWait(long usec)
 133 {
 134         return Wait();
 135 }
 136 #endif
 137
 138 // Server side : publish the semaphore in the global namespace
 139 bool JackPosixSemaphore::Allocate(const char* name, const char* server_name, int value)
 140 {
 141     BuildName(name, server_name, fName);
 142     jack_log("JackPosixSemaphore::Allocate name = %s val = %ld", fName, value);
 143
 144     if ((fSemaphore = sem_open(fName, O_CREAT, 0777, value)) == (sem_t*)SEM_FAILED) {
 145         jack_error("Allocate: can't check in named semaphore name = %s err = %s", fName, strerror(errno));
 146         return false;
 147     } else {
 148         return true;
 149     }
 150 }
 151
 152 // Client side : get the published semaphore from server
 153 bool JackPosixSemaphore::ConnectInput(const char* name, const char* server_name)
 154 {
 155     BuildName(name, server_name, fName);
 156     jack_log("JackPosixSemaphore::Connect %s", fName);
 157
 158     // Temporary...
 159     if (fSemaphore) {
 160         jack_log("Already connected name = %s", name);
 161         return true;
 162     }
 163
 164     if ((fSemaphore = sem_open(fName, O_CREAT)) == (sem_t*)SEM_FAILED) {
 165         jack_error("Connect: can't connect named semaphore name = %s err = %s", fName, strerror(errno));
 166         return false;
 167     } else {
 168         int val = 0;
 169         sem_getvalue(fSemaphore, &val);
 170         jack_log("JackPosixSemaphore::Connect sem_getvalue %ld", val);
 171         return true;
 172     }
 173 }
 174
 175 bool JackPosixSemaphore::Connect(const char* name, const char* server_name)
 176 {
 177     return ConnectInput(name, server_name);
 178 }
 179
 180 bool JackPosixSemaphore::ConnectOutput(const char* name, const char* server_name)
 181 {
 182     return ConnectInput(name, server_name);
 183 }
 184
 185 bool JackPosixSemaphore::Disconnect()
 186 {
 187     jack_log("JackPosixSemaphore::Disconnect %s", fName);
 188
 189     if (fSemaphore) {
 190         if (sem_close(fSemaphore) != 0) {
 191             jack_error("Disconnect: can't disconnect named semaphore name = %s err = %s", fName, strerror(errno));
 192             return false;
 193         } else {
 194             fSemaphore = NULL;
 195             return true;
 196         }
 197     } else {
 198         return true;
 199     }
 200 }
 201
 202 // Server side : destroy the semaphore
 203 void JackPosixSemaphore::Destroy()
 204 {
 205     if (fSemaphore != NULL) {
 206         jack_log("JackPosixSemaphore::Destroy");
 207         sem_unlink(fName);
 208         if (sem_close(fSemaphore) != 0) {
 209             jack_error("Destroy: can't destroy semaphore name = %s err = %s", fName, strerror(errno));
 210         }
 211         fSemaphore = NULL;
 212     } else {
 213         jack_error("JackPosixSemaphore::Destroy semaphore == NULL");
 214     }
 215 }
 216
 217 } // end of namespace
 218