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, int size)
  32 {
  33     char ext_client_name[JACK_CLIENT_NAME_SIZE + 1];
  34     JackTools::RewriteName(client_name, ext_client_name);
  35     snprintf(res, size, "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 deallocated!!", 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 deallocated!!", 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 deallocated!!", 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 deallocated!!", 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     while ((res = sem_timedwait(fSemaphore, &time)) < 0) {
 122         jack_error("JackPosixSemaphore::TimedWait err = %s", strerror(errno));
 123         jack_log("JackPosixSemaphore::TimedWait now : %ld %ld ", now.tv_sec, now.tv_usec);
 124         jack_log("JackPosixSemaphore::TimedWait next : %ld %ld ", time.tv_sec, time.tv_nsec/1000);
 125         if (errno != EINTR)
 126             break;
 127     }
 128     return (res == 0);
 129 }
 130
 131 #else
 132 #warning "JackPosixSemaphore::TimedWait is not supported: Jack in SYNC mode with JackPosixSemaphore will not run properly !!"
 133
 134 bool JackPosixSemaphore::TimedWait(long usec)
 135 {
 136         return Wait();
 137 }
 138 #endif
 139
 140 // Server side : publish the semaphore in the global namespace
 141 bool JackPosixSemaphore::Allocate(const char* name, const char* server_name, int value)
 142 {
 143     BuildName(name, server_name, fName, sizeof(fName));
 144     jack_log("JackPosixSemaphore::Allocate name = %s val = %ld", fName, value);
 145
 146     if ((fSemaphore = sem_open(fName, O_CREAT, 0777, value)) == (sem_t*)SEM_FAILED) {
 147         jack_error("Allocate: can't check in named semaphore name = %s err = %s", fName, strerror(errno));
 148         return false;
 149     } else {
 150         return true;
 151     }
 152 }
 153
 154 // Client side : get the published semaphore from server
 155 bool JackPosixSemaphore::ConnectInput(const char* name, const char* server_name)
 156 {
 157     BuildName(name, server_name, fName, sizeof(fName));
 158     jack_log("JackPosixSemaphore::Connect name = %s", fName);
 159
 160     // Temporary...
 161     if (fSemaphore) {
 162         jack_log("Already connected name = %s", name);
 163         return true;
 164     }
 165
 166     if ((fSemaphore = sem_open(fName, O_CREAT)) == (sem_t*)SEM_FAILED) {
 167         jack_error("Connect: can't connect named semaphore name = %s err = %s", fName, strerror(errno));
 168         return false;
 169     } else {
 170         int val = 0;
 171         sem_getvalue(fSemaphore, &val);
 172         jack_log("JackPosixSemaphore::Connect sem_getvalue %ld", val);
 173         return true;
 174     }
 175 }
 176
 177 bool JackPosixSemaphore::Connect(const char* name, const char* server_name)
 178 {
 179     return ConnectInput(name, server_name);
 180 }
 181
 182 bool JackPosixSemaphore::ConnectOutput(const char* name, const char* server_name)
 183 {
 184     return ConnectInput(name, server_name);
 185 }
 186
 187 bool JackPosixSemaphore::Disconnect()
 188 {
 189     if (fSemaphore) {
 190         jack_log("JackPosixSemaphore::Disconnect name = %s", fName);
 191         if (sem_close(fSemaphore) != 0) {
 192             jack_error("Disconnect: can't disconnect named semaphore name = %s err = %s", fName, strerror(errno));
 193             return false;
 194         } else {
 195             fSemaphore = NULL;
 196             return true;
 197         }
 198     } else {
 199         return true;
 200     }
 201 }
 202
 203 // Server side : destroy the semaphore
 204 void JackPosixSemaphore::Destroy()
 205 {
 206     if (fSemaphore != NULL) {
 207         jack_log("JackPosixSemaphore::Destroy name = %s", fName);
 208         sem_unlink(fName);
 209         if (sem_close(fSemaphore) != 0) {
 210             jack_error("Destroy: can't destroy semaphore name = %s err = %s", fName, strerror(errno));
 211         }
 212         fSemaphore = NULL;
 213     } else {
 214         jack_error("JackPosixSemaphore::Destroy semaphore == NULL");
 215     }
 216 }
 217
 218 } // end of namespace
 219