extmidi.cpp

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00001 /* $Id: extmidi.cpp 26544 2014-04-29 18:41:19Z frosch $ */
00002 
00003 /*
00004  * This file is part of OpenTTD.
00005  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
00006  * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
00007  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
00008  */
00009 
00012 #ifndef __MORPHOS__
00013 #include "../stdafx.h"
00014 #include "../debug.h"
00015 #include "../string_func.h"
00016 #include "../sound/sound_driver.hpp"
00017 #include "../video/video_driver.hpp"
00018 #include "../gfx_func.h"
00019 #include "extmidi.h"
00020 #include <fcntl.h>
00021 #include <sys/types.h>
00022 #include <sys/wait.h>
00023 #include <unistd.h>
00024 #include <signal.h>
00025 #include <sys/stat.h>
00026 #include <errno.h>
00027 
00028 #ifndef EXTERNAL_PLAYER
00029 
00030 #define EXTERNAL_PLAYER "timidity"
00031 #endif
00032 
00034 static FMusicDriver_ExtMidi iFMusicDriver_ExtMidi;
00035 
00036 const char *MusicDriver_ExtMidi::Start(const char * const * parm)
00037 {
00038   if (strcmp(VideoDriver::GetInstance()->GetName(), "allegro") == 0 ||
00039       strcmp(SoundDriver::GetInstance()->GetName(), "allegro") == 0) {
00040     return "the extmidi driver does not work when Allegro is loaded.";
00041   }
00042 
00043   const char *command = GetDriverParam(parm, "cmd");
00044   if (StrEmpty(command)) command = EXTERNAL_PLAYER;
00045 
00046   this->command = strdup(command);
00047   this->song[0] = '\0';
00048   this->pid = -1;
00049   return NULL;
00050 }
00051 
00052 void MusicDriver_ExtMidi::Stop()
00053 {
00054   free(command);
00055   this->song[0] = '\0';
00056   this->DoStop();
00057 }
00058 
00059 void MusicDriver_ExtMidi::PlaySong(const char *filename)
00060 {
00061   strecpy(this->song, filename, lastof(this->song));
00062   this->DoStop();
00063 }
00064 
00065 void MusicDriver_ExtMidi::StopSong()
00066 {
00067   this->song[0] = '\0';
00068   this->DoStop();
00069 }
00070 
00071 bool MusicDriver_ExtMidi::IsSongPlaying()
00072 {
00073   if (this->pid != -1 && waitpid(this->pid, NULL, WNOHANG) == this->pid) {
00074     this->pid = -1;
00075   }
00076   if (this->pid == -1 && this->song[0] != '\0') this->DoPlay();
00077   return this->pid != -1;
00078 }
00079 
00080 void MusicDriver_ExtMidi::SetVolume(byte vol)
00081 {
00082   DEBUG(driver, 1, "extmidi: set volume not implemented");
00083 }
00084 
00085 void MusicDriver_ExtMidi::DoPlay()
00086 {
00087   this->pid = fork();
00088   switch (this->pid) {
00089     case 0: {
00090       close(0);
00091       int d = open("/dev/null", O_RDONLY);
00092       if (d != -1 && dup2(d, 1) != -1 && dup2(d, 2) != -1) {
00093         #if defined(MIDI_ARG)
00094           execlp(this->command, "extmidi", MIDI_ARG, this->song, (char*)0);
00095         #else
00096           execlp(this->command, "extmidi", this->song, (char*)0);
00097         #endif
00098       }
00099       _exit(1);
00100     }
00101 
00102     case -1:
00103       DEBUG(driver, 0, "extmidi: couldn't fork: %s", strerror(errno));
00104       /* FALL THROUGH */
00105 
00106     default:
00107       this->song[0] = '\0';
00108       break;
00109   }
00110 }
00111 
00112 void MusicDriver_ExtMidi::DoStop()
00113 {
00114   if (this->pid <= 0) return;
00115 
00116   /* First try to gracefully stop for about five seconds;
00117    * 5 seconds = 5000 milliseconds, 10 ms per cycle => 500 cycles. */
00118   for (int i = 0; i < 500; i++) {
00119     kill(this->pid, SIGTERM);
00120     if (waitpid(this->pid, NULL, WNOHANG) == this->pid) {
00121       /* It has shut down, so we are done */
00122       this->pid = -1;
00123       return;
00124     }
00125     /* Wait 10 milliseconds. */
00126     CSleep(10);
00127   }
00128 
00129   DEBUG(driver, 0, "extmidi: gracefully stopping failed, trying the hard way");
00130   /* Gracefully stopping failed. Do it the hard way
00131    * and wait till the process finally died. */
00132   kill(this->pid, SIGKILL);
00133   waitpid(this->pid, NULL, 0);
00134   this->pid = -1;
00135 }
00136 
00137 #endif /* __MORPHOS__ */