diff options
| -rw-r--r-- | applause.c | 97 | ||||
| -rw-r--r-- | applause.lua | 34 |
2 files changed, 122 insertions, 9 deletions
@@ -5,6 +5,7 @@ #include <stdlib.h> #include <stdint.h> #include <signal.h> +#include <unistd.h> #include <errno.h> #include <sys/types.h> @@ -44,6 +45,8 @@ static sig_atomic_t buffer_xrun = 0; static sig_atomic_t interrupted = 0; +static sig_atomic_t playback = 0; + static jack_port_t *midi_port; /** @@ -127,18 +130,25 @@ svsem_free(int id) } /** - * Handler for SIGINT signals. + * Handler for SIGINT, SIGUSR1 and SIGUSR2 signals. * - * This handler is invoked e.g. when the user presses + * SIGINT is delivered e.g. when the user presses * CTRL+C. * It sets `interrupted` which is polled in the Lua play() * method which allows us to interrupt long (possibly infinite) * sound playback. + * + * SIGUSR1 and SIGUSR2 are sent by parent to child + * clients in order to control playback. */ static void -sigint_handler(int signum) +signal_handler(int signum) { - interrupted = 1; + switch (signum) { + case SIGINT: interrupted = 1; break; + case SIGUSR1: playback = 1; break; + case SIGUSR2: playback = 0; break; + } } /** @@ -301,6 +311,8 @@ init_audio(int buffer_size) } memset(&midi_controls, 0, sizeof(midi_controls)); + memset(&midi_notes, 0, sizeof(midi_notes)); + memset(&midi_notes_last, 0, sizeof(midi_notes_last)); pthread_mutexattr_t prioinherit; if (pthread_mutexattr_setprotocol(&prioinherit, PTHREAD_PRIO_INHERIT)) { @@ -568,6 +580,72 @@ l_Stream_play(lua_State *L) return 0; } +static int +l_Stream_fork(lua_State *L) +{ + int top = lua_gettop(L); + pid_t child_pid; + + luaL_argcheck(L, top == 1, top, "Stream object expected"); + luaL_checktype(L, 1, LUA_TTABLE); + + /* + * Query the parent client's ports. + * We need to clone them in the child. + */ + //port_names = jack_get_ports(client, NULL, NULL, 0); + + /* + * Deactivate parent client temporarily, so forking works + * safely. + * This is possible since we can assume that fork() is only + * called interactively - so the parent client is not currently + * generating samples. + */ + jack_client_close(client); + //jack_deactivate(client); + + child_pid = fork(); + if (child_pid != 0) { + /* in the parent process */ + //jack_activate(client); + init_audio(DEFAULT_BUFFER_SIZE); + + /* call Client:new(child_pid) */ + lua_getglobal(L, "Client"); + lua_getfield(L, -1, "new"); + /* make Client parameter to new() */ + lua_insert(L, -2); + lua_pushinteger(L, child_pid); + lua_call(L, 2, 1); + + return 1; + } + + //jack_client_close(client); + + init_audio(DEFAULT_BUFFER_SIZE); + + for (;;) { + /* + * Wait for start of playback (SIGUSR1) + */ + while (!playback) + pause(); + + /* get play() method */ + lua_getfield(L, -1, "play"); + luaL_checktype(L, -1, LUA_TFUNCTION); + /* duplicate the object table */ + lua_pushvalue(L, 1); + + lua_call(L, 1, 0); + } + + /* never reached */ + return 0; +} + typedef struct NativeMethod { const char *class_name; const char *method_name; @@ -576,6 +654,7 @@ typedef struct NativeMethod { static const NativeMethod native_methods[] = { {"Stream", "play", l_Stream_play}, + {"Stream", "fork", l_Stream_fork}, {"MIDIVelocityStream", "getValue", l_MIDIVelocityStream_getValue}, {"MIDINoteStream", "getValue", l_MIDINoteStream_getValue}, {"MIDICCStream", "getValue", l_MIDICCStream_getValue}, @@ -586,7 +665,7 @@ int main(int argc, char **argv) { int buffer_size = DEFAULT_BUFFER_SIZE; - struct sigaction sigint_action; + struct sigaction signal_action; lua_State *L; @@ -603,9 +682,11 @@ main(int argc, char **argv) * sound playing. * Otherwise it is ignored. */ - memset(&sigint_action, 0, sizeof(sigint_action)); - sigint_action.sa_handler = sigint_handler; - sigaction(SIGINT, &sigint_action, NULL); + memset(&signal_action, 0, sizeof(signal_action)); + signal_action.sa_handler = signal_handler; + sigaction(SIGINT, &signal_action, NULL); + sigaction(SIGUSR1, &signal_action, NULL); + sigaction(SIGUSR2, &signal_action, NULL); L = luaL_newstate(); if (!L) { diff --git a/applause.lua b/applause.lua index 644c23d..ee75701 100644 --- a/applause.lua +++ b/applause.lua @@ -66,7 +66,7 @@ function DeriveClass(base, ctor) for _, m in pairs{"len", "call", "tostring", "add", "sub", "mul", "div", "mod", "pow", "unm", - "concat", "lt", "le"} do + "concat", "lt", "le", "gc"} do class["__"..m] = base["__"..m] end end @@ -310,6 +310,11 @@ function Stream:play() error("C function not registered!") end +-- implemented in applause.c +function Stream:fork() + error("C function not registered!") +end + function Stream:save(filename, format) if self:len() == math.huge then error("Cannot save infinite stream") @@ -1352,3 +1357,30 @@ end function BRFStream:len() return self.stream:len() end + +-- +-- Jack client abstractions. This passes low level signals +-- and works only with clients created via Stream.fork() +-- + +ffi.cdef[[ +int kill(int pid, int sig); +]] + +Client = DeriveClass(null, function(self, pid) + self.pid = pid +end) + +function Client:play() + ffi.C.kill(self.pid, 10); -- SIGUSR1 +end + +function Client:stop() + ffi.C.kill(self.pid, 12); -- SIGUSR2 +end + +function Client:kill() + ffi.C.kill(self.pid, 15); -- SIGTERM +end + +Client.__gc = Client.kill |