VuoCompositionLoader.cc

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extern "C" {
 
#include <dlfcn.h>
#include <getopt.h>
#include <stdio.h>
#include <unistd.h>
#include <dispatch/dispatch.h>
#include <CoreFoundation/CoreFoundation.h>
#include <CoreServices/CoreServices.h>
#include <objc/runtime.h>
#include <objc/message.h>
#include <pthread.h>
#include "VuoTelemetry.hh"
#include "VuoEventLoop.h"
#include "VuoRuntime.h"
#include "VuoCompositionState.h"
 
void *ZMQLoaderControlContext = NULL;  
void *ZMQLoaderControl = NULL;  
static void *ZMQLoaderSelfReceive = 0;        
static void *ZMQLoaderSelfSend = 0;           
 
void *ZMQControlContext = NULL;  
void *ZMQControl = NULL;  
char *controlURL = NULL;  
char *telemetryURL = NULL;  
 
bool isReplacing = false;  
bool replacementFailed = false;  
void *dylibHandle = NULL;  
map<string, void *> resourceDylibHandles;  
vector<string> resourceDylibsToUnload;  
vector<string> resourceDylibsToLoad;  
pid_t runnerPid = 0;  
int runnerPipe = -1;  
bool continueIfRunnerDies = false;  
 
bool replaceComposition(const char *dylibPath, char *compositionDiff);
void stopComposition(void);
bool loadResourceDylib(const string &dylibPath);
bool unloadResourceDylib(const string &dylibPath);
 
void *VuoApp_mainThread = NULL; 
char *VuoApp_dylibPath = NULL;  
 
static bool isStoppedInitially(void)
{
    return false;
}
 
VuoIsCurrentCompositionStoppedType *isStopped = isStoppedInitially;  
 
} // extern "C"
 
static void __attribute__((constructor)) VuoCompositionLoader_init(void)
{
    VuoApp_mainThread = (void *)pthread_self();
 
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdeprecated-declarations"
    // Calls _TSGetMainThread().
    // https://b33p.net/kosada/node/12944
    YieldToAnyThread();
#pragma clang diagnostic pop
}
 
void vuoLoaderControlReplySend(enum VuoLoaderControlReply reply, zmq_msg_t *messages, unsigned int messageCount)
{
    vuoSend("VuoLoaderControl",ZMQLoaderControl,reply,messages,messageCount,false,NULL);
}
 
void vuoControlRequestSend(enum VuoControlRequest request, zmq_msg_t *messages, unsigned int messageCount)
{
    vuoSend("VuoControl",ZMQControl,request,messages,messageCount,false,NULL);
}
 
void vuoControlReplyReceive(enum VuoControlReply expectedReply)
{
    int reply = vuoReceiveInt(ZMQControl, NULL);
    if (reply != expectedReply)
        VUserLog("The composition loader received the wrong message from the composition (expected %d, received %d)", expectedReply, reply);
}
 
int main(int argc, char **argv)
{
    char *loaderControlURL = NULL;
 
    // Parse commandline arguments.
    {
        static struct option options[] = {
            {"vuo-control", required_argument, NULL, 0},
            {"vuo-telemetry", required_argument, NULL, 0},
            {"vuo-loader", required_argument, NULL, 0},
            {"vuo-runner-pipe", required_argument, NULL, 0},
            {"vuo-continue-if-runner-dies", no_argument, NULL, 0},
            {"vuo-runner-pid", required_argument, NULL, 0},
            {NULL, no_argument, NULL, 0}
        };
        int optionIndex=-1;
        int ret;
        while ((ret = getopt_long(argc, argv, "", options, &optionIndex)) != -1)
        {
            if (ret == '?')
                continue;
 
            switch(optionIndex)
            {
                case 0: // "vuo-control"
                    controlURL = strdup(optarg);
                    break;
                case 1: // "vuo-telemetry"
                    telemetryURL = strdup(optarg);
                    break;
                case 2: // "vuo-loader"
                    if (loaderControlURL)
                        free(loaderControlURL);
                    loaderControlURL = strdup(optarg);
                    break;
                case 3:  // --vuo-runner-pipe
                    runnerPipe = atoi(optarg);
                    break;
                case 4:  // --vuo-continue-if-runner-dies
                    continueIfRunnerDies = true;
                    break;
                case 5:  // --vuo-runner-pid
                    runnerPid = atoi(optarg);
                    break;
            }
        }
    }
 
    if (!loaderControlURL)
    {
        VUserLog("Error: Please specify a --vuo-loader URL.");
        return -1;
    }
 
    VuoDefer(^{ free(loaderControlURL); });
 
    // Set up ZMQ connections.
    {
        ZMQLoaderControlContext = zmq_init(1);
 
        ZMQLoaderControl = zmq_socket(ZMQLoaderControlContext,ZMQ_REP);
        if(zmq_bind(ZMQLoaderControl,loaderControlURL))
        {
            VUserLog("The composition couldn't start because the composition loader couldn't establish communication to control the composition : %s", zmq_strerror(errno));
            return -1;
        }
 
        ZMQLoaderSelfReceive = zmq_socket(ZMQLoaderControlContext, ZMQ_PAIR);
        if (zmq_bind(ZMQLoaderSelfReceive, "inproc://vuo-loader-self") != 0)
        {
            VUserLog("Couldn't bind self-receive socket: %s (%d)", zmq_strerror(errno), errno);
            return -1;
        }
 
        ZMQLoaderSelfSend = zmq_socket(ZMQLoaderControlContext, ZMQ_PAIR);
        if (zmq_connect(ZMQLoaderSelfSend, "inproc://vuo-loader-self") != 0)
        {
            VUserLog("Couldn't connect self-send socket: %s (%d)", zmq_strerror(errno), errno);
            return -1;
        }
    }
 
    // Launch control responder.
    dispatch_queue_t loaderControlQueue;
    dispatch_source_t loaderControlTimer;
    dispatch_semaphore_t loaderControlCanceledSemaphore;
    {
        loaderControlCanceledSemaphore = dispatch_semaphore_create(0);
        loaderControlQueue = dispatch_queue_create("org.vuo.runtime.loader", NULL);
        loaderControlTimer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, DISPATCH_TIMER_STRICT, loaderControlQueue);
        dispatch_source_set_timer(loaderControlTimer, dispatch_walltime(NULL,0), NSEC_PER_SEC/1000, NSEC_PER_SEC/1000);
        dispatch_source_set_event_handler(loaderControlTimer, ^{
 
                                              vuoMemoryBarrier();
 
                                              zmq_pollitem_t items[]=
                                              {
                                                  {ZMQLoaderControl,0,ZMQ_POLLIN,0},
                                                  {ZMQLoaderSelfReceive,0,ZMQ_POLLIN,0},
                                              };
                                              int itemCount = 2;
                                              long timeout = -1;  // Wait forever (we'll get a message on ZMQLoaderSelfReceive when it's time to stop).
                                              zmq_poll(items,itemCount,timeout);
                                              if(!(items[0].revents & ZMQ_POLLIN))
                                                  return;
 
                                              enum VuoLoaderControlRequest control = (enum VuoLoaderControlRequest) vuoReceiveInt(ZMQLoaderControl, NULL);
 
                                              switch (control)
                                              {
                                                  case VuoLoaderControlRequestCompositionReplace:
                                                  {
                                                      char *dylibPath = vuoReceiveAndCopyString(ZMQLoaderControl, NULL);
 
                                                      int numResourceDylibPathsAdded = vuoReceiveInt(ZMQLoaderControl, NULL);
                                                      for (int i = 0; i < numResourceDylibPathsAdded; ++i)
                                                      {
                                                          char *s = vuoReceiveAndCopyString(ZMQLoaderControl, NULL);
                                                          resourceDylibsToLoad.push_back(s);
                                                          free(s);
                                                      }
 
                                                      int numResourceDylibPathsRemoved = vuoReceiveInt(ZMQLoaderControl, NULL);
                                                      for (int i = 0; i < numResourceDylibPathsRemoved; ++i)
                                                      {
                                                          char *s = vuoReceiveAndCopyString(ZMQLoaderControl, NULL);
                                                          resourceDylibsToUnload.push_back(s);
                                                          free(s);
                                                      }
 
                                                      char *compositionDiff = vuoReceiveAndCopyString(ZMQLoaderControl, NULL);
 
                                                      bool ok = replaceComposition(dylibPath, compositionDiff);
 
                                                      zmq_msg_t messages[1];
                                                      vuoInitMessageWithBool(messages, ok);
                                                      vuoLoaderControlReplySend(VuoLoaderControlReplyCompositionReplaced, messages, 1);
 
                                                      if (! ok)
                                                      {
                                                          replacementFailed = true;
                                                          VuoEventLoop_break();
                                                      }
 
                                                      break;
                                                  }
                                              }
                                          });
        dispatch_source_set_cancel_handler(loaderControlTimer, ^{
                                               dispatch_semaphore_signal(loaderControlCanceledSemaphore);
                                           });
        dispatch_resume(loaderControlTimer);
    }
 
    // Wait until the composition is permanently stopped (not just temporarily stopped for replacing).
    {
        // Before the composition has started for the first time, isStopped is an alias for isStoppedInitially, which returns false.
        // While the composition is being replaced, isReplaced is true and isStopped is invalid for part of the time.
        // While the composition is running (started and not yet stopped), isStopped returns false.
        while ((isReplacing || ! isStopped()) && ! replacementFailed)
            VuoEventLoop_processEvent(VuoEventLoop_WaitIndefinitely);
    }
 
    // Clean up ZMQ connections.
    {
        vuoMemoryBarrier();
 
        zmq_close(ZMQControl);
 
        dispatch_source_cancel(loaderControlTimer);
 
        // Break out of zmq_poll().
        {
            char z = 0;
            zmq_msg_t message;
            zmq_msg_init_size(&message, sizeof z);
            memcpy(zmq_msg_data(&message), &z, sizeof z);
            if (zmq_msg_send(&message, static_cast<zmq_msg_t *>(ZMQLoaderSelfSend), 0) == -1)
                VUserLog("Couldn't break: %s (%d)", zmq_strerror(errno), errno);
            zmq_msg_close(&message);
        }
 
        dispatch_semaphore_wait(loaderControlCanceledSemaphore, DISPATCH_TIME_FOREVER);
        dispatch_release(loaderControlCanceledSemaphore);
        dispatch_release(loaderControlTimer);
        dispatch_sync(loaderControlQueue, ^{
            zmq_close(ZMQLoaderControl);
            zmq_close(ZMQLoaderSelfSend);
            zmq_close(ZMQLoaderSelfReceive);
        });
        dispatch_release(loaderControlQueue);
 
        if (! replacementFailed)
        {
            VuoFiniType *vuoFini = (VuoFiniType *) dlsym(dylibHandle, "vuoFini");
            if (! vuoFini)
            {
                VUserLog("The composition couldn't stop because vuoFini() couldn't be found in the composition library : %s", dlerror());
                return -1;
            }
            vuoFini();
        }
 
        // Before terminating the process, wait for any last messages to be sent.
        zmq_ctx_term(ZMQLoaderControlContext);
        zmq_ctx_term(ZMQControlContext);
    }
 
    return 0;
}
 
bool replaceComposition(const char *dylibPath, char *compositionDiff)
{
    // Store dylibPath for VuoApp_getName().
    if (VuoApp_dylibPath)
        free(VuoApp_dylibPath);
    VuoApp_dylibPath = strdup(dylibPath);
    // Provide the composition name to the crash reporter.
    {
        const char *filename = strrchr(dylibPath, '/');
        if (filename)
        {
            char *name = strdup(filename + 1); // Trim leading slash.
            name[strlen(name) - strlen("-XXXXXX.dylib")] = 0;
            VuoLog_status("Running Vuo composition \"%s\"", name);
            free(name);
        }
    }
 
    isReplacing = true;
 
    void *runtimePersistentState = NULL;
 
    // Stop the old composition (if any).
    if (dylibHandle)
    {
        isStopped = NULL;
 
        VuoCompositionState compositionState = { NULL, "" };
        void **vuoRuntimeState = (void **)dlsym(dylibHandle, "vuoRuntimeState");
        if (! vuoRuntimeState)
        {
            VUserLog("The composition couldn't be replaced because vuoRuntimeState couldn't be found in '%s' : %s", dylibPath, dlerror());
            return false;
        }
        compositionState.runtimeState = *vuoRuntimeState;
 
        typedef void (*vuoSetCompositionDiffType)(VuoCompositionState *, char *);
        vuoSetCompositionDiffType vuoSetCompositionDiff = (vuoSetCompositionDiffType) dlsym(dylibHandle, "vuoSetCompositionDiff");
        if (! vuoSetCompositionDiff)
        {
            VUserLog("The composition couldn't be replaced because vuoSetCompositionDiff() couldn't be found in the composition library : %s", dlerror());
            return false;
        }
        vuoSetCompositionDiff(&compositionState, compositionDiff);
 
        stopComposition();
 
        zmq_close(ZMQControl);
        ZMQControl = NULL;
 
        VuoFiniType *vuoFini = (VuoFiniType *)dlsym(dylibHandle, "vuoFini");
        if (! vuoFini)
        {
            VUserLog("The composition couldn't be replaced because vuoFini() couldn't be found in the composition library : %s", dlerror());
            return false;
        }
        runtimePersistentState = vuoFini();
 
        dlclose(dylibHandle);
        dylibHandle = NULL;
 
        for (vector<string>::iterator i = resourceDylibsToUnload.begin(); i != resourceDylibsToUnload.end(); ++i)
            unloadResourceDylib(*i);
        resourceDylibsToUnload.clear();
    }
 
    // Start the new composition paused.
    {
        for (vector<string>::iterator i = resourceDylibsToLoad.begin(); i != resourceDylibsToLoad.end(); ++i)
            loadResourceDylib(*i);
        resourceDylibsToLoad.clear();
 
        ZMQControlContext = zmq_init(1);
 
        ZMQControl = zmq_socket(ZMQControlContext,ZMQ_REQ);
        if (zmq_connect(ZMQControl,controlURL))
        {
            VUserLog("The composition couldn't be replaced because the composition loader couldn't establish communication to control the composition : %s", zmq_strerror(errno));
            return false;
        }
 
        VuoInitInProcessType *vuoInitInProcess = NULL;
 
        dylibHandle = dlopen(dylibPath, RTLD_NOW);
        if (! dylibHandle)
        {
            VUserLog("The composition couldn't be replaced because the library '%s' couldn't be loaded : %s", dylibPath, dlerror());
            return false;
        }
 
        vuoInitInProcess = (VuoInitInProcessType *)dlsym(dylibHandle, "vuoInitInProcess");
        if (! vuoInitInProcess)
        {
            VUserLog("The composition couldn't be replaced because vuoInitInProcess() couldn't be found in '%s' : %s", dylibPath, dlerror());
            return false;
        }
 
        isStopped = (VuoIsCurrentCompositionStoppedType *)dlsym(dylibHandle, "vuoIsCurrentCompositionStopped");
        if (! isStopped)
        {
            VUserLog("The composition couldn't be replaced because vuoIsCurrentCompositionStopped() couldn't be found in '%s' : %s", dylibPath, dlerror());
            return false;
        }
 
        vuoInitInProcess(ZMQControlContext, controlURL, telemetryURL, true, runnerPid, runnerPipe, continueIfRunnerDies,
                         "", dylibHandle, runtimePersistentState, false);
    }
 
    isReplacing = false;
 
    return true;
}
 
void stopComposition(void)
{
    vuoMemoryBarrier();
 
    const int timeoutInSeconds = -1;
    zmq_msg_t messages[2];
    vuoInitMessageWithInt(&messages[0], timeoutInSeconds);
    vuoInitMessageWithBool(&messages[1], true ); // isBeingReplaced
    vuoControlRequestSend(VuoControlRequestCompositionStop, messages, 2);
    vuoControlReplyReceive(VuoControlReplyCompositionStopping);
}
 
bool loadResourceDylib(const string &dylibPath)
{
    void *dylibHandle = dlopen(dylibPath.c_str(), RTLD_NOW);
    if (! dylibHandle)
    {
        VUserLog("The composition couldn't be replaced because the library '%s' couldn't be loaded : %s", dylibPath.c_str(), dlerror());
        return false;
    }
 
    resourceDylibHandles[dylibPath] = dylibHandle;
    return true;
}
 
bool unloadResourceDylib(const string &dylibPath)
{
    void *dylibHandle = resourceDylibHandles[dylibPath];
    if (! dylibHandle)
    {
        VUserLog("The library '%s' couldn't be unloaded because its handle was not found.", dylibPath.c_str());
        return false;
    }
 
    int ret = dlclose(dylibHandle);
    if (ret != 0)
    {
        VUserLog("The library '%s' couldn't be unloaded : %s", dylibPath.c_str(), dlerror());
        return false;
    }
 
    resourceDylibHandles.erase(dylibPath);
    return true;
}