Initial commit: testpattern → fakesink pipeline over MXL shared memory

- NodeBase, Signal, FlowDef, V210 shared headers - testpattern node: SMPTE 75% color bars writer at 25fps - fakesink node: non-blocking MXL reader with per-second stats - studio-manager: FlowGraph data model, graph-driven fork/exec launcher - mxl pinned as submodule at 0ae1dc5 Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-06-23 13:35:01 +03:00
commit ca682eaf0a
17 changed files with 1269 additions and 0 deletions
@@ -0,0 +1,162 @@
+// Studio Manager — launches and monitors node processes for a single-host pipeline.
+// Graph is defined in build_graph(). Later: load from graph.json, WebSocket API.
+// Node binaries are looked up next to this binary (same directory).
+
+#include <cstdio>
+#include <cstdlib>
+#include <filesystem>
+#include <string>
+#include <vector>
+#include <fcntl.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <mxl/time.h>
+#include "Signal.hpp"
+#include "FlowGraph.hpp"
+
+namespace fs = std::filesystem;
+
+// --- UUID generation ---------------------------------------------------------
+
+static std::string gen_uuid() {
+    uint8_t b[16];
+    int fd = open("/dev/urandom", O_RDONLY);
+    if (fd < 0) { perror("open /dev/urandom"); exit(1); }
+    if (read(fd, b, sizeof(b)) != sizeof(b)) { perror("read"); exit(1); }
+    close(fd);
+    b[6] = (b[6] & 0x0Fu) | 0x40u;  // version 4
+    b[8] = (b[8] & 0x3Fu) | 0x80u;  // variant 1
+    char s[37];
+    snprintf(s, sizeof(s),
+        "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
+        b[0],b[1],b[2],b[3],  b[4],b[5],  b[6],b[7],
+        b[8],b[9],  b[10],b[11],b[12],b[13],b[14],b[15]);
+    return s;
+}
+
+// --- Pipeline graph ----------------------------------------------------------
+
+static dmf::FlowGraph build_graph() {
+    dmf::FlowGraph g;
+    g.nodes = {
+        { "testpattern", "testpattern", {} },
+        { "fakesink",    "fakesink",    {} },
+    };
+    g.edges = {
+        { gen_uuid(), "testpattern", "flow_id", "fakesink", "flow_id",
+          { {"kind","video"}, {"width",1920}, {"height",1080}, {"fps_num",25}, {"fps_den",1} } },
+    };
+    return g;
+}
+
+// --- Process management ------------------------------------------------------
+
+struct NodeProcess {
+    std::string name;
+    pid_t       pid{-1};
+};
+
+// Fork the node binary, passing domain and config via environment variables.
+static NodeProcess launch_node(
+    const std::string&    binary,
+    const std::string&    domain,
+    const nlohmann::json& config)
+{
+    NodeProcess proc;
+    proc.name = config.value("node_id", binary);
+
+    pid_t pid = fork();
+    if (pid < 0) { perror("fork"); return proc; }
+
+    if (pid == 0) {
+        // Child: set env and exec
+        setenv("MXL_DOMAIN",  domain.c_str(),       1);
+        setenv("NODE_CONFIG", config.dump().c_str(), 1);
+        execl(binary.c_str(), binary.c_str(), nullptr);
+        // execl only returns on error
+        perror(("execl " + binary).c_str());
+        _exit(1);
+    }
+
+    proc.pid = pid;
+    fprintf(stderr, "[studio-manager] launched %s  pid=%d\n", proc.name.c_str(), pid);
+    return proc;
+}
+
+// Poll children with WNOHANG; log and clear pid if one has exited.
+static void check_children(std::vector<NodeProcess>& nodes) {
+    for (auto& node : nodes) {
+        if (node.pid <= 0) continue;
+        int wstatus = 0;
+        if (waitpid(node.pid, &wstatus, WNOHANG) == node.pid) {
+            fprintf(stderr, "[studio-manager] node %s (pid=%d) exited (status=%d)\n",
+                node.name.c_str(), node.pid, WEXITSTATUS(wstatus));
+            node.pid = -1;
+        }
+    }
+}
+
+// Send SIGTERM to all live children, then wait for them.
+static void shutdown_children(std::vector<NodeProcess>& nodes) {
+    fprintf(stderr, "[studio-manager] sending SIGTERM to all nodes\n");
+    for (auto& node : nodes) {
+        if (node.pid > 0) {
+            kill(node.pid, SIGTERM);
+        }
+    }
+    for (auto& node : nodes) {
+        if (node.pid > 0) {
+            waitpid(node.pid, nullptr, 0);
+            fprintf(stderr, "[studio-manager] node %s stopped\n", node.name.c_str());
+        }
+    }
+}
+
+// -----------------------------------------------------------------------------
+
+int main(int argc, char* argv[]) {
+    dmf::install_signal_handlers();
+
+    // Resolve node binary paths relative to this binary
+    const fs::path bin_dir = fs::path(argv[0]).parent_path();
+
+#ifdef __APPLE__
+    const std::string domain = "/tmp/dmf-studio";
+#else
+    const std::string domain = "/dev/shm/dmf-studio";
+#endif
+
+    // Ensure the domain directory exists
+    std::error_code ec;
+    fs::create_directories(domain, ec);
+    if (ec) {
+        fprintf(stderr, "[studio-manager] cannot create domain dir %s: %s\n",
+            domain.c_str(), ec.message().c_str());
+        return 1;
+    }
+    fprintf(stderr, "[studio-manager] domain: %s\n", domain.c_str());
+
+    // --- Build and launch the pipeline graph ---
+    const dmf::FlowGraph graph = build_graph();
+
+    for (const auto& e : graph.edges)
+        fprintf(stderr, "[studio-manager] flow %s → %s  id=%s\n",
+            e.from_node.c_str(), e.to_node.c_str(), e.id.c_str());
+
+    std::vector<NodeProcess> nodes;
+    for (const auto& node : graph.nodes) {
+        const std::string binary = (bin_dir / ("dmf-node-" + node.type)).string();
+        nodes.push_back(launch_node(binary, domain, graph.node_config(node.id)));
+    }
+
+    // --- Run until Ctrl+C or SIGTERM ---
+    fprintf(stderr, "[studio-manager] running — Ctrl+C to stop\n");
+    while (dmf::g_running.load(std::memory_order_relaxed)) {
+        check_children(nodes);
+        mxlSleepForNs(500'000'000); // check every 500 ms
+    }
+
+    shutdown_children(nodes);
+    fprintf(stderr, "[studio-manager] done\n");
+    return 0;
+}