posix_spawn() doomsims

The doomsim startup routine or the controller startup publish are broken.
The doomsims never transition from DP_DS_Ready state.

src/doompanning.cc

@@ -4,10 +4,15 @@
 #include <backends/imgui_impl_sdlrenderer.h>
 #include <SDL2/SDL.h>
 
+#include <algorithm>
+#include <cerrno>
 #include <cstdlib>
 #include <type_traits>
 #include <vector>
 
+#include <spawn.h>
+#include <sys/wait.h>
+
 #include "dp_common.h"
 #include "dp_util.hpp"
 
@@ -19,10 +24,13 @@ void dp_sdl_fatal(const char *const msg)
 
 struct DoomState
 {
-    bool alive = false; // FIXME for testing only
+    doomid_t id;
+    pid_t pid;
+    DP_DoomState state = DP_DS_Unknown;
 };
 
-static_assert(std::is_trivially_copyable<DoomState>::value, "DoomState must be a trivially copyable type");
+static_assert(std::is_trivially_copyable<DoomState>::value,
+    "DoomState must be a trivially copyable type");
 
 struct ControllerContext
 {
@@ -31,6 +39,7 @@ struct ControllerContext
     SDL_Window *window;
     SDL_Renderer *renderer;
     std::vector<DoomState> dooms;
+    doomid_t nextDoomid = 0;
     bool quit = false;
     ExampleAppLog appLog;
     int columns = 4;
@@ -43,13 +52,32 @@ struct ControllerActions
 
 void spawn_doom(ControllerContext &ctx)
 {
-    size_t nextId = ctx.dooms.size();
+    DoomState ds = {};
+    ds.id = ctx.nextDoomid;
 
+    std::array<char, 32> idBuf;
 
+    const char *const argv[] =
+    {
+        "doomsim",
+        "-doomid",
+        aprintf(idBuf, "%zu", ds.id),
+        nullptr
+    };
+
+    // Close stdin and stdout? Leave them open for now to see the logging
+    // output.
+    if (auto err = posix_spawn(&ds.pid, "doomsim", nullptr, nullptr,
+        const_cast<char *const *>(argv), nullptr))
+    {
+        log_error("Could not spawn doom: %s", strerror(err));
+        return;
+    }
 
-    DoomState ds;
-    ds.alive = true;
     ctx.dooms.emplace_back(ds);
+    ++ctx.nextDoomid;
+
+    log_info("Spawned doom#%zu, pid=%d", ds.id, ds.pid);
 }
 
 void perform_actions(ControllerContext &ctx, const ControllerActions &actions)
@@ -62,6 +90,53 @@ void perform_actions(ControllerContext &ctx, const ControllerActions &actions)
     }
 }
 
+void check_on_dooms(ControllerContext &ctx)
+{
+    pid_t pid = 0;
+
+    do
+    {
+        int wstatus = 0;
+
+        if (pid = waitpid(0, &wstatus, WNOHANG); pid > 0)
+        {
+            auto dit = find_in_container(ctx.dooms, [pid] (const auto &ds) { return ds.pid == pid; });
+            assert(dit != std::end(ctx.dooms));
+            if (dit != std::end(ctx.dooms))
+            {
+                if (WIFEXITED(wstatus))
+                    log_info("doom#%zu, pid=%d exited with status %d", dit->id, pid, WEXITSTATUS(wstatus));
+                else if (WIFSIGNALED(wstatus))
+                    log_warn("doom#%zu, pid=%d got killed by signal %d", dit->id, pid, WTERMSIG(wstatus));
+
+                ctx.dooms.erase(dit);
+            }
+        }
+    } while (pid > 0);
+}
+
+void do_networking(ControllerContext &ctx)
+{
+    // Publish { DP_MT_DoomReady, doomid }.
+    {
+        nng_msg *msg = nullptr;
+        int res = 0;
+
+        if ((res = nng_msg_alloc(&msg, sizeof(dmt_t))))
+            dp_nng_fatal("ctrl/alloc", res);
+
+        if ((res = nng_msg_append_u16(msg, DP_MT_DoomReady)))
+            dp_nng_fatal("ctrl/msg", res);
+
+        if ((res = nng_sendmsg(ctx.pub, msg, 0)))
+            dp_nng_fatal("ctrl/sendmsg", res);
+    }
+}
+
+void do_cleanup(ControllerContext &ctx)
+{
+}
+
 ControllerActions run_ui(ControllerContext &ctx)
 {
 #ifndef IMGUI_DISABLE_DEBUG_TOOLS
@@ -179,6 +254,8 @@ int doom_controller_loop(ControllerContext &ctx)
         }
 
         perform_actions(ctx, actions);
+        check_on_dooms(ctx);
+        do_networking(ctx);
 
         // Start the Dear ImGui frame
         ImGui_ImplSDLRenderer_NewFrame();
@@ -186,6 +263,7 @@ int doom_controller_loop(ControllerContext &ctx)
         ImGui::NewFrame();
 
         actions = run_ui(ctx);
+        // TODO render dooms
 
         // Rendering
         ImGui::Render();
@@ -196,6 +274,8 @@ int doom_controller_loop(ControllerContext &ctx)
         SDL_RenderPresent(ctx.renderer);
     }
 
+    do_cleanup(ctx);
+
     return 0;
 }
 
@@ -244,26 +324,18 @@ int main(int argc, char *argv[])
 
     dp_nng_init_limits(1, 1, 1);
 
-    auto pubSock = make_ctrl_pub(CtrlUrl);
+    ControllerContext ctx;
-    auto subSock = make_ctrl_sub(DoomUrl);
+    ctx.pub = make_ctrl_pub(CtrlUrl);
-
+    ctx.sub = make_ctrl_sub(DoomUrl);
-    ControllerContext ctx =
+    ctx.window = window;
-    {
+    ctx.renderer = renderer;
-        pubSock,
-        subSock,
-        window,
-        renderer,
-        {},
-        {},
-        {},
-    };
 
     log_add_callback(log_to_imgui, &ctx, LOG_TRACE);
 
     int ret = doom_controller_loop(ctx);
 
-    nng_close(pubSock);
+    nng_close(ctx.pub);
-    nng_close(subSock);
+    nng_close(ctx.sub);
 
     return ret;
 }

src/doomsim.cc

@@ -22,6 +22,9 @@ typedef struct DoomContext
     DoomStateFunc *f;
 } DoomContext;
 
+DEF_DOOM_STATE_FUNC(do_doom_ready);
+DEF_DOOM_STATE_FUNC(do_doom_running);
+
 DEF_DOOM_STATE_FUNC(do_doom_ready)
 {
     assert(ctx->state == DP_DS_Ready);
@@ -72,7 +75,10 @@ DEF_DOOM_STATE_FUNC(do_doom_ready)
         nng_msg_free(msg);
 
         if (mt == DP_MT_RunDoom)
+        {
             ctx->state = DP_DS_Running;
+            ctx->f = do_doom_running;
+        }
         else if (mt == DP_MT_QuitDoom)
             ctx->state = DP_DS_Quit;
     }

src/dp_common.h

@@ -39,6 +39,7 @@ typedef enum DP_MessageType
 
 typedef enum DP_DoomState
 {
+    DP_DS_Unknown,
     DP_DS_Ready,
     DP_DS_Running,
     DP_DS_Quit,

src/dp_util.hpp

@@ -31,13 +31,14 @@ template<size_t Size>
     return buf.data();
 }
 
+template<typename C, typename Pred>
+typename C::iterator find_in_container(C &c, Pred pred)
+{
+    return std::find_if(std::begin(c), std::end(c), pred);
+}
+
 // Copied from the ImGui demo code. Added the AddLog() overload taking a
 // va_list.
-
-// Usage:
-//  static ExampleAppLog my_log;
-//  my_log.AddLog("Hello %d world\n", 123);
-//  my_log.Draw("title");
 struct ExampleAppLog
 {
     ImGuiTextBuffer     Buf;