Use poll instead of clock_nanosleep, refactor a bit

2 files changed, 20 insertions, 9 deletions

diff --git a/emulator.cpp b/emulator.cpp
index 034fc57..0fb50dd 100644
--- a/emulator.cpp
+++ b/emulator.cpp
@@ -37,6 +37,7 @@
 #include <unistd.h>
 #include <signal.h>
 #include <netdb.h>
+#include <poll.h>
 
 #if !defined(DEBUG_TRACE_INSTRUCTIONS)
 #   define DEBUG_TRACE_INSTRUCTIONS 0
@@ -85,9 +86,9 @@ struct Backtrace {
 };
 
 static constexpr struct timespec kOneMillisecond{0, 1000000};
+static constexpr struct timespec kIdleSleepTime{0, 10000000};
 static char msg_buf[MESSAGE_BUFFER_SIZE];
 static M68KDebuggingControl g_m68k_debug{};
-static bool g_no_ack_mode{};
 static Backtrace<uint32_t, 10> g_pc_backtrace{};
 
 static int set_socket_reuseaddr(const int socket_fd)
@@ -231,7 +232,7 @@ static std::string CreateResponse(
         }
         break;
     case PacketType::kQStartNoAckMode:
-        g_no_ack_mode = true;
+        m68k_debug.SetNoAckMode(true);
         return "OK";
     case PacketType::kSetThreadForCont:
         return "OK";
@@ -242,7 +243,7 @@ static std::string CreateResponse(
     case PacketType::kEnableExtendedMode:
         break;
     case PacketType::kInterrupt:
-        g_m68k_debug.RaiseBreakpoint();
+        m68k_debug.RaiseBreakpoint();
         return "S05"; // TODO real reason
     case PacketType::kContinue:
         m68k_debug.SetRunning(true);
@@ -453,7 +454,7 @@ void ParseAndReact(
                     "   Packet type: \"%s\"\n",
                     GDBRemote::Packet::PacketTypeToString(packet.type));
         }
-        if (res->ack.length() > 0 && !g_no_ack_mode) {
+        if (res->ack.length() > 0 && !m68k_debug.IsNoAckModeEnabled()) {
             if (DEBUG_TRACE_GDB_REMOTE)
                 printf("-> \"%s\"\n", res->ack.c_str());
             if (send(conn_fd, &res->ack[0], res->ack.length(), 0) == -1)
@@ -529,7 +530,10 @@ static int emulator(M68KDebuggingControl& m68k_debug, Graphics& graphics, CharDe
                         m68k_debug.ResetPendingBreakpoint();
                     }
                 } else {
-                    clock_nanosleep(CLOCK_MONOTONIC, 0, &kOneMillisecond, nullptr);
+                    struct pollfd fds[1] = {
+                        {/*.fd = */socket_fd, /*.events = */POLLIN, /*.revents = */0}};
+                    const int timeout_msecs = 30;
+                    poll(fds, 1, timeout_msecs);
                 }
                 continue;
             }
@@ -547,13 +551,14 @@ static int emulator(M68KDebuggingControl& m68k_debug, Graphics& graphics, CharDe
         GDBRemote::ExchangeContext exchange_ctx{};
         while (!quit) {
             const ssize_t read_size = recv(conn_fd, msg_buf, MESSAGE_BUFFER_SIZE, 0);
+            const int err = errno;
             if (read_size > 0) {
                 ParseAndReact(conn_fd, exchange_ctx, m68k_debug, msg_buf, read_size);
                 continue;
             } else if (read_size == 0) {
                 puts("Client disconnected");
                 break;
-            } else if (read_size == -1 && errno != EWOULDBLOCK) {
+            } else if (read_size == -1 && err != EWOULDBLOCK) {
                 perror("Recv failed");
                 break;
             }
@@ -570,13 +575,16 @@ static int emulator(M68KDebuggingControl& m68k_debug, Graphics& graphics, CharDe
                     if (send(conn_fd, &response[0], response.length(), 0) == -1)
                         perror("Send failed (response)");
                 }
-            } else {
-                clock_nanosleep(CLOCK_MONOTONIC, 0, &kOneMillisecond, nullptr);
+            } else if (err == EWOULDBLOCK) {
+                struct pollfd fds[1] = {
+                    {/*.fd = */conn_fd, /*.events = */POLLIN, /*.revents = */0}};
+                const int timeout_msecs = 30;
+                poll(fds, 1, timeout_msecs);
             }
         }
         close(conn_fd);
         gdb_chardev.fd = -1;
-        g_no_ack_mode = false; // TODO move to GDB::ExchangeContext
+        m68k_debug.SetNoAckMode(false);
     }
     close(socket_fd);
     return 0;
diff --git a/m68k_debugging.hpp b/m68k_debugging.hpp
index 7141809..5bcdd73 100644
--- a/m68k_debugging.hpp
+++ b/m68k_debugging.hpp
@@ -54,6 +54,8 @@ public:
     void SetRegister(M68KRegister, uint32_t value);
     bool IsRunning() const { return _is_running; }
     void SetRunning(bool running) { _is_running = running; }
+    bool IsNoAckModeEnabled() const { return _no_ack_mode; }
+    void SetNoAckMode(bool enabled = true) { _no_ack_mode = enabled; }
     void Reset();
     void Continue();
     void Pause();
@@ -72,4 +74,5 @@ public:
 private:
     bool _is_running{};
     bool _have_break_risen{};
+    bool _no_ack_mode{};
 };