modern pipe

main.c

@@ -62,6 +62,7 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <errno.h>
+#include <poll.h>
 #endif
 
 #include <stdio.h>
@@ -715,6 +716,101 @@ void insert_marker_to_file(char* logfilename, char* marker_text){
 }
 
 #ifndef _WIN32
+// Function to check if pipe reader is present and ready
+// Returns: 1 if ready to write, 0 if should wait, -1 on error
+int check_pipe_ready(int pipe_fd) {
+	if (pipe_fd < 0) {
+		return -1;
+	}
+
+	struct pollfd pfd;
+	pfd.fd = pipe_fd;
+	pfd.events = POLLOUT;
+	pfd.revents = 0;
+
+	// Check with 0 timeout (non-blocking check)
+	int ret = poll(&pfd, 1, 0);
+
+	if (ret < 0) {
+		fprintf(stderr, "Error polling pipe: %s\n", strerror(errno));
+		return -1;
+	}
+
+	if (ret == 0) {
+		// Timeout - pipe buffer is full, reader is slow or absent
+		return 0;
+	}
+
+	// Check for errors
+	if (pfd.revents & (POLLERR | POLLHUP | POLLNVAL)) {
+		if (pfd.revents & POLLERR) {
+			fprintf(stderr, "Pipe error detected\n");
+		}
+		if (pfd.revents & POLLHUP) {
+			fprintf(stderr, "Pipe hangup - reader disconnected\n");
+		}
+		if (pfd.revents & POLLNVAL) {
+			fprintf(stderr, "Invalid pipe fd\n");
+		}
+		return -1;
+	}
+
+	// POLLOUT is set - ready to write
+	if (pfd.revents & POLLOUT) {
+		return 1;
+	}
+
+	return 0;
+}
+
+// Function to wait for pipe to become ready
+// Returns: 1 if ready, 0 if interrupted, -1 on error
+int wait_for_pipe_reader(int pipe_fd) {
+	if (pipe_fd < 0) {
+		return -1;
+	}
+
+	printf("Waiting for pipe reader to become ready...\n");
+
+	struct pollfd pfd;
+	pfd.fd = pipe_fd;
+	pfd.events = POLLOUT;
+
+	while (1) {
+		pfd.revents = 0;
+
+		// Wait with 1 second timeout
+		int ret = poll(&pfd, 1, 1000);
+
+		if (ret < 0) {
+			if (errno == EINTR) {
+				// Interrupted by signal, continue
+				continue;
+			}
+			fprintf(stderr, "Error waiting for pipe: %s\n", strerror(errno));
+			return -1;
+		}
+
+		if (ret == 0) {
+			// Timeout - print status and continue waiting
+			printf("Still waiting for pipe reader...\n");
+			continue;
+		}
+
+		// Check for errors
+		if (pfd.revents & (POLLERR | POLLHUP | POLLNVAL)) {
+			fprintf(stderr, "Pipe error while waiting\n");
+			return -1;
+		}
+
+		// Ready to write
+		if (pfd.revents & POLLOUT) {
+			printf("Pipe reader is ready!\n");
+			return 1;
+		}
+	}
+}
+
 // Function to initialize named pipe (FIFO)
 int init_pipe(const char* pipe_path) {
 	// Remove existing pipe if it exists
@@ -802,14 +898,35 @@ void receive_to_file(t_x502_hnd hnd, char* logfilename, uint32_t* inp_buff, uint
 #ifndef _WIN32
 	  // Write data to pipe if it's open
 	  if (pipe_fd >= 0) {
-		  // Write raw binary data to pipe
+		  // Check if pipe is ready before writing
+		  int pipe_status = check_pipe_ready(pipe_fd);
+
+		  if (pipe_status == 0) {
+			  // Pipe not ready (buffer full or no reader) - wait for reader
+			  printf("Pipe not ready - waiting for reader to catch up...\n");
+			  int wait_result = wait_for_pipe_reader(pipe_fd);
+			  if (wait_result != 1) {
+				  fprintf(stderr, "Warning: Could not write to pipe\n");
+				  return;
+			  }
+		  } else if (pipe_status < 0) {
+			  fprintf(stderr, "Warning: Pipe error detected, skipping pipe write\n");
+			  return;
+		  }
+
+		  // Pipe is ready, write data
 		  ssize_t bytes_written = write(pipe_fd, inp_buff, received_words * sizeof(uint32_t));
 		  if (bytes_written < 0) {
 			  if (errno == EPIPE) {
 				  fprintf(stderr, "Warning: Broken pipe (reader disconnected)\n");
+			  } else if (errno == EAGAIN || errno == EWOULDBLOCK) {
+				  fprintf(stderr, "Warning: Pipe write would block\n");
 			  } else {
 				  fprintf(stderr, "Warning: Error writing to pipe: %s\n", strerror(errno));
 			  }
+		  } else if (bytes_written < (ssize_t)(received_words * sizeof(uint32_t))) {
+			  printf("Warning: Partial write to pipe: %zd of %zu bytes\n",
+					 bytes_written, received_words * sizeof(uint32_t));
 		  } else {
 			  printf("Written %zd bytes to pipe\n", bytes_written);
 		  }