From ccd1d52b75fbb85f7e76180bb5641eaf48731600 Mon Sep 17 00:00:00 2001
From: Hiroshi Hatake <hiroshi@chronosphere.io>
Date: Wed, 11 Dec 2024 19:44:21 +0900
Subject: [PATCH] bin: config: Provide maxstdio option for increasing I/O limit
 on Windows

Signed-off-by: Hiroshi Hatake <hiroshi@chronosphere.io>
---
 include/fluent-bit/flb_config.h |  8 ++++++++
 src/flb_config.c                |  5 +++++
 src/fluent-bit.c                | 23 ++++++++++++++++++++++-
 3 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/include/fluent-bit/flb_config.h b/include/fluent-bit/flb_config.h
index 1cfc6301ff8..bfed0c80c56 100644
--- a/include/fluent-bit/flb_config.h
+++ b/include/fluent-bit/flb_config.h
@@ -269,6 +269,11 @@ struct flb_config {
     int shutdown_by_hot_reloading;
     int hot_reloading;
 
+#ifdef FLB_SYSTEM_WINDOWS
+    /* maxstdio (Windows) */
+    int maxstdio;
+#endif
+
     /* Co-routines */
     unsigned int coro_stack_size;
 
@@ -351,6 +356,9 @@ enum conf_type {
 #define FLB_CONF_STR_HOT_RELOAD        "Hot_Reload"
 #define FLB_CONF_STR_HOT_RELOAD_ENSURE_THREAD_SAFETY  "Hot_Reload.Ensure_Thread_Safety"
 
+/* Set up maxstdio (Windows) */
+#define FLB_CONF_STR_MAX_STDIO          "Max_Stdio"
+
 /* DNS */
 #define FLB_CONF_DNS_MODE              "dns.mode"
 #define FLB_CONF_DNS_RESOLVER          "dns.resolver"
diff --git a/src/flb_config.c b/src/flb_config.c
index 32dc34b7e83..0e82aefdda8 100644
--- a/src/flb_config.c
+++ b/src/flb_config.c
@@ -183,6 +183,11 @@ struct flb_service_config service_configs[] = {
      offsetof(struct flb_config, enable_chunk_trace)},
 #endif
 
+#ifdef FLB_SYSTEM_WINDOWS
+    {FLB_CONF_STR_MAX_STDIO,
+     FLB_CONF_TYPE_INT,
+     offsetof(struct flb_config, maxstdio)},
+#endif
     {FLB_CONF_STR_HOT_RELOAD,
      FLB_CONF_TYPE_BOOL,
      offsetof(struct flb_config, enable_hot_reload)},
diff --git a/src/fluent-bit.c b/src/fluent-bit.c
index 6444b333f2d..116b5acf79a 100644
--- a/src/fluent-bit.c
+++ b/src/fluent-bit.c
@@ -1036,6 +1036,9 @@ int flb_main(int argc, char **argv)
         { "http_port",       required_argument, NULL, 'P' },
 #endif
         { "enable-hot-reload",     no_argument, NULL, 'Y' },
+#ifdef FLB_SYSTEM_WINDOWS
+        { "maxstdio",        required_argument, NULL, 'M' },
+#endif
 #ifdef FLB_HAVE_CHUNK_TRACE
         { "enable-chunk-trace",    no_argument, NULL, 'Z' },
         { "trace",                 required_argument, NULL, FLB_LONG_TRACE },
@@ -1073,7 +1076,7 @@ int flb_main(int argc, char **argv)
 
     /* Parse the command line options */
     while ((opt = getopt_long(argc, argv,
-                              "b:c:dDf:C:i:m:o:R:F:p:e:"
+                              "b:c:dDf:C:i:m:M:o:R:F:p:e:"
                               "t:T:l:vw:qVhJL:HP:s:SWYZ",
                               long_opts, NULL)) != -1) {
 
@@ -1128,6 +1131,12 @@ int flb_main(int argc, char **argv)
                 flb_cf_section_property_add(cf_opts, s->properties, "match", 0, optarg, 0);
             }
             break;
+#ifdef FLB_SYSTEM_WINDOWS
+        case 'M':
+            flb_cf_section_property_add(cf_opts, service->properties,
+                                        "max_stdio", 0, optarg, 0);
+            break;
+#endif
         case 'o':
             s = flb_cf_section_create(cf_opts, "output", 0);
             if (!s) {
@@ -1350,6 +1359,18 @@ int flb_main(int argc, char **argv)
 #endif
 
 #ifdef FLB_SYSTEM_WINDOWS
+    /* Validate specified maxstdio */
+    if (config->maxstdio >= 512 && config->maxstdio <= 2048) {
+        _setmaxstdio(config->maxstdio);
+    }
+    else {
+        fprintf(stderr,
+                "maxstdio is invalid. From 512 to 2048 is vaild but got %d\n",
+                config->maxstdio);
+        flb_free(cfg_file);
+        flb_cf_destroy(cf_opts);
+        exit(EXIT_FAILURE);
+    }
     win32_started();
 #endif