fix: keep custom extensions registered after PHP restarts

frankenphp.c

@@ -2124,20 +2124,23 @@ int register_internal_extensions(void) {
     return FAILURE;
   }
 
+  /* modules is kept for the process lifetime: every php_module_startup()
+   * (main thread reboots, a new Init()) registers the modules again */
   for (int i = 0; i < modules_len; i++) {
     if (zend_register_internal_module(modules[i]) == NULL) {
       return FAILURE;
     }
   }
 
-  pefree(modules, 1);
-  modules = NULL;
-  modules_len = 0;
-
   return SUCCESS;
 }
 
 void register_extensions(zend_module_entry **m, int len) {
+  /* install the hook only once, or it would become its own predecessor */
+  if (modules != NULL || len <= 0) {
+    return;
+  }
+
   modules = pemalloc(len * sizeof(*modules), 1);
   memcpy(modules, m, len * sizeof(*modules));
   modules_len = len;

internal/testext/extensions.c

@@ -86,13 +86,50 @@ zend_module_entry module1_entry = {STANDARD_MODULE_HEADER,
                                    "0.1.0",
                                    STANDARD_MODULE_PROPERTIES};
 
+/* counts MINIT calls for the whole process: each PHP startup, including the
+ * main thread reboots, must register the module again */
+static zend_long ext2_minit_calls = 0;
+
+ZEND_BEGIN_MODULE_GLOBALS(ext2)
+zend_long answer;
+ZEND_END_MODULE_GLOBALS(ext2)
+
+ZEND_DECLARE_MODULE_GLOBALS(ext2)
+
+#define EXT2_G(v) ZEND_MODULE_GLOBALS_ACCESSOR(ext2, v)
+
+static PHP_GINIT_FUNCTION(ext2) { ext2_globals->answer = 42; }
+
+static PHP_MINIT_FUNCTION(ext2) {
+  REGISTER_LONG_CONSTANT("EXT2_MINIT_CALLS", ++ext2_minit_calls,
+                         CONST_PERSISTENT);
+
+  return SUCCESS;
+}
+
+static PHP_FUNCTION(ext2_answer) {
+  ZEND_PARSE_PARAMETERS_NONE();
+
+  RETURN_LONG(EXT2_G(answer));
+}
+
+ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_ext2_answer, 0, 0, IS_LONG, 0)
+ZEND_END_ARG_INFO()
+
+static const zend_function_entry ext2_functions[] = {
+    ZEND_FE(ext2_answer, arginfo_ext2_answer) ZEND_FE_END};
+
 zend_module_entry module2_entry = {STANDARD_MODULE_HEADER,
                                    "ext2",
-                                   NULL, /* Functions */
-                                   NULL, /* MINIT */
-                                   NULL, /* MSHUTDOWN */
-                                   NULL, /* RINIT */
-                                   NULL, /* RSHUTDOWN */
-                                   NULL, /* MINFO */
+                                   ext2_functions,  /* Functions */
+                                   PHP_MINIT(ext2), /* MINIT */
+                                   NULL,            /* MSHUTDOWN */
+                                   NULL,            /* RINIT */
+                                   NULL,            /* RSHUTDOWN */
+                                   NULL,            /* MINFO */
                                    "0.1.0",
-                                   STANDARD_MODULE_PROPERTIES};
+                                   PHP_MODULE_GLOBALS(ext2),
+                                   PHP_GINIT(ext2),
+                                   NULL, /* GSHUTDOWN */
+                                   NULL, /* post deactivate */
+                                   STANDARD_MODULE_PROPERTIES_EX};

internal/testext/exttest.go

@@ -12,6 +12,7 @@ package testext
 // #include "extension.h"
 import "C"
 import (
+	"fmt"
 	"io"
 	"net/http/httptest"
 	"runtime"
@@ -58,17 +59,31 @@ func testRegisterExtension(t *testing.T) {
 		_ = *p
 	})
 
-	req := httptest.NewRequest("GET", "http://example.com/index.php", nil)
-	w := httptest.NewRecorder()
+	assertExtensionsLoaded(t, 1)
+
+	// rebooting the main thread (file watcher, admin restart endpoint,
+	// opcache_reset()) starts the PHP modules again
+	frankenphp.RestartWorkers()
+	assertExtensionsLoaded(t, 2)
+
+	// so does a new Init(), which Caddy runs on every config reload
+	frankenphp.Shutdown()
+	require.NoError(t, frankenphp.Init())
+	assertExtensionsLoaded(t, 3)
+}
+
+// assertExtensionsLoaded checks that both test modules are registered and
+// that ext2's MINIT ran minitCalls times since the process started
+func assertExtensionsLoaded(t *testing.T, minitCalls int) {
+	t.Helper()
 
-	req, err = frankenphp.NewRequestWithContext(req, frankenphp.WithRequestDocumentRoot("./testdata", false))
-	assert.NoError(t, err)
+	req := httptest.NewRequest("GET", "http://example.com/index.php", nil)
+	req, err := frankenphp.NewRequestWithContext(req, frankenphp.WithRequestDocumentRoot("./testdata", false))
+	require.NoError(t, err)
 
-	err = frankenphp.ServeHTTP(w, req)
-	assert.NoError(t, err)
+	w := httptest.NewRecorder()
+	require.NoError(t, frankenphp.ServeHTTP(w, req))
 
-	resp := w.Result()
-	body, _ := io.ReadAll(resp.Body)
-	assert.Contains(t, string(body), "ext1")
-	assert.Contains(t, string(body), "ext2")
+	body, _ := io.ReadAll(w.Result().Body)
+	assert.Equal(t, fmt.Sprintf("ext1: loaded\next2: loaded\next2_answer: 42\nEXT2_MINIT_CALLS: %d\n", minitCalls), string(body))
 }

internal/testext/testdata/index.php

@@ -1,3 +1,7 @@
 <?php
 
-print_r(get_loaded_extensions());
+$extensions = get_loaded_extensions();
+printf("ext1: %s\n", in_array('ext1', $extensions, true) ? 'loaded' : 'missing');
+printf("ext2: %s\n", in_array('ext2', $extensions, true) ? 'loaded' : 'missing');
+printf("ext2_answer: %s\n", function_exists('ext2_answer') ? ext2_answer() : 'missing');
+printf("EXT2_MINIT_CALLS: %s\n", defined('EXT2_MINIT_CALLS') ? EXT2_MINIT_CALLS : 'missing');