From 1f312b2e42714ee80bec75a59662c448a8db1ed4 Mon Sep 17 00:00:00 2001
From: Max Kellermann <mk@cm4all.com>
Date: Fri, 11 Dec 2020 14:13:53 +0100
Subject: [PATCH] curl/Handler: disallow OnData() to throw
This eliminates some complexity from class CurlRequest.
---
src/lib/curl/Handler.hxx | 2 +-
src/lib/curl/Request.cxx | 19 +------------------
src/lib/curl/Request.hxx | 16 ----------------
test/RunCurl.cxx | 8 ++++++--
4 files changed, 8 insertions(+), 37 deletions(-)
diff --git a/src/lib/curl/Handler.hxx b/src/lib/curl/Handler.hxx
index ad5001e11..1259c4b3a 100644
--- a/src/lib/curl/Handler.hxx
+++ b/src/lib/curl/Handler.hxx
@@ -59,7 +59,7 @@ public:
/**
* Response body data has been received.
*
- * May throw #Pause.
+ * May throw #Pause (but nothing else).
*/
virtual void OnData(ConstBuffer<void> data) = 0;
diff --git a/src/lib/curl/Request.cxx b/src/lib/curl/Request.cxx
index 1f1c59940..d174fdb80 100644
--- a/src/lib/curl/Request.cxx
+++ b/src/lib/curl/Request.cxx
@@ -47,9 +47,7 @@
CurlRequest::CurlRequest(CurlGlobal &_global,
CurlResponseHandler &_handler)
- :global(_global), handler(_handler),
- postpone_error_event(global.GetEventLoop(),
- BIND_THIS_METHOD(OnPostponeError))
+ :global(_global), handler(_handler)
{
error_buffer[0] = 0;
@@ -243,13 +241,6 @@ CurlRequest::DataReceived(const void *ptr, size_t received_size) noexcept
return received_size;
} catch (CurlResponseHandler::Pause) {
return CURL_WRITEFUNC_PAUSE;
- } catch (...) {
- state = State::CLOSED;
- /* move the CurlResponseHandler::OnError() call into a
- "safe" stack frame */
- postponed_error = std::current_exception();
- postpone_error_event.Schedule();
- return CURL_WRITEFUNC_PAUSE;
}
}
@@ -266,11 +257,3 @@ CurlRequest::WriteFunction(char *ptr, size_t size, size_t nmemb,
return c.DataReceived(ptr, size);
}
-
-void
-CurlRequest::OnPostponeError() noexcept
-{
- assert(postponed_error);
-
- handler.OnError(postponed_error);
-}
diff --git a/src/lib/curl/Request.hxx b/src/lib/curl/Request.hxx
index abc2a46a7..654f3f179 100644
--- a/src/lib/curl/Request.hxx
+++ b/src/lib/curl/Request.hxx
@@ -31,11 +31,9 @@
#define CURL_REQUEST_HXX
#include "Easy.hxx"
-#include "event/DeferEvent.hxx"
#include <map>
#include <string>
-#include <exception>
struct StringView;
class CurlGlobal;
@@ -57,18 +55,6 @@ class CurlRequest final {
std::multimap<std::string, std::string> headers;
- /**
- * An exception caught by DataReceived(), which will be
- * forwarded into a "safe" stack frame by
- * #postpone_error_event. This works around the
- * problem that libcurl crashes if you call
- * curl_multi_remove_handle() from within the WRITEFUNCTION
- * (i.e. DataReceived()).
- */
- std::exception_ptr postponed_error;
-
- DeferEvent postpone_error_event;
-
/** error message provided by libcurl */
char error_buffer[CURL_ERROR_SIZE];
@@ -167,8 +153,6 @@ private:
void HeaderFunction(StringView s) noexcept;
- void OnPostponeError() noexcept;
-
/** called by curl when new data is available */
static size_t _HeaderFunction(char *ptr, size_t size, size_t nmemb,
void *stream) noexcept;
diff --git a/test/RunCurl.cxx b/test/RunCurl.cxx
index f81e8097e..6f5ce1a1f 100644
--- a/test/RunCurl.cxx
+++ b/test/RunCurl.cxx
@@ -50,8 +50,12 @@ public:
}
void OnData(ConstBuffer<void> data) override {
- if (fwrite(data.data, data.size, 1, stdout) != 1)
- throw std::runtime_error("Failed to write");
+ try {
+ if (fwrite(data.data, data.size, 1, stdout) != 1)
+ throw std::runtime_error("Failed to write");
+ } catch (...) {
+ OnError(std::current_exception());
+ }
}
void OnEnd() override {