curl/lib/easy_lock.h
Viktor Szakats 3f8fc25720
cmake: add support for "unity" builds
Aka "jumbo" or "amalgamation" builds. It means to compile all sources
per target as a single C source. This is experimental.

You can enable it by passing `-DCMAKE_UNITY_BUILD=ON` to cmake.
It requires CMake 3.16 or newer.

It makes builds (much) faster, allows for better optimizations and tends
to promote less ambiguous code.

Also add a new AppVeyor CI job and convert an existing one to use
"unity" mode (one MSVC, one MinGW), and enable it for one macOS CI job.

Fix related issues:
- add missing include guard to `easy_lock.h`.
- rename static variables and functions (and a macro) with names reused
  across sources, or shadowed by local variables.
- add an `#undef` after use.
- add a missing `#undef` before use.
- move internal definitions from `ftp.h` to `ftp.c`.
- `curl_memory.h` fixes to make it work when included repeatedly.
- stop building/linking curlx bits twice for a static-mode curl tool.
  These caused doubly defined symbols in unity builds.
- silence missing extern declarations compiler warning for ` _CRT_glob`.
- fix extern declarations for `tool_freq` and `tool_isVistaOrGreater`.
- fix colliding static symbols in debug mode: `debugtime()` and
  `statename`.
- rename `ssl_backend_data` structure to unique names for each
  TLS-backend, along with the `ssl_connect_data` struct member
  referencing them. This required adding casts for each access.
- add workaround for missing `[P]UNICODE_STRING` types in certain Windows
  builds when compiling `lib/ldap.c`. To support "unity" builds, we had
  to enable `SCHANNEL_USE_BLACKLISTS` for Schannel (a Windows
  `schannel.h` option) _globally_. This caused an indirect inclusion of
  Windows `schannel.h` from `ldap.c` via `winldap.h` to have it enabled
  as well. This requires `[P]UNICODE_STRING` types, which is apperantly
  not defined automatically (as seen with both MSVS and mingw-w64).
  This patch includes `<subauth.h>` to fix it.
  Ref: https://github.com/curl/curl/runs/13987772013
  Ref: https://dev.azure.com/daniel0244/curl/_build/results?buildId=15827&view=logs&jobId=2c9f582d-e278-56b6-4354-f38a4d851906&j=2c9f582d-e278-56b6-4354-f38a4d851906&t=90509b00-34fa-5a81-35d7-5ed9569d331c
- tweak unity builds to compile `lib/memdebug.c` separately in memory
  trace builds to avoid PP confusion.
- force-disable unity for test programs.
- do not compile and link libcurl sources to libtests _twice_ when libcurl
  is built in static mode.

KNOWN ISSUES:
- running tests with unity builds may fail in cases.
- some build configurations/env may not compile in unity mode. E.g.:
  https://ci.appveyor.com/project/curlorg/curl/builds/47230972/job/51wfesgnfuauwl8q#L250

Ref: https://github.com/libssh2/libssh2/issues/1034
Ref: https://cmake.org/cmake/help/latest/prop_tgt/UNITY_BUILD.html
Ref: https://en.wikipedia.org/wiki/Unity_build

Closes #11095
2023-06-07 13:06:08 +00:00

110 lines
3.1 KiB
C

#ifndef HEADER_CURL_EASY_LOCK_H
#define HEADER_CURL_EASY_LOCK_H
/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at https://curl.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
* SPDX-License-Identifier: curl
*
***************************************************************************/
#include "curl_setup.h"
#define GLOBAL_INIT_IS_THREADSAFE
#if defined(_WIN32_WINNT) && _WIN32_WINNT >= 0x600
#ifdef __MINGW32__
#ifndef __MINGW64_VERSION_MAJOR
#if (__MINGW32_MAJOR_VERSION < 5) || \
(__MINGW32_MAJOR_VERSION == 5 && __MINGW32_MINOR_VERSION == 0)
/* mingw >= 5.0.1 defines SRWLOCK, and slightly different from MS define */
typedef PVOID SRWLOCK, *PSRWLOCK;
#endif
#endif
#ifndef SRWLOCK_INIT
#define SRWLOCK_INIT NULL
#endif
#endif /* __MINGW32__ */
#define curl_simple_lock SRWLOCK
#define CURL_SIMPLE_LOCK_INIT SRWLOCK_INIT
#define curl_simple_lock_lock(m) AcquireSRWLockExclusive(m)
#define curl_simple_lock_unlock(m) ReleaseSRWLockExclusive(m)
#elif defined(HAVE_ATOMIC) && defined(HAVE_STDATOMIC_H)
#include <stdatomic.h>
#if defined(HAVE_SCHED_YIELD)
#include <sched.h>
#endif
#define curl_simple_lock atomic_int
#define CURL_SIMPLE_LOCK_INIT 0
/* a clang-thing */
#ifndef __has_builtin
#define __has_builtin(x) 0
#endif
#ifndef __INTEL_COMPILER
/* The Intel compiler tries to look like GCC *and* clang *and* lies in its
__has_builtin() function, so override it. */
/* if GCC on i386/x86_64 or if the built-in is present */
#if ( (defined(__GNUC__) && !defined(__clang__)) && \
(defined(__i386__) || defined(__x86_64__))) || \
__has_builtin(__builtin_ia32_pause)
#define HAVE_BUILTIN_IA32_PAUSE
#endif
#endif
static inline void curl_simple_lock_lock(curl_simple_lock *lock)
{
for(;;) {
if(!atomic_exchange_explicit(lock, true, memory_order_acquire))
break;
/* Reduce cache coherency traffic */
while(atomic_load_explicit(lock, memory_order_relaxed)) {
/* Reduce load (not mandatory) */
#ifdef HAVE_BUILTIN_IA32_PAUSE
__builtin_ia32_pause();
#elif defined(__aarch64__)
__asm__ volatile("yield" ::: "memory");
#elif defined(HAVE_SCHED_YIELD)
sched_yield();
#endif
}
}
}
static inline void curl_simple_lock_unlock(curl_simple_lock *lock)
{
atomic_store_explicit(lock, false, memory_order_release);
}
#else
#undef GLOBAL_INIT_IS_THREADSAFE
#endif
#endif /* HEADER_CURL_EASY_LOCK_H */