Try to use flock first to avoid the bugs in fcntl.

lib_acl/src/stdlib/acl_myflock.c

@@ -63,8 +63,7 @@ int acl_myflock(ACL_FILE_HANDLE fd, int lock_style, int operation)
 #endif
 
 	/*
-	 * fcntl() is standard and does more than we need, but we can handle
-	 * it.
+	 * fcntl() is standard and does more than we need, but we can handle it.
 	 */
 #ifdef ACL_HAS_FCNTL_LOCK
 	case ACL_FLOCK_STYLE_FCNTL:
@@ -105,7 +104,7 @@ int acl_myflock(ACL_FILE_HANDLE fd, int lock_style, int operation)
 			acl_set_error(ACL_EAGAIN);
 	}
 
-	return (status);
+	return status;
 }
 #endif /* ACL_UNIX */
 
@@ -152,7 +151,7 @@ int acl_myflock(ACL_FILE_HANDLE fd, int lock_style acl_unused, int operation)
 	}
 
 	acl_msg_error("%s(%d): invalid lock_op(%d)", myname, __LINE__, lock_op);
-	return (-1);
+	return -1;
 }
 # else
 /* use LockFileEx/UnlockFileEx */

lib_acl_cpp/src/stream/fstream.cpp

@@ -215,9 +215,14 @@ bool fstream::lock(bool exclude /* = true */)
 		return false;
 	}
 
-	int ret = acl_myflock(fd, ACL_FLOCK_STYLE_FCNTL,
-		exclude ? ACL_FLOCK_OP_EXCLUSIVE : ACL_FLOCK_OP_SHARED);
-	return ret == 0;
+#ifdef	ACL_HAS_FLOCK_LOCK
+	// Use flock mode first when flock is supported by OS.
+	return acl_myflock(fd, ACL_FLOCK_STYLE_FLOCK,
+		exclude ?  LOCK_EX : LOCK_SH) == 0;
+#else
+	return acl_myflock(fd, ACL_FLOCK_STYLE_FCNTL,
+		exclude ? ACL_FLOCK_OP_EXCLUSIVE : ACL_FLOCK_OP_SHARED) == 0;
+#endif
 }
 
 bool fstream::try_lock(bool exclude /* = true */)
@@ -231,13 +236,14 @@ bool fstream::try_lock(bool exclude /* = true */)
 		return false;
 	}
 
-	int oper =ACL_FLOCK_OP_NOWAIT;
-	if (exclude) {
-		oper |= ACL_FLOCK_OP_EXCLUSIVE;
-	} else {
-		oper |= ACL_FLOCK_OP_SHARED;
-	}
-	return acl_myflock(fd, ACL_FLOCK_STYLE_FCNTL, oper) == 0;
+#ifdef	ACL_HAS_FLOCK_LOCK
+	return acl_myflock(fd, ACL_FLOCK_STYLE_FLOCK,
+		exclude ?  (LOCK_EX | LOCK_NB) : (LOCK_SH | LOCK_NB)) == 0;
+#else
+	return acl_myflock(fd, ACL_FLOCK_STYLE_FCNTL,
+		exclude ? (ACL_FLOCK_OP_NOWAIT | ACL_FLOCK_OP_EXCLUSIVE)
+			: (ACL_FLOCK_OP_NOWAIT | ACL_FLOCK_OP_SHARED)) == 0;
+#endif
 }
 
 bool fstream::unlock(void)
@@ -251,7 +257,11 @@ bool fstream::unlock(void)
 		return false;
 	}
 
+#ifdef	ACL_HAS_FLOCK_LOCK
+	return acl_myflock(fd, ACL_FLOCK_STYLE_FLOCK, ACL_FLOCK_OP_NONE) == 0;
+#else
 	return acl_myflock(fd, ACL_FLOCK_STYLE_FCNTL, ACL_FLOCK_OP_NONE) == 0;
+#endif
 }
 
 } // namespace acl

lib_fiber/samples/file_lock/Makefile

@@ -0,0 +1,3 @@
+include ../Makefile_cpp.in
+CFLAGS += -DUSE_FIBER
+PROG = file_lock

lib_fiber/samples/file_lock/main.cpp

@@ -0,0 +1,147 @@
+#include "stdafx.h"
+#include <stdlib.h>
+#include <stdio.h>
+
+class locker {
+public:
+	locker(const char* filepath, bool close_reader, int sleep_s)
+	: filepath_(filepath), close_reader_(close_reader), sleep_s_(sleep_s) {}
+	~locker() {}
+
+	void run() {
+		if (!fp_.open(filepath_, O_RDWR | O_CREAT, 0600)) {
+			printf("open %s error\r\n", filepath_.c_str());
+			return;
+		}
+
+		if (!fp_.try_lock()) {
+			printf("lock %s error %s\r\n", filepath_.c_str(), acl::last_serror());
+			return;
+		}
+
+		printf("lock %s ok\r\n", filepath_.c_str());
+
+		acl::ifstream reader;
+		if (reader.open_read(filepath_)) {
+			printf("open_read %s ok\r\n", filepath_.c_str());
+		} else {
+			printf("open_read %s error\r\n", filepath_.c_str());
+		}
+
+		if (close_reader_) {
+			reader.close();
+		}
+
+		::sleep(sleep_s_);
+
+		if (!fp_.unlock()) {
+			printf("Unlock %s error %s\r\n", filepath_.c_str(), acl::last_serror());
+		} else {
+			printf("Unlock %s ok\r\n", filepath_.c_str());
+		}
+
+		::sleep(sleep_s_);
+	}
+
+private:
+	acl::string filepath_;
+	bool close_reader_;
+	int sleep_s_;
+
+	acl::fstream fp_;
+};
+
+#ifdef USE_FIBER
+class fiber_locker : public acl::fiber {
+public:
+	fiber_locker(const char* filepath, bool close_reader, int sleep_s)
+	: filepath_(filepath), close_reader_(close_reader), sleep_s_(sleep_s) {}
+	~fiber_locker() {}
+
+protected:
+	// @override
+	void run() {
+		printf("Running in fiber mode\r\n");
+		locker lk(filepath_, close_reader_, sleep_s_);
+		lk.run();
+	}
+
+private:
+	acl::string filepath_;
+	bool close_reader_;
+	int sleep_s_;
+};
+#endif
+
+class thread_locker : public acl::thread {
+public:
+	thread_locker(const char* filepath, bool close_reader, int sleep_s)
+	: filepath_(filepath), close_reader_(close_reader), sleep_s_(sleep_s) {}
+	~thread_locker() {}
+
+protected:
+	// @override
+	void* run() {
+		printf("Running in thread mode\r\n");
+		locker lk(filepath_, close_reader_, sleep_s_);
+		lk.run();
+		return NULL;
+	}
+
+private:
+	acl::string filepath_;
+	bool close_reader_;
+	int sleep_s_;
+};
+
+static void usage(const char* procname) {
+	printf("usage: %s -h [help]\r\n"
+		"  -t [if using thread mode, default: false]\r\n"
+		"  -c [if closing reader, default: false]\r\n"
+		"  -w sleep_time[default: 5]\r\n", procname);
+}
+
+int main(int argc, char* argv[]) {
+	int ch, sleep_s = 5;
+	bool use_thread = false, close_reader = false;
+
+	while ((ch = getopt(argc, argv, "htcw:")) > 0) {
+		switch (ch) {
+		case 'h':
+			usage(argv[0]);
+			return 0;
+		case 't':
+			use_thread = true;
+			break;
+		case 'c':
+			close_reader = true;
+			break;
+		case 'w':
+			sleep_s = atoi(optarg);
+			if (sleep_s <= 0) {
+				sleep_s = 5;
+			}
+			break;
+		default:
+			break;
+		}
+	}
+
+	acl::acl_cpp_init();
+	acl::log::stdout_open(true);
+
+	if (use_thread) {
+		thread_locker lk("./dummy.lock", close_reader, sleep_s);
+		lk.start();
+		lk.wait();
+	} else {
+#ifdef USE_FIBER
+		acl::fiber::stdout_open(true);
+		fiber_locker lk("./dummy.lock", close_reader, sleep_s);
+		lk.start();
+		acl::fiber::schedule();
+#endif
+	}
+
+	return 0;
+}

lib_fiber/samples/file_lock/stdafx.cpp

@@ -0,0 +1,8 @@
+// stdafx.cpp : 只包括标准包含文件的源文件
+// master_threads.pch 将成为预编译头
+// stdafx.obj 将包含预编译类型信息
+
+#include "stdafx.h"
+
+// TODO: 在 STDAFX.H 中
+//引用任何所需的附加头文件，而不是在此文件中引用

lib_fiber/samples/file_lock/stdafx.h

@@ -0,0 +1,20 @@
+// stdafx.h : 标准系统包含文件的包含文件，
+// 或是常用但不常更改的项目特定的包含文件
+//
+
+#pragma once
+
+
+//#include <iostream>
+//#include <tchar.h>
+
+// TODO: 在此处引用程序要求的附加头文件
+
+#include "lib_acl.h"
+#include "fiber/libfiber.hpp"
+#include "acl_cpp/lib_acl.hpp"
+
+#ifdef	WIN32
+#define	snprintf _snprintf
+#endif
+