From 7f8bb47fcaf8eaa817f8aad11c9c28b58215b66f Mon Sep 17 00:00:00 2001
From: Justin Kolberg <amd.prophet@gmail.com>
Date: Fri, 22 Nov 2019 12:31:57 -0800
Subject: [PATCH] Add support for aix (#189)

* add support for aix

Signed-off-by: Justin Kolberg <amd.prophet@gmail.com>

* rename bolt_aix.go to bolt_unix_aix.go

Signed-off-by: Justin Kolberg <amd.prophet@gmail.com>

* use go 1.12

Signed-off-by: Justin Kolberg <amd.prophet@gmail.com>
---
 bolt_unix.go     |  2 +-
 bolt_unix_aix.go | 88 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 90 insertions(+), 2 deletions(-)
 create mode 100644 bolt_unix_aix.go

diff --git a/bolt_unix.go b/bolt_unix.go
index 5f2bb51..2938fed 100644
--- a/bolt_unix.go
+++ b/bolt_unix.go
@@ -1,4 +1,4 @@
-// +build !windows,!plan9,!solaris
+// +build !windows,!plan9,!solaris,!aix
 
 package bbolt
 
diff --git a/bolt_unix_aix.go b/bolt_unix_aix.go
new file mode 100644
index 0000000..babad65
--- /dev/null
+++ b/bolt_unix_aix.go
@@ -0,0 +1,89 @@
+package bolt
+
+import (
+	"fmt"
+	"os"
+	"syscall"
+	"time"
+	"unsafe"
+
+	"golang.org/x/sys/unix"
+)
+
+// flock acquires an advisory lock on a file descriptor.
+func flock(db *DB, mode os.FileMode, exclusive bool, timeout time.Duration) error {
+	var t time.Time
+	if timeout != 0 {
+		t = time.Now()
+	}
+	fd := db.file.Fd()
+	var lockType int16
+	if exclusive {
+		lockType = syscall.F_WRLCK
+	} else {
+		lockType = syscall.F_RDLCK
+	}
+	for {
+		// Attempt to obtain an exclusive lock.
+		lock := syscall.Flock_t{Type: lockType}
+		err := syscall.FcntlFlock(fd, syscall.F_SETLK, &lock)
+		if err == nil {
+			return nil
+		} else if err != syscall.EAGAIN {
+			return err
+		}
+
+		// If we timed out then return an error.
+		if timeout != 0 && time.Since(t) > timeout-flockRetryTimeout {
+			return ErrTimeout
+		}
+
+		// Wait for a bit and try again.
+		time.Sleep(flockRetryTimeout)
+	}
+}
+
+// funlock releases an advisory lock on a file descriptor.
+func funlock(db *DB) error {
+	var lock syscall.Flock_t
+	lock.Start = 0
+	lock.Len = 0
+	lock.Type = syscall.F_UNLCK
+	lock.Whence = 0
+	return syscall.FcntlFlock(uintptr(db.file.Fd()), syscall.F_SETLK, &lock)
+}
+
+// mmap memory maps a DB's data file.
+func mmap(db *DB, sz int) error {
+	// Map the data file to memory.
+	b, err := unix.Mmap(int(db.file.Fd()), 0, sz, syscall.PROT_READ, syscall.MAP_SHARED|db.MmapFlags)
+	if err != nil {
+		return err
+	}
+
+	// Advise the kernel that the mmap is accessed randomly.
+	if err := unix.Madvise(b, syscall.MADV_RANDOM); err != nil {
+		return fmt.Errorf("madvise: %s", err)
+	}
+
+	// Save the original byte slice and convert to a byte array pointer.
+	db.dataref = b
+	db.data = (*[maxMapSize]byte)(unsafe.Pointer(&b[0]))
+	db.datasz = sz
+	return nil
+}
+
+// munmap unmaps a DB's data file from memory.
+func munmap(db *DB) error {
+	// Ignore the unmap if we have no mapped data.
+	if db.dataref == nil {
+		return nil
+	}
+
+	// Unmap using the original byte slice.
+	err := unix.Munmap(db.dataref)
+	db.dataref = nil
+	db.data = nil
+	db.datasz = 0
+	return err
+}
-- 
2.22.0