diff --git a/doc/go_mem.html b/doc/go_mem.html
index d2167a66a36..1ecddddff0a 100644
--- a/doc/go_mem.html
+++ b/doc/go_mem.html
@@ -15,16 +15,17 @@ Within a single goroutine, reads and writes must behave
as if they executed in the order specified by the program.
That is, compilers and processors may reorder the reads and writes
executed within a single goroutine only when the reordering
-does not change the execution behavior within that goroutine.
+does not change the behavior within that goroutine
+as defined by the language specification.
Because of this reordering, the execution order observed
-by one may differ from the order perceived
+by one goroutine may differ from the order perceived
by another. For example, if one goroutine
-executes a = 1; b = 2;
, a second goroutine might observe
+executes a = 1; b = 2;
, another might observe
the updated value of b
before the updated value of a
.
-To specify the requirements on reads and writes, we define
+To specify the requirements of reads and writes, we define
happens before, a partial order on the execution
of memory operations in a Go program. If event e1 happens
before event e2, then we say that e2 happens after e1.
@@ -34,7 +35,7 @@ after e2, then we say that
-For example, this program:
+This program:
-is also guaranteed to print "hello, world". The write to
-For example, this program:
+This program:
-var c = make(chan int);
-var a string;
+var c = make(chan int)
+var a string
func f() {
a = "hello, world";
@@ -211,7 +212,7 @@ func main() {
a
+is also guaranteed to print "hello, world"
. The write to a
happens before the receive on c
, which happens before
the corresponding send on c
completes, which happens
before the print
.
@@ -237,12 +238,12 @@ the n'th call to l.Unlock()
happens before the m'th c
-var l sync.Mutex;
-var a string;
+var l sync.Mutex
+var a string
func f() {
a = "hello, world";
@@ -278,16 +279,16 @@ but only one will run
f()
, and the other calls block
until f()
has returned.
-A single call to f()
happens before once.Do(f)
returns.
+
+A single call of f()
from once.Do(f)
happens (returns) before any call of once.Do(f)
returns.
-For example, in this program: +In this program:
-var a string; +var a string func setup() { a = "hello, world"; @@ -319,11 +320,11 @@ will observe writes that happened before w.-For example, in this program: +In this program:
-var a, b int; +var a, b int func f() { a = 1; @@ -346,18 +347,18 @@ it can happen thatg
prints2
and then0
.-This fact invalidates a few obvious idioms. +This fact invalidates a few common idioms.
Double-checked locking is an attempt to avoid the overhead of synchronization. -For example, the
twoprint
program above, might be +For example, thetwoprint
program might be incorrectly written as:-var a string; -var done bool; +var a string +var done bool func setup() { a = "hello, world"; @@ -389,8 +390,8 @@ Another incorrect idiom is busy waiting for a value, as in:-var a string; -var done bool; +var a string +var done bool func setup() { a = "hello, world"; @@ -407,7 +408,7 @@ func main() {As before, there is no guarantee that, in
main
, -observing of the write todone
+observing the write todone
implies observing the write toa
, so this program could print an empty string too. Worse, there is no guarantee that the write todone
will ever @@ -417,7 +418,7 @@ guaranteed to finish.-There are subtler variants on this theme. For example, in this program: +There are subtler variants on this theme, such as this program.
@@ -425,7 +426,7 @@ type T struct { msg string; } -var g *T; +var g *T func setup() { t := new(T); @@ -451,16 +452,3 @@ value forg.msg
. In all these examples, the solution is the same: use explicit synchronization. - - - - - - -