From 4247fafd0f361d2373df7213a1a0028554e93d93 Mon Sep 17 00:00:00 2001 From: Eric Wong Date: Sat, 13 Feb 2010 01:35:55 -0800 Subject: ext: fix memory leak when reentrant/multithreaded The optional C extension leaked memory due to improper use of the Ruby API, causing duplicated objects to never be garbage collected. I misread the Data_Make_Struct/Data_Wrap_Struct documentation and ended up passing NULL as the "free" argument instead of -1, causing the memory to never be freed. From README.EXT in the MRI source which I misread: > The free argument is the function to free the pointer > allocation. If this is -1, the pointer will be just freed. > The functions mark and free will be called from garbage > collector. --- ext/clogger_ext/clogger.c | 2 +- test/test_clogger.rb | 18 ++++++++++++++++++ 2 files changed, 19 insertions(+), 1 deletion(-) diff --git a/ext/clogger_ext/clogger.c b/ext/clogger_ext/clogger.c index da6b5d2..6e14938 100644 --- a/ext/clogger_ext/clogger.c +++ b/ext/clogger_ext/clogger.c @@ -188,7 +188,7 @@ static VALUE clogger_alloc(VALUE klass) { struct clogger *c; - return Data_Make_Struct(klass, struct clogger, clogger_mark, 0, c); + return Data_Make_Struct(klass, struct clogger, clogger_mark, -1, c); } static struct clogger *clogger_get(VALUE self) diff --git a/test/test_clogger.rb b/test/test_clogger.rb index b086bbb..4dab3fc 100644 --- a/test/test_clogger.rb +++ b/test/test_clogger.rb @@ -587,4 +587,22 @@ class TestClogger < Test::Unit::TestCase assert ! cl.reentrant? end + # so we don't care about the portability of this test + # if it doesn't leak on Linux, it won't leak anywhere else + # unless your C compiler or platform is otherwise broken + LINUX_PROC_PID_STATUS = "/proc/self/status" + def test_memory_leak + app = lambda { |env| [ 0, {}, [] ] } + clogger = Clogger.new(app, :logger => $stderr) + match_rss = /^VmRSS:\s+(\d+)/ + if File.read(LINUX_PROC_PID_STATUS) =~ match_rss + before = $1.to_i + 1000000.times { clogger.dup } + File.read(LINUX_PROC_PID_STATUS) =~ match_rss + after = $1.to_i + diff = after - before + assert(diff < 10000, "memory grew more than 10M: #{diff}") + end + end if RUBY_PLATFORM =~ /linux/ && test(?r, LINUX_PROC_PID_STATUS) + end -- cgit v1.2.3-24-ge0c7