Implement explicit tcache support.

Add the MALLOCX_TCACHE() and MALLOCX_TCACHE_NONE macros, which can be
used in conjunction with the *allocx() API.

Add the tcache.create, tcache.flush, and tcache.destroy mallctls.

This resolves #145.

1 files changed, 110 insertions, 0 deletions

diff --git a/test/unit/mallctl.c b/test/unit/mallctl.c
index f4b7d1a..10a6fcd 100644
--- a/test/unit/mallctl.c
+++ b/test/unit/mallctl.c
@@ -211,6 +211,114 @@ TEST_BEGIN(test_manpage_example)
 }
 TEST_END
 
+TEST_BEGIN(test_tcache_none)
+{
+	void *p0, *q, *p1;
+
+	test_skip_if(!config_tcache);
+
+	/* Allocate p and q. */
+	p0 = mallocx(42, 0);
+	assert_ptr_not_null(p0, "Unexpected mallocx() failure");
+	q = mallocx(42, 0);
+	assert_ptr_not_null(q, "Unexpected mallocx() failure");
+
+	/* Deallocate p and q, but bypass the tcache for q. */
+	dallocx(p0, 0);
+	dallocx(q, MALLOCX_TCACHE_NONE);
+
+	/* Make sure that tcache-based allocation returns p, not q. */
+	p1 = mallocx(42, 0);
+	assert_ptr_not_null(p1, "Unexpected mallocx() failure");
+	assert_ptr_eq(p0, p1, "Expected tcache to allocate cached region");
+
+	/* Clean up. */
+	dallocx(p1, MALLOCX_TCACHE_NONE);
+}
+TEST_END
+
+TEST_BEGIN(test_tcache)
+{
+#define	NTCACHES	10
+	unsigned tis[NTCACHES];
+	void *ps[NTCACHES];
+	void *qs[NTCACHES];
+	unsigned i;
+	size_t sz, psz, qsz;
+
+	test_skip_if(!config_tcache);
+
+	psz = 42;
+	qsz = nallocx(psz, 0) + 1;
+
+	/* Create tcaches. */
+	for (i = 0; i < NTCACHES; i++) {
+		sz = sizeof(unsigned);
+		assert_d_eq(mallctl("tcache.create", &tis[i], &sz, NULL, 0), 0,
+		    "Unexpected mallctl() failure, i=%u", i);
+	}
+
+	/* Flush empty tcaches. */
+	for (i = 0; i < NTCACHES; i++) {
+		assert_d_eq(mallctl("tcache.flush", NULL, NULL, &tis[i],
+		    sizeof(unsigned)), 0, "Unexpected mallctl() failure, i=%u",
+		    i);
+	}
+
+	/* Cache some allocations. */
+	for (i = 0; i < NTCACHES; i++) {
+		ps[i] = mallocx(psz, MALLOCX_TCACHE(tis[i]));
+		assert_ptr_not_null(ps[i], "Unexpected mallocx() failure, i=%u",
+		    i);
+		dallocx(ps[i], MALLOCX_TCACHE(tis[i]));
+
+		qs[i] = mallocx(qsz, MALLOCX_TCACHE(tis[i]));
+		assert_ptr_not_null(qs[i], "Unexpected mallocx() failure, i=%u",
+		    i);
+		dallocx(qs[i], MALLOCX_TCACHE(tis[i]));
+	}
+
+	/* Verify that tcaches allocate cached regions. */
+	for (i = 0; i < NTCACHES; i++) {
+		void *p0 = ps[i];
+		ps[i] = mallocx(psz, MALLOCX_TCACHE(tis[i]));
+		assert_ptr_not_null(ps[i], "Unexpected mallocx() failure, i=%u",
+		    i);
+		assert_ptr_eq(ps[i], p0,
+		    "Expected mallocx() to allocate cached region, i=%u", i);
+	}
+
+	/* Verify that reallocation uses cached regions. */
+	for (i = 0; i < NTCACHES; i++) {
+		void *q0 = qs[i];
+		qs[i] = rallocx(ps[i], qsz, MALLOCX_TCACHE(tis[i]));
+		assert_ptr_not_null(qs[i], "Unexpected rallocx() failure, i=%u",
+		    i);
+		assert_ptr_eq(qs[i], q0,
+		    "Expected rallocx() to allocate cached region, i=%u", i);
+		/* Avoid undefined behavior in case of test failure. */
+		if (qs[i] == NULL)
+			qs[i] = ps[i];
+	}
+	for (i = 0; i < NTCACHES; i++)
+		dallocx(qs[i], MALLOCX_TCACHE(tis[i]));
+
+	/* Flush some non-empty tcaches. */
+	for (i = 0; i < NTCACHES/2; i++) {
+		assert_d_eq(mallctl("tcache.flush", NULL, NULL, &tis[i],
+		    sizeof(unsigned)), 0, "Unexpected mallctl() failure, i=%u",
+		    i);
+	}
+
+	/* Destroy tcaches. */
+	for (i = 0; i < NTCACHES; i++) {
+		assert_d_eq(mallctl("tcache.destroy", NULL, NULL, &tis[i],
+		    sizeof(unsigned)), 0, "Unexpected mallctl() failure, i=%u",
+		    i);
+	}
+}
+TEST_END
+
 TEST_BEGIN(test_thread_arena)
 {
 	unsigned arena_old, arena_new, narenas;
@@ -431,6 +539,8 @@ main(void)
 	    test_mallctl_config,
 	    test_mallctl_opt,
 	    test_manpage_example,
+	    test_tcache_none,
+	    test_tcache,
 	    test_thread_arena,
 	    test_arena_i_purge,
 	    test_arena_i_dss,