Add memory barriers to multi-threaded code in test4.c.

FossilOrigin-Name: 9260f4e0fdc8066b4772999bacb5f4130ef714d4ac1967029ceacff618bc48ff

diff --git a/manifest b/manifest
index a85da37ade65474c5d5941c1ddee12edc91919eb..f301d1271b031f654c6448e40808e4f4f374144d 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Fix\sa\sproblem\sin\stest\sfile\sswarmvtab3.test\scausing\soccasional\sfailures.
-D 2022-05-16T16:10:04.466
+C Add\smemory\sbarriers\sto\smulti-threaded\scode\sin\stest4.c.
+D 2022-05-16T16:55:22.768
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -566,7 +566,7 @@ F src/tclsqlite.c 1f6673991147bc2cecc08a40d22f9803b84c805b24b499fe727f392256f734
 F src/test1.c 1356984e97bff07e4a8cc3863e892f05b3348678a74783bb6f350b76316736f1
 F src/test2.c 3efb99ab7f1fc8d154933e02ae1378bac9637da5
 F src/test3.c 61798bb0d38b915067a8c8e03f5a534b431181f802659a6616f9b4ff7d872644
-F src/test4.c 7c4420e01c577b5c4add2cb03119743b1a357543d347773b9e717195ea967159
+F src/test4.c 4533b76419e7feb41b40582554663ed3cd77aaa54e135cf76b3205098cd6e664
 F src/test5.c 328aae2c010c57a9829d255dc099d6899311672d
 F src/test6.c ae73a3a42bbc982fb9e301b84d30bda65a307be48c6dff20aba1461e17a9b0ce
 F src/test7.c 5612e9aecf934d6df7bba6ce861fdf5ba5456010
@@ -1954,8 +1954,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 2277f9ba7087dd993ac0f4007c523aa9cf74dba187f53af03d8c164886726fee
-R 68c24df5ae8824ce38e34e7cd46a31f1
+P f935c155ef205802c16b4ebea4a3fb01bf5689662b7b4f2af56f0f9021d6d4b1
+R c061fe23c974300044233fa5c2c2a108
 U dan
-Z e76e8801e618c61286f9010190950bf1
+Z f437a9eddd805a091e05b9805ba19805
 # Remove this line to create a well-formed Fossil manifest.

diff --git a/manifest.uuid b/manifest.uuid
index 22087ddd3d6cfde82126b60df57152dc681be7b1..270e063e23c16aa76d2e4200d6ff1686fd0a48ef 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-f935c155ef205802c16b4ebea4a3fb01bf5689662b7b4f2af56f0f9021d6d4b1
\ No newline at end of file
+9260f4e0fdc8066b4772999bacb5f4130ef714d4ac1967029ceacff618bc48ff
\ No newline at end of file

diff --git a/src/test4.c b/src/test4.c
index 5da9cc488de6f63326f28cd38194287369dcc029..2043a338309ef98586035f60ac6107a6efcb38ec 100644 (file)
--- a/src/test4.c
+++ b/src/test4.c
@@ -60,6 +60,11 @@ struct Thread {
 #define N_THREAD 26
 static Thread threadset[N_THREAD];
 
+static void test_barrier(){
+  sqlite3_mutex *pMutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_APP1);
+  sqlite3_mutex_enter(pMutex);
+  sqlite3_mutex_leave(pMutex);
+}
 
 /*
 ** The main loop for a thread.  Threads use busy waiting. 
@@ -76,16 +81,20 @@ static void *test_thread_main(void *pArg){
     p->db = 0;
   }
   p->pStmt = 0;
+  test_barrier();
   p->completed = 1;
   while( p->opnum<=p->completed ) sched_yield();
+  test_barrier();
   while( p->xOp ){
     if( p->zErr && p->zErr!=p->zStaticErr ){
       sqlite3_free(p->zErr);
       p->zErr = 0;
     }
     (*p->xOp)(p);
+    test_barrier();
     p->completed++;
     while( p->opnum<=p->completed ) sched_yield();
+    test_barrier();
   }
   if( p->pStmt ){
     sqlite3_finalize(p->pStmt);
@@ -99,6 +108,7 @@ static void *test_thread_main(void *pArg){
     sqlite3_free(p->zErr);
     p->zErr = 0;
   }
+  test_barrier();
   p->completed++;
 #ifndef SQLITE_OMIT_DEPRECATED
   sqlite3_thread_cleanup();
@@ -166,7 +176,9 @@ static int SQLITE_TCLAPI tcl_thread_create(
 ** Wait for a thread to reach its idle state.
 */
 static void test_thread_wait(Thread *p){
+  test_barrier();
   while( p->opnum>p->completed ) sched_yield();
+  test_barrier();
 }
 
 /*
@@ -456,6 +468,7 @@ static int SQLITE_TCLAPI tcl_thread_compile(
   threadset[i].xOp = do_compile;
   sqlite3_free(threadset[i].zArg);
   threadset[i].zArg = sqlite3_mprintf("%s", argv[2]);
+  test_barrier();
   threadset[i].opnum++;
   return TCL_OK;
 }
@@ -507,6 +520,7 @@ static int SQLITE_TCLAPI tcl_thread_step(
   }
   test_thread_wait(&threadset[i]);
   threadset[i].xOp = do_step;
+  test_barrier();
   threadset[i].opnum++;
   return TCL_OK;
 }
@@ -551,6 +565,7 @@ static int SQLITE_TCLAPI tcl_thread_finalize(
   threadset[i].xOp = do_finalize;
   sqlite3_free(threadset[i].zArg);
   threadset[i].zArg = 0;
+  test_barrier();
   threadset[i].opnum++;
   return TCL_OK;
 }