Add an experimental OPFS VFS-specific URI flag, opfs-unlock-asap, which tells the VFS to release implicit locks ASAP. This permits higher concurrency but hurts performance considerably. This may or may not be obsoleted by other concurrency-related experimentation.

FossilOrigin-Name: d23c917013485ec2793125221f3936b05c39d6eca941629fb819b6b4aa714520

5 files changed, 41 insertions, 31 deletions

diff --git a/ext/wasm/api/sqlite3-api-opfs.js b/ext/wasm/api/sqlite3-api-opfs.js
index 53f68a1d5..deb8bf04e 100644
--- a/ext/wasm/api/sqlite3-api-opfs.js
+++ b/ext/wasm/api/sqlite3-api-opfs.js
@@ -355,6 +355,25 @@ const installOpfsVfs = function callee(options){
         toss("Maintenance required: not found:",k);
       }
     });
+    state.opfsFlags = Object.assign(Object.create(null),{
+      /**
+         Flag for use with xOpen(). "opfs-unlock-asap=1" enables
+         this. See defaultUnlockAsap, below.
+       */
+      OPFS_UNLOCK_ASAP: 0x01,
+      /**
+         If true, any async routine which implicitly acquires a sync
+         access handle (i.e. an OPFS lock) will release that locks at
+         the end of the call which acquires it. If false, such
+         "autolocks" are not released until the VFS is idle for some
+         brief amount of time.
+
+         The benefit of enabling this is much higher concurrency. The
+         down-side is much-reduced performance (as much as a 4x decrease
+         in speedtest1).
+      */
+      defaultUnlockAsap: false
+    });
 
     /**
        Runs the given operation (by name) in the async worker
@@ -845,9 +864,15 @@ const installOpfsVfs = function callee(options){
       //xSleep is optionally defined below
       xOpen: function f(pVfs, zName, pFile, flags, pOutFlags){
         mTimeStart('xOpen');
+        let opfsFlags = 0;
         if(0===zName){
           zName = randomFilename();
         }else if('number'===typeof zName){
+          if(capi.sqlite3_uri_boolean(zName, "opfs-unlock-asap", 0)){
+            /* -----------------------^^^^^ MUST pass the untranslated
+               C-string here. */
+            opfsFlags |= state.opfsFlags.OPFS_UNLOCK_ASAP;
+          }
           zName = wasm.cstringToJs(zName);
         }
         const fh = Object.create(null);
@@ -855,7 +880,7 @@ const installOpfsVfs = function callee(options){
         fh.filename = zName;
         fh.sab = new SharedArrayBuffer(state.fileBufferSize);
         fh.flags = flags;
-        const rc = opRun('xOpen', pFile, zName, flags);
+        const rc = opRun('xOpen', pFile, zName, flags, opfsFlags);
         if(!rc){
           /* Recall that sqlite3_vfs::xClose() will be called, even on
              error, unless pFile->pMethods is NULL. */
diff --git a/ext/wasm/api/sqlite3-opfs-async-proxy.js b/ext/wasm/api/sqlite3-opfs-async-proxy.js
index cbe0549b3..b14494a0c 100644
--- a/ext/wasm/api/sqlite3-opfs-async-proxy.js
+++ b/ext/wasm/api/sqlite3-opfs-async-proxy.js
@@ -202,18 +202,6 @@ const releaseImplicitLocks = async ()=>{
 };
 
 /**
-   If true, any routine which implicitly acquires a sync access handle
-   (i.e. an OPFS lock) will release that locks at the end of the call
-   which acquires it. If false, such "autolocks" are not released
-   until the VFS is idle for some brief amount of time.
-
-   The benefit of enabling this is much higher concurrency. The
-   down-side is much-reduced performance (as much as a 4x decrease
-   in speedtest1).
-*/
-state.defaultReleaseImplicitLocks = false;
-
-/**
    An experiment in improving concurrency by freeing up implicit locks
    sooner. This is known to impact performance dramatically but it has
    also shown to improve concurrency considerably.
@@ -536,7 +524,8 @@ const vfsAsyncImpls = {
     mTimeEnd();
   },
   xOpen: async function(fid/*sqlite3_file pointer*/, filename,
-                        flags/*SQLITE_OPEN_...*/){
+                        flags/*SQLITE_OPEN_...*/,
+                        opfsFlags/*OPFS_...*/){
     const opName = 'xOpen';
     mTimeStart(opName);
     const create = (state.sq3Codes.SQLITE_OPEN_CREATE & flags);
@@ -566,13 +555,8 @@ const vfsAsyncImpls = {
         deleteOnClose: !!(state.sq3Codes.SQLITE_OPEN_DELETEONCLOSE & flags)
       });
       fh.releaseImplicitLocks =
-        state.defaultReleaseImplicitLocks
-        /* TODO: check URI flags for "opfs-auto-unlock". First we need to
-           reshape the API a bit to be able to pass those on to here
-           from the other half of the proxy. */;
-      /*if(fh.releaseImplicitLocks){
-        console.warn("releaseImplicitLocks is ON for",fh);
-      }*/
+        (opfsFlags & state.opfsFlags.OPFS_UNLOCK_ASAP)
+        || state.opfsFlags.defaultUnlockAsap;
       if(0 /* this block is modelled after something wa-sqlite
               does but it leads to horrible contention on journal files. */
          && (0===(flags & state.sq3Codes.SQLITE_OPEN_MAIN_DB))){
@@ -887,6 +871,7 @@ navigator.storage.getDirectory().then(function(d){
           state.sabS11nView = new Uint8Array(state.sabIO, state.sabS11nOffset, state.sabS11nSize);
           state.opIds = opt.opIds;
           state.sq3Codes = opt.sq3Codes;
+          state.opfsFlags = opt.opfsFlags;
           Object.keys(vfsAsyncImpls).forEach((k)=>{
             if(!Number.isFinite(state.opIds[k])){
               toss("Maintenance required: missing state.opIds[",k,"]");
diff --git a/ext/wasm/tests/opfs/concurrency/worker.js b/ext/wasm/tests/opfs/concurrency/worker.js
index 9b4898f4c..1a896e714 100644
--- a/ext/wasm/tests/opfs/concurrency/worker.js
+++ b/ext/wasm/tests/opfs/concurrency/worker.js
@@ -44,7 +44,7 @@ self.sqlite3InitModule().then(async function(sqlite3){
   };
   const run = async function(){
     db = new sqlite3.oo1.DB({
-      filename: 'file:'+dbName,
+      filename: 'file:'+dbName,//+'?opfs-unlock-asap=1'/*EXPERIMENTAL*/,
       flags: 'c',
       vfs: 'opfs'
     });
diff --git a/manifest b/manifest
index d6e43cfa4..d9cc7cb9d 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Initial\sinfrastructure\sfor\sadding\sa\smode\sto\sthe\sOPFS\sVFS\swhich\scauses\simplicit\slocks\sto\sbe\sreleased\sASAP,\swhich\sincreases\sconcurrency\sat\sthe\scost\sof\sperformance.
-D 2022-11-23T16:39:07.866
+C Add\san\sexperimental\sOPFS\sVFS-specific\sURI\sflag,\sopfs-unlock-asap,\swhich\stells\sthe\sVFS\sto\srelease\simplicit\slocks\sASAP.\sThis\spermits\shigher\sconcurrency\sbut\shurts\sperformance\sconsiderably.\sThis\smay\sor\smay\snot\sbe\sobsoleted\sby\sother\sconcurrency-related\sexperimentation.
+D 2022-11-23T19:03:22.450
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -502,11 +502,11 @@ F ext/wasm/api/pre-js.js b88499dc303c21fc3f55f2c364a0f814f587b60a95784303881169f
 F ext/wasm/api/sqlite3-api-cleanup.js ecdc69dbfccfe26146f04799fcfd4a6f5790d46e7e3b9b6e9b0491f92ed8ae34
 F ext/wasm/api/sqlite3-api-glue.js 056f44b82c126358a0175e08a892d56fadfce177b0d7a0012502a6acf67ea6d5
 F ext/wasm/api/sqlite3-api-oo1.js e4df25e7fd1a0b67a9f3df9eea8cbcbcdecab55be481c903488a9e8dcaf356e4
-F ext/wasm/api/sqlite3-api-opfs.js 69a897eae705816a002f44e8a37693e2ceb7b3e32f9889df2302aeba7df24c70
+F ext/wasm/api/sqlite3-api-opfs.js 23b5c51d7c48134eb5a2d23c1dca06315c738aa365f1c9620e649805c62e5781
 F ext/wasm/api/sqlite3-api-prologue.js 08e96d26d329e8c1e08813fe0b84ee93e0e78b087efdd6eb2809ae2672902437
 F ext/wasm/api/sqlite3-api-worker1.js e94ba98e44afccfa482874cd9acb325883ade50ed1f9f9526beb9de1711f182f
 F ext/wasm/api/sqlite3-license-version-header.js a661182fc93fc2cf212dfd0b987f8e138a3ac98f850b1112e29b5fbdaecc87c3
-F ext/wasm/api/sqlite3-opfs-async-proxy.js 3142ed3a636d9a1a3f4793c6af6373996593c615a3a5fa29de59ba3e0ea45bee
+F ext/wasm/api/sqlite3-opfs-async-proxy.js 20030993ccc04e42b4c7111db31d8f22ca02a00879f183a9067738d7bc9f10b9
 F ext/wasm/api/sqlite3-wasi.h 25356084cfe0d40458a902afb465df8c21fc4152c1d0a59b563a3fba59a068f9
 F ext/wasm/api/sqlite3-wasm.c 8fc8f47680df0e9a6c0f2f03cb004148645ecc983aa216daba09cb21f7e092a2
 F ext/wasm/api/sqlite3-worker1-promiser.js 0c7a9826dbf82a5ed4e4f7bf7816e825a52aff253afbf3350431f5773faf0e4b
@@ -554,7 +554,7 @@ F ext/wasm/tester1.c-pp.html 74aa9b31c75f12490653f814b53c3dd39f40cd3f70d6a53a716
 F ext/wasm/tester1.c-pp.js 0c129495d057c77788b59715152d51f9bf9002ebbcce759ef8b028272ce3519d
 F ext/wasm/tests/opfs/concurrency/index.html bb9b0f6da86df34c67fa506db9c45b7c4cf0045a211611cc6b8d2b53fa983481
 F ext/wasm/tests/opfs/concurrency/test.js 5993c08657d547d3a26b78ff3480122aed2b7361823bc127e96e558931093aff
-F ext/wasm/tests/opfs/concurrency/worker.js cc43ea47bb59582523e3f27c2198247c4adca2fae9a891f84dd3bccfccef2833
+F ext/wasm/tests/opfs/concurrency/worker.js e1b10dc5d96117ac58f4eedde97a970816adc60e007f0a0f20a41d880ab59ca9
 F ext/wasm/version-info.c 3b36468a90faf1bbd59c65fd0eb66522d9f941eedd364fabccd72273503ae7d5
 F ext/wasm/wasmfs.make 8fea9b4f3cde06141de1fc4c586ab405bd32c3f401554f4ebb18c797401a678d
 F install-sh 9d4de14ab9fb0facae2f48780b874848cbf2f895 x
@@ -2059,8 +2059,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 5f135575b923cb59947667071c6af9ff14063c933cedf37d6c2a0a1b86c85032
-R 5ffa2a11b06c4a44d92d27455a2fc3e8
+P c5b7a9715a13b696ab3ee965aa0a310f59b65f07cecd72faa2e3504bfd8eb632
+R 37d44560e41f4eab685876e5b8c66c33
 U stephan
-Z 70f5adf76d87ddf8a488ff2bcd290afb
+Z 1cab17b5c5d56b08d5be52571107da20
 # Remove this line to create a well-formed Fossil manifest.
diff --git a/manifest.uuid b/manifest.uuid
index 54a2776a7..8365ac9b1 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-c5b7a9715a13b696ab3ee965aa0a310f59b65f07cecd72faa2e3504bfd8eb632
\ No newline at end of file
+d23c917013485ec2793125221f3936b05c39d6eca941629fb819b6b4aa714520
\ No newline at end of file